Acetazolamide improves action myoclonus in Ramsay Hunt syndrome.

The myoclonus of two patients with Ramsay Hunt syndrome was only partially controlled under treatment with clonazepam, sodium valproate, primidone, and piracetam. Acetazolamide (200 mg daily) was added to these drugs, resulting in a dramatic improvement. Placebo substitution (one patient) and withdrawal of acetazolamide in the other patient resulted in marked aggravation of the myoclonus. The mechanism of action of acetazolamide in myoclonus is unknown. Acetazolamide may be an additional therapeutic possibility for patients with severe action myoclonus.