Steroid responsive encephalopathy with autoimmune thyroiditis (SREAT) is a clinical syndrome characterized by non-specific neuropsychiatric symptoms not explained by any other etiology, elevated anti-thyroid antibodies and improvement in symptoms following corticosteroid administration. The pathogenesis of SREAT is unclear and the clinical presentations is highly variable, rendering the diagnosis difficult.

Case 1: A 63-year-old woman was brought to the Emergency Room for confusion and fluent, non-sensical speech.  Stroke work-up and brain MRI were unrevealing. Symptoms self-resolved. Two days later, patient re-presented to the hospital with convulsions. Video-EEG showed right hemispheric slowing. Lumbar puncture revealed elevated protein and repeat MRI with gadolinium was unchanged. Levetiracetam was started. Two days later, she was readmitted with lethargy, staring spells, and unsteady gait. She was found to have serum anti-thyroid peroxidase > 2,000 IU/mL (<78) and anti-thyroglobulin of 143 IU/mL (0.0 - 4.0). Treatment with solumedrol 1 g IV for 5 days was initiated with dramatic improvement in symptoms.

Case 2:  A 59-year-old man with history of rheumatoid arthritis presented to the hospital with mood changes and transient aphasia. Non-contrast head CT, CT angiogram, CT perfusion, and brain MRI with gadolinium were all unrevealing. EEG showed mild diffuse slowing, frequent frontal intermittent rhythmic delta activity and intermittent left frontotemporal delta slowing during drowsiness. CSF studies and malignancy work-up was negative. Serum anti-TPO was found to be 1,696 IU/mL (< 78) with normal anti-Tg. TSH was 5.69 (0.3 - 4.5). Treatment with solumedrol 1 g IV for 5 days and levothyroxine was initiated with improvement in symptoms.

Patients presenting with transient aphasia in addition to other neuropsychiatric symptoms may have SREAT and may benefit from early treatment with corticosteroids.