Intention myoclonus: successful treatment with clonazepam.

Clonazepam, a new benzodiazepine derivative, was used in the treatment of intention myoclonus with excellent results. Five patients, three with postanoxic encephalopathy and two with degenerative central nervous system disorders, all refractory to other therapy, responded with marked decrease in myoclonus. The effective dosage was 7 to 12 mg a day in divided doses. One patient has been treated for over 4 years with no toxicity or breakthrough of symptoms. Except for transient sedation, there have been no untoward side effects. Clonazepam is an important addition to the therapy of intention myoclonus.