Delayed Diagnosis of Myxedema Coma in a Patient With Concurrent Severe Intracranial Atherosclerotic Disease

Myxedema coma is a severe and life-threatening presentation of hypothyroidism that is less prevalent in more developed countries. It is associated with hypothermia, altered mental status, and multi-system organ failure and can be precipitated by acute stressors like infection, surgery, or myocardial infarction. Rapid diagnosis and treatment of myxedema coma are imperative due to the significant mortality seen. In this case, an 83-year-old male presented to the emergency department intubated after being found unresponsive on the floor of his home by family members. Initial examination with labs and imaging led to suspicion of acute hypoxic respiratory failure and acute metabolic encephalopathy, potentially due to an ischemic event. Imaging confirmed multiple cerebellar infarcts and severe intracranial atherosclerotic disease. The absence of clinical improvement led to further laboratory and physical examination workup, which resulted in a delayed diagnosis of myxedema coma precipitated by ischemic brain injury. Once the diagnosis was confirmed, treatment was initiated with thyroid hormone replacement and glucocorticoid supplementation. Slight initial improvement was seen after treatment with incremental rises in free thyroxine hormone levels and decreases in thyroid-stimulating hormone (TSH), but the patient's medical power of attorney decided on comfort measures only, and the patient ultimately expired. This report should highlight the importance of early suspicion and diagnosis of myxedema coma in patients who present with altered mental status, bradycardia, hypothermia, and anemia in the setting of other potential confounding diagnoses.