平山病颈椎自然位和过屈位MRI及临床特征探讨

Cervical Vertebra MRI and Clinical Features of Hirayama Disease

目的:分析平山病颈椎自然位和过屈位磁共振成像(MRI)表现,探讨平山病MRI及临床特征。方法:总结7例平山病患者临床资料,分析低位颈髓在自然位和过屈位MRI上的动态变化,描述5例MRI增强扫描表现。结果:7例均为青少年男性,17岁前起病,就诊时病程3-36月。7例均表现为右上肢肌萎缩,肌电图提示神经源性损伤。在自然位上4例低位颈髓并1例上段胸髓轻度萎缩,阳性率57%,其中1例T2WI见髓内高信号;5例横轴位脊髓前角非对称性萎缩。在过屈位上7例低位颈髓前移、扁平,脊髓背侧硬脊膜外腔增宽,内见条状软组织信号,其中2例伴流空血管影。5例过屈位增强上显示硬脊膜外条状强化软组织影,恢复自然位后强化影消失。结论:平山病低位颈髓平扫和增强MRI动态变化具有特征性,结合临床可提示平山病的诊断。

Objective： To analyze MRI signs of Hirayama disease on the natural and fully flexing position of cervical vertibra,and to explore the MRI and clinical features.Methods： The clinical data and dynamic MRI characteristics of seven cases of Hirayama disease,and enhancing MRI features of five cases were studied.Results： All seven cases were male juveniles,whose on-set ages were younger than 17 years and course of disease ranged 3-36 months.Their initial symptom was muscular atrophy of right upper extremity with positive electromyography signs.On the natural position,four cases（57%） presented slight atrophy of lower cervical cord,including one case of upper thoracic cord involvement and one case with intramedullary high signals on T2WI.On the transverse,5 cases showed dissymmetric atrophy of cornu anterius medullae spinalis.On the fully flexing position,the lower cervical cords showed antedisplacement and flatting with widening spinal epidural space within abnormal strip shadow in seven cases,of which two cases showed flow-void vessel signs.Five cases showed the strip enhancement but the enhancement shadow was disappeared on the natural position.Conclusion： The characteristic dynamic MRI changes of Hirayama disease on the natural position and the fully flexing position are helpful for the accurate diagnosis as combined with clinical data.