Hashimoto's Encephalopathy: A Rare Cause of Seizure-like Activity

Hashimoto's encephalopathy is an uncommon disorder that may present with a wide variety of different neurological signs and symptoms that can include acute altered level of consciousness, psychosis, seizures, ataxia, dementia, myoclonus, and stupor. We present a case of a 60-year-old female patient who was admitted to the internal medicine floor for workup for seizures of unknown etiology. Investigations, including a complete blood count, basic metabolic panel, magnetic resonance imaging (MRI) of the brain, cerebrospinal fluid analysis, and NMDA (N-methyl-D-aspartate) receptor encephalitis screen, were all unremarkable. Thyroid-stimulating hormone levels and anti-thyroid peroxidase antibodies were found to be elevated, suggesting an underlying etiology of Hashimoto's thyroiditis. Treatment with corticosteroids and levothyroxine can lead to resolution of symptoms. This case report is presented to suggest the importance of serological screening for anti-thyroid antibodies in the workup of all patients with unknown causes of encephalopathy along with providing a review of the literature.