~?Charsley, M. M. Abram, S. E.2001^The injection of intrathecal normal saline reduces the severity of postdural puncture headache301-5Reg Anesth Pain Med264Blood Patch, Epidural Cerebrospinal Fluid/physiology Female Headache/*prevention & control Human Injections, Spinal Pregnancy Sodium Chloride/*administration & dosageJul-AugrBACKGROUND AND OBJECTIVES: We investigated whether the injection of 10 mL of normal saline into the subarachnoid space following accidental dural puncture reduced the incidence of postdural puncture headache (PDPH) and the need for epidural blood patch (EBP). METHODS: Twenty-eight patients who experienced accidental dural puncture with an epidural needle had 10 mL of normal saline injected into the subarachnoid space. In 22 patients, the injection was performed immediately through the epidural needle. In 6 patients who had intrathecal catheters placed through the epidural needle, the saline was injected through the catheter before removal. All other patients who experienced wet taps during the same period that the study was in progress but did not receive the saline injection served as a control group, 26 in number. Patients with severe or persistent PDPHs were treated with EBP. RESULTS: Of those patients who received intrathecal normal saline immediately through the epidural needle, 32% developed a headache compared with 62% of controls. Of these, 1 patient who received saline required EBP compared with nine in the control group (P =.004). Of those patients who had intrathecal catheters placed, there were no headaches in the saline group of 6 compared with 3 in the control group of 5, 1 of whom was treated with EBP (P >.05). CONCLUSIONS: The immediate injection of 10 mL intrathecal normal saline after a wet tap significantly reduced the incidence of PDPH and the need for EBP. When an intrathecal catheter had been placed following a wet tap, injection of 10 mL of normal saline before its removal effectively prevented PDPH.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=11464346"21357115 1098-7339 Journal Article11464346KAlbuquerque Veterans Administration Hospital, Albuquerque, New Mexico, USA.e~?+Nilsson, C. Lindvall-Axelsson, M. Owman, C.1992UNeuroendocrine regulatory mechanisms in the choroid plexus-cerebrospinal fluid system109-38Brain Res Brain Res Rev172Animal Atrial Natriuretic Factor/metabolism Blood-Brain Barrier Cerebrospinal Fluid/drug effects/metabolism/*physiology Choline O-Acetyltransferase/metabolism Choroid Plexus/anatomy & histology/drug effects/metabolism/*physiology Neurosecretory Systems/*physiology Prealbumin/pharmacology Receptors, Somatomedin/metabolism Serotonin/metabolism Support, Non-U.S. Gov't Sympathetic Nervous System/physiology Thyroid Hormones/metabolism Vasoactive Intestinal Peptide/pharmacology Vasopressins/metabolismMay-AugThe CSF is often regarded as merely a mechanical support for the brain, as well as an unspecific sink for waste products from the CNS. New methodology in receptor autoradiography, immunohistochemistry and molecular biology has revealed the presence of many different neuroendocrine substances or their corresponding receptors in the main CSF-forming structure, the choroid plexus. Both older research on the sympathetic nerves and recent studies of peptide neurotransmitters in the choroid plexus support a neurogenic regulation of choroid plexus CSF production and other transport functions. Among the endocrine substances present in blood and CSF, 5-HT, ANP, vasopressin and the IGFs have high receptor concentrations in the choroid plexus and have been shown to influence choroid plexus function. Finally, the choroid plexus produces the growth factor IGF-II and a number of transport proteins, most importantly transthyretin, that might regulate hormone transport from blood to brain. These studies suggest that the choroid plexus-CSF system could constitute an important pathway for neuroendocrine signalling in the brain, although clearcut evidence for such a role is still largely lacking.dhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=1393190:93006555 0165-0173 Journal Article Review Review, Tutorial1393190@Department of Medical Cell Research, University of Lund, Sweden.~?>Nilsson, C. Stahlberg, F. Gideon, P. Thomsen, C. Henriksen, O.1994kThe nocturnal increase in human cerebrospinal fluid production is inhibited by a beta 1-receptor antagonistR1445-8 Am J Physiol2676 Pt 2Adrenergic beta-Antagonists/*pharmacology Adult Atenolol/*pharmacology Cerebrospinal Fluid/*physiology *Circadian Rhythm Female Heart Rate Human Magnetic Resonance Imaging Male Receptors, Adrenergic, beta/physiology Support, Non-U.S. Gov'tDec4A circadian variation in human cerebrospinal fluid (CSF) production has recently been demonstrated using magnetic resonance phase imaging. A nightly peak in CSF production was found at approximately 0200, when production is approximately twice the daytime values. In the present study, we have investigated the effect of a beta 1-receptor antagonist, atenolol, on the production of CSF, specifically the nocturnal production peak. CSF production was measured in fourteen healthy volunteers of both sexes in the time interval 1500-1800, with or without drug administration (100 mg orally) at 1800, and a second measurement was made in the time interval 2300-0200. In the absence of drug administration, all nine volunteers showed a significant increase in CSF production at night, from 0.34 +/- 0.06 ml/min in the time interval 1500-1800 to 0.61 +/- 0.05 (SE) ml/min (P < 0.005), confirming the presence of a circadian variation in these individuals. One week later, the experiment was repeated in five of these volunteers, plus an additional five volunteers, but with the administration of 100 mg atenolol orally immediately after the first measurement (at 1800). In five of the volunteers a decrease in CSF production was seen at midnight compared with daytime production values; in two volunteers CSF production remained unchanged, while three volunteers showed increased production. The average CSF production was 32% lower at night (0.27 +/- 0.10 ml/min) compared with the afternoon (0.40 +/- 0.07 ml/min), after administration of atenolol (P = 0.37).(ABSTRACT TRUNCATED AT 250 WORDS)dhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=7810751"95109788 0002-9513 Journal Article7810751@Department of Medical Cell Research, University of Lund, Sweden.~?INilsson, C. Stahlberg, F. Thomsen, C. Henriksen, O. Herning, M. Owman, C.1992bCircadian variation in human cerebrospinal fluid production measured by magnetic resonance imagingR20-4 Am J Physiol2621 Pt 2Adult Calibration Cerebrospinal Fluid/*metabolism *Circadian Rhythm Female Human *Magnetic Resonance Imaging Male Regression Analysis Support, Non-U.S. Gov'tJan9Recent advances in magnetic resonance imaging have made it possible to visualize and quantify flow of cerebrospinal fluid (CSF) in the brain. The net flow of CSF through the cerebral aqueduct was used to measure CSF production in six normal volunteers at different times during a 24-h period. CSF production varied greatly both intra- and interindividually. The average CSF production in each time interval showed a clear tendency to circadian variation, with a minimum production 30% of maximum values (12 +/- 7 ml/h) approximately 1800 h and a nightly peak production approximately 0200 h of 42 +/- 2 ml/h. The total CSF production during the whole 24-h period, calculated as an average of all measurements, was 650 ml for the whole group and 630 ml for repeated measurements in each time interval in one of the volunteers.dhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=1733335"92125570 0002-9513 Journal Article1733335@Department of Medical Cell Research, University of Lund, Sweden. ~?ZKroin, J. S. Nagalla, S. K. Buvanendran, A. McCarthy, R. J. Tuman, K. J. Ivankovich, A. D.2002{The mechanisms of intracranial pressure modulation by epidural blood and other injectates in a postdural puncture rat model423-9 Anesth Analg952Animal *Blood Patch, Epidural Cisterna Magna/physiology Epidural Space/anatomy & histology Infusions, Intravenous Injections, Epidural Intracranial Hypotension/etiology/therapy Intracranial Pressure/*physiology Male Rats Rats, Sprague-Dawley Spinal Puncture/*adverse effectsAugThe epidural blood patch is considered effective in treating postdural puncture headache. We have developed a postdural puncture model in rats for quantitative evaluation of the magnitude and duration of changes in cerebrospinal fluid (CSF) pressure in the cisterna magna in response to the administration of epidural blood or other moieties. This model was used to compare the efficacy of various methods of epidural injection for restoring and maintaining CSF pressure for up to 240 min. After lumbar dural puncture, CSF pressure declined 3.6 +/- 0.2 mm Hg. Epidural saline (100 microL) injected at the puncture site initially increased pressure by 7.2 +/- 0.7 mm Hg, but it rapidly (7.8 +/- 0.6 min) returned to postdural puncture baseline. A similar initial increase of CSF pressure was observed with equal volumes of all other epidural injectates, but the duration of pressure increase varied greatly. Hetastarch and dextran 40 produced results similar to saline. Only whole blood or fibrin glue consistently increased CSF pressure for the entire 240-min observation period. Whole blood mixed with anticoagulant or injected 20-mm cephalad to the puncture site did not sustain pressure. After laminectomy, direct application of blood or adhesive to the dural defect caused no pressure increase. Continuous infusion of saline after bolus could maintain pressure increase for 180 min, but within 60 min of stopping infusion, pressure returned to baseline. These results confirm the efficacy of the epidural administration of blood or fibrin glue to correct CSF hypotension after dural puncture and also provide insight into the mechanisms of intracranial pressure modulation. Sealing the dural defect does not effectively correct CSF pressure unless an epidural tamponade effect is also maintained. IMPLICATIONS: A rat model was developed to evaluate different drugs that may be injected epidurally to treat postdural puncture headache. Epidural injection of blood or fibrin glue was the most effective method of maintaining increased cerebrospinal fluid pressure after dural puncture. Sealing the dural defect does not effectively correct cerebrospinal fluid pressure unless an epidural tamponade effect is maintained.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=12145065"22139652 0003-2999 Journal Article12145065Department of Anesthesiology, Rush Medical College at Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois 60612, USA. jkroin@rush.edu)~?Johnston, M. Papaiconomou, C.20026Cerebrospinal fluid transport: a lymphatic perspective227-30News Physiol Sci17wArachnoid/*physiology Cerebrospinal Fluid/*physiology Human Hydrocephalus/*physiopathology Lymphatic System/*physiologyDecThe textbook view that projections of the arachnoid membrane into the cranial venous sinuses represent the primary cerebrospinal fluid (CSF) absorption sites seems incompatible with many clinical and experimental observations. On balance, there is more quantitative evidence suggesting a function for extracranial lymphatic vessels than exists to support a role for arachnoid villi and granulations in CSF transport.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=12433975;22321713 0886-1714 Journal Article Review Review Literature12433975Neuroscience Research, Department of Laboratory Medicine and Pathobiology, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, 2075 Bayview Avenue, Ontario M4N 3M5, Canada.~? Eldevik, O. P.1983zElimination of metrizamide from the spinal subarachnoid space: a study of patients with abolished intracranial circulation585-7AJNR Am J Neuroradiol43m*Blood-Brain Barrier Brain Death Human Metrizamide/diagnostic use/*metabolism *Myelography Subarachnoid SpaceMay-Jun>Two absorptive pathways for contrast media injected into the lumbar subarachnoid space have been postulated: (1) through the intracranial parasagittal arachnoid granulations and (2) direct absorption through the spinal arachnoid villi into the blood. To study the capacity of the spinal absorptive pathway, serial measurements of metrizamide concentrations in blood serum and urine were obtained before and after lumbar intrathecal injection of contrast medium in four patients with arrested intracranial blood circulation ("brain death") and intracranial pressure exceeding systolic blood pressure who had no circulation of cerebrospinal fluid from the spinal subarachnoid space to the parasagittal arachnoid granulations. These measurements indicated a high capacity of the spinal absorptive pathway for metrizamide elimination.dhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=6410802"83279607 0195-6108 Journal Article6410802 ]~? 0Bozanovic-Sosic, R. Mollanji, R. Johnston, M. G.2001GSpinal and cranial contributions to total cerebrospinal fluid transportR909-16&Am J Physiol Regul Integr Comp Physiol2813Animal Biological Transport Body Fluid Compartments/physiology Brain/physiology Cerebrospinal Fluid/*physiology Cerebrospinal Fluid Pressure/physiology Infusion Pumps Injections, Spinal Iodine Radioisotopes Models, Neurological Perfusion/instrumentation/methods Radioactive Tracers Rheology Serum Albumin/administration & dosage/physiology Sheep Spinal Cord/*physiology Subarachnoid Space/*physiology Support, Non-U.S. Gov'tSepsIn this study, we quantified cerebrospinal fluid (CSF) transport from the cranial and spinal subarachnoid spaces separately in sheep and determined the relative proportion of total CSF drainage that occurred from both CSF compartments. Cranial and spinal CSF systems were separated by placement of an extradural ligature over the spinal cord between C(1) and C(2). In one approach, two different radiolabeled human serum albumins (HSA) were introduced into the appropriate CSF compartment by a perfusion system (method 1) or as a bolus injection (method 2). Plasma tracer recoveries in conjunction with a mass balance equation were used to estimate CSF transport. In method 3, catheters connected to reservoirs filled with artificial CSF were introduced into the cranial and spinal CSF compartments. Incremental CSF pressures were established in each CSF system, and the corresponding steady-state flow rates were measured. Total CSF drainage ranged from 0.51 to 0.75 ml. h(-1). cmH(2)O(-1). Expressed as a percentage of the total CSF transport, the ratios of cranial-to-spinal clearance estimated from methods 1, 2, and 3 were 75:25, 88:12, and 75:25, respectively. Primarily on the basis of the data derived from methods 1 and 3, we conclude that the spinal subarachnoid compartment has an important role in CSF clearance and is responsible for approximately one-fourth of total CSF transport.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=11507008"21397832 0363-6119 Journal Article11507008Trauma Research Program, Department of Laboratory Medicine and Pathobiology, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, 2075 Bayview Ave., Toronto, Ontario, Canada M4N 3M5.o~? JMollanji, R. Bozanovic-Sosic, R. Zakharov, A. Makarian, L. Johnston, M. G.2002lBlocking cerebrospinal fluid absorption through the cribriform plate increases resting intracranial pressureR1593-9&Am J Physiol Regul Integr Comp Physiol2826Absorption/*physiology Animal Biological Transport/physiology Blood Pressure/physiology Body Fluid Compartments/physiology Cerebrospinal Fluid/*physiology Cisterna Magna/physiology Ethmoid Bone/*physiology/surgery Intracranial Pressure/*physiology Sheep Spinal Cord/physiologyJunCerebrospinal fluid (CSF) drains through the cribriform plate (CP) in association with the olfactory nerves. From this location, CSF is absorbed into nasal mucosal lymphatics. Recent data suggest that this pathway plays an important role in global CSF transport in sheep. In this report, we tested the hypothesis that blocking CSF transport through this pathway would elevate resting intracranial pressure (ICP). ICP was measured continuously from the cisterna magna of sheep before and after CP obstruction in the same animal. To block CSF transport through the CP, an external ethmoidectomy was performed. The olfactory and adjacent mucosa were removed, and the bone surface was sealed with tissue glue. To restrict our analysis to the cranial CSF system, CSF transport into the spinal subarachnoid compartment was prevented with a ligature tightened around the thecal sac between C1 and C2. Sham surgical procedures had no significant effects, but in the experimental group CP obstruction elevated ICP significantly. Mean postobstruction steady-state pressures (18.0 +/- 3.8 cmH(2)O) were approximately double the preobstruction values (9.2 +/- 0.9 cmH(2)O). These data support the concept that the olfactory pathway represents a major site for CSF drainage.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=12010739"22005585 0363-6119 Journal Article12010739Trauma Research Program, Department of Laboratory Medicine and Pathobiology, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, Toronto, Ontario M4N 3M5, Canada.m~? QMollanji, R. Bozanovic-Sosic, R. Silver, I. Li, B. Kim, C. Midha, R. Johnston, M.2001gIntracranial pressure accommodation is impaired by blocking pathways leading to extracranial lymphaticsR1573-81&Am J Physiol Regul Integr Comp Physiol2805Animal Cerebrospinal Fluid/physiology Female Homeostasis Hydrocephalus/physiopathology Intracranial Pressure/*physiology Lymphatic System/*physiology Models, Animal Nasal Mucosa/physiology Sheep Support, Non-U.S. Gov'tMayYTracer studies indicate that cerebrospinal fluid (CSF) transport can occur through the cribriform plate into the nasal submucosa, where it is absorbed by cervical lymphatics. We tested the hypothesis that sealing the cribriform plate extracranially would impair the ability of the CSF pressure-regulating systems to compensate for volume infusions. Sheep were challenged with constant flow or constant pressure infusions of artificial CSF into the CSF compartment before and after the nasal mucosal side of the cribriform plate was sealed. With both infusion protocols, the intracranial pressure (ICP) vs. flow rate relationships were shifted significantly to the left when the cribriform plate was blocked. This indicated that obstruction of the cribriform plate reduced CSF clearance. Sham surgical procedures had no significant effects. Estimates of the proportional flow through cribriform and noncribriform routes suggested that cranial CSF absorption occurred primarily through the cribriform plate at low ICPs. Additional drainage sites (arachnoid villi or other lymphatic pathways) appeared to be recruited only when intracranial pressures were elevated. These data challenge the conventional view that CSF is absorbed principally via arachnoid villi and provide further support for the existence of several anatomically distinct cranial CSF transport pathways.