Hashimoto's encephalopathy.

Dra. Renata Telles Rudge de Aquino – Rua Ourânia 408 05445-030 São Paulo SP Brasil. E-mail: [email protected] Hashimoto’s encephalitis (HE), encephalitis which responds to steroids and is associated with auto-immune thyroiditis, was described by Brain et al. in 1966. Since then, about 100 cases have been described. It is probably under diagnosed as it is not well known. It presents with acute or sub-acute encephalopathy, tremor, myoclonus, ataxia, fits, psychosis or stroke like events, progressive or relapsing, high titres of anti-thyroid antibodies but independent of thyroid function. Its two sub-types can co-exist: multiple stroke like events, and diffuse progressive, with dementia and psychiatric symptoms. Diagnostic criteria are encephalopathy with elevated anti-thyroid antibodies in the absence of infection, tumour or alteration in the cerebral vascular system. A good response to corticoteroids is typical.