Baclofen in the treatment of polymyoclonus and ataxia in a patient with homocystinuria.

A patient with homocystinuria due to cystathionine beta-synthase deficiency developed severe progressive polymyoclonus and ataxia. To our knowledge, this is the first time polymyoclonus and ataxia have been reported in association with homocystinuria. Although cerebrovascular thrombosis is usually thought to be responsible for neurologic dysfunction in homocystinuric patients, no infarctions were demonstrated on magnetic resonance imaging scans in our case. We have previously reported that baclofen dramatically improved the polymyoclonus and ataxia in a patient with Unvericht-Lundborg disease. Baclofen given to our patient reversed the polymyoclonus and the ataxia as well. This suggests that patients with polymyoclonus and ataxia, no matter what the etiology, may benefit from the use of baclofen.