Clinical and experimental studies of Bell's palsy.

1型单纯疱疹是贝尔氏麻痹最可能的病因。我们证实了从贝尔氏麻痹患者获得的神经内膜液和耳肌中存在HSV-1 DNA，并阐明了HSV-1感染与贝尔氏麻痹的发病直接相关。我们还成功地制造了急性和短暂性面瘫，模拟贝尔麻痹，通过接种HSV到老鼠的耳廓。本研究通过动物模型和贝尔麻痹对面神经麻痹的发病机制进行了研究。小鼠模型的组织病理学表现为严重的神经肿胀、炎性细胞浸润和面神经空泡变性。完整的、脱髓鞘的和退化的神经混杂在面神经干中。电生理研究表明，眨眼反射测试中R1潜伏期的时间过程与面神经麻痹的恢复具有良好的平行性，而ENoG的恢复则比面神经麻痹的恢复有延迟的趋势；这些反应通常出现在贝尔氏麻痹中。部分贝尔麻痹患者面神经血流量有不同程度的减少。然而，没有面瘫的胆脂瘤患者的血流量也有同样的减少。提示单纯疱疹病毒1型感染是贝尔麻痹患者面瘫的主要原因，神经缺血是继发于病毒感染。回顾性分析69例Bell患者应用阿昔洛韦-强的松治疗的疗效。总回收率为95.7%。在发病后3天内开始这种治疗的患者的比率为100%。这些结果表明，早期治疗是有效的阿昔洛韦-强的松治疗贝尔麻痹的必要条件。

Herpes simplex type 1 is the most probable cause of Bell's palsy. We have demonstrated the presence of HSV-1 DNA in the endoneural fluid and auricular muscle obtained from patients with Bell's palsy, and clarified that HSV-1infection is directly related to the pathogenesis of Bell's palsy. We have also succeeded in producing an acute and transient facial paralysis, simulating Bell's palsy, by inoculating HSV into the auricle of mice. In the present study, we have studied pathomechanism of facial palsy by using animal model and Bell's palsy. Histopathology of the mouse model demonstrated severe nerve swelling, inflammatory cell infiltration and vacuolar degeneration in the affected facial nerve. Intact, demyelinated, and degenerated nerves were intermingled in the facial nerve trunk. Electro physiological study has demonstrated that the time course of R1 latency in the blink reflex tests paralleled the recovery of the facial nerve paralysis well, whereas ENoG recovery tended to be delayed, compared to that of the paralysis ; these responses are usually seen in Bell's palsy. The blood flow in the facial nerve was decreased to some extent in some patients with Bell's palsy. However, the same decrease of blood flow was noted in patients with cholesteatoma without facial paralysis. These results suggested that viral infection of HSV-1 was the primary cause of facial palsy in Bell's palsy and ischemia of the nerve was secondary to the viral infection. The effect of acyclovir-prednisone treatment was analyzed retrospectively in 69 Bell's patients. The overall recovery rate was 95.7 %. The rate in patients who started this treatment within 3 days after onset was 100 %. These results suggest that early treatment is necessary for effective acylovir-prednisone therapy in Bell's palsy.