Hashimoto encephalopathy: an undeniably significant cause for altered mental status

Summary: Hashimoto's encephalopathy (HE), also known as steroid-responsive encephalopathy, is associated with autoimmune thyroiditis. The condition typically develops gradually and presents symptoms such as impaired concentration, memory issues, delusions, hallucinations, personality changes, tremors, hemiparesis, and seizures. Diagnosis involves three key steps: 1) identifying neurological symptoms while excluding other causes, 2) detecting elevated anti-thyroid antibodies, and 3) noting improvement after immunomodulation treatment. Many patients are euthyroid, although some may have subclinical hypothyroidism. Treatment options include steroids, intravenous immunoglobulin (IVIg), or plasmapheresis, or immunosuppression such as methotrexate. Most patients improve with corticosteroids, but relapse rates can reach 12.5%-40% within two years. Additionally, 12.5% of patients may not respond to corticosteroids and will need immunosuppressors.