[Juvenile, non-progressive muscular atrophy localized in the hand and forearm. Report of 16 cases (author's transl)].

Sixteen cases of juvenile, non-progressive muscular atrophy localized in the hand and forearm were seen at our neurology out-patient clinic for the past 8 years. The analyses of these 16 cases disclosed characteristic features as follows: 1) juvenile onset 2) male preponderance 3) unique distribution of muscular atrophy and weakness in the hand and forearm. 4) insidious onset, initial progressive period and subsequent non-progressive course 5) tendon reflexes of the arms are hypoactive in half of the cases 6) no pathological reflexes 7) cold paresis 8) no definite sensory disturbance 9) no cranial nerve involvement 10) neurogenic patterns on EMG According to these features, this clinical entity carrying good prognosis must be differentiated from several diseases associated with similar muscular atrophy of extremities, especially amyotrophic lateral sclerosis which is notorious as a fetal disease.