Clinical analysis of 17 patients in 12 Japanese families with autosomal-recessive type juvenile parkinsonism.

We present the clinical features of 17 patients from 12 Japanese families with familial juvenile parkinsonism suggesting autosomal-recessive inheritance (AR-JP). Because the marriages of the parents in all but one family were consanguineous and all patients were only first generation, an autosomal-recessive trait was strongly suspected. Analysis of the clinical features showed female predominance, mean age at onset 27.8 years, and slow progression. The symptoms of the parkinsonian triad (tremor, rigidity, and bradykinesia) were mild, but gait freezing, hyperreflexia, foot dystonia, and retropulsion were relatively prominent. A characteristic finding was amelioration of parkinsonian symptoms after sleep in all patients. Response to levodopa was satisfactory, but dopa-induced choreic limb dyskinesia and wearing-off phenomenon occurred frequently. Juvenile parkinsonism is a syndrome that encompasses several clinical entities. The similarity of clinical findings in these patients, and the differences from other types of parkinsonism, indicates that AR-JP is distinct clinical entity.