实验性脑弥漫性轴索损伤的组织病理学变化

目的探讨钝力致脑弥漫性轴索损伤(DAI)的法医病理学鉴定依据。方法采用液压冲击方法建立钝力致家猫脑DAI模型;通过H．E．、Bodian、Kluver-Barrera普通组织化学染色及NF免疫组化染色,观察致伤后不同时间脑实质内轴索及其髓鞘的变化,并通过图像分析系统对轴索内NF免疫组化染色阳性反应物面积进行定量检测,所得数据用SPSS 11．5 for Windows软件进行统计学分析。结果致伤后1-2h,猫大脑皮质下白质、胼胝体及脑干轴索轻度肿胀、弯曲;4h轴索肿胀、弯曲显著,呈断续状,且在胼胝体、丘脑及脑干出血区周围出现收缩球,髓鞘开始疏松崩解。随着观察时间的延长,收缩球进一步变大,中心空泡出现,髓鞘疏松、水肿、崩解。经对轴索内NF免疫组化染色阳性反应物的图像分析数据进行统计学分析,对比组间差别具有非常显著性差异意义(P<0．01)。结论脑轴索肿胀、弯曲、增粗、离断以及收缩球的形成,是DAI法医病理学鉴定的依据。

An experimental study on histopathological changes of diffuse axonal injury

Objective To investigate the indicators for identifying diffuse axonal injury by blunt forces in forensic pathological practice. Methods The DAI model was produced by the fluid - percussion method in cats. The cerebral samples were stained by H. E. , Bodian, Kluver - Barrera stain and NF Immunohistochemistry. Changes of axons and myeline sheath were observed at different intervals after injury. Positive NF immunostained area in axons was measured, and the data was analyzed by SPSS 11.5 for windows. Results Changes of axons in subcortical white matter and brainstem were observed in the forms of swollen, waved and distorted axons in early stage after injury (1-2 hours). Markedly torn, vacuolated axons with formation of the retraction balls from 4 hours after injury were specifically demonstrated in NF immunohistochemistry (P<0.01).Conclusion The axonal changes including markedly tore, vacuolated axons with formation of the retraction balls was a specific indicator for identifying DAI.