Shafieian Mehdi, Darvish Kurosh K, Stone James R
Department of Mechanical Engineering, Temple University, PA 19122, Philadelphia, USA.
J Biomech. 2009 Sep 18;42(13):2136-42. doi: 10.1016/j.jbiomech.2009.05.041. Epub 2009 Aug 20.
While it has been shown that repetitive mild brain injuries can cause cumulative damage to the brain, changes to the mechanical properties of brain tissue at large deformations were also noted in the literature. The goal of this study was to show that the viscoelastic properties of brain tissue significantly change after traumatic axonal injury (TAI). An impact acceleration model was used to create TAI in the rat brainstem which was quantified with an immunohistochemistry technique at the ponto-medullary junction (PmJ) and pyramidal decussation (PDx). The viscoelastic properties at these two points with and without preconditioning were characterized using an indentation technique combined with finite element analysis and a comparison was made between injured and uninjured specimens, which revealed statistically significant reduction in the instantaneous elastic force at PDx where the brain tissue sustained a significantly higher level of injury. The result of this study can be used to characterize a damage function for the brain tissue undergoing large deformation.
虽然已有研究表明重复性轻度脑损伤会对大脑造成累积性损伤，但文献中也提到了在大变形情况下脑组织力学性能的变化。本研究的目的是表明创伤性轴索损伤（TAI）后脑组织的粘弹性特性会发生显著变化。采用冲击加速度模型在大鼠脑干中造成TAI，并通过免疫组织化学技术在脑桥延髓交界处（PmJ）和锥体交叉（PDx）进行量化。使用压痕技术结合有限元分析对这两个点在有无预处理情况下的粘弹性特性进行表征，并对损伤和未损伤标本进行比较，结果显示在脑组织损伤程度显著更高的PDx处，瞬时弹力有统计学意义的降低。本研究结果可用于表征经历大变形的脑组织的损伤函数。
