Nerve conduction abnormalities in patients with newly diagnosed diabetes mellitus

Abstract

Background: Peripheral neuropathy is the most common neurologic complication of diabetes mellitus (DM). The incidence of neuropathy increases with increasing duration of diabetes. Diabetes may be preceded by a long period of clinically silent impaired glucose tolerance, altering the nerve function by the time diabetes is diagnosed. Objectives: Assessment of early electrophysiological evidence of peripheral neuropathy in patients with newly diagnosed DM. Materials and Methods: Patients with newly diagnosed type 2 DM within 1 month of detection with or without clinical features of neuropathy were prospectively recruited. Nerve conduction studies were performed on the right upper and lower limbs. Sympathetic skin response and heart rate variability were studied. Results: Twenty-four patients (14 men and 10 women) with newly diagnosed DM were included in the study whose age was 57.66 ± 14.52 years. Eight patients had distal paresthesiae in the lower limbs of whom two had sensory deficit and two had mild motor deficit clinically. Thirteen patients (54.16%) had abnormal sensory conductions and nine patients had abnormal motor conductions. F-wave latencies were significantly prolonged in the upper and lower limbs. Sympathetic skin response was absent in four patients and R-R variation was subnormal in ten patients. Nerve conduction parameters showed correlation with increasing age and hyperglycemia values. Conclusion: Patients with newly detected diabetes have high incidence of clinically manifest and subclinical peripheral neuropathy.