Hypothyroidism and polyneuropathy.

The prevalence and characteristics of polyneuropathy were assessed using standard clinical and electrophysiological criteria in 39 consecutive outpatients with primary hypothyroidism, 15 of whom were previously untreated. Subjective complaints, mainly paraesthesiae, were recorded from 25 cases (64%) and objective findings supporting a clinical diagnosis of polyneuropathy were present in 13 (33%). Using standard electrophysiological criteria, a definite diagnosis of polyneuropathy was made in 28 cases (72%). The commonest sites of abnormal nerve conduction were the sensory nerves, especially the sural nerve. Polyneuropathy was generally mild. None of the clinical and biochemical indicators of hypothyroidism were significantly correlated with the electrophysiological signs of peripheral nerve impairment or the diagnosis of polyneuropathy.