title: Effect of non-linear permeability in a spherically symmetric model of hydrocephalus.
abstract: We examine a spherically symmetric model of the brain and apply non-linear permeability in a small strain poroelastic framework. Numerical solutions to the model show that non-linear effects tend to improve predictions of ventricle wall displacement and pressure increase in acute hydrocephalus in comparison with a constant permeability model. Our model is used to study different mechanisms for hydrocephalus: complete blockage of the aqueduct and normal pressure hydrocephalus (NPH), as well as offering observations on mechanical effects in idiopathic intracranial hypertension. In each situation it is possible to apply different parameter conditions to quantify mechanical effects that correspond to some observed symptoms. The results support and quantify ideas from Levine (2000, Ventricle size in pseudotumor cerebri and the theory of impaired CSF absorption. J. Neurol. Sci., 177, 85-94) on a poroelastic mechanism for some features of NPH and idiopathic intracranial hypertension.
authors.affiliation: Computing Laboratory, University of Oxford, Wolfson Building, Parks Road, Oxford OX1 3QD, UK. ian.sobey@comlab.ox.ac.uk
authors.forename: Ian
authors.initials: I
authors.lastname: Sobey
authors.forename: Benedikt
authors.initials: B
authors.lastname: Wirth
mesh_terms: D000465:Algorithms; D001696:Biomechanical Phenomena; D001921:Brain / Q000503:physiopathology*; D002535:Cerebral Aqueduct / Q000503:physiopathology; D002552:Cerebral Ventricles / Q000503:physiopathology; D015170:Cerebrospinal Fluid Pressure / Q000502:physiology; D006801:Humans; D006849:Hydrocephalus / Q000503:physiopathology*; D006850:Hydrocephalus, Normal Pressure / Q000503:physiopathology; D007427:Intracranial Pressure / Q000502:physiology; D008954:Models, Biological; D010539:Permeability; D011559:Pseudotumor Cerebri / Q000503:physiopathology