Psychiatric presentation of Hashimoto's encephalopathy

Hashimoto's encephalopathy is an unusual condition that is associated with Hashimoto's thyroiditis. Myoclonus, epileptic seizures, dementia, and disturbances of consciousness are the most common features.

We present an atypical case of Hashimoto's encephalopathy in a 33-year-old woman who presented with several brief and acute psychotic episodes. After treatment with steroids, there was an improvement in the patient's psychiatric symptoms and electroencephalogram, and antithyroglobulin antibody titers returned to normal levels.

It is our opinion that Hashimoto's encephalopathy should be considered in the differential diagnosis of atypical psychosis, especially because this is a treatable syndrome. This is particularly important in patients with a previous history of thyroid disease, despite current normal thyroid function.