A physical model for brain ventricle dynamics

Brain ventricles (Rouvière and Delmas 2002) are four cavities filled with a liquid which they secrete, the cerebrospinal fluid (CSF). This fluid flows from ventricles to both the spinal cord and the subarachnoid spaces (around the brain) to eventually return to the bloodstream. As ventricles lose their ability to regulate the CSF pressure, serious brain pathologies called hydrocephalus can occur (Greenberg 1990). Characterised by a dilation of the ventricular space, these diseases can be deadly if not treated. The work of our team consists in a physical study of intracranial mechanics, taking into account the coupling of ventricular dynamics to the brain and surrounding compartments, be it of mechanical nature, or through fluid exchanges. We first address the problem from a theoretical view, making use of the fundamental laws of thermodynamics, hydrodynamics and the theory of elasticity. We then numerically assess the leading equations with a homemade code written on MATLAB. Dynamical instabilities are revealed, inducing an ‘explosion’ or a contraction of the ventricular space, making a possible link with the causes of hydrocephalus and the slit ventricle syndrome (Greenberg 1990).