Hashimoto's encephalopathy: an anatomicoclinical observation

Hashimoto's encephalopathy (HE) is a rare neurological complication of chronic lymphocytic thyroiditis. As its clinical presentation is aspecific, other etiologies of acute encephalopathy have to be ruled out. We report the case of a 29-year old woman with neuropsychiatric signs preceding coma, myoclonus and epileptic seizures. Clinical and electroencephalographic features were consistent with the diagnosis of new variant of Creutzfeldt-Jakob disease. However, high titres of antithyroid antibodies in serum directed towards the diagnosis of HE. Despite oral steroids, the patient died five months later. Neuropathological findings ruled out spongiform encephalopathy and disclosed aspecific activated microglia. Our observation suggests that this process could be involved in the pathogenesis of HE. Even in the absence of clinical dysthyroidism, HE diagnosis has to be suspected in the settings of acute encephalopathy associated with seric antithyroid antibodies.