Hashimoto's encephalopathy presenting as catatonia in a bipolar patient

Hashimoto's encephalopathy is a rare autoimmune disease the presentation of which can include a variety of neurological signs and psychiatric symptoms. Here we present a 53-year-old woman with a history of bipolar disorder who experienced catatonia, consciousness disturbance, and general weakness after the aggravation of symptoms depression. After laboratory data revealed increased blood anti-thyroid peroxidase antibodies, the patient was diagnosed as having Hashimoto's encephalopathy, and her neuropsychiatric symptoms resolved soon after she received steroid pulse therapy. Hashimoto's encephalopathy rarely presents as catatonia, but the symptoms might mimic the manifestation of a previous mental illness. Clinicians should therefore consider Hashimoto's encephalopathy an underlying cause of catatonia.