Electromyography and nerve conduction velocity study in diabetic patients without clinical signs of peripheral neuropathy

ABSTRACT

The aim of the present study was to evaluate the functional state of peripheral nerve [motor and sensory] conduction velocity before the occurrence of subjective or objective manifestations of peripheral neuropathy in diabetic patients. Clinical and laboratory findings and electrophysiological studies were assessed in forty diabetic patients as well as to healthy subjects. They were classified into three groups Group I Insulin required diabetes mellitus [IRDM] [20]. Group] II Non Insulin dependent diabetes mellitus [NIDDM] and Group III Control [10] healthy subjects. All patients of both groups had no clinical symptoms or signs suggesting peripheral neuropathy. The laboratory tests included estimation of the levels of the fasting blood glucose, 2 hours postprandial and glycosylated haemoglobin. The electrophysiological procedures done were estimation of MNCV of the median and the common peroneal nerves and SNCV of the median and sural nerve. The electromyographic examination revealed polyphasic changes in 5% of the cases in group I, while in group II it was present in 20% of cases. The mean value of the MNCV of both median and common peroneal nerves were significantly lower in both studied groups as compared with the healthy control. The mean value of SNCV of both median and sural nerves were significantly lower in both studied groups as compared with healthy control. The pathogenetic mechanism of diabetic neuropathy remains unclear since many factors have been implicated. The theory of metabolic derangements associated with diabetes mellitus as a cause of abnormal conduction velocity has received a substantial support. It can be finally concluded that the results of EMG, MNCV and SNCV measurements in our diabetic patients without clinical symptoms or signs seem to be mandatory for the detection of early cases of subclinical neuropathy