Febrile Hashimoto's encephalopathy associated with Graves' disease and acute pancytopenia: A case report.

Rationale: Hashimoto's encephalopathy (HE) is an autoimmune-mediated encephalopathy rarely seen in Graves' disease, with <20 cases reported previously, associated with elevated concentration of circulating serum anti-thyroid antibodies usually responsive to steroid therapy.

Patient Concerns: We present a HE case (25-year-old male) with Graves' disease, complicated by fever and pancytopenia. The patient presented with fever, gait impairment, delirium, agitation and disorientation.

Diagnoses: Thyroid-related antibodies were elevated and brain magnetic resonance imaging confirmed symmetrical white-matter lesion. There was no evidence of infection or other reasons to explain all of his clinical manifestations. Hashimoto's encephalopathy (HE) is an autoimmune encephalopathy with various manifestations and the characteristic of elevated anti-thyroid antibodies and has no relationship to thyroid function.

Interventions: The patient had nonspecific clinical manifestations and excellently respond to glucocorticoid therapy.The symptoms and the radiographic abnormalities disappeared after glucocorticoid therapy.

Outcomes: We followed up with him for 5 years, in which there was no recurrence and his thyroid function continued to be normal.

Lessons: It is important to evaluate thyroid function and related antibodies in patients present with neuropsychological symptoms to avoid delay in diagnosis.