Document Detail

A mathematical model of the relationship between cerebral blood volume and intracranial pressure changes: the generation of plateau waves.
MedLine Citation:
PMID:  2035909     Owner:  NLM     Status:  MEDLINE    
The relationship between intracranial pressure (ICP), cerebral blood volume (CBV), cerebrospinal fluid dynamics, and the action of cerebral blood-flow (CBF) regulatory mechanisms is examined in this work with the help of an original mathematical model. In building the model, particular emphasis is placed on reproducing the mechanical properties of proximal cerebral arteries and small pial arterioles, and their active regulatory response to perfusion pressure and cerebral blood flow changes. The model allows experimental results on cerebral vessel dilatation and cerebral blood-flow regulation, following cerebral perfusion pressure decrease, to be satisfactorily reproduced. Moreover, the effect of cerebral blood volume changes--induced by autoregulatory adjustments--on the intracranial pressure time pattern can be examined at different levels of arterial hypotension. The results obtained with normal parameter values demonstrate that, at the lower limits of autoregulation, when dilatation of small arterioles becomes maximal, the increase in cerebral blood volume can cause a significant, transient increase in intracranial pressure. This antagonism between intracranial pressure and autoregulatory adjustments can lead to instability of the intracranial system in pathological conditions. In particular, analysis of the linearized system "in the small" demonstrates that an impairment in cerebrospinal fluid (CSF) reabsorption, a decrease in intracranial compliance and a high-regulatory capacity of the cerebrovascular bed are all conditions which can lead the system equilibrium to become unstable (i.e., the real part of at least one eigenvalue to turn out positive). Accordingly, mathematical simulation "in the large," in the above-mentioned conditions, exhibits intracranial pressure periodic fluctuations which closely resemble, in amplitude, duration, frequency and shape, the well-known Lundberg A-waves (or plateau waves).
M Ursino; P Di Giammarco
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Annals of biomedical engineering     Volume:  19     ISSN:  0090-6964     ISO Abbreviation:  Ann Biomed Eng     Publication Date:  1991  
Date Detail:
Created Date:  1991-06-21     Completed Date:  1991-06-21     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  0361512     Medline TA:  Ann Biomed Eng     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  15-42     Citation Subset:  IM    
Department of Electronics, Computer Science, and Systems, University of Bologna, Italy.
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MeSH Terms
Blood Volume / physiology*
Brain / blood supply*
Cerebrospinal Fluid / physiology
Homeostasis / physiology
Hypotension / physiopathology
Intracranial Pressure / physiology*
Models, Biological*
Stress, Mechanical

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