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=11294783"21193258 0363-6119 Journal Article11294783Trauma Research Program, Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario M4N 3M5, Canada. ~?,Silver, I. Kim, C. Mollanji, R. Johnston, M.2002~Cerebrospinal fluid outflow resistance in sheep: impact of blocking cerebrospinal fluid transport through the cribriform plate67-74Neuropathol Appl Neurobiol281Animal Arachnoid/metabolism Cerebrospinal Fluid/*metabolism Ethmoid Bone/*pathology/*physiology Female Intracranial Pressure/*physiology Lateral Ventricles Lymphatic System/metabolism Sheep Support, Non-U.S. Gov'tFebiRecent studies in sheep suggest that a significant proportion of global cerebrospinal fluid (CSF) drainage (50% or greater) occurs through the cribriform plate into nasal mucosal lymphatics. If this is true, obstructing CSF clearance through the cribriform plate should have an impact on the ability of the intracranial pressure regulating systems to compensate for volume infusions. To test this concept, bolus infusions of artificial CSF were administered into one lateral ventricle in sheep and the intracranial pressure monitored from the contralateral side. Peak intracranial pressures (ICP) were measured and CSF outflow resistances were calculated from the pressure patterns observed in response to bolus infusions administered before and after the cribriform plate was sealed in the same animal. To obstruct the cribriform plate, a portion of nasal bone was removed to expose the nasal mucosa. The olfactory mucosa, a portion of the nasal mucosa and all soft tissue on the extracranial surface of the cribriform plate were scraped away with a curette and the bone surface sealed with bone wax. Obstruction of CSF transport through the cribriform plate increased the peak ICP after infusion (P = 0.016) and augmented the time required for ICP to return to baseline. CSF outflow resistance was elevated approximately 2.7 times (P = 0.006). When the cribriform plate was left intact (sham surgery), no significant changes in peak ICP or CSF outflow resistance were observed. We conclude that the cribriform plate represents an important site for CSF clearance. Obstruction of this pathway reduces volumetric CSF transport significantly.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=11849565"21839724 0305-1846 Journal Article11849565Trauma Research Program, Department of Laboratory Medicine and Pathobiology, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.~?6Kotani, J. Momota, Y. Sugioka, S. Umemura, A. Ueda, Y.1993oEffect of head-down tilt on intracranial pressure and sagittal sinus pressure during general anesthesia in cats209-11 Anesth Prog396Analysis of Variance *Anesthesia, General Animal Cats *Cerebrovascular Circulation Female Intracranial Pressure/*physiology Male Nitrous Oxide/cerebrospinal fluid/*pharmacokinetics *Posture Venous Pressure/*physiologyThe effect of head-down tilt during general anesthesia on intracranial pressure (ICP) dynamics was examined in eight cats. Changes in lateral ventricular pressure (LVP), sagittal sinus pressure (SSP), and effective CSF pressure (ECSFP), which is the driving pressure of cerebrospinal fluid (CSF) absorption, were studied in association with a shift from the horizontal prone position to the 20 degrees head-down tilt position. Both LVP and SSP values were significantly (P < 0.01) increased at 10 min in the head-down tilt position as compared with the control position, remained elevated during the next 110 min, and returned to baseline when the horizontal position was restored. However, ECSFP (expressed by LVP - SSP) was not significantly different from the control value, because changes in LVP and SSP were similar. These results suggest that head-down tilt does not impair CSF absorption.dhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=8250342"94071203 0003-3006 Journal Article8250342=Department of Anesthesiology, Osaka Dental University, Japan.~?FTatebayashi, K. Asai, Y. Maeda, T. Shiraishi, Y. Miyoshi, M. Kawai, Y.2003KEffects of head-down tilt on the intracranial pressure in conscious rabbits55-61 Brain Res9771Jul.Head-down tilt (HDT) causes a fluid shift towards the upper body, which increases intracranial pressure (ICP). In the present study, the time course of ICP changes during prolonged exposure to HDT was investigated in conscious rabbits through a catheter chronically implanted into the subarachnoid space. The production of cerebrospinal fluid (CSF) after exposure to 7-days HDT was also examined by a ventriculo-cisternal perfusion method. The ICP increased from 4.3+/-0.4 (mean+/-S.E.M.) mmHg to 8.0+/-0.8 mmHg immediately after the onset of 45 degrees HDT, reached a peak value of 15.8+/-1.9 mmHg at 11 h, and then decreased to 10.4+/-1.1 mmHg at 24 h. During 7-days HDT, it also increased from 4.8+/-0.9 mmHg to 9.2+/-1.6 mmHg immediately after the onset of 45 degrees HDT, reached a peak value of 12.8+/-2.5 mmHg at 12 h of HDT, and then decreased gradually towards the pre-HDT baseline value for 7 days. The rate of CSF production was 10.1+/-0.6 microl/min in rabbits exposed to 7-days HDT, and 9.7+/-0.5 microl/min in control rabbits. These results suggest that the rabbits begin to adapt to HDT within a few days and that the production of CSF is preserved after exposure to 7-days HDT. The time course of ICP changes during HDT in conscious rabbits seems to be considerably different from that in anesthetized rabbits.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=12788513"22671023 0006-8993 Journal Article12788513oSecond Department of Physiology, Faculty of Medicine, Tottori University, 86 Nishi-cho, Yonago 683-8503, Japan.~?Zlotnik, E. I. Stolkarts, I. Z.19845[Cerebrospinal fluid hypotension after brain surgery]48-53!Zh Vopr Neirokhir Im N N Burdenko22Adolescent Adult Brain/*surgery *Brain Diseases Cerebral Hemorrhage/diagnosis Diagnostic Errors English Abstract Female Hematoma, Subdural/surgery Human Intracranial Aneurysm/surgery *Intracranial Pressure Male Meningeal Neoplasms/surgery Meningioma/surgery Middle Age Postoperative Complications/diagnosisMar-Apr A severe complication, c. s. f. hypotension ( CSFH ), developed in 9 patients after intracranial manipulations for meningioma (4), intracranial aneurysm (3), and subdural hematoma (2). It occurred on the second or third postoperative day and was characterized by rapid development of general cerebral disorders (even to deep loss of consciousness) and aggravation of focal disorders. An important role in the differential diagnosis of the hypotensive and the hypertensive syndromes is attached to lumbar puncture which in cases of CSFH reveals very low c. s. f. pressure or none at all. Effective therapy for the disease includes subarachnoid infusion of up to 50-80 ml of physiological solution through a lumbar puncture and daily intravenous infusions of fluid (2 500-3 000 ml).dhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=6741377"84252524 0042-8817 Journal Article6741377~?gPleasure, S. J. Abosch, A. Friedman, J. Ko, N. U. Barbaro, N. Dillon, W. Fishman, R. A. Poncelet, A. N.1998[Spontaneous intracranial hypotension resulting in stupor caused by diencephalic compression1854-7 Neurology506Brain/pathology/radiography Case Report Cerebrospinal Fluid/physiology Cysts/complications/physiopathology/surgery Diencephalon/*physiopathology Human Intracranial Hypotension/diagnosis/*etiology Magnetic Resonance Imaging Male Middle Age Peripheral Nervous System Diseases/complications/physiopathology/surgery Pressure Rupture, Spontaneous Sleep Stages/*physiology Spinal Nerve Roots Tomography, X-Ray ComputedJunA 51-year-old man had a 4-month history of progressive headache and gradual onset of somnolence. MRI suggested spontaneous intracranial hypotension (SIH) with diencephalic compression, but he did not improve after three epidural blood patches. He became alert following intrathecal saline infusion that normalized his CSF pressure. A CSF leak was noted on spinal MRI and confirmed with CT contrast myelography. Surgical ligation of a torn dural root sleeve isolating a ruptured Tarlov's cyst resulted in permanent cure.dhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=9633740"98295497 0028-3878 Journal Article9633740YDepartment of Neurology, University of California, San Francisco School of Medicine, USA. ~?9Binder, D. K. Dillon, W. P. Fishman, R. A. Schmidt, M. H.2002Intrathecal saline infusion in the treatment of obtundation associated with spontaneous intracranial hypotension: technical case report830-6; discussion 836-7 Neurosurgery513Adult Case Report Coma/diagnosis/*drug therapy/*etiology Human Injections, Spinal Intracranial Hypotension/*complications/diagnosis Magnetic Resonance Imaging Male Myelography Sodium Chloride/*administration & dosage/therapeutic use Tomography, X-Ray ComputedSepEOBJECTIVE AND IMPORTANCE: Spontaneous intracranial hypotension is an increasingly recognized cause of postural headache. However, appropriate management of obtundation caused by intracranial hypotension is not well defined. CLINICAL PRESENTATION: A 43-year-old man presented with postural headache followed by rapid decline in mental status. Imaging findings were consistent with the diagnosis of spontaneous intracranial hypotension, with bilateral subdural hematomas, pachymeningeal enhancement, and caudal displacement of posterior fossa structures and optic chiasm. INTERVENTION: Despite treatment with lumbar epidural blood patch, worsening stupor necessitated intubation and mechanical ventilation. Contrast-enhanced magnetic resonance imaging and computed tomographic myelography of the spine failed to demonstrate the site of cerebrospinal fluid fistula. The enlarging subdural fluid collections were drained, and a ventriculostomy was performed. Postoperatively, the patient remained semicomatose. To restore intraspinal and intracranial pressures, intrathecal infusion of saline was initiated. After several hours of lumbar saline infusion, lumbar and intracranial pressures normalized, and the patient's stupor resolved rapidly. Repeat computed tomographic myelography accomplished via C1-C2 puncture demonstrated a large ventrolateral T1-T3 leak, which was treated successfully with a thoracic epidural blood patch. Follow-up magnetic resonance imaging demonstrated resolution of intracranial hypotension, and the patient was discharged in excellent condition. CONCLUSION: Spontaneous intracranial hypotension may cause a decline of mental status and require lumbar intrathecal saline infusion to arrest or reverse impending central (transtentorial) herniation. This case demonstrates the use of simultaneous monitoring of lumbar and intracranial pressures to appropriately titrate the infusion and document resolution of intracranial hypotension. Maneuvers aimed at sealing the cerebrospinal fluid fistula then can be performed in a less emergent fashion after the patient's mental status has stabilized.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=12188967"22176878 0148-396x Journal Article12188967Department of Neurological Surgery, University of California, San Francisco, San Francisco, California 94143-0112, USA. dbinder@itsa.ucsf.eduW~?uIFrancel, P. C. Persing, J. A. Cantrell, R. W. Levine, P. A. Newman, S. A.1992DNeurological deterioration after lumbar cerebrospinal fluid drainage145-8J Craniofac Surg33Carcinoma, Squamous Cell/surgery Case Report *Cerebrospinal Fluid Shunts/*adverse effects Comparative Study Drainage/adverse effects Dura Mater/*surgery Ethmoid Sinus/surgery Female Human Lumbar Vertebrae Male Middle Age Nervous System Diseases/*etiology Neuroectodermal Tumors, Primitive, Peripheral/surgery Paranasal Sinus Neoplasms/surgery Skull Neoplasms/*surgery Spinal Puncture/*adverse effectsNovLarge-bore lumbar spinal fluid drainage is used frequently as part of the preoperative and intraoperative management of patients undergoing cranial base tumor resection. Such drainage allows displacement of the brain with minimal force, thereby potentially decreasing retraction damage to it. We document 2 patients in whom serious complications resulted from lumbar drainage systems. These patients deteriorated into a coma state following cerebrospinal fluid (CSF) drainage. Reinfusion of synthetic CSF solutions caused a brisk return to normal neurological status. These plus other potential complications associated with lumbar drainage, such as persistent CSF leaks into the back and soft-tissue nerve root injury, warranted abandoning the lumbar cistern drainage route of CSF drainage in favor of drainage directly from the intracranial compartment. Depending on the particular operation performed, drainage of CSF near the cribriform plate, the suprachiasmatic cistern, or from the sylvian fissure may be effective sites for CSF drainage. Unlike lumbar drainage, intracranial CSF drainage does not have the added risk of promoting cerebral herniation.dhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=1298413"93222384 1049-2275 Journal Article1298413\Department of Neurological Surgery, Yale University School of Medicine, New Haven, CT 06510.~?Mawera, G. Asala, S. A.19966The function of arachnoid villi/granulations revisited281-4Cent Afr J Med429Absorption Arachnoid/anatomy & histology/*physiology Cerebrospinal Fluid/*physiology Cerebrospinal Fluid Proteins/metabolism Human Retrospective StudiesSepOBJECTIVE: To establish the current viewpoint with regards to the role of arachnoid villi/granulations in cerebrospinal fluid (CSF) absorption. DESIGN: Retrospective study. SUBJECTS: Journal articles published between 1913 and 1993. MAIN OUTCOME MEASURE: The contribution of arachnoid villi/granulations to CSF absorption from the subarachnoid space. RESULTS: From available literature, it is yet to be proved that arachnoid villi/granulations are the major sites for CSF absorption from the subarachnoid space into the venous system. They may, however, play an important role in the absorption of CSF's waste products of neuronal metabolism (mainly CSF proteins) under normal physiological conditions. Furthermore, it would appear that, under pathological conditions, the absorption of CSF proteins can take place at other CSF absorption sites. CONCLUSION: The paucity of data on the relationship between the development of arachnoid villi, the superior sagittal sinus, the superficial cortical vessels and the subarachnoid space warrants that an ontogenic study be conducted in order to achieve a better understanding of the function of arachnoid villi which is currently speculative.dhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=8997824:97151875 0008-9176 Journal Article Review Review, Tutorial8997824UDepartment of Anatomy, Faculty of Medicine, University of Zimbabwe, Harare, Zimbabwe. ~?_Chiapparini, L. Farina, L. D'Incerti, L. Erbetta, A. Pareyson, D. Carriero, M. R. Savoiardo, M.2002WSpinal radiological findings in nine patients with spontaneous intracranial hypotension143-50; discussion 151-2Neuroradiology442Adult Dura Mater/pathology/radiography Female Headache/complications Human Intracranial Hypotension/cerebrospinal fluid/complications/*radiography Italy Magnetic Resonance Imaging Male Middle Age Spine/*blood supply/*radiography Tomography, X-Ray ComputedFebCranial magnetic resonance imaging (MRI) findings in spontaneous intracranial hypotension (SIH) are well known, while spinal studies have received less attention. Radiological spinal findings in nine patients with SIH are presented, looking for possible characteristic features. Five of the nine patients had histories of previous minor trauma, one of previous surgery; in three patients possible relevant preceding events were completely absent. All nine patients had cervical, seven thoracic, and four lumbar spine MRI studies; post-contrast studies were obtained in seven cases, MRI myelograms in five. Radioisotope myelocisternography was performed in four patients and myelo-CT in four. Epidural fluid collections were found in seven patients. In six cases the dural sac had collapsed, with a festooned appearance; intense epidural enhancement on post-contrast studies demonstrated marked dilatation of the epidural venous plexus. In three cases an irregular root sleeve suggested a possible point of cerebrospinal fluid (CSF) leakage. Myelo-CT demonstrated the CSF fistula in two cases, radioisotope myelocisternography in three. The pattern of spinal abnormalities is different from that seen in cranial MRI for anatomical reasons: in the spinal canal the dura is not adherent to the bone; therefore, collapse of the dural sac and dilatation of epidural venous plexus occur, rather than subdural hematomas. In most cases the search for the dural tear is difficult. Radioisotope cisternography is probably the most sensitive examination for documenting the leakage of CSF out of the subarachnoid space; myelo-CT may precisely demonstrate the point of the CSF fistula, whereas MRI may only suggest it.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=11942367521938878 0028-3940 Evaluation Studies Journal Article11942367mDepartment of Neuroradiology, Istituto Nazionale Neurologico C. Besta, Milan, Italy. l.chiapparini@doctor.com ~?!Nishiyama, K. Mori, H. Tanaka, R.2003Changes in cerebrospinal fluid hydrodynamics following endoscopic third ventriculostomy for shunt-dependent noncommunicating hydrocephalus1027-31 J Neurosurg985NAdolescent Adult Cerebrospinal Fluid/*physiology Cerebrospinal Fluid Pressure/physiology Cerebrospinal Fluid Shunts Child *Endoscopy Female Human Hydrocephalus/cerebrospinal fluid/*surgery Magnetic Resonance Imaging Male Middle Age Postoperative Complications/*cerebrospinal fluid Reoperation Third Ventricle/*surgery *VentriculostomyMayXOBJECT: The aim of this study was to analyze physiological changes in cerebrospinal fluid (CSF) dynamics following endoscopic third ventriculostomy (ETV) for shunt-dependent noncommunicating hydrocephalus. METHODS:. Clinical data obtained in 15 patients treated with ETV for shunt malfunction were analyzed. Magnetic resonance imaging studies demonstrated the obstruction of the ventricular system preoperatively. After ETV, the existing shunt system was removed and a continuous extraventricular drain, set at 30 cm H2O in height, was installed to measure daily amounts of CSF outflow. Cerebrospinal fluid dynamics after ETV were also evaluated using 111In-diethylenetriamine pentaacetic acid radioisotope cisternography in six of 15 patients within 1 month of the procedure. Three patients underwent cisternography at 6 months after ETV. Cisternograms were obtained at 1, 5, 24, and 48 hours after injection of the radioisotope. To study CSF absorptive capacity, ratios of radioisotope counts at 48 and 5 hours after injection were calculated (C48:C5). Seven of 15 patients had daily outflows of CSF of less than 20 ml; this volume decreased quickly within a few days. The other eight patients demonstrated an outflow of more than 150 ml of CSF for several days, three of whom had signs of transiently increased intracranial pressure. Their CSF outflow volume decreased gradually and symptoms improved within 1 week. Ratios of C48:C5 were within normal limits in five of six patients who had undergone cisternography 1 month after ETV. These ratios were decreased in all three patientswho had undergone cisternography at 6 months after ETV compared with that measured at 1 month after the procedure. CONCLUSIONS: Our data suggest that CSF dynamics convert from a shunt-dependent state to a shunt-independent state within I week following ETV in patients with shunt-dependent noncommunicating hydrocephalus. Nonetheless, intraventricular pressure does not decrease quickly in certain cases. Cerebrospinal fluid absorptive capacity or CSF circulation through the subarachnoid space may show further improvement several months after ETV.