Abstract:

A 12-year-old girl presented with talipes equinus of both legs, attenuation of upper and lower limb tendon reflexes, thermal hyperalgesia, and reduction of vibratory sensation. On clinical examination, muscle twitches of fingers of both hands, as well as the abductor halluces and the dorsal interossei muscles of the right foot were observed. Nerve conduction velocity was significantly declined in the upper and lower extremities. Needle electromyography (EMG) was not performed; however, ultrasonography revealed repetitive, semi-regular muscle twitches lasting 0.2-0.4s, concomitant with muscle discharges on surface EMG in the right foot muscles. These findings were compatible with contraction fasciculation in muscles under chronic reinnervation. Nerve and muscle biopsies were suggestive of chronic motor, sensory, and autonomic neuropathy. This is the first case of pediatric peripheral neuropathy where muscle fasciculation was noninvasively identified by simultaneous surface EMG and ultrasonography.

日本語要旨:

症例は両側の尖足、上下肢の腱反射減弱、音痛覚過敏、振動覚低下を認めた12歳女児。両測手指、右母趾外転筋と背側骨間筋の筋痙攣があり、上下肢で神経伝導速度が低下していた。筋電図は施行しなかったが、右下肢に、筋超音波検査で、表面筋電図と一致した0.2-0.4秒間持続する反復性、準規則的な筋痙攣を認めた。この所見は、慢性の神経再支配の際に見られる筋線維束攣縮に合致していた。神経、筋生検では、慢性の運動、感覚、自律神経ニューロパチーが示唆された。小児のニューロパチー患者で、筋線維束攣縮を、表面筋電図、超音波検査を併用して、非侵襲的に検出した初めての報告である。