[Juvenile parkinsonism. 18 cases].

The accepted Juvenile Parkinson denomination includes patients who present the characteristic symptoms before 40 years old. We are reporting 18 such patients, between 15 and 34 years old, who had a follow-up between 9 to 17 years. Based on our observations and a revision of the literature, and after considering inheritance, clinical, evolutive and therapeutic outlook we were able to reach a conclusion as to the essential features of this particular form of parkinsonism. Apparently the impairment to L-Dopa therapy developed more slowly in these patients than in presenile forms and it would be related more with the duration of the illness than with that of L-Dopa therapy.