[Parkinsonism in a patient receiving interferon alpha therapy for chronic hepatitis C].

We report a case of Parkinsonism due to interferon alpha (IFN alpha) therapy for chronic hepatitis C. A 51-year-old female received IFN alpha (Sumipheron@6 x 10(6) IU), three times a week by intramuscular injection. Six months after the initiation of IFN alpha therapy, she noticed tremor of bilateral fingers, and was admitted to our hospital. Neurological examination revealed muscle rigidity, bilateral finger tremor, mild bradykinesia. Tremor was more extreme at posture rather than at rest. She was diagnosed as Parkinsonism, and carbidopa-levodopa therapy was effective. Attention must be paid to Parkinsonism, when IFN alpha is administered.