Abstract
In line with the first law of thermodynamics, Bernoulli’s principle states that the total energy in a fluid is the same at all points. We applied Bernoulli’s principle to understand the relationship between intracranial pressure (ICP) and intracranial fluids. We analyzed simple fluid physics along a tube to describe the interplay between pressure and velocity. Bernoulli’s equation demonstrates that a fluid does not flow along a gradient of pressure or velocity; a fluid flows along a gradient of energy from a high-energy region to a low-energy region. A fluid can even flow against a pressure gradient or a velocity gradient. Pressure and velocity represent part of the total energy. Cerebral blood perfusion is not driven by pressure but by energy: the blood flows from high-energy to lower-energy regions. Hydrocephalus is related to increased cerebrospinal fluid (CSF) resistance (i.e., energy transfer) at various points. Identification of the energy transfer within the CSF circuit is important in understanding and treating CSF-related disorders. Bernoulli’s principle is not an abstract concept far from clinical practice. We should be aware that pressure is easy to measure, but it does not induce resumption of fluid flow. Even at the bedside, energy is the key to understanding ICP and fluid dynamics.
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References
http://books.google.fr/books?id=4TlQAAAAcAAJ&printsec=frontcover&hl=fr&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false. Accessed 20 Oct 2013
http://theory.uwinnipeg.ca/mod_tech/node68.html. Accessed 25 Oct 2013
http://www.princeton.edu/~asmits/Bicycle_web/Bernoulli.html. Accessed 25 Oct 2013
Burton A (1965) Physiology and biophysics of the circulation. Year Book Medical Publishers, Chicago
http://hyperphysics.phy-astr.gsu.edu/hbase/pber.html. Accessed 25 Oct. 2013
Shepard RB, Simpson DC, Sharp JF (1966) Energy equivalent pressure. Arch Surg 93(5):730–740
Pollay M (2010) The function and structure of the CSF outflow system. Cerebrospinal Fluid Res 7:9
Rekate HL (2011) A consensus on the classification of hydrocephalus: its utility in the assessment of abnormalities of cerebrospinal fluid dynamics. Childs Nerv Syst 27:1535–1541
Bering EA Jr, Sato O (1963) Hydrocephalus: changes in formation and absorption of cerebrospinal fluid within the cerebral ventricles. J Neurosurg 20:1050–1063
Di Rocco C, Pettorossi VE, Caldarelli M, Mancinelli R, Velardi F (1978) Communicating hydrocephalus induced by mechanically increased amplitude of the intraventricular cerebrospinal fluid pressure: experimental studies. Exp Neurol 59(1):40–52
Wagshul M, Eide PK, Madsen JR (2011) The pulsating brain: a review of experimental and clinical studies of intracranial pulsatility. Fluids Barriers CNS 8:5
Czosnyka M, Pickard JD (2004) Monitoring and interpretation of intracranial pressure. J Neurol Neurosurg Psychiatry 75:813–821
Acknowledgments
This paper is dedicated to Eric T. MacKenzie.
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Schmidt, E., Ros, M., Moyse, E., Lorthois, S., Swider, P. (2016). Bernoulli’s Principle Applied to Brain Fluids: Intracranial Pressure Does Not Drive Cerebral Perfusion or CSF Flow. In: Ang, BT. (eds) Intracranial Pressure and Brain Monitoring XV. Acta Neurochirurgica Supplement, vol 122. Springer, Cham. https://doi.org/10.1007/978-3-319-22533-3_21
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DOI: https://doi.org/10.1007/978-3-319-22533-3_21
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