Iranian Red Crescent Medical Journal IRCMJ 2009; 11(2):218-219 ©Iranian Red Crescent Medical Journal LETTER TO THE EDITOR An Overview of Hashimoto’s Encephalopathy

Hashimoto's encephalopathy is a rare complication of autoimmune thyroid disease with an estimated preva-lence of 2.1/100,000.1 It is also known as steroid re-sponsive encephalopathy associated with autoimmune thyroiditis, SREAT.2 The pathogenesis is still un-known, but the possible mechanism could be due to cerebral vasculitis with or without immune complex deposition.3 It is an inflammatory condition proposed by the presence of elevated TPO,4 elevated CSF pro-tein,4 histological feature of vasculitis of venules, and lymphocytic perivascular cuff.1 Patients may present with encephalopathy (100%) which usually develop over 1 to 7 days, tremor (84%), transient aphasia (73%), seizure (66%), gait ataxia (63%), hypersomnolence (63%), myoclonu