Hashimoto's Encephalopathy Presenting with Chorea.

Hashimoto's encephalopathy (HE) is a steroid-responsive relapsing neuropsychiatric disorder associated with high titers of antithyroid antibody with or without thyroid dysfunction. We report a case of HE in a 78 year old female who developed sudden onset behavioral abnormalities associated with choreiform movement of extremities. All causes of vascular, infective, metabolic, autoimmune, paraneoplastic and toxic encephalopathy were excluded. Anti-thyroid peroxidase (anti-TPO) antibody was found to be raised with very high titre. A diagnosis of HE was made. Prompt treatment with high dose steroid led to dramatic improvement of symptoms including choreiform movement.