Bilateral Foot Drop due to Uncontrolled Hypothyroidism

Case Diagnosis: Atypical presentation of Myopathy secondary to Hypothyroidism

Case Description or Program Description: A 46-year-old male with DMT2 presents with two years of muscle weakness in lower extremities and sudden development of bilateral foot drop. He was referred to PM&R clinics which EDX had findings of neuropathy and myopathy for which hypothyroidism was suggested as differential diagnosis as patient had no lab work-up on referral. Afterwards, primary physician performed work-up and patient was diagnosed with uncontrolled hypothyroidism. He was referred to the PM&R clinic for evaluation.

Setting: Secondary Care

Assessment/Results: A comprehensive physical exam showed bilateral weakness in the upper and lower extremities, decreased reflexes, and reduced sensation in a stocking-glove pattern. Lab results indicated severe hypothyroidism (TSH >50), elevated CPK levels, and controlled diabetes (A1C). Electromyography (EDX) revealed moderate symmetric sensory motor peripheral neuropathy with increased spontaneous activity in the right upper extremity and thoracic paraspinal areas, indicating a myopathy due to hypothyroidism. A subsequent lower extremity EDX showed spontaneous activity in the right lower extremity. Currently, the patient's TSH is well-controlled, upper extremity weakness has improved, but lower extremity weakness persists, necessitating orthosis for ambulation but able to work.

Discussion (relevance): The relationship between myopathy and hypothyroidism has been extensively studied. While myopathy is a relatively common complication of hypothyroidism, it often goes unrecognized. Typically, symptoms develop gradually; however, in this patient, they appeared suddenly, which is an atypical presentation. This could potentially be attributed to undiagnosed severe hypothyroidism. It is crucial for clinicians to maintain a high level of suspicion and provide appropriate follow-up care, as the patient's quality of life may be significantly impacted.

Conclusions: This case illustrates how a patient's metabolic disturbances can impact their overall functionality and quality of life. These disturbances may also influence the effectiveness of treatments, emphasizing the need for ongoing primary care screening and prevention to optimize the patient's well-being.