Isolated global amnesia associated with autoimmune thyroid disease

Abstract

One week after developing a gastrointestinal illness, a 32-year-old man with a 15-year history of Hashimoto thyroiditis, with no previous cognitive or comportment changes, presented with confusion and extreme forgetfulness over 3 days. He repeated himself in conversations and lost memories from his recent past. There were no headaches, fevers, seizures, or focal elementary neurologic or systemic symptoms or signs. His judgment, personality, language, and reasoning abilities remained normal by history and mental status testing. Brain MRI on day 3 of his amnesia, with and without gadolinium, was normal. An EEG 3 weeks later was also normal. Ten days later, tests for antinuclear and anti-Hu antibodies were negative, CSF leukocyte count was 3/mm3, protein concentration was 20 mg/dL, and viral and bacterial cultures were negative. At this time, the serum thyroid peroxidase antibody concentration was 1,860 IU/mL (reference range, 0.0 to 2.0 IU/mL). Based …