CSF dynamics and pressure-volume relationships in communicating hydrocephalus

1986 ◽  
Vol 64 (1) ◽  
pp. 45-52 ◽  
Author(s):  
Michael Kosteljanetz
Keyword(s):  
Cerebrospinal Fluid ◽  
Bolus Injection ◽  
Formation Rate ◽  
Cerebral Atrophy ◽  
Pulse Amplitude ◽  
Volume Index ◽  
Communicating Hydrocephalus ◽  
Csf Dynamics ◽  
Content Type ◽  
Normal Individuals

✓ Twenty-nine patients consecutively admitted with a diagnosis of communicating hydrocephalus underwent 1) continuous intracranial pressure (ICP) monitoring; 2) pressure-volume studies; and 3) measurement of resistance to outflow of cerebrospinal fluid (Rout). The two latter calculations were made by the bolus injection and pressure-volume index (PVI) techniques. In 19 patients mean ICP never exceeded 15 mm Hg. In the other 10 patients varying degrees of mildly raised ICP was noted. The frequency of waves at ½ to 2/min varied from 3% to 58%. The ICP pulse amplitude ranged from 0.5 to 10 mm Hg, and PVI from 4.6 to 18.2 ml. The Rout ranged from 2.5 to 31.4 mm Hg/ml/min, and was linearly correlated to the ICP. Thus, patients with a higher Rout also had a higher ICP as compared with patients with lower Rout, yet ICP could still be within limits considered normal. The cerebrospinal fluid dynamics (formation rate × resistance) contributed much more to the ICP than in normal individuals. It is postulated that communicating hydrocephalus represents one endpoint of a continuum, where the preceding phase is high-pressure and high-resistance hydrocephalus as, for instance, is seen after subarachnoid hemorrhage. In some patients, there is a possibility of cerebral atrophy accompanied by otherwise insignificant increased Rout. In this study, the PVI technique proved to be a fast and safe method of measuring Rout.

The arrest of treated hydrocephalus in children

1984 ◽  
Vol 61 (4) ◽  
pp. 752-756 ◽  
Author(s):  
Ian H. Johnston ◽  
Robert Howman-Giles ◽  
Ian R. Whittle
Keyword(s):  
Cerebrospinal Fluid ◽  
Clinical Findings ◽  
Communicating Hydrocephalus ◽  
Csf Dynamics ◽  
Aqueduct Stenosis ◽  
Content Type ◽  
A Prospective Study ◽  
Neonates And Infants ◽  
Radionuclide Scanning ◽  
Fine Print

✓ A prospective study was made of the incidence of arrest of treated non-neoplastic hydrocephalus in 30 neonates and infants over a 5-year period. Radionuclide assessment of shunt function and cerebrospinal fluid (CSF) dynamics was carried out at intervals over this period, using a method that allowed injection of the radionuclide into the ventricular system independent of the shunt apparatus. The radionuclide scanning results were correlated with computerized tomography and clinical findings. Of 24 patients still available for analysis at the end of 5 years, four patients showed restoration of CSF circulation independent of the shunt apparatus and, in three of these, the shunt has either been clipped or clipped and removed without any ill effects. Clinical details of these three patients are provided. Two initially had communicating hydrocephalus, and one had probable aqueduct stenosis.

Pressure-volume conditions in patients with subarachnoid and/or intraventricular hemorrhage

1985 ◽  
Vol 63 (3) ◽  
pp. 398-403 ◽  
Author(s):  
Michael Kosteljanetz
Keyword(s):  
Intracranial Pressure ◽  
Blood Volume ◽  
Intraventricular Hemorrhage ◽  
Bolus Injection ◽  
Pulse Amplitude ◽  
Volume Index ◽  
Icp Monitoring ◽  
Content Type ◽  
The Relationship ◽  
Fine Print

