平山病的临床、神经电生理及影像学特点

A clinical, electrophysiological and imaging features study of Hirayama disease

目的分析平山病的临床特征、神经电生理及影像学特点,以提高对平山病的诊断水平。方法分析15例平山病的患者临床、神经电生理、影像学资料。结果 1 15例均为青春期男性,均表现为上肢远端肌肉萎缩及无力,尺侧肌肉萎缩较重。单侧者12例,双侧者3例。8例手指伸展时出现震颤,6例伴寒冷麻痹;2肌电图均提示受累侧及对侧上肢远端肌肉神经源性受损,尺神经和正中神经分别有12例和3例复合肌肉动作电位(CMAP)波幅下降的现象;3颈髓MRI均可见颈髓下段轻度萎缩,3例髓内异常信号。过屈位颈MRI显示下段颈髓前移、变平,硬脊膜向前移位,硬脊膜外间隙内半月形信号影,11例在增宽的硬膜外腔见流空血管信号,6例增强扫描见硬脊膜外腔强化的静脉丛。结论在临床上遇到年青患者出现非对称性、局限于上肢远端肌群无力和萎缩时,应考虑平山病的诊断;神经电生理和颈髓MRI自然位+过屈位动态检查是诊断平山病的重要手段。

Objective To promote the diagnostic acuity of Hirayama disease by studying the features of clinical,electrophysiological and imaging feature.Methods Clinical data of 15 cases with Hirayama disease were retrospectively analyzed.Results ① All of the 15 patients were young male and characterized by muscular atrophy in the hand and forearm,the brachioradial was spared （oblique amyotroph）,twelve showed unilateral involvement and three showed bilateral but asymmetric involvement.Cold paresis was present in six patients.Tremor on finger extension was present in eight patients.② The neurogenic electromyography （EMG） abnormalities were detected bilaterally in the proximal muscle of upper limb in all of the patients.Motor nerve conduction study revealed decreased compound muscle action potential（CMAP） amplitudes in ulnar（nine patients） and median（three patients） nerve.③In the neck neutral position,all patients showed the localized lower cervical cord atrophy,and three patients showed the signal abnormalities of the spinal cord.In a fully flexed position of the neck,all patients showed forward displacement and flattening of the lower cervical cord,and a crescent-shaped high signal area behind the cord,and eleven patients showed small flow void signals insides the passive dilation of the posterior epidural space.On the post contrast flexion position MRI images in six patients disclosed the venous plexus located in the passive dilation of the posterior epidural space.Conclusion In a young patient with clinical evidence of hand and/or forearm muscle atrophy and asymmetric thinning of the cervical spinal cord,a diagnosis of Hirayama disease should always be considered.Electrophysiological,neck neutral position and flexion position MRI scans play an important role in the diagnosis of the Hirayama disease.