Clinical and Radiological Features of Hirayama Disease: A Review of Four Cases
许蕾(Lei Xu)；黄勃源(Bo-Yuan Huang)；李彩英(Cai-Ying Li)；刘亚玲(Ya-Ling Liu)；郭艳苏(Yan-Su Guo)；李春岩(Chun-Yan Li)
平山病 ； 肌萎缩 ； 屈性脊髓病 ； Hirayama disease ； Muscular atrophy ； Flexion myelopathy
|Volume or Term/Year and Month of Publication||
32卷1期（2006 / 01 / 25）
23 - 26
目的 探讨平山病的临床特征、影像学特点及发病机制。方法 对4例患者的临床、神经电生理、影像学资料进行分析。颈部屈曲位，采用平卧位时骨盆下放置一个定制的楔形物而获得。结果 4例均为青春期男性。主要表现为局限于手和前臂的肌萎缩，尺侧肌肉萎缩较重，上肢呈斜坡样。4例手指伸展时出现震颤；3例伴寒冷麻痹。常规颈MR均可见颈髓下段轻度萎缩，均未发现髓内异常信号。屈颈MR均见下段颈髓前移、变平，硬脊膜向前移位；硬脊膜外间隙增宽；硬脊膜外间隙内半月形信号影，在T1加权像与脊髓的信号相同，在T2加权像呈高信号，其中有一些弧线形或圆形的血管流空信号。结论 屈颈位MR，出现下颈髓及其硬膜囊的异常表现是平山病的一个显著特点，当遇到青少年（尤其是男性）出现手及前臂不对称的肌无力和萎缩时，应进一步行屈颈MR检查。
Objective To study the clinical and radiological features, pathogenetic mechanisms of Hirayama Disease. Methods Four men with Hirayama disease were screened and confirmed by cervical MR in a neutral and a fully flexed position at their 14, 23, 23, 18 years old respectively. In order to obtain full flexion of the neck, maximal elevation of the head against the trunk is needed while the trunk is tilted down rostrally using a pelvic wedge. Results Hirayama disease occurs predominantly in young males in puberty and characterized by muscular atrophy in the hand and forearm; the brachioradial is spared (oblique amyotrophy). The amyotrophy was unilateral in 3 cases and asymmetrically bilateral in 1 case. Fine postural tremor (4 cases) and cold paresis (3 cases) were associated with symptoms. In a neutral neck position, the spinal cord showed locallized lower cervical cord atrophy. There was no abnormal intrinsic cord signal. During neck flexion, the spinal cord was displaced forward and flattened from the C5 to T1 vertebral levels. A crescent-shaped epidural mass, isointense T1-weighted images and hyperintense T2-weighted images was noted behind the spinal cord with some curvilinear and round flow void signals inside it. Conclusions MR abnormalities of the lower cervical dural sac and spinal cord in a fully flexed position are typical features of Hirayama disease. When the patient is a adolescence, especially male with asymmetric muscular weakness and atrophy in the hand and forearm, flexion MR study should be considered.