When Severe Hypothyroidism Mimics Neuromuscular Diseases: A Case Supporting Outpatient Management in Contemporary Endocrinology

Severe hypothyroidism may present with symptoms similar to those of primary neuromuscular or acute neurological disorders, resulting in diagnostic delays and potentially unnecessary hospitalizations. A 40-year-old man presented to the emergency department with postural instability, diplopia, myalgia, and elevated creatine kinase, suggestive of a neuromuscular disorder. Laboratory test results revealed thyrotropin (TSH) levels over 170 μU/mL and suppressed free thyroxine (fT4). Despite severe biochemical parameters, clinical stability allowed for outpatient management with levothyroxine administration and endocrinological follow-up. The case mimicked inflammatory myopathy or brainstem stroke, but the absence of 'red flags' allowed for safe outpatient treatment. Literature confirms that hypothyroidism can present with neurologic signs and that structured outpatient pathways are effective. This report emphasizes the importance of recognizing endocrine causes in neuromuscular presentations and advocates for outpatient management models in stable hypothyroid patients.