Nerve conduction studies in patients with primary hypothyroidism

Background: Hypothyroidism is an important cause of peripheral as well as focal neuropathy. Reported prevalence of neuropathy in hypothyroidism is varied widely. Objective: To study nerve conduction abnormalities and to correlate electrodiagnostic findings with clinical features in patients with primary hypothyroidism. Materials and Methods: This study was done in Smt. Kashibai Navale Medical College, Pune, Maharashtra. Adult patients with primary hypothyroidism were included. Patients with other possible causes of neuropathy were excluded. Detailed medical history was obtained, and clinical examination and nerve conduction study by electrophysiological method were done in all patients. Results: Total 40 patients were included, of which, 25% patients showed evidence of neuropathy. Six patients had carpal tunnel syndrome while four had other peripheral neuropathy. Presence of neuropathy correlated independently with advanced age and female gender. There was significant correlation between presence of signs and symptoms of neuropathy to electrophysiologically confirmed neuropathy. Occurrence of neuropathy was more common in patients with duration of disease more than 5 years (44.44%) and obesity (50%), but these findings were not statistically significant (P = 0.08 and 0.09, respectively). No correlation found between etiology of disease, serum thyroid-stimulating hormone level and occurrence of neuropathy (P = 0.43, 0.9, respectively). Conclusion: Advanced age and female gender are important risk factors for development of neuropathy in patients with hypothyroidism. The thorough clinical examination is very important as clinical signs and symptoms are sensitive predictors for the presence of neuropathy.