Hashimoto’s Encephalopathy in a Critically Ill Patient With Polysubstance Use: A Diagnostic Challenge

This case underscores the importance of pursuing early autoimmune testing in cases of encephalopathy with unclear etiology. HE remains a diagnosis of exclusion, a consideration that should only arise after comprehensive evaluation and treatment of potential metabolic, toxic, structural, and infectious causes have failed to yield improvement. In this case, timely recognition allowed for an appropriate corticosteroid trial and subsequent clinical response, reaffirming the critical need to include HE in the differential when other common causes have been ruled out.