Idiopathic dystonia. Clinical profile of 76 Brazilian patients.

Dystonia may be classified by age of onset (childhood, adolescence, adult onset), body distribution of the abnormal movements (focal, segmental, unilateral, multifocal and generalized) and etiology (idiopathic and symptomatic). We studied 76 patients with idiopathic dystonia among 122 cases of dystonic syndrome (62.3% of the total). There were 48 female and 28 male patients. Adult-onset focal dystonia was the most frequent feature (37 patients). The onset of generalized dystonia was more frequently seen under the age of 20, whereas focal and segmental dystonia usually started over this age. Postural tremor of the hands was observed in 19.7% of the patients. Spasmodic torticollis was the most prevalent form of dystonia overall. Except for writer's cramp, which occurred more frequently in males, and generalized dystonia, which was equally divided between sexes, all other forms were more frequent in females. Our data suggest that differences in racial origin, social and economical status and environmental factors do not account for a different manifestation in dystonia pattern.