A 44-year-old concert violinist presents with a 6-month history of painful involuntary flexion and abnormal posturing of the right hand exclusively during performance. Vital signs are normal (BP 128/82, HR 72, RR 14, Temp 37°C). Neurologic examination reveals focal dystonia of the right hand with preserved strength and reflexes; cranial nerves and gait are normal. Brain MRI shows no structural abnormalities. He denies tremor at rest. Which of the following is the most likely diagnosis?

1. A)Hemiballismus
2. B)Drug-induced parkinsonism
3. C)Essential tremor
4. D)Myoclonus
5. E)Focal dystoniaGABARITO