Pathophysiological Study on the Mechanism of Whiplash Shaking Injury

摇晃婴儿综合征（SBS）是儿童虐待导致的以颅内出血和进行性脑萎缩为特征的死亡或严重神经损伤的最常见原因。然而，急性硬膜下血肿、眼出血、脑萎缩等特征性病变是否仅由摇头引起尚不清楚。在这项研究中，我们建立了一个婴儿大鼠SBS模型来研究脑损伤的病理生理机制。用加速度计对3、4周龄大鼠头部以10G的加速度剧烈震荡300次/min，持续10分钟，大鼠出现严重的发绀和呼吸暂停，约20%死亡。虽然摇晃后立即测量的血氧水平下降是短暂的，并在大约10分钟后恢复，但脑氧水平和脑血流量的下降持续30分钟或更长时间。5只6日龄大鼠连续摇3天，3周后，体重和脑重均明显低于对照组。震荡后冷冻3周的脑切片，用HE、Fe染色，免疫组化染色，ABC法（anti - gfap, anti - β APP）。震荡组3例蛛网膜下腔轻度出血。然而，在脑和颈脊髓中未发现其他异常，包括实质出血和梗死。免疫组化染色未见星形胶质细胞反应性和轴突变性等异常。虽然本次研究没有得出单纯摇晃是否会导致脑损伤的病理结论，但从脑重量的减少来看，大脑可能出现了某种异常，需要进一步的研究。此外，我们强烈建议，缺氧可能是SBS的一种非常真实的继发性损伤，它可以加重因震动引起的原发性机械损伤引起的脑损伤。少

Shaken Baby Syndrome (SBS) is the most common cause of death or serious neurological injury characterized by intracranial hemorrhage and progressive brain atrophy, resulting from child abuse. However, it is still unknown whether the characteristic lesions, such as acute subdural hematoma, ocular hemorrhage and cerebral atrophy are caused by shaking head alone. In this study, we developed a infant rat model of SBS to investigate the pathophysiological mechanisms underlying the brain damage. When heads of 3 or 4 week old rats with accelerometers were violently shaken 300 times/min at the acceleration of 10G for 10 minutes, the animals developed serious cyanosis and apnea, and about 20% of them died. Although decrease in the blood oxygen level measured immediately after shaking was transient and recovered about 10 minutes later, decline in the cerebral oxygen level and cerebral blood flow persisted for 30 minutes or longer. Five 6 day old rats were shaken for three consecutive days, and t … More hree weeks after that, the body weight and brain weight of them were significantly lower than those of controls. Frozen sections of brains that had been kept for three weeks after shaking were stained with HE and Fe and immunohistochemical staining, ABC method (antiGFAP, anti β APP). In three cases of the shaken group, mild subarachnoid hemorrhage were noticed. However, no other abnormalities including parenchymal hemorrhage and infarction were noted in the brain and cervical spinal cord. Neither did the immunohistchemical staining reveal any abnormalities such as reactive astrocyte and axonal degeneration. Although this study failed to find a pathological conclusion as to if brain damage is caused by shaking alone, further investigation is required since some kind of abnormalities might occur in the brain, judging from decrease in the brain weight. In addition, it is strongly suggested that hypoxia may be a very real secondary insult in SBS, which serves to exacerbate brain damage due to the primary mechanical injury of shaking. Less