Nerve conduction study in neurologically asymptomatic diabetic patients and correlation with glycosylated hemoglobin and duration of diabetes

Abstract

Background: Diabetes-induced neuropathy is one of the most challenging complications of diabetes mellitus (DM). Large number of patients has subclinical neuropathy at the time of detection of diabetes. Nerve conduction studies (NCS) remain the most reliable, accurate, and sensitive measure of peripheral nerve function. The study of F waves is particularly useful for the diagnosis of peripheral neuropathy. Aims and Objectives: The present study was conducted to study various nerve conduction parameters in neurologically asymptomatic diabetic patients with an attempt to evaluate their value in the early detection of subclinical diabetic neuropathy and to find out if any correlation exists. Materials and Methods: This case–control study was carried out on 44 neurologically asymptomatic established patients of Type II DM of both sexes, aged 40–60 years attending the medicine outpatient department (OPD). NCS parameters of various nerves were studied. Blood sugar and glycosylated hemoglobin (HbA1c) were determined. Results: A longer latency, smaller amplitude and slower conduction velocity were found in all the nerves. Persistence was found to be lower and F-wave minimum latency prolonged amongst the cases. Sensory and motor NCS were found to be inferior in those with higher HbA1c. Latency, amplitude, and Nerve conduction velocity (NCV) of sural nerve showed deterioration with the duration of diabetes. All parameters of median, ulnar and common peroneal nerves showed deterioration with the duration of diabetes with the exception of NCV in common peroneal nerve and persistence in median nerve. Conclusions: NCS parameters are valuable for identification and future prediction of diabetic peripheral neuropath.