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=12744362"22629162 0022-3085 Journal Article12744362pDepartment of Neurosurgery, Brain Research Institute, Niigata University, Niigata, Japan. nishiken@d4.dion.ne.jp~? Yamashima, T.1988[Functional ultrastructure of cerebrospinal fluid drainage channels in human arachnoid villi633-41 Neurosurgery224 Adolescent Adult Aged Aged, 80 and over Arachnoid/blood supply/physiopathology/*ultrastructure Cerebrospinal Fluid/*physiology Child Endothelium/cytology/ultrastructure Erythrocytes/ultrastructure Human Middle Age Subarachnoid Hemorrhage/pathology Veins/ultrastructureAprThe functional ultrastructure of the human arachnoid villi was studied to clarify drainage channels of cerebrospinal fluid (CSF). The apical portion of each villus was usually covered by the arachnoid cell layer alone with no endothelial investment, whereas most of the stromal central core was further encompassed by a fibrous capsule with an endothelial investment. Accordingly, the CSF-blood interface was assumed to be in both the endothelial cells and the arachnoid cell layer. The former were characterized by abundant micropinocytotic vesicles and occasional intracytoplasmic vacuoles, whereas the latter was characterized by numerous extracellular cisterns measuring 10 micron in maximal diameter. There were no free communications such as endothelial open junctions or endothelium-lined tubules. In the villi affected by subarachnoid hemorrhage, endothelial cells were intact and continuous despite the erythrocyte-packed subendothelial space, which appeared to be on the verge of rupturing. Intracytoplasmic vacuoles, measuring less than 1 micron diameter, sometimes contained serum protein-like substance. Furthermore, the extracellular cisterns were distended by intact or disintegrating erythrocytes that served as a natural tracer, suggesting CSF drainage channels. It is conceivable that, in human arachnoid villi, the extracellular cisterns of the arachnoid cell layer contribute to the passive transport of CSF, whereas micropinocytosis and vacuolization mechanisms of the endothelial cells are available for active transport.dhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=3374774"88233207 0148-396x Journal Article3374774MDepartment of Neurosurgery, University of Kanazawa School of Medicine, Japan. ~?4Killer, H. E. Laeng, H. R. Flammer, J. Groscurth, P.2003Architecture of arachnoid trabeculae, pillars, and septa in the subarachnoid space of the human optic nerve: anatomy and clinical considerations777-81Br J Ophthalmol876Arachnoid/*anatomy & histology/ultrastructure Cadaver Human Microscopy, Electron, Scanning Transmission Optic Nerve/*anatomy & histology/ultrastructure Subarachnoid Space/anatomy & histology/ultrastructure Support, Non-U.S. Gov'tJunAIMS: To describe the anatomy and the arrangement of the arachnoid trabeculae, pillars, and septa in the subarachnoid space of the human optic nerve and to consider their possible clinical relevance for cerebrospinal fluid dynamics and fluid pressure in the subarachnoid space of the human optic nerve. METHODS: Postmortem study with a total of 12 optic nerves harvested from nine subjects without ocular disease. All optic nerves used in this study were obtained no later than 7 hours after death, following qualified consent for necropsy. The study was performed with transmission (TEM) and scanning electron microscopy (SEM). RESULTS: The subarachnoid space of the human optic nerve contains a variety of trabeculae, septa, and stout pillars that are arranged between the arachnoid and the pia layers of the meninges of the nerve. They display a considerable numeric and structural variability depending on their location within the different portions of the optic nerve. In the bulbar segment (ampulla), adjacent to the globe, a dense and highly ramified meshwork of delicate trabeculae is arranged in a reticular fashion. Between the arachnoid trabeculae, interconnecting velum-like processes are observed. In the mid-orbital segment of the orbital portion, the subarachnoid space is subdivided, and can appear even loosely chambered by broad trabeculae and velum-like septa at some locations. In the intracanalicular segment additionally, few stout pillars and single round trabeculae are observed. CONCLUSION: The subarachnoid space of the human optic nerve is not a homogeneous and anatomically empty chamber filled with cerebrospinal fluid, but it contains a complex system of arachnoid trabeculae and septa that divide the subarachnoid space. The trabeculae, septa, and pillars, as well as their arrangement described in this study, may have a role in the cerebrospinal fluid dynamics between the subarachnoid space of the optic nerve and the chiasmal cistern and may contribute to the understanding of the pathophysiology of asymmetric and unilateral papilloedema. All the structures described are of such delicate character that they can not even be visualised with high resolution magnetic resonance imaging (MRI).ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=12770980"22654457 0007-1161 Journal Article12770980LDepartment of Ophthalmology, Kantonsspital Aarau, Switzerland. Killer@ksa.ch~?#Oreskovic, D. Klarica, M. Vukic, M.2002lThe formation and circulation of cerebrospinal fluid inside the cat brain ventricles: a fact or an illusion?103-6 Neurosci Lett3272Animal Cats Cerebral Ventricles/*physiology Cerebrospinal Fluid/*physiology Female Hypertonic Solutions/pharmacology Injections, Intraventricular Male Osmotic Pressure Subarachnoid Space/physiology Support, Non-U.S. Gov'tJulFormation and circulation of cerebrospinal fluid (CSF) have been studied in the isolated brain ventricles of anesthetized cats by a new approach and under direct observation. A plastic cannula was introduced into the aqueduct of Sylvius through the vermis cerebelli and the outflow of CSF from the cannula was used as the CSF formation and circulation index. During the 60 min of observation at a physiological CSF pressure not a single drop of CSF escaped out of the end of the cannula. This indicates that CSF net formation and circulation inside the brain ventricles, proposed by classical hypothesis regarding CSF dynamics, should be at least re-evaluated.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=12098646"22093412 0304-3940 Journal Article12098646Department of Molecular Genetics, Laboratory of Neurochemistry and Molecular Neurobiology, Ruder Boskovic Institute, Bijenicka c. 54, Zagreb, Croatia. doresk@rudjer.irb.hrt~?!-Grant, R. Condon, B. Hart, I. Teasdale, G. M.1991cChanges in intracranial CSF volume after lumbar puncture and their relationship to post-LP headache440-2J Neurol Neurosurg Psychiatry545Adolescent Adult Cerebrospinal Fluid/*physiology *Cerebrospinal Fluid Pressure Female Follow-Up Studies Headache/*cerebrospinal fluid/etiology/physiopathology Human Intracranial Pressure Magnetic Resonance Imaging Male Middle Age *Spinal Puncture/adverse effectsMayPost-lumbar puncture (LP) headache may be due to "low CSF pressure", leading to stretching of pain sensitive intracranial structures. The low intracranial pressure is secondary to net loss of intracranial CSF. It has, however, not been possible to measure intracranial CSF volume accurately during life until recently. Intracranial CSF volume can now be measured non-invasively by a MRI technique. The changes in intracranial CSF volume were studied in 20 patients who had LP. Total intracranial CSF volume was reduced in 19 of the 20 patients 24 hours after LP (range -1.8 mls to -158.6 mls). Most of the CSF was lost from the cortical sulci. Very large reductions in intracranial CSF volume were frequently related to post-LP headache but some patients developed headache with relatively little alteration in the intracranial CSF volume. There was not a measurable change in position of the intracranial structures following LP.dhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=1865208"91324886 0022-3050 Journal Article1865208NUniversity Department of Neurosurgery, Southern General Hospital, Glasgow, UK.~?" Hakim, C. A. Hakim, R. Hakim, S.2001Normal-pressure hydrocephalus761-73Neurosurg Clin N Am124Brain/physiopathology Cerebral Ventricles/physiopathology Cerebrospinal Fluid Pressure/physiology Diagnostic Imaging Human Hydrocephalus, Normal Pressure/*diagnosis/pathology/physiopathology Neurologic Examination Prognosis Ventriculoperitoneal ShuntOctThis article presents a brief history of normal-pressure hydrocephalus, its clinical presentation, and different theories on its pathophysiology. The different diagnostic tests, differential diagnosis, and its treatment are presented.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=11524297:21415877 1042-3680 Journal Article Review Review, Tutorial11524297bNeuroscience Department, Fundacion Santafe de Bogota, Bogota, Colombia. 110772.3376@compuserve.com~?#Johnston, I. Teo, C.2000Disorders of CSF hydrodynamics776-99Childs Nerv Syst1610-11JAdolescent Adult Brain Diseases/etiology/*physiopathology/surgery Cerebrospinal Fluid/*physiology Cerebrospinal Fluid Pressure/*physiology Cerebrospinal Fluid Shunts Child Child, Preschool Cysts/etiology/*physiopathology/surgery Human Hydrocephalus/etiology/*physiopathology/surgery Infant Reference Values Support, Non-U.S. Gov'tNovThis article reviews the range of hydrodynamic disorders affecting the CSF circulation. Initially consideration is given to questions of definition and classification. A scheme for the practical, clinical analysis for the diagnosis of such disorders is then presented. The physiology and pathophysiology of the CSF circulation is reviewed, with particular emphasis on issues that remain unresolved. This provides a background to consideration of the adverse consequences of abnormal CSF hydrodynamics, again focusing on areas where further information is required. Methods of clinical investigation of CSF hydrodynamics are reviewed, followed by general considerations of treatment. Finally, each of the main, clinically important, forms of disordered CSF hydrodynamics is briefly considered, with particular emphasis, again, on areas where current knowledge is deficient. The conditions considered include hydrocephalus of various forms (childhood, adult, arrested, multi-compartment), infantile macrocephaly, arachnoid and glioependymal cysts, syringo- and hydromyelia, pseudotumour cerebri, impaired cranial venous outflow, altered CSF composition, shunt obstruction without ventricular enlargement and low-CSF-pressure states.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=11151732:21026240 0256-7040 Journal Article Review Review, Tutorial11151732PDepartment of Surgery, University of Sydney, N.S.W., Australia. hdtd@bigpond.com~?$QMay, C. Kaye, J. A. Atack, J. R. Schapiro, M. B. Friedland, R. P. Rapoport, S. I.1990:Cerebrospinal fluid production is reduced in healthy aging500-3 Neurology403 Pt 1Adult Aged Aged, 80 and over Aging/*physiology Analysis of Variance Cerebrospinal Fluid/metabolism/*physiology Cerebrospinal Fluid Pressure/physiology Cerebrospinal Fluid Proteins/analysis Female Human MaleMar In order to study age-related differences in cerebrospinal fluid (CSF) production in humans, we measured the rate of CSF production in 7 young (age 21 to 36 years) and 7 elderly (age 67 to 84 years) healthy volunteers, using a modified Masserman method. In addition, we evaluated CSF protein gradients by collecting CSF in serial fractions up to the 30th ml and assaying for total protein concentration. The mean rate of CSF production was significantly less in the elderly than in the young subjects. Mean CSF total protein concentrations were higher in the elderly than in the young, and significant rostrocaudal protein gradients with similar slopes were present in both groups. However, there was no correlation between CSF production and CSF total protein concentrations or protein gradient slopes. Age-related reductions in CSF production, together with the ventricular dilatation that occurs with aging, should presumably result in reduced CSF turnover and therefore influence measured concentrations of lumbar CSF constituents.dhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=2314595"90191153 0028-3878 Journal Article2314595fLaboratory of Neurosciences, National Institute on Aging, National Institutes of Health, Bethesda, MD.W~?%Bergsneider, M.20013Evolving concepts of cerebrospinal fluid physiology631-8Neurosurg Clin N Am124Arnold-Chiari Malformation/physiopathology Cerebral Ventricles/physiopathology Cerebrospinal Fluid/*physiology Human Hydrocephalus/*physiopathologyOctThis article reviews the basic known functions of cerebrospinal fluid (CSF). The traditional concepts of CSF production and absorption are reviewed and recent challenges to these concepts are discussed. MR imaging studies have begun to elucidate the complex interaction between pulsatile CSF movement, bulk CSF flow, and intracranial compliance. An understanding of a variety of disorders, including hydrocephalus and Chiari malformations, continue to evolve as knowledge of CSF physiology is increased.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=11524285:21415865 1042-3680 Journal Article Review Review, Tutorial11524285Division of Neurosurgery, Adult Hydrocephalus Center, University of California, Los Angeles, CA 90095-7039, USA. mbergsneider@mednet.ucla.edub~?&6Hidaka, M. Matsumae, M. Ito, K. Tsugane, R. Suzuki, Y.2001\Dynamic measurement of the flow rate in cerebrospinal fluid shunts in hydrocephalic patients888-93Eur J Nucl Med287Adolescent Adult Aged Aged, 80 and over Cerebrospinal Fluid/*physiology Gamma Cameras Human Hydrocephalus/*physiopathology/radionuclide imaging/therapy Middle Age Posture Radiopharmaceuticals Rheology Sodium Pertechnetate Tc 99m/diagnostic use *Ventriculoperitoneal Shunt/instrumentationJul\We compared clinical outcomes in hydrocephalic patients and observed variation in the rate of flow in ventriculoperitoneal shunts with changes in posture in 231 separate examinations of shunt flow in 148 patients. A small cadmium telluride detector was placed over the shunt reservoir, and clearance of radioisotope injected into the reservoir was recorded as a measure of flow. Flow rate tended to increase during head elevation. Four patterns of radioisotope clearance were seen: type I, no flow; type II, adequate flow with moderate opening pressure; type III, adequate flow with low opening pressure; and type IV, excessive flow. This categorisation reflected clinical shunt function. Our method effectively assesses flow rate with the patient in a variety of postures or during movement, yielding useful information for adjustment of shunt valve pressure.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=11504085"21394834 0340-6997 Journal Article11504085sDepartment of Neurosurgery, Tokai University School of Medicine, Isehara, Kanagawa, Japan. kmhidaka@eurus.dti.ne.jp~?'7King, J. O. Mitchell, P. J. Thomson, K. R. Tress, B. M.2002QManometry combined with cervical puncture in idiopathic intracranial hypertension26-30 Neurology581Jan 8OBJECTIVE: To determine by cerebral venography and manometry in patients with idiopathic intracranial hypertension the cause of the previously demonstrated venous hypertension in the superior sagittal and proximal transverse sinuses. METHODS: Cerebral venous sinus pressure was measured before and immediately after C1-2 puncture with removal of 20 to 25 mL of CSF. RESULTS: Lowering the intracranial pressure by lateral C1-2 puncture during manometry has shown that the venous hypertension resolves immediately. CONCLUSION: These studies indicate that the venous hypertension is due to compression of the transverse sinuses by raised intracranial pressure and not due to a primary obstructive process in the cerebral venous sinuses.http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=11781401 http://www.neurology.org/cgi/content/abstract/58/1/26 http://www.neurology.org/cgi/eletters/58/1/26"21640681 0028-3878 Journal Article11781401\Department of Neurology, Royal Melbourne Hospital, Victoria, Australia. jking@bigpond.net.au q~?([ Lavrencic, D.1970The Intracraniovertebral Volumes, the Cerebrospinal Fluid Flow and the Cerebrospinal Fluid Pressure, Their Homeostasis and Its Physical Regulation11 LjubljanaDarko LavrencicPreface. After publication of the presented hypothesis some predictions were verified independently by other authors: (1) Monro-Kellie "four compartments" doctrine, (2) relation between cerebrospinal fluid (CSF) formation and CSF removal in physiological phase as presented with illustrative curves, (3) hypovolemia during intracranial hypotension syndrome, (4) increased CSF proteins in decreased CSF flow and (5) influence of neuro-vegetative system on CSF pressure. The predictions not yet verified: (1) turning points B-low and B-high that represent physiological borders, (2) pathophysiological self-sustaining phases of very low (around -10mmHg) and very high (around +30mmHg) CSF pressure with corresponding minimal or maximal CSF volume (maximal dural sac collapse or distension) and no CSF transport, (3) compensated and de-compensated conditions. None of the predictions were disproved yet. There are three types of CSF hydrodynamic processes according to their duration in time: (1) rapid changes (in second(s), e.g., hydrodynamic changes caused by arterial pulsations in craniospinal space, etc), (2) homeostatic changes (in minutes to hours, e.g., as described in this article) and (3) long-term changes and adaptations, e.g., chronic hydrocephalus, etc. This article is not discussing (1) and (3) processes. The purpose of this presentation on the INTERNET is to promote further discussions about unverified predictions and to encourage clinical research and experimenting in this direction. Summary. Physiological and pathophysiological processes in the intracraniovertebral space are specific because of its rigid and constant volume (Monro-Kellie doctrine). The hypothesis presents how the homeostasis of the intracraniovertebral compartments' volumes, cerebrospinal fluid (CSF) flow and CSF pressure is physically regulated. The hypothesis takes into account the quantitative and qualitative relations regulating CSF formation and CSF removal on which the homeostasis is based.Yhttp://www.med-lavrencic.si/raziskava.htm, http://www.med-lavrencic.si/correspondence.htmRetyped 12. Nov 2001The Slovene National and University Library Catalogue Number: II 229751 (http://www.izum.si/scripts/cobiss?ukaz=getid&lani=EN&sblk=c&bno=50001) The Intracraniovertebral Volumes=Vrzdenec 90, 1354 Horjul, Ljubljana, Slovenia, European Union,~?