中文摘要：

目的 研究不同损伤程度原发性脑干损伤的功能及病理变化特点。方法 用家兔原发性脑干损伤分级模型,Ⅰ-Ⅳ组撞击能量逐渐增大,每组10只对照组5组。通过解剖肉眼观察、组织HE普通组织化学染色及电镜检测来研究原发性脑干损伤的病理学变化。结果 Ⅰ组脑干损伤功能变化轻微,组织病理表现为局部散在蛛网膜下腔出血,软脑膜局部剥脱,脑干浅表层有少量点状出血,神经细胞水肿,髓鞘和轴索基本正常;Ⅱ组脑干损伤功能变化较明显,病理表现为蛛网膜下腔片状出血,脑干浅层少量点（片）状出血,神经细胞轻度肿胀和空泡化;Ⅲ组脑干损伤反应明显,表现为脑干厚层蛛网膜下腔出血,脑干浅层及深部多处点片状出血,神经细胞变性,轴索变性断裂、轴浆萎缩;Ⅳ组脑干损伤异常严重,出现长时间呼吸抑制,8/10动物死亡,病理表现为脑干被厚层蛛网膜下腔血肿包裹,脑干损伤累及全层,镜下可见多发性小出血灶,神经细胞仅残留的细胞核,髓鞘板层严重分层且断裂,轴索离断、崩解;对照组生理功能及病理无异常。结论 随撞击能量增大,脑干损伤功能变化更明显,病理变化更严重,且损伤区域由浅层向深层变化。

英文摘要：

Objective To study characters of pathology associated with functional alteration of primary brainstem injury（PBI）at different injury severities in rabbits.Methods Animal model of graded PBI was produced using rabbits.Animals were divided into five groups,groupⅠtoⅣ with an increase of impact power,10 cases in each group,and the control group with 5cases.The pathology characters of PBI were investigated combining dissection observation with unaided eye,tissue HE histochemical staining and electron microscope.Results Slight brainstem injury were observed in groupⅠ,and pathological results showed regional subarachnoid hemorrhage（SAH）,stripping of regional cerebral pia mater,a few petechial hemorrhage in surface,nerve cell edema,normal medulla sheath and axon roughly.The brainstem injuries were apparent in group Ⅱ,and the pathological changes indicated SAH in sheet,petechial and sheeted hemorrhage in surface,and slight swelling and vacuoles in nerve cells.The brainstem injuries were observed obviously in groupⅢ,exhibiting thick SAH,petechial and sheeted hemorrhage in surface and inside,degeneration of nerve cells,abruption of axon,and atrophy of axoplasm.Eight of ten animals died of respiratory depression induced by brainstem injury in group Ⅳ,presenting thick hemorrhage in subarachnoid surrounding brainstem,the whole brainstem injured,microscopically with multiple small hemorrhage,nerve cells only residual nuclei,myelin lamellar severe stratification and fracture,and axonal transection,disintegration.No abnormal pathological changes were shown in control group.Conclusion The impacts to brainstem with higher powers lead to more manifest functional and more severe pathological changes,with an alternation of injury location from surface to deep.