A micro-mechanical brain model for prediction of neurological disorders

Abstract

Growing evidence indicate the significant role of Mechanics in neurological disorders such as stroke, dementia, and multiple sclerosis (MS). Previous studies indicate that brain white matter is particularly vulnerable to mechanical damage and structural changes. In previous studies on micromechanical behavior of white brain tissue, only axonal fibers and ECM have been employed in the model. Our research takes a unique approach by utilizing the myelin sheath to assess its influence on the mechanical characteristics of axons and the overall behavior of brain tissue. The model is built on electron micrograph data and the probabilistic distribution of axonal fibers within the extracellular matrix (ECM), allowing for qualitative analysis of tensile, compressive, and shear stress distribution on nerve fibers using the finite element method. Additionally, the quantitative analysis of mechanical properties and stress thresholds on nerve fibers was made possible by placing this model in a multi-parameter optimization process. The results showed that, compared to the previous models proposed by other researchers, the present model provides far more accurate hyperelastic material properties for axonal fibers and ECM.