Bell's palsy and choreiform movements during peginterferon alpha and ribavirin therapy.

Neuropsychiatric side effects of long-term recombinant interferon-alpha therapy consist of a large spectrum of symptoms. In the literature, cranial neuropathy, especially Bell's palsy, and movement disorders, have been reported much less often than other neurotoxic effects. We report a case of Bell's palsy in a patient with chronic hepatitis C during peginterferon-alpha and ribavirin therapy. The patient subsequently developed clinically inapparent facial nerve involvement on the contralateral side and showed an increase in choreic movements related to Huntington's disease during treatment.