良性局限性下肢肌萎缩是一隐匿起病,缓慢进展,继之以3年以上稳定期的局限性肌萎缩疾病。该病肌萎缩与肌无力不成比例,无感觉障碍,锥体束损害和延髓麻痹。病例都呈散发性,无脊髓灰质炎病史。患者血肌酸磷酸激酶正常,抗神经节苷脂抗体阴性,肌电图上运动和感觉传导速度正常。肌电图和肌活检检查除萎缩肌肉外,在其他肢体上也可见到广泛前角细胞损害。肌肉CT显示肌萎缩呈不对称性,主要或选择性损害下肢后组肌群和股二头肌长头。该病是脊肌萎缩症的一种变异类型,预后良好。 Acute limitations Muscle atrophy of the lower extremities is an insidious onset with slow progression, followed by a limited myosis of more than 3 years of stable disease. The disease atrophy and muscle weakness disproportionate, no sensory disturbances, pyramidal tract damage and bulbar palsy. All cases were sporadic and had no history of poliomyelitis. Patients with normal blood creatine phosphokinase, anti-ganglioside antibody negative, electromyography and motor and sensory conduction velocity of the normal. Electromyography and muscle biopsy in addition to shrinking the muscles, but also in other limbs can also be seen extensive anterior horn cell damage. Muscle CT showed muscle atrophy was asymmetric, the main or selective damage to the lower limb muscle and biceps femoris long head. The disease is a variant of spinal muscular atrophy with a good prognosis.