✓ Pressure-volume conditions were studied in 17 patients with subarachnoid and/or intraventricular hemorrhage, who underwent continuous intracranial pressure (ICP) monitoring. The pressure-volume index (PVI) technique was used. The interrelationship between the ICP pulse amplitude and compliance was also examined. All patients were admitted in Hunt and Hess Grades II to V, and 11 had a proven aneurysm. The ICP was above 15 mm Hg in all patients during some part of the monitoring period. The pressure-volume conditions were abnormal in all patients. Median PVI was 12.7 ml (5.8 to 40.0 ml). The PVI did not correlate with ICP; the PVI based on bolus injection was significantly greater than PVI based on fluid withdrawal. The ICP pulse amplitude varied from 1.5 to 15 mm Hg and rose concomitantly with increasing ICP. Considering the pulsatile shift in intracranial blood volume as an endogenous bolus that increases ICP from the diastolic (Pdiast) to the systolic (Psyst) level, an equation was derived from the PVI model that describes the relationship between the Psyst:Pdiast ratio and the PVI.

Resistance to Outflow of Cerebrospinal Fluid Determined by Bolus Injection Technique and Constant Rate Steady State Infusion in Humans

Neurosurgery ◽  
1985 ◽  
Vol 16 (3) ◽  
pp. 336-340 ◽  
Author(s):  
Michael Kosteljanetz
Keyword(s):  
Cerebrospinal Fluid ◽  
Steady State ◽  
Bolus Injection ◽  
Point Of View ◽  
Injection Technique ◽  
Communicating Hydrocephalus ◽  
Constant Rate ◽  
High Degree ◽  
Infusion Technique

Abstract Two methods for the determination of resistance to the outflow of cerebrospinal fluid, the bolus injection technique and the constant rate steady state infusion technique, were compared. Thirty-two patients with a variety of intracranial diseases (usually communicating hydrocephalus) were studied. There was a high degree of correlation between the resistance values obtained with the two methods, but values based on the bolus injection technique were systematically and statistically significantly lower than those obtained with the constant rate infusion test. From a practical point of view. both methods were found to be applicable in a clinical setting.

Evaluation of the central canal of the spinal cord in experimentally induced hydrocephalus

1978 ◽  
Vol 48 (6) ◽  
pp. 970-974 ◽  
Author(s):  
A. Everette James ◽  
William J. Flor ◽  
Gary R. Novak ◽  
Ernst-Peter Strecker ◽  
Barry Burns
Keyword(s):  
Spinal Cord ◽  
Cerebrospinal Fluid ◽  
Experimental Model ◽  
Alternative Pathway ◽  
Central Canal ◽  
Communicating Hydrocephalus ◽  
Csf Flow ◽  
Content Type ◽  
Histological Appearance ◽  
Fine Print

✓ The central canal of the spinal cord has been proposed as a significant compensatory alternative pathway of cerebrospinal fluid (CSF) flow in hydrocephalus. Ten dogs were made hydrocephalic by a relatively atraumatic experimental model that simulates the human circumstance of chronic communicating hydrocephalus. The central canal was studied by histopathology and compared with 10 normal control dogs. In both groups the central canal of the spinal cord was normal in size, configuration, and histological appearance. In this experimental model dilatation of the canal and increased movement of CSF does not appear to be a compensatory alternative pathway.

Posttraumatic ventriculomegaly: hydrocephalus or atrophy? A new approach for diagnosis using CSF dynamics

1996 ◽  
Vol 85 (6) ◽  
pp. 1026-1035 ◽  
Author(s):  
Anthony Marmarou ◽  
Montasser A. Abd-Elfattah Foda ◽  
Kuniaki Bandoh ◽  
Masaaki Yoshihara ◽  
Takuji Yamamoto ◽  
...  
Keyword(s):  
Head Injury ◽  
Normal Pressure ◽  
Volume Index ◽  
Injection Technique ◽  
Benign Intracranial Hypertension ◽  
Ventricular Size ◽  
Csf Dynamics ◽  
Content Type ◽  
Group 5 ◽  
Fine Print