+Lyons, M. K. Meyer, F. B.1990TCerebrospinal fluid physiology and the management of increased intracranial pressure684-707Mayo Clin Proc655Absorption Blood-Brain Barrier/physiology Cerebrospinal Fluid/analysis/metabolism/*physiology Combined Modality Therapy Evaluation Studies Homeostasis/physiology Human Monitoring, Physiologic Posture Pseudotumor Cerebri/complications/physiopathology/prevention & control/*therapyMaylIncreased intracranial pressure can result in irreversible injury to the central nervous system. Among the many functions of the cerebrospinal fluid, it provides protection against acute changes in venous and arterial blood pressure or impact pressure. Nevertheless, trauma, tumors, infections, neurosurgical procedures, and other factors can cause increased intracranial pressure. Both surgical and nonsurgical therapeutic modalities can be used in the management of increased intracranial pressure attributable to traumatic and nontraumatic causes. In patients with cerebral injury and increased intracranial pressure, monitoring of the intracranial pressure can provide an objective measure of the response to therapy and the pressure dynamics. Intraventricular, intraparenchymal, subarachnoid, and epidural sites can be used for monitoring, and the advantages and disadvantages of the various devices available are discussed. With the proper understanding of the physiologic features of the cerebrospinal fluid, the physician can apply the management principles reviewed herein to minimize damage from intracranial hypertension.dhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=2190050:90271624 0025-6196 Journal Article Review Review, Academic2190050CDepartment of Neurologic Surgery, Mayo Clinic, Rochester, MN 55905.'~?,$Seyfert, S. Koch, H. C. Kunzmann, V.2003DConditions of iodine contrast transfer from lumbosacral CSF to blood85-90 J Neurol Sci2061Adult Aged Aged, 80 and over Biological Transport Contrast Media/*pharmacokinetics Female Human Iopamidol/blood/cerebrospinal fluid/*pharmacokinetics Lumbar Vertebrae/radiography Male Middle Age Radiculopathy/*radiography Sacrum/radiographyJan_PURPOSE: To determine conditions which influence transfer of iopamidol from lumbosacral cerebrospinal fluid (CSF) to blood. METHODS: Iopamidol transfer was measured in 32 patients over 180 min after radiculography and compared with patient variables. RESULTS: Iopamidol transfer began early in 12 patients, more slowly in 13 patients, and was not detected during sample period in 7 patients. Transfer of sequential samples correlated highly with each other (r>0.8). Transfer was more pronounced in patients with prominent nerve root sleeves on radiculogram (p=0.006, t test), and correlated inversely with body weight (r=-0.4258), and with albumin CSF/serum quotient (r=-0.4702). CONCLUSION: Early iopamidol transfer probably indicates transfer through spinal arachnoid villi and granulations with CSF bulk flow. Prominent nerve root sleeves may facilitate access to transfer sites. No transfer during sample period suggests no such spinal transfer, possibly due to sparse access to or presence of spinal transfer sites. Inverse correlation of transfer with body weight may reflect influence of body weight on retroperitoneal venous pressure, which regulates outflow of CSF and of compounds dissolved in it. Awareness of wide interindividual transfer variation and steady intraindividual transfer may help to specify dosage and effect expectation of intrathecal drug therapy.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=12480090"22368653 0022-510x Journal Article12480090Department of Neurology, University Hospital Benjamin Franklin, Free University of Berlin, D-12200 Berlin, Germany. seyfert@medizin.fu-berlin.de~?-CSeyfert, S. Kunzmann, V. Schwertfeger, N. Koch, H. C. Faulstich, A.20020Determinants of lumbar CSF protein concentration1021-6J Neurol2498 Adolescent Adult Age Factors Aged Aged, 80 and over Albumins/*cerebrospinal fluid Body Mass Index Cerebrospinal Fluid Proteins/*chemistry Comparative Study Female Human Immunoglobulin G/*cerebrospinal fluid Male Middle Age Posture/physiology Radiculopathy/metabolismAugOBJECTIVE: To determine factors influencing the wide variation of protein concentration in lumbar cerebrospinal fluid (CSF). METHODS: Patient variables with potential influence on spinal CSF flow and resorption were measured in different patient settings and compared with albumin and IgG CSF/serum quotients. RESULTS: In patients whose diagnostic lumbar puncture produces normal CSF the albumin quotient increased with body mass index (r = 0.408), abdominal circumference (r = 0.399), and body weight (r = 0.317), age-corrected with partial correlation. Body motion before lumbar puncture showed only marginal influence on albumin quotient. In patients with radiculography the albumin quotient decreased with iodine contrast medium elimination from spinal subarachnoid space (r = -0.598) and increased with narrowing of lumbosacral spinal canal (r = 0.515). CONCLUSION: Correlation of albumin quotient with body mass index and related variables may be mediated by spinal CSF resorption, which should be impaired in overweight patients with elevated venous pressure. Negative correlation of albumin quotient with iodine resorption from spinal CSF supports this assumption. Correlation of albumin quotient with narrowing of lumbosacral canal should be due to slowed spinal CSF flow which does increase protein concentration. Tested variables explain part of variation of CSF protein concentration. Other variables like blood-CSF barrier permeability and pulsatile spinal CSF flow should have additional influence.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=12195448"22182985 0340-5354 Journal Article12195448Dept. of Neurology, University Hospital Benjamin Franklin, Free University of Berlin, 12200 Berlin, Germany. seyfert@medizin.fu-berlin.de?.N Elman, R.1923LSpinal arachnoid granulations with especial reference to cerebrospinal fluid99-104Johns Hopkins Hosp. Bull.Mar 1923385Mars?/N?Kerr, M.E. Weber, B.B. Sereika, S.M. Wilberger, J. Marion, D.W.2001eDose response to cerebrospinal fluid drainage on cerebral perfusion in traumatic brain-injured adults Article 1Neurosurg Focus114October2http://www.neurosurgery.org/focus/oct01/11-4-1.pdfe~?0Fishman, R. A. Dillon, W. P.1993QDural enhancement and cerebral displacement secondary to intracranial hypotension609-11 Neurology433 Pt 1Adult Arachnoid Cysts/*surgery Case Report Dura Mater/*pathology Female Human *Intracranial Pressure Magnetic Resonance Imaging Optic Chiasm/*pathology Pons/*pathologyMar*We studied a patient with spontaneous intracranial hypotension whose gadolinium-enhanced MRI revealed an extraordinary degree of dural enhancement and striking displacement of the optic chiasm, flattening of the pons, and downward displacement of the cerebellar tonsils. These changes were reversed when a CSF leak at the site of a T12-L1 arachnoid cyst was closed following an epidural blood patch. Such diffuse meningeal enhancement results from the dural venous dilatation that accompanies a reduced CSF volume, a consequence of the Monro-Kellie rule.dhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=8451008"93196899 0028-3878 Journal Article8451008GDepartment of Neurology, University of California, San Francisco 94143.?1 Fishman, R.A.19920Cerebrospinal Fluid in Disease of Nervous System Philadelphia WB Sounders?2Mitchell, G. A. G.1958CIBA Foundation Symposium on the Cerebrospinal Fluid. Production, Circulation and Absorption of the Cerebrospinal Fluid 27-29 May 1957LondonJ. & A. Churchill, Ltd8 http://www.glaserrarebooks.com/cgi-bin/glaser/7459.htmlp~?3Levine, D. N. Rapalino, O.2001/The pathophysiology of lumbar puncture headache1-8 J Neurol Sci1921-2/Age Factors Cerebral Veins/physiopathology Cerebrospinal Fluid/physiology Headache/etiology/*physiopathology Human Intracranial Pressure/physiology Postoperative Complications/etiology/*physiopathology Spinal Puncture/*adverse effects Subarachnoid Space/pathology/physiopathology Vasodilation/physiologyNovnThe pathophysiology of lumbar puncture headache (LPH) is still unclear. There is evidence that leakage of cerebrospinal fluid (CSF) leads to CSF hypotension, which causes dilation of intracranial veins, resulting in LPH. However, CSF leaks at the skull base are not associated with orthostatic headache; there is poor correlation between recumbent CSF pressure and LPH; and there has been no satisfactory explanation of how venous dilation causes orthostatic headache. We propose the hypothesis that LPH is caused by an abnormal distribution of craniospinal elasticity. Increased compliance at the lumbar end of the spinal CSF space, resulting both from anatomic joining of the subarachnoid to the epidural space and from reduced CSF filling pressure, causes the hydrostatic indifferent point to move caudally, creating additional intracranial hypotension and venous dilation in the erect position. We are, thus, able to explain the orthostatic character of LPH, the fact that spinal but not cranial sites of leakage produce orthostatic headache and the imperfect correlations both between recumbent CSF pressure and LPH and between reduced CSF volume and LPH. The near absence of LPH in the very young and in the elderly relates to the relative stiffness of the epidural space at these ages. Epidural injections of blood or saline give immediate relief by reducing epidural distensibility.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=11701146:21558650 0022-510x Journal Article Review Review, Tutorial11701146Department of Neurology, New York University School of Medicine, RIRM-311, 400 East 34th Street, New York, NY 10016, USA. david.levine@med.nyu.edu~?4DParkkola, R. K. Komu, M. E. Aarimaa, T. M. Alanen, M. S. Thomsen, C.2001]Cerebrospinal fluid flow in children with normal and dilated ventricles studied by MR imaging33-8 Acta Radiol421Adolescent Brain Diseases/diagnosis/*physiopathology Cerebral Ventricles/*abnormalities *Cerebrospinal Fluid/physiology Child Child, Preschool Comparative Study Female Human Infant Magnetic Resonance Imaging/*methods Male Prognosis Severity of Illness IndexJan=PURPOSE:. To quantify the cerebrospinal fluid (CSF) dynamics in the aqueduct of children with normal and dilated ventricles using MR phase-contrast technique. MATERIAL AND METHODS: Eighteen patients (6 months to 17 years of age) with various neurological symptoms underwent routine brain MR imaging and CSF flow measurement in the aqueduct. Nine patients had normal ventricles, 5 had dilated ventricles and 4 had a ventriculoperitoneal shunt. RESULTS: The CSF velocity and flow rates in the aqueduct in patients with normal and dilated ventricles showed marked inter-individual variation and clear overlap. In a patient with tight aqueductal stenosis and increased ventricular pressure, pronounced CSF flow in the aqueduct was measured. Absence of flow in another patient with aqueductal stenosis was detected. Measurable although low flow in the aqueduct in 4 patients with a ventriculoperitoneal shunt was found. CONCLUSION: Quantitative phase MR flow measurement in the aqueduct demonstrated aqueductal stenosis; these patients had either pronounced flow or no flow in the aqueduct.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=11167329"21039351 0284-1851 Journal Article11167329JDepartment of Diagnostic Radiology, University Hospital of Turku, Finland.?7o Piper, Ian1997#Intracranial pressure and elastancex, 478DHead injury : pathophysiology and management of severe closed injuryReilly, Peter Bullock, RossLondon ; New YorkChapman & Hall MedicalHead Wounds and injuries. Brain damage. Head Injuries, Closed physiopathology. Head Injuries, Closed therapy. Brain Injuries physiopathology. Brain Injuries therapy.;http://www.edc.gsph.pitt.edu/neurotrauma/thebook/Chap06.pdfyedited by Peter Reilly and Ross Bullock. Pathophysiology and management of severe closed injury ill. (some col.) ; 29 cm. 04125854058RD521 .H446 1997 1997 I-709 WE 706 H4327 1997 617.5/1044~?8%Martins, A. N. Newby, N. Doyle, T. F.1977\Sources of error in measuring cerebrospinal fluid formation by ventriculocisternal perfusion645-50J Neurol Neurosurg Psychiatry407Animal Carbon Dioxide Central Venous Pressure Cerebral Ventricles Cerebrospinal Fluid/*secretion Cisterna Magna Haplorhini Intracranial Pressure Macaca mulatta Methods Perfusion Support, U.S. Gov't, Non-P.H.S.JulVentriculocisternal perfusion is regarded as a precise method of measuring the rate of formation of cerebrospinal fluid (CSF) but it possesses inherent potential sources of error. Using the technique to measure CSF formation rate in the rhesus monkey, we have observed rate changes when none were expected. Most puzzling has been the steady decline of CSF formation rate at 4 percent each hour during the final five hours of a seven hour perfusion although variables known to affect CSF formation remained stable. In addition, alterations in rate caused by artefacts were observed in experiments in which craniospinal blood volume was changed by sudden changes of either PCO2 or central venous pressure. Mobilisation or sequestration of incompletely equilibrated CSF is believed responsible. In other experiments, a small increase of intracranial pressure produced by increasing outflow resistance was quickly followed by an apparent reduction of CSF formation. We have concluded that to assess accurately the effect a variable has on the rate of CSF formation, one must control perfusion time and craniospinal blood volume as well as intracranial pressure.chttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=410910"78028148 0022-3050 Journal Article410910 ~?9>Tokoro, K. Chiba, Y. Abe, H. Tanaka, N. Yamataki, A. Kanno, H.1994MImportance of anti-siphon devices in the treatment of pediatric hydrocephalus236-8Childs Nerv Syst104Adolescent Adult Case Report Cerebral Ventricles/physiopathology Cerebrospinal Fluid Shunts/*instrumentation Child Child, Preschool Equipment Design Equipment Failure Female Human Hydrocephalus/physiopathology/*surgery Hydrocephalus, Normal Pressure/physiopathology/surgery Intracranial Pressure/*physiology Male Postoperative Complications/physiopathology Posture/physiology ReoperationMayqThe effects of an anti-siphon device (ASD) on shunt flow and intracranial pressure (ICP) in 16 children with hypertensive hydrocephalus were examined using quantitative radionuclide shuntography (99mTc) with the children in supine and sitting positions. The average age of these patients was 9.5 years. Results were compared with those recorded in 36 patients with adult normal-pressure hydrocephalus (NPH). The closing pressure levels of shunt valve used were low in 8 cases, medium in 7 and high in 1. Half the children (8) had shunt systems with, and the other 8 without, ASD. In the children who had the shunt system without ASD, sitting shunt flow was significantly greater than supine shunt flow, which indicated overdrainage. Conversely, in children who had the shunt system with ASD, supine shunt flow was greater than sitting shunt flow. Because ASD prevented overdrainage, ICP was higher with the shunt system with ASD than with the shunt system without ASD. Without ASD, sitting shunt flow of children was lower than that of adult patients with NPH because of the lower hydrostatic pressure, which correlated with their height. Conversely, in the presence of a shunt system with ASD, sitting shunt flow of children was greater than that of adults, because of the higher ICP and lower hydrostatic pressure. The effect of ASD was smaller in children than in adults, because positive pressure over the ASD was greater (hypertension vs normal pressure) and negative pressure under the ASD was less (short vs tall) in children than in adults. Thus, in children the ASD was effective in preventing overdrainage.(ABSTRACT TRUNCATED AT 250 WORDS)dhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=7923233"95007627 0256-7040 Journal Article7923233BDepartment of Neurosurgery, Kanagawa Rehabilitation Center, Japan.~?:7Kadowaki, C. Hara, M. Numoto, M. Takeuchi, K. Saito, I.19957CSF shunt physics: factors influencing inshunt CSF flow203-6Childs Nerv Syst114QAdolescent Adult Aged Cerebrospinal Fluid Pressure/*physiology Cerebrospinal Fluid Shunts/*instrumentation Female Human Hydrocephalus/cerebrospinal fluid/*surgery Intracranial Pressure/physiology Male Middle Age Physics Posture/physiology Pulmonary Ventilation/physiology Reference Values Rheology/instrumentation Support, Non-U.S. Gov'tAprCerebrospinal fluid (CSF) in a shunt does not have a constant flow rate. The flow fluctuates from 0.01 ml/min to 1.93 ml/min according to each patient's own daily supine rhythmic pattern. We determined and evaluated the factors influencing CSF flow in a shunt in 19 cases of hydrocephalus. Postural changes, such as head elevation, led to increases by over 0.04 ml/min in inshunt CSF flow, while inshunt CSF flow in the supine position was less than 0.04 ml/min. Respiratory changes, such as coughing and apnea-hyperventilation, also influenced inshunt CSF flow. Changes in intracranial pressure (ICP) corresponded to changes in inshunt CSF flow. Inshunt CSF flows were higher than average during the night, the flows being stimulated by increases in ICP especially during REM sleep.dhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=7621480"95346957 0256-7040 Journal Article7621480ODepartment of Neurosurgery, Kyorin University School of Medicine, Tokyo, Japan. ?CYHRaksin, P.B. Alperin, N. Sivaramakrishnan, A. Surapaneni, S. Lichtor, T.2003Noninvasive intracranial compliance and pressure based on dynamic magnetic resonance imaging of blood flow and cerebrospinal fluid flow: review of principles, implementation, and other noninvasive approaches Article 4Neurosurg Focus144intracranial pressure intracranial elastance motion-sensitive magnetic resonance imaging cerebrospinal fluid flow dynamics total cerebral blood flowAprQCurrent techniques for intracranial pressure (ICP) measurement are invasive. All require a surgical procedure for placement of a pressure probe in the central nervous system and, as such, are associated with risk and morbidity. These considerations have driven investigators to develop noninvasive techniques for pressure estimation. A recently developed magnetic resonance (MR) imaging-based method to measure intracranial compliance and pressure is described. In this method the small changes in intracranial volume and ICP that occur naturally with each cardiac cycle are considered. The pressure change during the cardiac cycle is derived from the cerebrospinal fluid (CSF) pressure gradient waveform calculated from the CSF velocities. The intracranial volume change is determined by the instantaneous differences between arterial blood inflow, venous blood outflow, and CSF volumetric flow rates into and out of the cranial vault. Elastance (the inverse of compliance) is derived from the ratio of the measured pressure and volume changes. A mean ICP value is then derived based on a linear relationship that exists between intracranial elastance and ICP. The method has been validated in baboons, flow phantoms, and computer simulations. To date studies in humans demonstrate good measurement reproducibility and reliability. Several other noninvasive approaches for ICP measurement, mostly nonimaging based, are also reviewed. Magnetic resonance imaging-based ICP measurement may prove valuable in the diagnosis and serial evaluation of patients with a variety of disorders associated with alterations in ICP.2http://www.neurosurgery.org/focus/apr03/14-4-4.pdfNoam Alperin, Ph.D., Physiological Imaging and Modeling Lab, Department of Radiology (M/C 711), University of Illinois at Chicago, 830 South Wood Street, Chicago, Illinois 60612. email: alperin@uic.edu.