Miller—Fisher综合征和Bickerstaff脑干脑炎临床及电生理特点

Clinical and electrophysiological study of Miller-Fisher syndrome and Bickerstaff＇ s brainstem encephalitis

目的总结Miller—Fisher综合征（MFS）和Bickerstaff脑干脑炎（BBE）患者临床及电生理特点，并探索其机制。方法回顾性分析北京协和医院2000--2011年符合MFS诊断标准的患者（13例）和BBE诊断标准的患者（7例）的病历资料，收集患者临床资料和电生理测定参数，包括感觉和运动神经传导、针极肌电图、F波、皮肤交感反应、脑干听觉诱发电位、瞬目反射等，统计MFS和BBE临床特点和各项电生理检查异常的患者比例。结果MFS和BBE患者前驱感染以呼吸道症状为主，眼球活动障碍、面瘫、延髓部症状较常见，均有脑脊液蛋白细胞分离，都存在抗GQlb抗体。但临床上，BBE还有意识障碍等中枢神经系统受累表现。电生理上，MFS和BBE患者感觉神经受累比例分别为6／13、2／7，主要表现为感觉神经动作电位波幅明显下降，感觉神经传导速度轻度减慢或正常；运动神经受累比例分别为2／13、1／7，多表现为运动末端潜伏期轻度延长，复合肌肉动作电位波幅正常；肢体针极肌电图异常比例分别为1／7、0／4；F波出现率异常比例分别为3／13、5／7，部分患者可出现F波出现率明显下降，但可以恢复；皮肤交感反应异常比例分别为1／2、1／3；瞬目反射异常比例分别为1／2、1／1，BBE患者表现为中枢性损害；脑干听觉诱发电位异常比例分别为3／5、1／4，均表现为I波潜伏期延长或波幅低。结论MFS和BBE中枢神经系统和周围神经系统均可受累，但BBE以中枢神经系统受累更常见。MFS和BBE可能是中枢神经系统和周围神经系统受累程度不同的同一种疾病的连续疾病谱。

Objective To investigate the underlying mechanisms of Miller-Fisher syndrome （MFS） and Bickerstaff＇ s brainstem encephalitis （BBE） by studying their clinical and electrophysiological characteristics. Methods The clinical and electrophysiological characteristics of 13 MFS and 7 BBE cases in Peking Union Medical College Hospital between 2000 and 2011 were retrospectively analyzed. The electrophysiological parameters included sensory and motor nerve conduction, electromyography, F wave, sympathetic skin response and brainstem auditory evoked potential and blink reflex. Results MFS and BBE had similar clinical characteristics： respiratory symptoms were the most common infectious symptoms before disease onset; Ophthalmoplegia, facial palsy and bulbar symptoms were common; They both had cerebrospinal fluid albuminocytologieal dissociation and positive serum anti-GQlb antibody. However, BBE had more central nervous system lesion signs clinically such as conscious disturbance, positive Babinski＇ s sign and central facial palsy. Electrophysiologically, MFS and BBE also had similar electrophysiological features： sensory nerve abnormality ratios were 6/13, 2/7 respectively, with prominently reduced sensory nerve active potential amplitude, normal or slightly slowed sensory conduction velocity; Motor nerves abnormality ratios were 2/13, 1/7 respectively, with slightly prolonged distal motor latency and normal compound muscle action potential; Electromyography abnormality ratios were 1/7, 0/4 respectively; F wave frequency abnormality ratios were 3/13, 5/7 respectively, and in some cases, F wave frequency would restore; Sympathetic skin response abnormality ratios were 1/2, 1/3 respectively; Blink reflex abnormality ratios were 1/2, 1/1 respectively, with central involvement in BBE; Brainstem auditory evoked potential abnormality ratios were 3/5, 1/4 respectively, with wave I latency or amplitude abnormality. Conclusion The similarities of clinical and electrophysiological features suggest that MFS and BBE have the same mechanism and they form a continuous spectrum with variable central nervous system and peripheral nervous system involvement.