Comparing sural/radial amplitude ratio and minimal F-wave latency to conventional nerve conduction studies for the evaluation of sensitive nerve conduction parameters in type 2 diabetic patients with sensorimotor polyneuropathy

Introduction: Measurement instruments used to evaluate neuropathy include several questionnaires, Biothesiometry, monofilament testing, and nerve conduction studies (NCS), the gold standard test. The purpose of this research is to develop a straightforward diagnostic procedure for the early diagnosis of diabetic peripheral neuropathy (DPN) by comparing the diagnostic accuracy of minimum F-wave latency and sural Radial Amplitude Ratio (SRAR) to that of traditional NCS. Material and methods: This was a cross-sectional observational research conducted on 82 patients. Every patient had type 2 diabetes, with an average of 5.95 ± 4.85 years of diabetic control. The patients were then split into three groups: those with an HbA1c of less than 7.5%, those with an HbA1c of between 7.5 and 8.5%, and those with a HbA1c of more than 8.5%. Research on the nerve conduction of the tibial, Peroneal, sural, superficial radial, median, and ulnar nerves was included. The nerves were stimulated with supramaximum intensity 0.1 ms electric pulses in order to produce the highest possible amplitude of sensory nerve action potentials (SNAPs) and CMAPs. P-values < 0.05 were considered significant. Results: When comparing the motor conduction velocity (MCV) of the ulnar, tibial, and median nerves to their respective F-wave latencies, the Z-score for CMAP amplitude was higher in all four motor nerves. In all four motor nerves, there was a significant relationship between MCV and the Z scores for low F-wave delay. Abnormal minimum F-wave latencies were seen in 69, 58, 18, and 22% of the nerves with normal MCV (the median, ulnar, tibial, and Peroneal nerves, respectively). Regular nerve conduction data showed that all groups showed a pattern of solely sensory involvement with a notable decrease in SNAP amplitudes but no change in nerve conduction velocities. Conclusions: Electrophysiologic investigations of diabetic polyneuropathy should take into account minimal F-wave delay and the ratio between the amplitudes of the sural and superficial radial sensory nerve action potentials. These are sensitive markers for the diagnosis of nerve damage.