Objective: Peripheral neuropathy is one of the most common major complications of DM. It affects about 50% of diabetic patients. Dysautonomia is a special form of diabetic neuropathy that occurs in about 30% of diabetic patients. This study aimed to find a correlation between peripheral, somatosensory and autonomic system study and clinical scoring in diabetic patients. Methods: This study included 50 diabetic patients having type 2 DM with clinically manifest diabetic neuropathy (CMDN), 20 type 2 DM without (CMDN), and 20 normal subjects. The diabetic patients with (CMDN), were subgrouped according to the Michigan Diabetic Neuropathy Score (MDNS) into three subgroups: mild Ia, moderate Ib and severe Ic neuropathy. Nerve conduction studies of median, common peroneal, and sural nerves were done for every one. Needle electromyography of right abductor pollicis brevis was done. Median nerve and tibial nerve somatosensory evoked potentials were performed to all patients and the control subjects. Results: Median, peroneal and sural nerves studies of different groups revealed significant difference at P<0.05. Posthoc test showed that the means of subgroups Ib and Ic were significantly higher compared to the other groups. Somatosensory evoked potential study revealed delayed N9, N13, N20, P31, P37 latencies and N9-N13 interpeak latency were significantly higher in subgroups Ib and Ic. Significant correlations were found between (MDNS score, duration of DM, PP blood glucose and glycated hemoglobin) and each of N9, N13, and N20, LP, P31 and P37 latencies. Also, significant correlations were found between (MDNS score, duration of DM, PP blood glucose and glycated hemoglobin) and each of autonomic tests of resting heart rate, sinus arrhythmia ratio, Valsalva ratio and QTc. Conclusion: DM affects conductive function in the central as well as peripheral pathways, with good predictive and correlative value of applied MDNS.
(Egypt J. Neurol. Psychiat. Neurosurg., 2004, 41(2): 559-568).