Abstract
Intracranial hypertension is a severe therapeutic problem, as there is insufficient knowledge about the physiology of cerebrospinal fluid (CSF) pressure. In this paper a new CSF pressure regulation hypothesis is proposed. According to this hypothesis, the CSF pressure depends on the laws of fluid mechanics and on the anatomical characteristics inside the cranial and spinal space, and not, as is today generally believed, on CSF secretion, circulation and absorption. The volume and pressure changes in the newly developed CSF model, which by its anatomical dimensions and basic biophysical features imitates the craniospinal system in cats, are compared to those obtained on cats with and without the blockade of craniospinal communication in different body positions. During verticalization, a long-lasting occurrence of negative CSF pressure inside the cranium in animals with normal cranio-spinal communication was observed. CSF pressure gradients change depending on the body position, but those gradients do not enable unidirectional CSF circulation from the hypothetical site of secretion to the site of absorption in any of them. Thus, our results indicate the existence of new physiological/pathophysiological correlations between intracranial fluids, which opens up the possibility of new therapeutic approaches to intracranial hypertension.
Highlights
According to the generally accepted classical hypothesis of cerebrospinal fluid (CSF) physiology, CSF is actively formed mostly inside the ventricles, than it flows unidirectionally through the system of ventricles to the cisterna magna (CM) [1,2,3]
The mock CSF pressure inside the ‘‘cranial’’ part in a position of 45u- amounts to 0.360.1 cm H2O (p,0.001), while in a position of 90u- it is reduced to negative values and amounts to 24.160.1 cm H2O (p,0.001)
Fluid pressure changes obtained on our new model, which mimics the cerebrospinal fluid system in cats by its anatomical dimensions and basic biophysical characteristics of the cranial and spinal intradural space are, not different from CSF pressure changes obtained on animals during the changes of body position (Figures 3, 4 and 5)
Summary
According to the generally accepted classical hypothesis of cerebrospinal fluid (CSF) physiology, CSF is actively formed mostly inside the ventricles, than it flows unidirectionally through the system of ventricles to the cisterna magna (CM) [1,2,3]. The largest part of the CSF is passively absorbed through the arachnoid villae into the dural venous sinuses of the brain convexity. Except this main site of absorption, there is a large amount of literature which suggests that the absorption of CSF occurs from the subarachnoid space to the lymphatic system [4,5,6,7]. For the mentioned theory of CSF physiology to be true, the key is the fourth premise: the existence of a hydrostatic pressure gradient inside the CSF system, without which there can be neither CSF circulation nor passive CSF absorption
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.