✓ Cerebrospinal fluid (CSF) dynamics were correlated to the changes in ventricular size during the first 3 months posttrauma in patients with severe head injury (Glasgow Coma Scale score ≤ 8, 75 patients) to distinguish between atrophy and hydrocephalus as the two possible causes of posttraumatic ventriculomegaly. Using the bolus injection technique, the baseline intracranial pressure (ICP), pressure volume index, and resistance for CSF absorption (R0) provided a threedimensional profile of CSF dynamics that was correlated with ventricular size and Glasgow Outcome Scale (GOS) score at 3, 6, and 12 months posttrauma. Patients were separated into five different groups based on changes in ventricular size, presence of atrophy, and CSF dynamics. Group 1 (normal group, 41.3%) demonstrated normal ventricular size and normal ICP. Group 2 (benign intracranial hypertension group, 14.7%) showed normal ventricular size and elevated ICP. Group × (atrophy group, 24%) displayed ventriculomegaly, normal ICP, and normal R0. Group 4 (normal-pressure hydrocephalus group, 9.3%) had ventriculomegaly, normal ICP, and high R0. Group 5 (high-pressure hydrocephalus group, 10.7%) showed ventriculomegaly and elevated ICP with or without high R0. The GOS score in the nonhydrocephalic groups (Groups 1, 2, and 3) was better than in the hydrocephalic groups (Groups 4 and 5). It is concluded from these results that 44% of head injury survivors may develop posttraumatic ventriculomegaly. Posttraumatic hydrocephalus, as identified by abnormal CSF dynamics, was diagnosed in 20% of survivors and their outcome was significantly worse. This study demonstrates the importance of using CSF dynamics as an aid in diagnosis of posttraumatic hydrocephalus and identifying those patients who may benefit from shunt placement.

Changes in cerebrospinal fluid hydrodynamics following endoscopic third ventriculostomy for shunt-dependent noncommunicating hydrocephalus

2003 ◽  
Vol 98 (5) ◽  
pp. 1027-1031 ◽  
Author(s):  
Kenichi Nishiyama ◽  
Hiroshi Mori ◽  
Ryuichi Tanaka
Keyword(s):  
Cerebrospinal Fluid ◽  
Absorptive Capacity ◽  
Endoscopic Third Ventriculostomy ◽  
Third Ventriculostomy ◽  
Csf Dynamics ◽  
Shunt System ◽  
Independent State ◽  
Content Type ◽  
Noncommunicating Hydrocephalus ◽  
Fine Print

Object. 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 patients who 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 1 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.

Clinical applications of the pressure-volume index in treatment of pediatric head injuries

1982 ◽  
Vol 56 (6) ◽  
pp. 819-825 ◽  
Author(s):  
Kenneth Shapiro ◽  
Anthony Marmarou
Keyword(s):  
Intracranial Hypertension ◽  
Bolus Injection ◽  
Head Injuries ◽  
Volume Index ◽  
Content Type ◽  
Spinal Axis ◽  
Neural Axis ◽  
Predicted Values ◽  
Axis Length ◽  
Accurate Indicator

✓ The pressure-volume index (PVI) technique of assessing neural axis pressure-volume relationships was used as an adjunct to managing 22 children with severe head injuries and a Glasgow Coma Scale score of 8 or less. Ventricular cannulation was used to continuously monitor intracranial pressure (ICP). Actual PVI was measured by bolus injection of fluid and compared with predicted values determined from head circumference and spinal axis length in each patient. In 55% of the children, ICP was below 20 mm Hg at initial monitoring. During the course of monitoring, 86% of the children had ICP's exceeding 20 mm Hg. Reduced PVI (less than 80% of predicted normal) proved to be an accurate indicator of impending intracranial hypertension. The PVI proved to be a useful test for assessing the response to therapies for lowering ICP. This study demonstrates that reduced neural axis compliance accompanies intracranial hypertension following severe head injury in children, and that treatment of reduced neural axis compliance may prevent refractory intracranial hypertension.

CSF dynamics in patients with subarachnoid and/or intraventricular hemorrhage

1984 ◽  
Vol 60 (5) ◽  
pp. 940-946 ◽  
Author(s):  
Michael Kosteljanetz
Keyword(s):  
Intraventricular Hemorrhage ◽  
Bolus Injection ◽  
Outflow Resistance ◽  
Csf Dynamics ◽  
Content Type ◽  
Constant Rate ◽  
Acute Subarachnoid Hemorrhage ◽  
Csf Diversion ◽  
Csf Absorption ◽  
Fine Print