~?D Kuczkowski, K. M. Benumof, J. L.2003QDecrease in the incidence of post-dural puncture headache: maintaining CSF volume98-100Acta Anaesthesiol Scand471Adult Anesthesia, Epidural/*adverse effects Anesthesia, Obstetrical/*adverse effects Apgar Score Cerebrospinal Fluid Pressure/*physiology Delivery, Obstetric Female Headache/*cerebrospinal fluid/*prevention & control Human Infant, Newborn PregnancyJanThe incidence of epidural needle-induced post-dural puncture headache (PDPH) in parturients following dural puncture with a large bore (18-gauge) needle has been reported to range 76-85%. We describe seven cases in which the performance of epidural anesthesia in parturients was complicated by an unintentional dural puncture with an 18-gauge epidural needle. In all seven cases, the unintentional dural puncture was followed by (i) injection of the CSF in the glass syringe back into the subarachnoid space through the epidural needle, (ii) insertion of a epidural catheter into the subarachnoid space (now referred to as an intrathecal catheter), (iii) injection of a small amount of preservative free saline (3-5 ml) into the subarachnoid space through the intrathecal catheter, (iv) administration of bolus and then continuous intrathecal labor analgesia through the intrathecal catheter and then (v) leaving the intrathecal catheter in-situ for a total of 12-20 h. PDPH occurred in only one of these cases (14%).ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=12492806122380187 0001-5172 Clinical Trial Journal Article12492806[Department of Anesthesiology, University of California San Diego, USA. kkuczkowski@ucsd.edu ~?E Reiber, H.2003^Proteins in cerebrospinal fluid and blood: Barriers, CSF flow rate and source-related dynamics79-96Restor Neurol Neurosci213,4Cerebrospinal fluid (CSF) routine analysis for diagnosis of neurological diseases is based on the concepts for discrimination of blood-derived and brain-derived immunoglobulin fractions in CSF. The actual molecular flux/CSF flow theory of the blood/CSF barrier function, which founded the hyperbolic discrimination lines in quotient diagrams, is derived from the laws of molecular diffusion combined with CSF flow rate. It emerged from this theory that the decrease of CSF flow rate is sufficient to explain quantitatively the increase of CSF protein concentrations as observed in many neurological diseases. With this concept of CSF flow rate as the modulator of the normal and pathological blood-CSF barrier function, we got for the first time a theoretical frame work to explain also quantitatively the dynamics of brain-derived proteins and their source related (neurons and glial cells or leptomeningal cells) differences. The review of the anatomical, physiological and biophysical knowledge points to the new interpretations: The changing albumin quotient is an indicator of changing CSF flow rate and not for a morphological "leakage" of the blood-brain barrier. As an application of these concepts the dynamics of brain-derived molecules in blood are discussed with two examples: beta trace protein, flowing with CSF into venous blood, and neuron-specific enolase, passing from tissue into blood the opposite direction of serum proteins, again a gradient-dependent protein diffusion across the intact blood vessel wall.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=145305720 0922-6028 Journal article14530572Neurochemisches Labor der Neurologischen Klinik, Robert-Koch-Str. 40, Universitat Gottingen, D - 37075 Gottingen, Germany. Tel.: +49 551 39 66 19; Fax: +49 551 39 20 28; E-mail: hreiber@med.uni-goettingen.dew~?GEnzmann, D. R. Pelc, N. J.1991oNormal flow patterns of intracranial and spinal cerebrospinal fluid defined with phase-contrast cine MR imaging467-74 Radiology1782Adult Aged Blood Flow Velocity Brain/anatomy & histology Carotid Arteries/physiology Cerebrospinal Fluid/*physiology Electrocardiography Female Human Jugular Veins/physiology *Magnetic Resonance Imaging/methods Male Middle Age Spinal Cord/anatomy & histology/blood supply SystoleFebA phase-contrast cine magnetic resonance (MR) imaging technique was used to study normal dynamics of cerebrospinal fluid (CSF) in 10 healthy volunteers and four patients with normal MR images. This pulse sequence yielded 16 quantitative flow-encoded images per cardiac cycle (peripheral gating). Flow encoding depicted craniocaudal flow as high signal intensity and caudo-cranial flow as low signal intensity. Sagittal and axial images of the head, cervical spine, and lumbar spine were obtained, and strategic sites were analyzed for quantitative CSF flow. The onset of CSF systole in the subarachnoid space was synchronous with the onset of systole in the carotid artery. CSF systole and diastole at the foramen of Monro and aqueduct were essentially simultaneous. The systolic and diastolic components were different in the subarachnoid space, where systole occupied approximately 40% and diastole 60% of the cardiac cycle, compared with the ventricular system, where they were equal. This difference results in systole in the intracranial and spinal subarachnoid spaces preceding that in the ventricular system; the same is true for diastole. The fourth ventricle and cisterna magna serve as mixing chambers. The high-velocity flow in the cervical spine and essentially no flow in the distal lumbar sac indicate that a portion of the capacitance necessary in this essentially closed system resides in the distal spinal canal.dhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=1987610"91102252 0033-8419 Journal Article1987610fDepartment of Diagnostic Radiology and Nuclear Medicine, Stanford University Medical Center, CA 94305.~?HRamadan, N. M.1996LHeadache caused by raised intracranial pressure and intracranial hypotension214-8Curr Opin Neurol93Brain Diseases/*physiopathology Headache/*complications Human Hypotension/*physiopathology *Intracranial Pressure Support, U.S. Gov't, P.H.S.JunExtremes of intracranial pressure commonly cause headache. Benign intracranial hypertension is a rare syndrome of increased intracranial pressure manifesting as headache, intracranial noises, transient visual obscuration, and palsy of the sixth cranial nerve. Endocrine disorders such as obesity and hypoparathyroidism, hypervitaminosis A, tetracycline use and thyroid replacement are probable causes of benign intracranial hypertension. In the majority of cases, however, it is idiopathic. Benign intracranial hypertension is though to be caused by cerebral edema, high cerebrospinal fluid outflow resistance and high cerebral venous pressure, or a combination of the three. The management of benign intracranial hypertension includes, symptomatic headache relief, removal of offending risk factor(s), and medical or surgical reduction of intracranial pressure. Spontaneous intracranial hypotension is more rare than benign intracranial hypertension. Postural headache (worse in the upright position) is the hallmark of spontaneous intracranial hypotension. Typically, the cerebrospinal fluid pressure is less than 60 mm H2O. Diminished cerebrospinal fluid production, hyperabsorption, and leak are postulated mechanisms of spontaneous intracranial hypotension. Empirical treatment includes bed rest, administration of caffeine, corticosteroids or mineralocorticoids, epidural blood patch, and epidural saline infusion.dhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=8839614:96436798 1350-7540 Journal Article Review Review, Tutorial8839614`Department of Neurology, Henry Ford Hospital and Health Sciences Center, Detroit, MI 48202, USA.~?JhBaledent, O. Gondry-Jouet, C. Meyer, M. E. De Marco, G. Le Gars, D. Henry-Feugeas, M. C. Idy-Peretti, I.2004Relationship Between Cerebrospinal Fluid and Blood Dynamics in Healthy Volunteers and Patients with Communicating Hydrocephalus45-55 Invest Radiol391JanSUMMARY: RATIONALE AND OBJECTIVES Using magnetic resonance imaging (MRI), we investigated cerebral blood and cerebrospinal fluid (CSF) flows in patients with communicating hydrocephalus (CH) and in healthy volunteers to determine the contribution of CSF flow to brain pressure regulation in CH patients.METHODS Cine phase-contrast MRI data from 16 healthy volunteers and 12 patients with CH characterized by hyperdynamic aqueductal CSF flow were analyzed using in-house image-processing software that automatically measured flow curves. Amplitude and temporal CSF and blood flow parameters were compared in the 2 groups.RESULTS Jugular peak flow occurred significantly earlier (P < 0.01) in the CH patients than in the healthy volunteers. Cervical CSF oscillations were not significantly different between the 2 groups.CONCLUSION Venous vessel compression and/or changes in intracranial subarachnoid CSF flow produce an increase in ventricular CSF flush that compensates for vascular brain expansion in patients with CH.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=147019880020-9996 Journal article14701988Department of Imaging and Biophysics, UMR 6600 CNRS, Teaching Hospitals, Jules Verne University of Picardie, Amiens, France; dagger Department of Radiology A, Teaching Hospitals, Amiens, France; double dagger Department of Neurosurgery, Teaching Hospitals, Amiens, France; section sign Department of Radiology, UPRES JE 2156, Bichat Teaching Hospital, Paris, France; and paragraph sign Department of Biophysics and Nuclear Medicine, Lariboisiere Teaching Hospital, Paris, France.~?KQZakharov, A. Papaiconomou, C. Koh, L. Djenic, J. Bozanovic-Sosic, R. Johnston, M.2004rIntegrating the roles of extracranial lymphatics and intracranial veins in cerebrospinal fluid absorption in sheep96-104 Microvasc Res671JanAt relatively low cerebrospinal fluid (CSF) pressures, the majority of CSF drainage in 6- to 8-month-old sheep occurs through the cribriform plate into lymphatic vessels in the nasal submucosa. As CSF pressures are elevated, other absorption sites are recruited and these may include transport through arachnoid projections. To test for the transport of CSF directly into the venous sinus, the concentration of a tracer (131I-human serum albumin [HSA]) administered into the CSF compartment was measured in the confluence of the intracranial venous sinuses (torcular) and in the peripheral blood (inferior vena cava). CSF pressures were adjusted to favor absorption. Enrichment of the CSF tracer in the cranial venous system was most evident when the CSF-venous sinus pressure gradients were high. Peak concentration differences occurred 90 s after the CSF pressures were elevated. When pressure gradients approached 30 cm H(2)O, tracer concentrations in the torcular were approximately twofold higher than those observed in peripheral blood. The greatest concentration differences favoring the torcular were obtained when the CSF-venous sinus pressure gradients were elevated to high levels (20- to 40 cm H(2)O) and when CSF access to the paranasal lymphatics and CSF transport into the spinal subarachnoid compartment were prevented. In conjunction with previous studies, these results are compatible with the view that CSF absorption in the adult animal can occur directly into the cranial venous system. However, contrary to the established view, this pathway may represent a secondary system that is recruited to compliment lymphatic transport when global absorption capacity is stressed or compromised.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=147094070026-2862 Journal Article14709407Neuroscience Research, Department of Laboratory Medicine and Pathobiology, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, M4N 3M5, Toronto, Ontario, Canada~?L4Friese, S. Hamhaber, U. Erb, M. Kueker, W. Klose, U.2004NThe Influence of Pulse and Respiration on Spinal Cerebrospinal Fluid Pulsation120-130 Invest Radiol392FebSUMMARY: RATIONALE AND OBJECTIVES The aim of the study is to elucidate the location and amount of spinal cerebrospinal fluid pulsations and to differentiate and quantify the cardiac and the respiratory influence.MATERIALS AND METHODS An echo planar imaging sequence was applied to 5 different levels of the spinal canal of 7 healthy volunteers. The amount of maximal flow and respiratory signal variation were determined by a time and frequency domain analysis, respectively.RESULTS CSF pulsation was high in the anterior cervical and in the thoracolumbar spine. Respiratory influence rose by 19% at C1 and by 28% at T12. The systolic flow was elevated during late expiration and the diastolic upward movement was pronounced by early expiration.CONCLUSION The pulsation in the lower spine seems to be related to a second motor of CSF movement because there is a rising respiratory influence and a reappearance of pulsation waves. Physiological spinal CSF pulsation contains a relevant respiratory component.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=147349270020-9996 Journal article14734927Department of Neuroradiology and the dagger Section of Experimental Magnetic Resonance of the CNS of the Department of Neuroradiology, University Hospital, Eberhard-Karls-University, Tuebingen, Germany. Department of Neuroradiology and the dagger Section of Experimental Magnetic Resonance of the CNS of the Department of Neuroradiology, University Hospital, Eberhard-Karls-University, Tuebingen, Germany.~?MDijkstra, C. D.2003k[The Nobel Prize in Chemistry 2003 awarded for discoveries concerning molecular channels in cell membranes]2570-2Ned Tijdschr Geneeskd14752*Aquaporins/chemistry/physiology Cell Physiology Chemistry/history English Abstract History of Medicine, 20th Cent. Human Models, Chemical *Nobel Prize *Potassium Channels/chemistry/physiology United States Water/physiologyDec 27About 70% of the human body consists of salt water. The Nobel Prize 2003 in Chemistry rewards Peter Agre for the discovery of water channels and Roderick MacKinnon for structural and mechanistic studies of ion channels. Their studies have demonstrated how ions and water are transported through cell membranes. This transport is essential for the regulation of size and osmotic pressure in cells and organelles and it plays a major role in salt and water homoeostasis and in the generation of electrical signals in nerve cells. Agre succeeded in isolating a membrane protein which later studies revealed to be a long-postulated water channel, MacKinnon succeeded in determining the spatial structure of a potassium channel.