Torsion dystonia: a case report.

A 35-year-old black female with typical torsion dystonia is discussed. Tremors in the right upper extremity began with a febrile illness at age eight. Difficulty in using the extremity began two years later. Overt writhing movements and torticollis began at age 17. The disorder has been progressive, but not disabling. Neurological examination revealed only extrapyramidal motor system dysfunction. Serum dopamine Beta hydroxylase levels were normal, and an evaluation for Wilson's disease was negative. A sibling has minor writing difficulties.