Shahim K, Drezet J-M, Martin Bryn A, Momjian S
LSMX, Ecole Polytechnique,Fédérale de Lausanne, Station 12, CH-1015 Lausanne, Switzerland.
J Biomech Eng. 2012 Apr;134(4):041007. doi: 10.1115/1.4006466.
The driving force that causes enlargement of the ventricles remains unclear in case of normal pressure hydrocephalus (NPH). Both healthy and NPH brain conditions are characterized by a low transparenchymal pressure drop, typically 1 mm Hg. The present paper proposes an analytical model for normal and NPH brains using Darcy's and Biot's equations and simplifying the brain geometry to a hollow sphere with an internal and external radius. Self-consistent solutions for the large deformation problem that is associated with large ventricle dilation are presented and the notion of equilibrium or stable ventricle position is highlighted for both healthy and NPH conditions. The influence of different biomechanical parameters on the stable ventricle geometry is assessed and it is shown that both CSF seepage through the ependyma and parenchymal permeability play a key role. Although very simple, the present model is able to predict the onset and development of NPH conditions as a deviation from healthy conditions.
在正常压力脑积水（NPH）的情况下，导致脑室扩大的驱动力仍不明确。健康大脑和NPH大脑状况的特征均为跨实质压力降较低，通常为1毫米汞柱。本文提出了一个针对正常大脑和NPH大脑的分析模型，该模型使用达西方程和比奥方程，并将大脑几何形状简化为具有内半径和外半径的空心球体。给出了与大脑室扩张相关的大变形问题的自洽解，并强调了健康和NPH状况下平衡或稳定脑室位置的概念。评估了不同生物力学参数对稳定脑室几何形状的影响，结果表明脑脊液通过室管膜的渗漏和实质通透性均起着关键作用。尽管该模型非常简单，但它能够预测NPH状况作为偏离健康状况的发病和发展情况。