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=1472302360028-2162 Biography Historical Article Journal Article14723023VU Medisch Centrum, faculteit Geneeskunde, vakgroep Celbiologie, Van der Boechorststraat 7, 1081 BT Amsterdam. cd.dijkstra@vumc.nl'ۿ?NS Mayor, Susan2003/Nobel prize in medicine awarded to MRI pioneers827-BMJ3277419October 11, 2003Hhttp://bmj.com http://bmj.bmjjournals.com/cgi/content/full/327/7419/827BMJq~?OdVigh, B. Manzano, E. Silva M. J. Frank, C. L. Vincze, C. Czirok, S. J. Szabo, A. Lukats, A. Szel, A.2004{The system of cerebrospinal fluid-contacting neurons. Its supposed role in the nonsynaptic signal transmission of the brain607-28Histol Histopathol192AprCRecent investigations confirm the importance of nonsynaptic signal tranmission in several functions of the nervous tissue. Present in various periventricular brain regions of vertebrates, the system of cerebrospinal fluid (CSF)-contacting neurons seems to have a special role in taking up, transforming and emitting nonsynaptic signals mediated by the internal and external CSF and intercellular fluid of the brain. Most of the CSF-contacting nerve cells send dendritic processes into the internal CSF of the brain ventricles or central canal where they form terminals bearing stereocilia and a 9+0-, or 9+2-type cilium. Some of these neurons resemble known sensory cells of chemoreceptor-type, others may be sensitive to the pressure or flow of the CSF, or to the illumination of the brain tissue. The axons of the CSF-contacting neurons transmit information taken up by dendrites and perikarya to synaptic zones of various brain areas. By forming neurohormonal terminals, axons also contact the external CSF space and release various bioactive substances there. Some perikarya send their axons into the internal CSF, and form free endings there, or synapses on intraventricular dendrites, perikarya and/or on the ventricular surface of ependymal cells. Contacting the intercellular space, sensory-type cilia were also demonstrated on nerve cells situated in the brain tissue subependymally or farther away from the ventricles. Among neuronal elements entering the internal CSF-space, the hypothalamic CSF-contacting neurons are present in the magnocellular and parvicellular nuclei and in some circumventricular organs like the paraventricular organ and the vascular sac. The CSF-contacting dendrites of all these areas bear a solitary 9x2+0-type cilium and resemble chemoreceptors cytologically. In electrophysiological experiments, the neurons of the paraventricular organ are highly sensitive to the composition of the ventricular CSF. The axons of the CSF-contacting neurons terminate not only in the hypothalamic synaptic zones but also in tel-, mes- and rhombencephalic nuclei and reach the spinal cord as well. The supposed chemical information taken up by the CSF-contacting neurons from the ventricular CSF may influence the function of these areas of the central nervous system. Some nerve cells of the photoreceptor areas form sensory terminals similar to those of the hypothalamic CSF-contacting neurons. Special secondary neurons of the retina and pineal organ contact the retinal photoreceptor space and pineal recess respectively, both cavities being embryologically derived from the 3rd ventricle. The composition of these photoreceptor spaces is important in the photochemical transduction and may modify the activity of the secondary neurons. Septal and preoptic CSF-contacting neurons contain various opsins and other compounds of the phototransduction cascade and represent deep encephalic photoreceptors detecting the illumination of the brain tissue and play a role in the regulation of circadian and reproductive responses to light. The medullo-spinal CSF-contacting neurons present in the oblongate medulla, spinal cord and terminal filum, send their dendrites into the fourth ventricle and central canal. Resembling mechanoreceptors of the lateral line organ, the spinal CSF-contacting neurons may be sensitive to the pressure or flow of the CSF. The axons of these neurons terminate at the external CSF-space of the oblongate medulla and spinal cord and form neurohormonal nerve endings. Based on information taken up from the CSF, a regulatory effect on the production or composition of CSF was supposed for bioactive materials released by these terminals. Most of the axons of the medullospinal CSF-contacting neurons and the magno- and parvicellular neurosecretory nuclei running to neurohemal areas (neurohypophysis, median eminence, terminal lamina, vascular sac and urophysis) do not terminate directly on vessels, instead they form neurohormonal nerve terminals attached by half-desmosomes on the basal lamina of the external and vascular surface of the brain tissue. Therefore, the bioactive materials released from these terminals primarily enter the external CSF and secondarily, by diffusion into vessels and the composition of the external CSF, may have a modulatory effect on the bioactive substances released by the neurohormonal terminals. Contacting the intercellular space, sensory-type cilia were also demonstrated on nerve cells situated subependymally or farther away from the ventricles, among others in the neurosecretory nuclei. Since tight-junctions are lacking between ependymal cells of the ventricular wall, not only CSF-contacting but also subependymal ciliated neurons may be influenced by the actual composition of the CSF besides that of the intercellular fluid of the brain tissue. According to the comparative histological data summarised in this review, the ventricular CSF-contacting neurons represent the phylogenetically oldest component detecting the internal fluid milieu of the brain. The neurohormonal terminals on the external surface of the brain equally represent an ancient form of nonsynaptic signal transmission.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=150247190213-3911 Journal Article15024719uDepartment of Human Morphology and Developmental Biology, Semmelweis University, Budapest, Hungary. vigh@ana2.sote.hu~?P"Seyfert, S. Faulstich, A. Marx, P.2004IWhat determines the CSF concentrations of albumin and plasma-derived IgG?31-3 J Neurol Sci2191-2Apr 15Objectives: To estimate the mean influence of the main determinants of the cerebrospinal fluid (CSF) concentration of albumin and plasma-derived immunoglobulin G (IgG). Methods: Correlations of serum and CSF concentrations of albumin and IgG and assumptions of the mode of action of the determinants (plasma concentration, barrier permeability, and CSF flow) are used to quantify the determinants' influences in a sample of 1700 patients. Results: We estimated in patients with normal CSF albumin that the serum concentrations of albumin and IgG explained 3.3% and 23% of the variation of the respective CSF concentrations, whereas the barrier permeability accounted for 41.9% and 22.2%, and CSF flow for 54.8%. In patients with pathologic CSF albumin concentration, the serum concentrations were estimated to explain 0.2% and 8.2% of the variation of the respective CSF concentrations, the barrier permeability 19.7% and 11.7%, and CSF flow 80.1%. Conclusions: CSF flow had the strongest mean influence, especially at elevated CSF albumin levels. The serum concentrations and barrier permeabilities of albumin and IgG influenced the respective CSF concentrations quite differently, which should be due to the different physicochemical properties of the two molecules. Mean influences from large patient samples, as explored here, can give only an overview. Understanding the determinants in individuals will need further specific measurements, especially of CSF flow.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=150504340022-510x Journal Article15050434Neurologische Klinik am UKBF, Department of Neurology, University Hospital Benjamin Franklin, Freie Universitat Berlin, Berlin D-12200, Germany.?QM Weed, L.H.19359Forces concerned in the absorption of cerebrospinal fluid40-45 Am J Physiol114F~?S2Edsbagge, M. Tisell, M. Jacobsson, L. Wikkelso, C.2004,Spinal CSF absorption in healthy individuals&Am J Physiol Regul Integr Comp PhysiolAug 12The present study examines the extent of spinal cerebrospinal fluid (CSF) absorption in healthy individuals in relation to physical activity, CSF production, intracranial pressure (ICP) and spinal CSF movement. Thirty-four healthy individuals aged 21-35 years were examined by lumbar puncture and radionuclide cisternographies with repeated imaging. ICP was registered previous to and after CSF drainage and CSF production was calculated. Spinal CSF absorption was calculated as reduction in spinal radionuclide activity. The radionuclide activity in the spinal subarachnoidal space (SAS) was gradually decreased by 20 +/- 13 % (mean +/- SD) during one hour. The reduction was higher in active than in resting individuals (27 +/- 12 % vs. 13 +/- 9 %, mean +/- SD). The mean ICP in 19 of the individuals was 13.6 +/- 3.1 (+/- SD) cm H2O. B-waves were found in 79 % of the individuals with a mean frequency of 0.6 +/- 0.3 (+/- SD) / minute. The mean CSF production rate was 0.34 +/- 0.13 (+/- SD) ml / minute. There were no correlations between radionuclide reduction, spinal movement of the radionuclide and CSF production rate. The spinal radionuclide reduction found in this study indicates a spinal CSF absorption of 0.11 - 0.23 ml / min, more pronounced in active than in resting individuals.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=153084840363-6119 Journal article15308484Hydrocephalus Research Unit, Institute of Clinical Neuroscience, Sahlgrenska University Hospital, Goteborg University, Goteborg, Sweden.~?TDWilkinson, H. A. Yarzebski, J. Wilkinson, E. C. Anderson, F. A., Jr.1989vErroneous measurement of intracranial pressure caused by simultaneous ventricular drainage: a hydrodynamic model study348-54 Neurosurgery243Brain/physiopathology Cerebral Ventricles/*physiopathology *Cerebrospinal Fluid Shunts Human *Intracranial Pressure *Models, NeurologicalMariIntracranial pressure (ICP) is often measured from intraventricular catheters, a technique that allows therapeutic drainage of ventricular cerebrospinal fluid (CSF) as an aid in controlling ICP and circumventing obstruction. Drainage of CSF simultaneously with ongoing ICP measurement has been advocated as safe and efficient, and devices are commercially available to permit this practice; however, this concept has been seriously challenged, based on clinical observations. The inaccuracy induced by simultaneous CSF drainage and ICP monitoring is quantitated in this report in a mechanical brain model using a standard ventricular catheter. The following conclusions have been confirmed: 1) rapid CSF drainage induces a severe artifactual reduction in measured ICP, more extreme at higher pressures; 2) calibrated slower rates of CSF drainage produce a severe, although less immediate, reduction in measured ICP; 3) severe artifact appears even in the presence of continuous CSF outflow, so a system that measures ICP only in the presence of CSF flow does not prevent artifact; 4) with simultaneous CSF drainage, measured ICP is determined more by the outflow pressure setting than by actual brain pressure; 5) Since ICP elevation of 25 to 30 mm Hg blocks CSF production, even slow fluid drainage at high pressures should ultimately lead to ventricular collapse and severe artifact.dhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=29276080148-396x Journal Article2927608UDepartment of Surgery, University of Massachusetts Health Sciences Center, Worcester. W~?U>Fischer,R Vollmar,C Thiere,M Born,C Leitl,M Pfluger,T Huber, R2004@No evidence of cerebral oedema in severe acute mountain sickness66-71 Cephalalgia241High al-titude Acute mountain sickness Cerebral oedema Diffusion weighted imaging Acetazolamide/*therapeutic use Altitude Sickness/complications/*diagnosis/drug therapy/*prevention & control Brain/drug effects Brain Edema/*diagnosis/drug therapy/etiology/*prevention & control Comparative Study Cross-Over Studies Double-Blind Method Human Magnetic Resonance Imaging Male Placebo Effect Reproducibility of Results Sensitivity and Specificity Support, Non-U.S. Gov't Theophylline/*therapeutic use Vasodilator Agents/therapeutic useJan=In a randomized, double-blind cross-over study 10 subjects were exposed to a simulated altitude of 4500 m for 10 h after administration of placebo, acetozolamide (250 mg bid) or theophylline (250 mg bid). T2-weighted magnetic resonances images (MRI) and diffusion weighted MRI were obtained directly after exposure to altitude under hypoxic conditions. Although eight of 10 subjects had moderate to severe acute mountain sickness (AMS), we found no evidence of cerebral oedema, irrespective of the medication taken. Almost all subjects showed a decrease in inner cerebrospinal fluid (iCSF) volumes (placebo - 10.3%, P= 0.02; acetazolamide - 13.2%, P= 0.008, theophylline -12.2%, n.s.). There was no correlation between AMS symptoms and fluid shift. However, we found a significantly positive correlation of large (>10 ml) iCSF volume and more severe AMS after administration of placebo (r = 0.76, P= 0.01). Moderate to severe AMS after high altitude exposure for 10 h is associated with a decreased iCSF-volume independent of AMS severity or medication without signs of cerebral oedemahttp://www.ingenta.com/isis/searching/ExpandTOC/ingenta;jsessionid=17alob7j38yi5.crescent?issue=infobike://bsc/cha/2004/00000024/00000001&index=12 http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=14687016Randomized Controlled Trial Document Type: Research article ISSN: 0333-1024 DOI (article): 10.1111/j.1468-2982.2004.00619.x SICI (online): 0333-1024(20040101)24:1L.66;1-14687016Department of Medicine, Division of Pneumology, Medizinische Klinik Innenstadt, University of Munich, Ziemssenstrasse 1, D-80336 Munich, Germany. rfischer@medinn.med.uni-muenchen.de~?XVerrees, M. Selman, W. R.2004+Management of normal pressure hydrocephalus1071-8Am Fam Physician706Sep 15CGait instability, urinary incontinence, and dementia are the signs and symptoms typically found in patients who have normal pressure hydrocephalus. Estimated to cause no more than 5 percent of cases of dementia, normal pressure hydrocephalus often is treatable, and accurate recognition of the clinical triad coupled with radiographic evidence most commonly identifies likely responders. Magnetic resonance imaging or computed tomography typically demonstrates ventricular dilation with preservation of the surrounding brain tissue. The abnormality in normal pressure hydrocephalus occurs secondary to an abnormality in fluid removal, leading to an increase in ventricular size and encroachment of enlarged ventricles on adjacent brain tissue. The pressure exerted on the cerebral parenchyma by immense fluid-filled cavities deforms white matter tracts, instigating gait abnormalities and incomplete control of the bladder, as well as difficulties in processing incoming stimulation and in producing expeditious responses. Signs and symptoms often occur as sequelae to an imbalance between the expected ongoing production of cerebrospinal fluid and continuous efflux. Ventriculoperitoneal shunting is used to relieve excess ventricular fluid not absorbed by normal physiologic channels. Multiple studies have explored various techniques to identify patients with normal pressure hydrocephalus in an effort to predict likely benefit from shunting. However, the effectiveness of cerebrospinal fluid diversion has never been proven in a randomized controlled trial comparing use of a shunt versus no shunt.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=154561160002-838x Journal Article15456116Department of Neurosurgery, Case Western Reserve University, University Hospitals of Cleveland, Cleveland, Ohio 44106, USA. megverrees@yahoo.com ~?Z]Metafratzi, Z. Argyropoulou, M. I. Mokou-Kanta, C. Konitsiotis, S. Zikou, A. Efremidis, S. C.2004aSpontaneous intracranial hypotension: morphological findings and CSF flow dynamics studied by MRI1013-6 Eur Radiol146Adult Cavernous Sinus/pathology Cerebrospinal Fluid/*physiology Female Human Intracranial Hypotension/*pathology/*physiopathology *Magnetic Resonance Imaging Magnetic Resonance Imaging, CineJunVWe report on a case of spontaneous intracranial hypotension (SIH) presenting with classic MR findings, such as diffuse smooth thickening and intense contrast enhancement of the dura matter, increased size of the pituitary gland and downward displacement of the brain. In this case an engorgement of the cavernous sinuses is reported as an additional imaging finding of SIH. Moreover, phase-contrast MR study of the CSF flow dynamics revealed at the level of the aqueduct a decrease of the systolic and diastolic flow volume of CSF. A normalization of the flow volume was observed when SIH subsided.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=14605844&0938-7994 Case Reports Journal Article14605844XDepartment of Radiology, Medical School, University of Ioannina, 45110 Ioannina, Greece.~?[ Greitz, D.2004SRadiological assessment of hydrocephalus: new theories and implications for therapy145-65; discussion 166-7 Neurosurg Rev273Animals Brain/physiopathology Cerebrospinal Fluid/*physiology Human Hydrocephalus/physiopathology/*radiography/*therapy Intracranial Pressure/physiology Pulsatile Flow/physiology Support, Non-U.S. Gov'tJulIt is almost a century since Dandy made the first experimental studies on hydrocephalus, but its underlying mechanism has been unknown up to now. The conventional view is that cerebrospinal fluid (CSF) malabsorption due to hindrance of the CSF circulation causes either obstructive or communicating hydrocephalus. Analyses of the intracranial hydrodynamics related to the pulse pressure show that this is an over-simplification. The new hydrodynamic concept presented here divides hydrocephalus into two main groups, acute hydrocephalus and chronic hydrocephalus. It is still accepted that acute hydrocephalus is caused by an intraventricular CSF obstruction, in accordance with the conventional view. Chronic hydrocephalus consists of two subtypes, communicating hydrocephalus and chronic obstructive hydrocephalus. The associated malabsorption of CSF is not involved as a causative factor in chronic hydrocephalus. Instead, it is suggested that increased pulse pressure in the brain capillaries maintains the ventricular enlargement in chronic hydrocephalus. Chronic hydrocephalus is due to decreased intracranial compliance, causing restricted arterial pulsations and increased capillary pulsations. The terms "restricted arterial pulsation hydrocephalus" or "increased capillary pulsation hydrocephalus" can be used to stress the hydrodynamic origin of both types of chronic hydrocephalus. The new hydrodynamic theories explain why third ventriculostomy may cure patients with communicating hydrocephalus, a treatment incompatible with the conventional view.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=1516425510344-5607 Journal Article Review Review, Tutorial15164255Department of Neuroradiology and MR Research Center, Karolinska University Hospital, 171 76, Stockholm, Sweden. dan.greitz@kus.se ~?\*Zakharov, A. Papaiconomou, C. Johnston, M.2004eLymphatic vessels gain access to cerebrospinal fluid through unique association with olfactory nerves139-46Lymphat Res Biol23BACKGROUND: Physiological studies suggest that a major portion of cerebrospinal fluid (CSF) drainage is associated with transport along cranial and spinal nerves with absorption taking place into lymphatic vessels external to the central nervous system. Especially important is CSF transport through the cribriform plate in association with the olfactory nerves. This study examined the anatomical connections that link the CSF and extracranial lymphatics at the base of the brain. METHODS AND RESULTS: The contrast agent, Yellow Microfil, was infused into the cranial sub-arachnoid compartment of 2- to 7-day-old lambs postmortem. In some animals, blue Microfil was perfused into the carotid arteries. Yellow Microfil was observed in extensive lymphatic networks in the submucosa associated with the olfactory and respiratory epithelium. Since little of the contrast agent was present within the interstitium of the olfactory submucosa, there appeared to be direct continuity between the subarachnoid space, the perineurial spaces of the olfactory nerve fibers that penetrated the cribriform plate, and the lumens of the lymphatic vessels within the olfactory submucosa. Lymphatics encircled the olfactory nerves at the level of the emerging nerve rootlets (in many cases providing the outer limit of the perineurial space) and then dispersed freely in the submucosa at greater distance from the crib-riform plate. These vessels converged into larger collecting ducts that emptied into various lymph nodes in the head and neck. CONCLUSIONS: Lymphatic vessels gain access to the brain extracellular fluid (CSF) in an unusual anatomical association with the olfactory nerves external to the cranial vault. This study highlights the important role played by lymphatic vessels in CSF absorption.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=156098131539-6851 Journal Article15609813Neuroscience Research, Department of Laboratory Medicine and Pathobiology, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.~?]