Early Detection of Diabetic Peripheral Neuropathy Using Nerve Conduction Studies

Abstract

Diabetic Peripheral Neuropathy (DPN) is one of the most common complications of diabetes mellitus. It is characterized by progressive damage to peripheral nerves, resulting in sensory disturbances, pain, numbness, muscle weakness and, in advanced cases, diabetic foot ulcers and amputations. Early stages of neuropathy may remain asymptomatic, making timely diagnosis challenging. Nerve Conduction Studies (NCS) provide an objective method of assessing peripheral nerve function and may identify electrophysiological abnormalities before significant clinical manifestations develop. Aim: To evaluate the role of nerve conduction studies in the early detection of diabetic peripheral neuropathy and to compare electrophysiological parameters between patients with type 2 diabetes mellitus and healthy individuals. Materials and Methods: A proposed hospital-based observational cross-sectional study included 100 patients with type 2 diabetes mellitus and 50 age- and sex-matched healthy controls. Detailed clinical histories, neurological examinations and biochemical investigations, including fasting blood glucose and glycated haemoglobin (HbA1c), were obtained. Nerve conduction studies were performed on selected motor and sensory nerves of the upper and lower limbs. Parameters assessed included distal motor latency, compound muscle action potential amplitude, sensory nerve action potential amplitude and motor and sensory conduction velocities. Results: In the illustrative dataset, 32% of diabetic participants demonstrated electrophysiological abnormalities suggestive of peripheral neuropathy despite having no obvious clinical manifestations. Reduced sensory nerve action potential amplitude, decreased conduction velocity and prolonged distal latencies were observed more frequently among diabetic participants than healthy controls. Lower-limb sensory nerves, particularly the sural nerve, demonstrated prominent abnormalities. The frequency of abnormalities was higher among patients with longer diabetes duration and poorer glycaemic control. Conclusion: Nerve conduction studies can provide objective evidence of large-fibre peripheral nerve dysfunction and may help identify subclinical diabetic neuropathy. Incorporating appropriate electrophysiological assessment alongside routine clinical screening may improve the recognition of early nerve damage in selected patients with diabetes mellitus.