A preliminary exploration of acute intracranial pressure-cerebrospinal fluid production relationships in experimental hydrocephalus

• Published in: Brain circulation Vol. 6; no. 3; pp. 200 - 207
• Main Authors: Khasawneh, Ahmad, Alexandra, Petroj, Zajciw, Paul, Harris, Carolyn
• Format: Journal Article
• Language: English
• Published: Mumbai Wolters Kluwer India Pvt. Ltd 01.07.2020; Medknow Publications and Media Pvt. Ltd; Medknow Publications & Media Pvt. Ltd; Wolters Kluwer - Medknow; Wolters Kluwer Medknow Publications
• Subjects: Cerebrospinal fluid; cerebrospinal fluid production; Clay; experimental hydrocephalus; Heart rate; Hydrocephalus; Intracranial pressure; Original; Physiological aspects; ventriculomegaly; experimental hydrocephalus; Cerebrospinal fluid production; ventriculomegaly; hydrocephalus; intracranial pressure
• ISSN: 2394-8108; 2455-4626; 2455-4626
• DOI: 10.4103/bc.bc_42_20

CONTEXT: By occluding the fourth ventricle simultaneously obtaining telemetric data on intracranial pressure (ICP) and cerebrospinal fluid (CSF) production, the authors of this study investigate a variety of physiologic parameters in cases of experimental hydrocephalus. AIMS: The aim of this study is to provide a new context on the disrupted homeostasis in hydrocephalus and guide toward improved treatment based on multiple physiological parameters. MATERIALS AND METHODS: Hydrocephalus was induced in ten 21-day-old Sprague-Dawley rats by blocking the flow of CSF to the fourth ventricle with kaolin. Ten days post induction, when physical signs of ventriculomegaly reached Evan's ratio (ER) of ≥0.46, CSF flow and ICP were measured while manipulating body position (0°, 45°, 90°) and heart rate. RESULTS: In hydrocephalic animals (ER ≥0.46), we found a near-steady average acute ICP (13.638 ± 2.331) compared to age-matched controls (ER <0.30) (13.068 ± 8.781), whose ICP fluctuated with the position. Hydrocephalic and controls exhibited an insignificant degree of parabolic shifts in CSF production when body position was changed from prone to 90° and again when moved back to the prone position, a trend more noteworthy in controls (P = 0.1322 and 0.2772). A Pearson's Correlation found CSF production and ICP to be correlated at baseline 0° posture (P = 0.05) in the control group, but not the hydrocephalic group. Weight appeared to play a role when animals were held at 90°. No significant changes in ICP or CSF flow patterns were observed when the heart rate was increased within either group. CONCLUSIONS: These preliminary findings suggest that our standard assumptions of posture-dependent changes in ICP created using data from physiologic data may be inaccurate in the hydrocephalic patient, and thus describe a need to further explore these relationships.