<Oshio, K. Watanabe, H. Song, Y. Verkman, A. S. Manley, G. T.2005yReduced cerebrospinal fluid production and intracranial pressure in mice lacking choroid plexus water channel Aquaporin-176-8Faseb J191Jan Aquaporin-1 (AQP1) is a water channel expressed strongly at the ventricular-facing surface of choroid plexus epithelium. We developed novel methods to compare water permeability in isolated choroid plexus of wild-type vs. AQP1 null mice, as well as intracranial pressure (ICP) and cerebrospinal fluid (CSF) production and absorption. Osmotically induced water transport was rapid in choroid plexus from wild-type mice and reduced by fivefold by AQP1 deletion. AQP1 deletion did not affect choroid plexus size or structure. By stereotaxic puncture of the lateral ventricle with a microneedle, ICP was 9.5 +/- 1.4 cm H2O in wild-type mice and 4.2 +/- 0.4 cm H2O in AQP1 null mice. CSF production, an isosmolar fluid secretion process, was measured by a dye dilution method involving fluid collections using a second microneedle introduced into the cisterna magna. CSF production in wild-type mice was (in microl min(-1)) 0.37 +/- 0.04 (control), 0.16 +/- 0.03 (acetazolamide-treated), and 1.14 +/- 0.15 (forskolin-treated), and reduced by approximately 25% in AQP1 null mice. Pressure-dependent CSF outflow, measured from steady-state ICP at different ventricular infusion rates, was not affected by AQP1 deletion. In a model of focal brain injury, AQP1 null mice had remarkably reduced ICP and improved survival compared with wild-type mice. The reduced ICP and CSF production in AQP1 null mice provides direct functional evidence for the involvement of AQP1 in CSF dynamics, suggesting AQP1 inhibition as a novel option for therapy of elevated ICP.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=155339491530-6860 Journal Article15533949[Department of Neurosurgery, University of California, San Francisco, California 94110, USA. G~?^DJohnston, M. Zakharov, A. Papaiconomou, C. Salmasi, G. Armstrong, D.2004Evidence of connections between cerebrospinal fluid and nasal lymphatic vessels in humans, non-human primates and other mammalian species2Cerebrospinal Fluid Res11Dec 10BACKGROUND: The parenchyma of the brain does not contain lymphatics. Consequently, it has been assumed that arachnoid projections into the cranial venous system are responsible for cerebrospinal fluid (CSF) absorption. However, recent quantitative and qualitative evidence in sheep suggest that nasal lymphatics have the major role in CSF transport. Nonetheless, the applicability of this concept to other species, especially to humans has never been clarified. The purpose of this study was to compare the CSF and nasal lymph associations in human and non-human primates with those observed in other mammalian species. METHODS: Studies were performed in sheep, pigs, rabbits, rats, mice, monkeys and humans. Immediately after sacrifice (or up to 7 hours after death in humans), yellow Microfil was injected into the CSF compartment. The heads were cut in a sagittal plane. RESULTS: In the seven species examined, Microfil was observed primarily in the subarachnoid space around the olfactory bulbs and cribriform plate. The contrast agent followed the olfactory nerves and entered extensive lymphatic networks in the submucosa associated with the olfactory and respiratory epithelium. This is the first direct evidence of the association between the CSF and nasal lymph compartments in humans. CONCLUSIONS: The fact that the pattern of Microfil distribution was similar in all species tested, suggested that CSF absorption into nasal lymphatics is a characteristic feature of all mammals including humans. It is tempting to speculate that some disorders of the CSF system (hydrocephalus and idiopathic intracranial hypertension for example) may relate either directly or indirectly to a lymphatic CSF absorption deficit.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=156799481743-8454 Journal article15679948Neuroscience Program, Department of Laboratory Medicine and Pathobiology, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, 2075 Bayview Avenue, Toronto, Ontario, M4N 3M5, Canada. miles.johnston@sw.ca. '~?_=Bradley, W. G. Safar, F. G. Hurtado, C. Ord, J. Alksne, J. F.2004bIncreased intracranial volume: a clue to the etiology of idiopathic normal-pressure hydrocephalus?1479-84AJNR Am J Neuroradiol259EAged Aged, 80 and over *Cephalometry Cerebral Ventricles/pathology Cerebrospinal Fluid/physiology Diagnosis, Differential Female Humans Hydrocephalus, Normal Pressure/diagnosis/*etiology *Image Processing, Computer-Assisted *Magnetic Resonance Imaging Male Middle Aged Reference Values Sensitivity and Specificity Sex FactorsOctBACKGROUND AND PURPOSE: The etiology of idiopathic normal-pressure hydrocephalus (NPH) is unknown. The purpose of this study was to examine the hypothesis that NPH begins in infancy as benign external hydrocephalus due to decreased uptake of CSF by the arachnoid villi. Since this occurs before the sutures fuse, a secondary hypothesis is that the intracranial volumes of patients with NPH should be larger than those of healthy individuals. METHODS: Intracranial volumes of 51 patients with clinically suspected NPH were compared with those of age- and sex-matched control subjects. All patients underwent phase-contrast CSF velocity MR imaging. They had aqueductal CSF stroke volumes of at least 60 microL, which was 50% higher than previously published normal values. Intracranial volumes were measured and compared between groups. RESULTS: The average intracranial volume for men with NPH (n = 22) was 1682 mL compared with 1565 for male control subjects (n = 55). The NPH volume averaged 118 mL (7.5%) larger than the control volume (P = .003). The average intracranial volume for women with NPH (n = 29) was 1493 mL compared with 1405 mL for female control subjects (n = 55). The NPH volume was 88 mL (6.3%) larger than the control volume (P = .002). CONCLUSION: Patients with NPH have intracranial volumes significantly larger than normal, suggesting that the initial insult occurs before the sutures fuse at 1 year of age. The patients somehow remain asymptomatic until their later years, when a second insult must occur, leading to symptomatic NPH.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=155021250195-6108 Journal Article15502125MDepartment of Radiology, University of California, San Diego 92103-8224, USA. 8~?`#Zenker, W. Bankoul, S. Braun, J. S.1994Morphological indications for considerable diffuse reabsorption of cerebrospinal fluid in spinal meninges particularly in the areas of meningeal funnels. An electronmicroscopical study including tracing experiments in rats243-58Anat Embryol (Berl)1893Absorption Animals Arachnoid/metabolism Cerebrospinal Fluid/*metabolism Dura Mater/metabolism Ferritin/pharmacokinetics Male Meninges/*metabolism/ultrastructure Microscopy, Electron Rats Rats, Inbred Strains Research Support, Non-U.S. Gov't Spinal Cord/*metabolism/ultrastructureMar Transmission and scanning electron microscopical observations in the rat indicate a considerable capacity of the spinal meninges to reabsorb cerebrospinal fluid. The density of blood vessels and lymphatics in the duramater is extremely high, particularly in the areas of meningeal funnels and spinal nerve root sleeves. Arterioles with closely related unmyelinated nerve fibres, many fenestrated capillaries and venules predetermine these areas as sites where absorption processes could take place. At certain sites of the meningeal angle region, the arachnoid membrane, mostly multilayered, is reduced to only three or four layers. Intercellular discontinuities and cytoplasmic fenestrations occurring in the arachnoid lining cell layer result in direct communications between the subarachnoid space and cisterns of the arachnoid "reticular layer". These cisterns are partly fluid-filled, partly occupied by a net of collagen fibre bundles. Some cisterns harbour macrophages that often project filiform processes through the lining cell layer into the subarachnoid space, contacting cerebrospinal fluid. Desmosomes and gap junctions are present in all layers of the arachnoid. However, tight junctions and the continuous electrondense intercellular gap, known to occur normally within the "arachnoid barrier layer", were not seen in many sites of the meningeal angle region. Numerous arachnoid cells display a high degree of vesiculation. Cationized ferritin, introduced in vivo into the rat subarachnoid space, passes inter- and intracellularly from the cerebrospinal fluid compartment through the arachnoid membrane, reaching dural blood vessels and lymphatics. Tracer could be visualized both in the cytoplasm of the endothelium and on the luminal surface of the cells. Tracer also passed through pial cell layers into pial vessels, through leptomeningeal sheaths into vessels crossing the subarachnoid space, into the connective tissue compartment and into vessels of spinal dorsal root ganglia. In the angle region, a particularly large number of macrophages can be found on the surface of leptomeninges, within the arachnoid reticular layers, and in close relation to dural and epidural capillaries, venules and lymphatics. Their possible role in the process of cerebrospinal fluid reabsorption is discussed.dhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=80427660340-2061 Journal Article80427668Institute of Anatomy, University of Zurich, Switzerland.~?bStockman, H. W.2006gEffect of anatomical fine structure on the flow of cerebrospinal fluid in the spinal subarachnoid space106-14 J Biomech Eng1281FebThe lattice Boltzmann method is used to model oscillatory flow in the spinal subarachnoid space. The effect of obstacles such as trabeculae, nerve bundles, and ligaments on fluid velocity profiles appears to be small, when the flow is averaged over the length of a vertebra. Averaged fluid flow in complex models is little different from flow in corresponding elliptical annular cavities. However, the obstacles stir the flow locally and may be more significant in studies of tracer dispersion.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=16532623!0148-0731 (Print) Journal Article16532623FSandia Laboratories, Department 6118, Albuquerque, NM 87185-0750, USA.~?cBergsneider, M. Egnor, M. R. Johnston, M. Kranz, D. Madsen, J. R. McAllister, J. P., 2nd Stewart, C. Walker, M. L. Williams, M. A.20063What we don't (but should) know about hydrocephalus157-9 J Neurosurg1043 SupplAdolescent Adult Age Factors Brain/pathology Cerebrospinal Fluid Pressure Child Child, Preschool Humans Hydrocephalus/complications/etiology/*physiopathology/*therapy TerminologyMarIn an effort to identify critical gaps in the prevailing knowledge of hydrocephalus, the authors formulated 10 key questions. 1) How do we define hydrocephalus? 2) How is cerebrosinal fluid (CSF) absorbed normally and what are the causes of CSF malabsorption in hydrocephalus? 3) Why do the ventricles dilate in communicating hydrocephalus? 4) What happens to the structure and function of the brain when it is compressed and stretched by the expanding ventricles? 5) What is the role of cerebrovenous pressure in hydrocephalus? 6) What causes normal-pressure hydrocephalus? 7) What causes low-pressure hydrocephalus? 8) What is the pathophysiology of slit ventricle syndrome? 9) What is the pathophysiological basis for neurological impairment in hydrocephalus, and to what extent is it reversible? 10) How is the brain of a child with hydrocephalus different from that of a young or elderly adult? Rigorous answers to these questions should lead to more effective and reliable treatments for this disorder.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=16572631!0022-3085 (Print) Journal Article16572631UDepartment of Neurosurgery, University of California at Los Angeles, California, USA.4http://thejns.org/doi/pdf/10.3171/ped.2006.104.3.157\~?d Tobinick, E.2006OThe cerebrospinal venous system: anatomy, physiology, and clinical implications53 MedGenMed81There is substantial anatomical and functional continuity between the veins, venous sinuses, and venous plexuses of the brain and the spine. The term "cerebrospinal venous system" (CSVS) is proposed to emphasize this continuity, which is further enhanced by the general lack of venous valves in this network. The first of the two main divisions of this system, the intracranial veins, includes the cortical veins, the dural sinuses, the cavernous sinuses, and the ophthalmic veins. The second main division, the vertebral venous system (VVS), includes the vertebral venous plexuses which course along the entire length of the spine. The intracranial veins richly anastomose with the VVS in the suboccipital region. Caudally, the CSVS freely communicates with the sacral and pelvic veins and the prostatic venous plexus. The CSVS constitutes a unique, large-capacity, valveless venous network in which flow is bidirectional. The CSVS plays important roles in the regulation of intracranial pressure with changes in posture, and in venous outflow from the brain. In addition, the CSVS provides a direct vascular route for the spread of tumor, infection, or emboli among its different components in either direction.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=16915183&1531-0132 (Electronic) Journal Article16915183qAssistant Clinical Professor of Medicine, David Geffen School of Medicine, University of California, Los Angeles.?eLavrencic, D.D.Correspondence.http://www.med-lavrencic.si/correspondence.htm fLavrencic, D.D.2006#The enigma of the third circulationVrhnikaEObstacles involved in resolving the enigma of the third circulation. =http://www.med-lavrencic.si/download/Lavrencic_CSF_enigma.pdfEnglish29 August 200629 August 2006 [N}?lBThiery, Jean-Claude Lomet, Didier Bougoin, Sylvain Malpaux, Benoit2009dT~?g!Andersson, N. Malm, J. Eklund, A.2008MDependency of cerebrospinal fluid outflow resistance on intracranial pressure918-22 J Neurosurg1095NovObject The outflow resistance (R(out)) of the cerebrospinal fluid (CSF) system has generally been accepted by most investigators as independent of intracranial pressure (ICP), but there are also those claiming that it is not. The general belief is that this question has been investigated numerous times in the past, but few studies have actually been specifically aimed at looking at this relationship, and no study has been able to provide scientific evidence to elucidate fully this fundamental and important issue. The objective of this study was to investigate the relationship between ICP and CSF outflow in 30 patients investigated for idiopathic normal-pressure hydrocephalus. Methods Lumbar infusion tests with constant pressure levels were performed, and ICP and corresponding flow were measured on 6 pressure levels for each patient. All data were standardized for comparison. Results In the range of moderate increases from baseline pressure (~ 5-12 mm Hg, mean baseline pressure 11.7 mm Hg), the assumption of a pressure-independent R(out) was confirmed (p = 0.5). However, when the pressure increment from baseline pressure was larger (~ 15-22 mm Hg), the relationship had a nonlinear tendency (p < 0.05). Conclusions The results of this study support the classic textbook theory of a pressure-independent R(out) in the normal ICP range, where the CSF system is commonly operating. However, the theory might have to be questioned in regions where ICP exceeds baseline pressure by too much.fhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=18976085 !0022-3085 (Print) Journal Article189760851 Department of Biomedical Engineering and Informatics, Umea University Hospital; and, 2 Department of Clinical Neuroscience and, 3 Centre of Biomedical Engineering and Physics, Umea University, Umea, Sweden.~?h[Johanson, C. E. Duncan, J. A., 3rd Klinge, P. M. Brinker, T. Stopa, E. G. Silverberg, G. D.2008SMultiplicity of cerebrospinal fluid functions: New challenges in health and disease10Cerebrospinal Fluid Res5ABSTRACT: This review integrates eight aspects of cerebrospinal fluid (CSF) circulatory dynamics: formation rate, pressure, flow, volume, turnover rate, composition, recycling and reabsorption. Novel ways to modulate CSF formation emanate from recent analyses of choroid plexus transcription factors (E2F5), ion transporters (NaHCO3 cotransport), transport enzymes (isoforms of carbonic anhydrase), aquaporin 1 regulation, and plasticity of receptors for fluid-regulating neuropeptides. A greater appreciation of CSF pressure (CSFP) is being generated by fresh insights on peptidergic regulatory servomechanisms, the role of dysfunctional ependyma and circumventricular organs in causing congenital hydrocephalus, and the clinical use of algorithms to delineate CSFP waveforms for diagnostic and prognostic utility. Increasing attention focuses on CSF flow: how it impacts cerebral metabolism and hemodynamics, neural stem cell progression in the subventricular zone, and catabolite/peptide clearance from the CNS. The pathophysiological significance of changes in CSF volume is assessed from the respective viewpoints of hemodynamics (choroid plexus blood flow and pulsatility), hydrodynamics (choroidal hypo- and hypersecretion) and neuroendocrine factors (i.e., coordinated regulation by atrial natriuretic peptide, arginine vasopressin and basic fibroblast growth factor). In aging, normal pressure hydrocephalus and Alzheimer's disease, the expanding CSF space reduces the CSF turnover rate, thus compromising the CSF sink action to clear harmful metabolites (e.g., amyloid) from the CNS. Dwindling CSF dynamics greatly harms the interstitial environment of neurons. Accordingly the altered CSF composition in neurodegenerative diseases and senescence, because of adverse effects on neural processes and cognition, needs more effective clinical management. CSF recycling between subarachnoid space, brain and ventricles promotes interstitial fluid (ISF) convection with both trophic and excretory benefits. Finally, CSF reabsorption via multiple pathways (olfactory and spinal arachnoidal bulk flow) is likely complemented by fluid clearance across capillary walls (aquaporin 4) and arachnoid villi when CSFP and fluid retention are markedly elevated. A model is presented that links CSF and ISF homeostasis to coordinated fluxes of water and solutes at both the blood-CSF and blood-brain transport interfaces. OUTLINE: 1 Overview2 CSF formation2.1 Transcription factors2.2 Ion transporters2.3 Enzymes that modulate transport2.4 Aquaporins or water channels2.5 Receptors for neuropeptides3 CSF pressure3.1 Servomechanism regulatory hypothesis3.2 Ontogeny of CSF pressure generation3.3 Congenital hydrocephalus and periventricular regions3.4 Brain response to elevated CSF pressure3.5 Advances in measuring CSF waveforms4 CSF flow4.1 CSF flow and brain metabolism4.2 Flow effects on fetal germinal matrix4.3 Decreasing CSF flow in aging CNS4.4 Refinement of non-invasive flow measurements5 CSF volume5.1 Hemodynamic factors5.2 Hydrodynamic factors5.3 Neuroendocrine factors6 CSF turnover rate6.1 Adverse effect of ventriculomegaly6.2 Attenuated CSF sink action7 CSF composition7.1 Kidney-like action