Shizukawa H, Imai T, Kobayashi N, Chiba S, Matsumoto H
Department of Neurology, School of Medicine, Sapporo Medical University.
Rinsho Shinkeigaku. 1994 May;34(5):500-3.
A 16-year-old girl noticed weakness in the left hand in 1990, which gradually progressed over the next 2 years but then stabilized. Her neurologic and electrophysiological signs were compatible with juvenile muscular atrophy of unilateral upper extremity (Hirayama disease). Cine MRIs demonstrated a mild cervical cord atrophy at the C6 spine level together with an engorged epidural vein at the C4-C6 extradural spaces during neck flexion. Transcranial magnetic stimulation over the motor cortex was carried out with a pickup placed on the contralateral abductor brevis muscle. While neck flexion was maintained, the amplitude of the evoked potentials steadily attenuated and the central motor conduction time lengthened as time passed. After 8 minutes, she began to feel some dullness in the left upper limb. These phenomena were reversible and were observed only on the affected limb. The above facts not only supported the presence of a reversible cortico-efferent dysfunction in Hirayama disease, but also appeared to justify the use of neck collars to treat those afflicted with this entity.
1990年，一名16岁女孩发现左手无力，在接下来的2年里逐渐加重，但随后病情稳定。她的神经学和电生理体征与青少年单侧上肢肌肉萎缩（平山病）相符。电影磁共振成像显示，在颈部屈曲时，C6椎体水平的颈髓轻度萎缩，同时C4 - C6硬膜外间隙的硬膜外静脉充血。在运动皮层进行经颅磁刺激，采集电极置于对侧短展肌上。在保持颈部屈曲的同时，诱发电位的幅度随着时间的推移而稳步衰减，中枢运动传导时间延长。8分钟后，她开始感到左上肢有些麻木。这些现象是可逆的，且仅在患侧肢体上观察到。上述事实不仅支持平山病存在可逆的皮质传出功能障碍，而且似乎也证明了使用颈托治疗该病患者的合理性。
