Motor conduction parameters in recently diagnosed and untreated hypothyroidism

BACKGROUND The severity of neuromuscular symptoms and signs in hypothyroidism is known to be related to the duration and degree of hormone deficiency. PURPOSE The present study was aimed to assess whether recently diagnosed and untreated hypothyroidism affects peripheral nervous system. METHODS The study included a total of 120 female subjects with age ranging from 20 to 45 years. The motor nerve conduction parameters viz. Distal latency (DL), amplitude of compound muscle action potential (CMAP) and motor nerve conduction velocity (MNCV) were recorded bilaterally in median, ulnar and posterior tibial nerves using standard protocols and settings. RESULTS The observations revealed significantly prolonged distal motor latencies, reduced CMAP amplitudes and slowed MNCV in the peripheral nerves in hypothyroid. CONCLUSION The results indicated that the alteration in motor conduction parameters in recently diagnosed and untreated hypothyroidism might be due to various functional and structural changes in peripheral nerves associated with deficiency of thyroid hormones.