Miller R G, Buchthal F
Department of Neurology, California Pacific Medical Center, San Francisco 94118.
Muscle Nerve. 1992 Jan;15(1):111-3. doi: 10.1002/mus.880150119.
A 16-year-old boy had a 10-year history of stiffness in leg muscles. There was marked weakness of neck flexors, shoulder abductors, and ankle dorsiflexors, with hypertrophy of most muscle groups and both action and percussion myotonia. The parents were normal. Motor unit potential mean duration was reduced in the weakest muscle (tibialis anterior), and a biopsy of the same muscle showed only minimal abnormalities. Exercise and repetitive stimulation (30 Hz) of the tibialis anterior disclosed a decline in the compound muscle action potential that appeared to correlate with the muscular weakness.
一名16岁男孩有10年腿部肌肉僵硬病史。颈屈肌、肩外展肌和踝背屈肌明显无力，多数肌群肥大，存在动作性和叩击性肌强直。其父母正常。最无力的肌肉（胫前肌）运动单位电位平均时限缩短，对同一块肌肉进行活检仅显示轻微异常。对胫前肌进行运动及重复刺激（30Hz）时，复合肌肉动作电位下降，这似乎与肌无力相关。
