Kennedy病患者电生理、病理学特点及临床误诊分析

The electrophysiological、myopathological features and misdiagnostic reasons of Kennedy disease

目的研究肯尼迪病(Kennedy disease,KD)患者电生理学特征和肌肉病理学特点,探讨临床误诊原因,以加强对此病电生理学改变和肌肉病理学的认识,减少误诊误治。方法对9例经基因确诊的KD患者行针极肌电图、神经传导、F波和H反射检测。肌电图取舌肌、胸锁乳突肌、三角肌、第一骨间肌、胸椎旁肌、股四头肌、胫前肌。神经电图取双侧正中神经、尺神经、腓总神经、腓肠神经和胫神经。1例患者取股四头肌肌肉活检行病理学检查。结果肌电图检查显示9例肯尼迪病患者均表现为广泛的慢性神经源性损害。CMAP和SNAP波幅均显著降低(P<0.01),以腓肠神经动作电位波幅异常率最高(88.89%),腓总神经和腓肠神经传导速度减慢(P<0.01),正中神经和胫神经远端潜伏期延长(P<0.01),正中神经和胫神经F波响应率降低,胫神经的H反射潜伏期延长(P<0.01)。肌活检示神经源性肌损害,表现为肌纤维萎缩,萎缩纤维群组化分布。结论 KD患者电生理以广泛的慢性神经源性损害为最主要改变,感觉和运动神经传导异常,且感觉神经受累较运动神经受累更多见,病理学表现为肌肉萎缩及群组化分布。电生理和肌肉活检对该病的早期诊断和减少误诊率有重要指导价值。

Objective To understand the electrophysiology and myopathological features and the misdiagnostic reasons of the patients with Kennedy disease （KD） to further understand the electrophysiology and myopathological change of KD and to reduce the misdiagnosis rate. Methods Nine KD patients whose diagnosis were defined by gene analysis accepted EMG,nerve conduction,F-wave and H-reflexes detection. Standard EMG was recorded at glossus,sternocleidomastoid muscles,triangular muscles,first interosseous muscle,paravertebral muscles,alquadriceps femoris muscles and anterior tibial muscles. Standard nerve conduction velocity （NCV） was recorded at bilateral median nerves,common peroneal nerves,sural nerves and tibial nerves. Results Electromyography of all the 9 cases showed a wide range of chronic neurogenic damage. Compound muscle action potentials （CMAP） and sensory nerve action potentials （SNAP） were significantly decreased in KD patients compared with the findings in the normal controls（P〈0.01）,the abnormal rate of sural nerve action potential was the highest （88.89%）. The motor conduction velocities （MCV） of peroneal motor and the sensory conduction velocities （SCV） of sural sensory were significantly decreased in KD patients （P〈0.01）. Latencies of F-wave and H-reflexes were significantly prolonged （P〈0.01）. The muscle biopsy is was neurogenic damage,showed atrophy of muscle fibers and atrophic fibers in groups and clumps shapes. Conclusion The characteristics of electrophysiological findings in KD patients were widespread chronic neurogenic changes accompanied with sensory and motor conduction abnormalities. Sensory nerve conduction was more involved than motor nerve. Muscle biopsy showed atrophic fibers in groups and clumps shapes. Recognition of the hallmark of electrophysiological and myopathological changes in KD will be very useful in the early diagnosis of KD and reduce the misdiagnosis rate.