HASHIMOTOS MYOCLONIC ENCEPHALOPATHY - AN UNDERDIAGNOSED TREATABLE CONDITION

We report two patients with subacute diffuse encephalopathy characteri zed by confusion, myoclonic encephalopathy, and mild akineto-rigid ext rapyramidal signs in one case and by apathy, memory deficit, and parti al complex seizures in the other. Hashimoto's thyroiditis with high ti ters of anti thyroglobulin antibodies was diagnosed in both patients, who were unresponsive to anticonvulsant medication, but showed rapid n eurological improvement following steroid treatment. On neuropsycholog ical examination, predominant frontotemporal dysfunction was noted. El ectroencephalographic activity was remarkable for its rhythmical delta activity, unresponsive to, or even paradoxically increased by, antico nvulsant treatment. On magnetic resonance imaging, atrophy with tempor al predominance was found. These observations support the idea that th is potentially treatable dementia and movement disorder should be clas sified as a separate clinical entity.