Steroid responsive myoclonus as a presentation of Hashimoto′s encephalopathy

Hashimoto′s Encephalopathy (HE) can have highly variable neuropsychiatric manifestations, making it difficult to diagnose, and may go unrecognized for a long time. HE is a diagnosis of exclusion and should be kept in mind when evaluating a patient with cognitive dysfunction and high titres of antithyroid antibodies as it responds dramatically to steroids. Steroid responsive myoclonus can be a presentation of HE.