✓ The purpose of this study was to examine the extent to which reduction of cerebrospinal fluid (CSF) absorption contributes to raised intracranial pressure (ICP) in patients with acute subarachnoid hemorrhage (SAH). Seventeen patients suffering from SAH and/or intraventricular hemorrhage were studied; all were admitted in Grades II to V according to Hunt and Hess. Eleven patients had a proven aneurysm. The ICP, monitored via an intraventricular catheter, was above 15 mm Hg (2 kPa) during part of the monitoring period in all patients. B-waves at 1/min were noted in all patients. Resistance to outflow of CSF was determined by the following techniques: 1) bolus injection; 2) constant-rate steady-state infusion; or 3) controlled withdrawal (“inverse infusion”). Resistance to outflow of CSF was increased in all patients, ranging from 11.5 to 85 mm Hg/ml/min. The ICP was linearly correlated with outflow resistance. Four (50%) of the eight survivors required a shunt. Neither the presence of hydrocephalus on admission, nor the level of ICP, nor the magnitude of resistance to outflow of CSF was clearly related to the requirement of a permanent CSF diversion.

Cerebrospinal fluid conductance and compliance of the craniospinal space in normal-pressure hydrocephalus

1979 ◽  
Vol 51 (4) ◽  
pp. 521-525 ◽  
Author(s):  
Svend Erik Børgesen ◽  
Flemming Gjerris ◽  
Søren Claus Sørensen
Keyword(s):  
Cerebrospinal Fluid ◽  
Normal Pressure Hydrocephalus ◽  
Bolus Injection ◽  
Normal Pressure ◽  
Poor Correlation ◽  
Injection Technique ◽  
Pressure Monitoring ◽  
Perfusion Technique ◽  
Content Type

✓ Conductance to outflow of cerebrospinal fluid (CSF) has been measured by both a lumboventricular perfusion and a bolus injection method in 24 patients with normal-pressure hydrocephalus. One purpose was to investigate whether the less time-consuming technique of bolus, injection gave results comparable to the results obtained by the lumboventricular perfusion technique. There was a poor correlation between the results obtained by the two measurements of conductance to outflow of CSF. It is concluded that the bolus-injection technique cannot substitute for the lumboventricular perfusion test. Compliance of the CSF space was measured by the bolus injection. The presence of B-waves, recorded from long-term intraventricular pressure monitoring, could be correlated to the sum of conductance to outflow and compliance. The correlation offers a possible explanation of the nature of B-waves.

A new method for measuring cerebrospinal fluid flow in shunts

1983 ◽  
Vol 58 (4) ◽  
pp. 557-561 ◽  
Author(s):  
Mitsuhiro Hara ◽  
Chikafusa Kadowaki ◽  
Yoshifumi Konishi ◽  
Motohide Ogashiwa ◽  
Mitsuo Numoto ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Flow Rate ◽  
High Frequency ◽  
Animal Experiments ◽  
Communicating Hydrocephalus ◽  
Maximum Output ◽  
Csf Flow ◽  
Content Type ◽  
Cerebrospinal Fluid Flow ◽  
Shunt Tube

✓ An implantable device for measurement of cerebrospinal fluid (CSF) flow in a ventriculoperitoneal shunt tube has been developed. The unit is energized by an extracorporeal high-frequency generator (200 KHz), and electrolysis creates bubbles in the shunt tube. Velocity of bubble flow is detected by a pair of ultrasonic Doppler probes placed a certain distance apart on the skin surface and in parallel with the implanted tube. The CSF flow rate is calculated taking into account velocity and tube diameter, and is expressed in ml/min. The unit consists of a coil with a capacitor, a silicon diode to rectify the high frequency, and a Zener diode to regulate maximum output voltage of 20 V. The output is fed to a pair of platinum electrodes placed inside the unit's tunnel through which the CSF flows. These components are molded in epoxy resin and coated with medical-grade silicone rubber. In animal experiments, CSF flow rates ranging from 0.033 to 1.0 ml/min could be measured by this flowmeter. Clinically, CSF flow has been measured to date in several cases. In two cases of communicating hydrocephalus occurring after the onset of cerebrovascular disease, and in which the CSF flow was continuously monitored for 24 hours, the flow rate ranged between 0.05 and 0.78 ml/min. The CSF flow rate fluctuates in a 24-hour period, increasing in the morning, especially between 12 midnight and 6 a.m., which suggests a circadian rhythm.

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