神经电生理及核磁共振检查对平山病的诊断价值

Role of electrophysiological test and MRI in the diagnosis of Hirayama disease

摘要:

目的：探讨神经电生理及核磁共振检查对平山病的诊断价值。方法：对14例确诊的平山病患者的临床特点、神经电生理特征及影像学表现进行回顾性分析。结果：所有患者有症状侧上肢正中神经和尺神经感觉运动传导速度及正中神经复合肌肉动作电位（compound motor active potentials，CMAPs）均正常，8条尺神经CMAPs降低超过正常值20%。14例患者有症状侧下颈段脊髓前角细胞支配肌肉均出现神经源性损害（C7~8、T1水平）；其中4例呈有症状侧上肢肌肉神经源性损害；7例呈双侧上肢肌肉神经源性损害（其中2例仅有单侧上肢肌肉无力萎缩表现）；3例呈广泛神经源性损害（1例为单侧上肢2例为双上肢肌肉无力萎缩）。常规颈椎生理位MRI平扫10例未见异常或略变细；4例提示颈胸段脊髓萎缩变细。颈椎前屈位MRI扫描提示14例患者均有颈胸段椎管后方硬膜前移，脊髓呈明显受压变形、变细改变。结论：大多数平山病患者肌电图检查呈节段性下颈段脊髓前角损害的特征性异常，因而神经电生理检查在平山病的诊断中有重要作用。平山病患者肌电图检查亦可能出现广泛神经源性损害，因而疑诊平山病患者均应行颈段脊髓生理位及前屈位MRI扫描。

Abstract:

Objective：To investigate the role of electrophysiological test and MRI in the diagnosis of Hirayama disease. Methods：Ｃlinical features，electrophysiological characteristics and MRI findings of 14 patients with Hirayama disease were retrospectively re－viewed. Results：All symptomatic upper limbs had normal sensory nerve conduction velocity and motor nerve conduction velocity in the median and ulnar nerves. Compound motor active potentials（CMAPs） were normal in median nerve. Ulnar nerve CMAPs were de－creased by 20% of the normal value in 8 patients. Fourteen patients had neurological damage in muscles innervated by lower cervi－cal anterior horn cells（C7-8，T1） in the symptomatic limbs. Four patients had neurological damages in the symptomatic upper limbs. Seven patients had neurological damages in both upper limbs. Three patients had diffused neurological damages. No abnormality was observed in 10 patients according to MRI of cervical vertebra at normal physiological position. Four patients had atrophy of the cervi－cal and thoracic spinal segments. MRI of cervical vertebra at head-down position indicated anterior displacement of dura mater in the cervical and thoracic spinal segments in 14 patients with spinal cord being compressed and atrophic. Conclusions：Most patients with Hirayama disease have anterior horn damage in the lower cervical spinal segment on electromyography. Electrophysiological exam is important in the diagnosis of Hirayama disease. Diffused neurological damage could also be noticed in patients with Hiraya－ma disease. All patients with suspected Hirayama disease should have MRI scan of the cervical spinal cord at both normal physiological position and head-down position.