The physiological backdrop for an increase in intracranial pressure (ICP) during brain compression is currently unknown. The current understanding of the relationship between ICP and brain compression volume is based on animal trials, which led to the notion of elastic brain tissue compression, which causes the ICP to rise like a loaded spring. Tests of brain tissue composition, or compression, however, reveal no evidence of elasticity or compression.
The purpose of this article is to discuss the physiological aspects that influence ICP, not only because they are crucial for understanding intracranial physiology, but also because ICP is a key measure in neuro-intensive care medicine.
The physiological consequences of the closed intracranial compartment, the thin-walled, compressible venous bed, the autoregulation of cerebral blood flow, CBF, to blood pressure changes, and the coupling between ICP and intra-capillary blood pressure through the thin, flexible capillary wall are all taken into account in this assessment. The intracranial venous blood volume, venous vascular resistance, and CBF are all affected by these factors.
The ICP dependence on the volume of brain volume compression is demonstrated to be rejected when both properties are combined.
As a result of the evaluation, a formula that represents the link between ICP and changes in brain volume has been developed. The formula predicts an exponential ICP increase at brain compression, similar to animal experiments, but a steadily greater exponential for bigger compression, in contrast to the elastic tissue theory.
Conclusion: The discovered link between ICP and changes in brain volume may prove to be a helpful tool for monitoring intracranial volume changes in neuro-intensive care patients using continuous ICP measurements.
Because the arterial pulse volume is included in the brain-compressing volumes, the ICP formula may be used to calculate CBF from ICP readings. The volume reduction in the CBF direction clearly removes any intravascular pressure drop.
The physiological linkages that led to the description of the relationship between ICP and brain volume change may help to explain other intracranial phenomena such as ICP plateau-waves.
Department of Clinical Neurophysiology, Skane University Hospital, Lund, Sweden.
View Book:- https://stm.bookpi.org/NVST-V8/article/view/4839