Progressive dementia caused by Hashimoto's encephalopathy -- report of two cases.

Dementia induced by Hashimoto's encephalopathy (HE) seems to be a rare condition. We report on two patients, who revealed a syndrome consisting of a rapid progressive dementia with myocloni. In both patients, the detection of antithyroid antibodies enabled the diagnosis of HE. The symptoms receded completely during a high-dose glucocorticoid therapy. In patients with rapidly progressive dementia or with dementia of unknown origin, HE should be considered.