RESUMEN
BACKGROUND: Hashimoto's encephalopathy is an unusual brain disorder consisting of focal and diffuse cerebral dysfunction that may present in a stroke-like fashion. Treatment has consisted of steroids and immunosuppression. Treatment with a potentially less toxic modality such as intravenous immunoglobulin (IVIG), if found to be effective, might offer an alternative approach to these patients. CASE DESCRIPTION: We present an 82-year-old woman who developed headache, changes in mental status, and multifocal neurological deficits. Investigation revealed significantly elevated titers of antithyroid antibodies. Treatment with prednisone and methotrexate was unsuccessful. Treatment with monthly courses of IVIG resulted in marked clinical improvement. CONCLUSION: Hashimoto's encephalopathy may be more common than is generally recognized. A trial of IVIG should be considered for patients with this devastating condition.