Hashimoto Encephalopathy Presenting as Schizophrenia-like Disorder

Objective: Hashimoto encephalopathy (HE) is associated with numerous neuropsychiatric symptoms and responds well to steroid therapy. In the past, only a few cases were reported to present with pure psychiatric syndromes. We describe a case of HE with presenting symptoms like that of schizophrenic patients. Methods: We describe a 73-year-old woman with a history of autoimmune Line thyroiditis. She had psychotic symptoms for 3 years that responded poorly to antipsychotic agents, and she was thus admitted in 2007. Results: The diagnosis of HE was made, although the patient presented neurologic symptoms and signs including abnormal electroencephalography, recent memory impairment, and executive function declination. The psychotic symptoms subsided completely in a few days after high-dose intravenous steroid therapy. Conclusions: The neuropsychiatric manifestation of HE can be similar to typical schizophrenia. Considering the effectiveness of steroid therapy for HE, we suggested HE as an important differential diagnosis for psychotic disorders, particularly for those patients of late onset, with abnormal electroencephalography, history of autoimmune thyroiditis, or poor response to conventional psychiatric treatment, so as to provide prompt and effective treatment for these patients.