of CP-CSF system7.2 Altered CSF biochemistry in aging and disease7.3 Importance of clearance transport7.4 Therapeutic manipulation of composition8 CSF recycling in relation to ISF dynamics8.1 CSF exchange with brain interstitium8.2 Components of ISF movement in brain8.3 Compromised ISF/CSF dynamics and amyloid retention9 CSF reabsorption9.1 Arachnoidal outflow resistance9.2 Arachnoid villi vs. olfactory drainage routes9.3 Fluid reabsorption along spinal nerves9.4 Reabsorption across capillary aquaporin channels10 Developing translationally effective models for restoring CSF balance11 Conclusion.fhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=18479516 &1743-8454 (Electronic) Journal Article18479516Department of Clinical Neurosciences, Warren Alpert Medical School at Brown University, Providence, RI 02903, USA. Conrad_Johanson@Brown.edu.F~?i&Linninger, A. A. Sweetman, B. Penn, R.2009xNormal and Hydrocephalic Brain Dynamics: The Role of Reduced Cerebrospinal Fluid Reabsorption in Ventricular EnlargementAnn Biomed EngApr 17CINE phase-contrast MRI (CINE-MRI) was used to measure cerebrospinal fluid (CSF) velocities and flow rates in the brain of six normal subjects and five patients with communicating hydrocephalus. Mathematical brain models were created using the MRI images of normal subjects and hydrocephalic patients. In our model, the effect of pulsatile vascular expansion is responsible for pulsatile CSF flow between the cranial and the spinal subarachnoidal spaces. Simulation results include intracranial pressure gradients, solid stresses and strains, and fluid velocities throughout the cranio-spinal system. Computed velocities agree closely with our in vivo CINE-MRI CSF flow measurements. In addition to normal intracranial dynamics, our model captures the transition to acute communicating hydrocephalus. By increasing the value for reabsorption resistance in the subarachnoid villi, our model predicts that the poroelastic parenchyma matrix will be drained and the ventricles enlarge despite small transmantle pressure gradients during the transitional phase. The poroelastic simulation thus provides a plausible explanation on how reabsorption changes could be responsible for enlargement of the ventricles without large transmantle pressure gradients.fhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19373558 &1521-6047 (Electronic) Journal article19373558Laboratory for Product and Process Design (LPPD), Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, USA, linninge@uic.edu. 1~?jSaliou, G. Baledent, O. Lehmann, P. Paradot, G. Gondry-Jouet, C. Bouzerar, R. Devisme, G. Theaudin, M. Deramond, H. Le Gars, D. Meyer, M. E. Vallee, J. N.2009e[Acute CSF changes in the mesencephalon aqueduct after subarachnoid hemorrhage as measured by PC-MRI]41-7 J Neuroradiol361Acute Disease Cerebral Aqueduct/*pathology Female Humans Hydrocephalus/*cerebrospinal fluid/pathology Magnetic Resonance Imaging/*methods Male Mesencephalon/*pathology Middle Aged Prospective Studies Subarachnoid Hemorrhage/*cerebrospinal fluid/pathologyMarPPURPOSE: Determining acute intracranial hydrodynamic changes after subarachnoid hemorrhage through an analysis of the CSF stroke volume (SV) as measured by phase-contrast MRI (PC-MRI) in the mesencephalon aqueduct. METHOD: A prospective study was performed in 33 patients with subarachnoid hemorrhage. A PC-MRI imaging study was performed n the acute phase (< 48 hours). CSF flow was measured in the aqueduct. The appearance of acute hydrocephalus (HCA) was then compared with data on CSF flow, and the location of the intraventricular and perimesencephalic bleeding. RESULTS: CSF analysis was performed on 27 patients, 11 of whom presented with an acute HCA. All 11 patients had an abnormal SV in the aqueduct: patients with a communicating HCA had an increased SV (n=8); and patients with a noncommunicating HCA had a nil SV (n=3). Patients with a normal SV in the aqueduct did not develop an acute HCA. Intraventricular bleeding significantly led to HCA (P=0.02), which was of the communicating type in 70% of cases. CONCLUSION: Subarachnoid hemorrhage leads to intracranial CSF hydrodynamic modifications in the aqueduct in the majority of patients. CSF flow can help us to understand the mechanism of the appearance of acute HCA. Indeed, hydrocephalus occurred - of the communicating type in most cases - even in the presence of intraventricular bleeding.fhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=18701163 20150-9861 (Print) English Abstract Journal Article18701163Caracterisation des perturbations du flux de LCS dans l'aqueduc du mesencephale par IRM-CP a la phase aigue de l'hemorragie meningee.lService de neurologie, hopital de Bicetre, 94275 Kremlin-Bicetre cedex, France. guillaume.saliou@bct.aphp.frF~?k.Schibli, M. Wyss, M. Boesiger, P. Guzzella, L.2009Investigation of ventricular cerebrospinal fluid flow phase differences between the foramina of Monro and the aqueduct of Sylvius / Phasendifferenzen zwischen den Liquorstromungen im Aquadukt und in den Foramina MonroBiomed Tech (Berl)Jul 17Abstract In this paper, phase contrast magnetic resonance flow measurements of the foramina of Monro and the aqueduct of Sylvius of seven healthy volunteers are pre-sented. Peak volume flow rates are of the order of 150 mm(3)/s for the aqueduct of Sylvius and for the foramina of Monro. The temporal shift between these volume flows is analyzed with a high-resolution cross-correlation scheme which reveals high subject-specific phase differences. Repeated measurements show the invariability of the phase differences over time for each volunteer. The phase differences as a fraction of one period range from -0.0537 to 0.0820. A mathematical model of the pressure dynamics is presented. The model features one lumped compartment per ventricle. The driving force of the cerebrospinal fluid is modeled through pulsating choroid plexus. The model includes variations of the distribution of the choroid plexus between the ventricles. The proposed model is able to reproduce the measured phase differences with a very small (5%) variation of the distribution of the choroid plexus between the ventricles and, therefore, supports the theory that the choroid plexus drives the cerebrospinal fluid motion.fhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19614268 !0013-5585 (Print) Journal article19614268sDepartment of Mechanical and Process Engineering, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland. urnover rate of cerebrospinal fluid in female sheep: changes related to different light-dark cycles9Cerebrospinal Fluid Research61BACKGROUND:Sheep are seasonal breeders. The key factor governing seasonal changes in the reproductive activity of the ewe is increased negative feedback of estradiol at the level of the hypothalamus under long-day conditions. It has previously been demonstrated that when gonadotropin secretions are inhibited during long days, there is a higher concentration of estradiol in the cerebrospinal fluid (CSF) than during short days. This suggests an involvement of the CSF and choroid plexus in the neuroendocrine regulatory loop, but the mechanisms underlying this phenomenon remain unknown. One possible explanation of this difference in hormonal content is an effect of concentration or dilution caused by variations in CSF secretion rate. The aim of this study was thus to investigate changes in the CSF turnover rate related to light-dark cycles. METHODS:The turnover rate of the CSF was estimated by measuring the time taken for the recovery of intraventricular pressure (IVP) after removal of a moderate volume (0.5 to 2 ml) of CSF (slope in mmHg/min). The turnover rate was estimated three times in the same group of sheep: during a natural period of decreasing day-length corresponding to the initial period when gonadotropin activity is stimulated (SG1), during a long-day inhibitory period (IG), and finally during a short-day stimulatory period (SG2). RESULTS:The time taken and the speed of recovery of initial IVP differed between groups: 8 min 30 sec, 0.63 +/- 0.07 mmHg/min(SG1), 11 min 1 sec, 0.38 +/- 0.06 mmHg/min (IG) and 9 min 0 sec, 0.72 +/- 0.15 mmHg/min (SG2). Time changes of IVP differed between groups (ANOVA, p<0.005, SG1 different from IG, p<0.05). The turnover rate in SG2: 183.16 +/- 23.82 ul/min was not significantly different from SG1: 169. 23 +/- 51.58 ul/min (Mann-Whitney test, p = 0.41), but was significantly different from IG: 71.33 +/- 16.59 ul/min (p = 0.016).CONCLUSION:This study shows that the turnover rate of CSF in ewes changes according to the light-dark cycle; it is increased during short day periods and reduced in long day periods. This phenomenon could account for differences in hormonal concentrations in the CSF in this seasonal species.8http://www.cerebrospinalfluidresearch.com/content/6/1/9 1743-8454doi:10.1186/1743-8454-6-9 }?m9Genzen, Jonathan Yang, Dan Ravid, Katya Bordey, Angelique2009pActivation of adenosine A2B receptors enhances ciliary beat frequency in mouse lateral ventricle ependymal cells15Cerebrospinal Fluid Research61BACKGROUND:Ependymal cells form a protective monolayer between the brain parenchyma and cerebral spinal fluid. They possess motile cilia important for directing the flow of cerebral spinal fluid through the ventricular system. While ciliary beat frequency in airway epithelia has been extensively studied, fewer reports have looked at the mechanisms involved in regulating ciliary beat frequency in ependyma. Prior studies have demonstrated that ependymal cells express at least one purinergic receptor (P2X7). An understanding of the full range of purinergic receptors expressed by ependymal cells, however, is not yet complete. The objective of this study was to identify purinergic receptors which may be involved in regulating ciliary beat frequency in lateral ventricle ependymal cells. METHODS:High-speed video analysis of ciliary movement in the presence and absence of purinergic agents was performed using differential interference contrast microscopy in slices of mouse brain (total number of animals = 67). Receptor identification by this pharmacological approach was corroborated by immunocytochemistry, calcium imaging experiments, and the use of two separate lines of knockout mice. RESULTS:Ciliary beat frequency was enhanced by application of a commonly used P2X7 agonist. Subsequent experiments, however, demonstrated that this enhancement was observed in both P2X7+/+ and P2X7-/- mice and was reduced by pre-incubation with an ecto-5'-nucleotidase inhibitor. This suggested that enhancement was primarily due to a metabolic breakdown product acting on another purinergic receptor subtype. Further studies revealed that ciliary beat frequency enhancement was also induced by adenosine receptor agonists, and pharmacological studies revealed that ciliary beat frequency enhancement was primarily due to A2B receptor activation. A2B expression by ependymal cells was subsequently confirmed using A2B-/- / beta-galactosidase reporter gene knock-in mice. CONCLUSIONS:This study demonstrates that A2B receptor activation enhances ciliary beat frequency in lateral ventricle ependymal cells. Ependymal cell ciliary beat frequency regulation may play an important role in cerebral fluid balance and cerebral spinal fluid dynamics.9http://www.cerebrospinalfluidresearch.com/content/6/1/15 1743-8454doi:10.1186/1743-8454-6-15 }?rFTNagra, Gurjit Wagshul, Mark Rashid, Shams Li, Jie McAllister, J. Pat Johnston, Miles2010Elevated CSF outflow resistance associated with impaired lymphatic CSF absorption in a rat model of kaolin-induced communicating hydrocephalus4Cerebrospinal Fluid Research71BACKGROUND:We recently reported a lymphatic cerebrospinal fluid (CSF) absorption deficit in a kaolin model of communicating hydrocephalus in rats with ventricular expansion correlating negatively with the magnitude of the impediment to lymphatic function. However, it is possible that CSF drainage was not significantly altered if absorption at other sites compensated for the lymphatic defect. The purpose of this study was to investigate the impact of the lymphatic absorption deficit on global CSF absorption (CSF outflow resistance). METHODS:Kaolin was injected into the basal cisterns of Sprague Dawley rats. The development of hydrocephalus was assessed using MRI. In one group of animals at about 3 weeks after injection, the movement of intraventricularly injected human serum albumin (125I-HSA) into the olfactory turbinates provided an estimate of CSF transport through the cribriform plate into nasal lymphatics. In a second group at about 3.5 weeks after injection, intraventricular pressure was measured continuously during infusion of saline into the spinal subarachnoid space at various flow rates. CSF outflow resistance was calculated as the slope of the steady-state pressure versus flow relationship. Control animals received saline injection in place of kaolin. RESULTS:Compared to saline injected controls, lateral ventricular volume in the kaolin group was significantly greater (0.087 +/- 0.013 ml, n=27 versus 0.015 +/- 0.001 ml, n=17) and lymphatic function was significantly less (2.14 +/- 0.72 % injected/gm, n=18 versus 6.38 +/- 0.60 % injected/gm, n=10). Additionally, the CSF outflow resistance was significantly greater in the kaolin group (0.46 +/- 0.04 cm H2O.microL-1.min, n=9) than in saline injected (0.28 +/- 0.03 cm H2O.microL-1.min, n=8) or intact animals (0.18 +/- 0.03 cm H2O.microL-1.min, n=11). There was a significant positive correlation between CSF outflow resistance and ventricular volume. CONCLUSIONS:The data suggest that the impediment to lymphatic CSF absorption in a kaolin-induced model of communicating hydrocephalus has a significant impact on global CSF absorption. A lymphatic CSF absorption deficit would appear to play some role (either direct or indirect) in the pathogenesis of ventriculomegaly.8http://www.cerebrospinalfluidresearch.com/content/7/1/4 1743-8454doi:10.1186/1743-8454-7-4 ependymal cells15Cerebrospinal Fluid Research61BACKGROUND:Ependymal cells form a protective monolayer between the brain parenchyma and cerebral spinal fluid. They possess motile cilia important for directing the flow of cerebral spinal fluid through the ventricular system. While ciliary beat frequency in airway epithelia has been extensively studied, fewer reports have looked at the mechanisms involved in regulating ciliary beat frequency in ependyma. Prior studies have demonstrated that ependymal cells express at least one purinergic receptor (P2X7). An understanding of the full range of purinergic receptors expressed by ependymal cells, however, is not yet complete. The objective of this study was to identify purinergic receptors which may be involved in regulating ciliary beat frequency in lateral ventricle ependymal cells. METHODS:High-speed video analysis of ciliary movement in the presence and absence of purinergic agents was performed using differential interference contrast microscopy in slices of mouse brain (total number of animals = 67). Receptor identification by this pharmacological approach was corroborated by immunocytochemistry, calcium imaging experiments, and the use of two separate lines of knockout mice. RESULTS:Ciliary beat frequency was enhanced by application of a commonly used P2X7 agonist. Subsequent experiments, however, demonstrated that this enhancement was observed in both P2X7+/+ and P2X7-/- mice and was reduced by pre-incubation with an ecto-5'-nucleotidase inhibitor. This suggested that enhancement was primarily due to a metabolic breakdown product acting on another purinergic receptor subtype. Further studies revealed that ciliary beat frequency enhancement was also induced by adenosine receptor agonists, and pharmacological studies revealed that ciliary beat frequency enhancement was primarily due to A2B receptor activation. A2B expression by ependymal cells was subsequently confirmed using A2B-/- / beta-galactosidase reporter gene knock-in mice. CONCLUSIONS:This study demonstrates that A2B receptor activation enhances ciliary beat frequency in lateral ventricle ependymal cells. Ependymal cell ciliary beat frequency regulation may play an important role in cerebral fluid balance and cerebral spinal fluid dynamics.9http://www.cerebrospinalfluidresearch.com/content/6/1/15 1743-8454doi:10.1186/1743-8454-6-15 ldzen, Jonathan Yang, Dan Ravid, Katya Bordey, Angelique2009pActivation of adenosine A2B receptors enhances ciliary beat frequency in mouse lateral ventricle ependymal cells15Cerebrospinal Fluid Research61BACKGROUND:Ependymal cells form a protective monolayer between the brain parenchyma and cerebral spinal fluid. They possess motile cilia important for directing the flow of cerebral spinal fluid through the ventricular system. While ciliary beat frequency in airway epithelia has been extensively studied, fewer reports have looked at the mechanisms involved in regulating ciliary beat frequency in ependyma. Prior studies have demonstrated that ependymal cells express at least one purinergic receptor (P2X7). An understanding of the full range of purinergic receptors expressed by ependymal cells, however, is not yet complete. The objective of this study was to identify purinergic receptors which may be involved in regulating ciliary beat frequency in lateral ventricle ependymal cells. METHODS:High-speed video analysis of ciliary movement in the presence and absence of purinergic agents was performed using differential interference contrast microscopy in slices of mouse brain (total number of animals = 67). Receptor identification by this pharmacological approach was corroborated by immunocytochemistry, calcium imaging experiments, and the use of two separate lines of knockout mice. RESULTS:Ciliary beat frequency was enhanced by application of a commonly used P2X7 agonist. Subsequent experiments, however, demonstrated that this enhancement was observed in both P2X7+/+ and P2X7-/- mice and was reduced by pre-incubation with an ecto-5'-nucleotidase inhibitor. This suggested that enhancement was primarily due to a metabolic breakdown product acting on another purinergic receptor subtype. Further studies revealed that ciliary beat frequency enhancement was also induced by adenosine receptor agonists, and pharmacological studies revealed that ciliary beat frequency enhancement was primarily due to A2B receptor activation. A2B expression by ependymal cells was subsequently confirmed using A2B-/- / beta-galactosidase reporter gene knock-in mice. CONCLUSIONS:This study demonstrates that A2B receptor activation enhances ciliary beat frequency in lateral ventricle ependymal cells. Ependymal cell ciliary beat frequency regulation may play an important role in cerebral fluid balance and cerebral spinal fluid dynamics.9http://www.cerebrospinalfluidresearch.com/content/6/1/15 1743-8454doi:10.1186/1743-8454-6-15