Study Of Electrical Diagnosis Of The Peripheral Nerve In Patients With Pre-diabetes Mellitus

ObjectiveTo evaluate the function of peripheral nerve by nerve conduction study(NCS), skin sympathetic response(SSR) and contact heat evoked potential(CHEP) in patients with early diabetes mellitus (eDM) and impaired glucose tolerance(IGT), In order to investigate the characteristics of the peripheral nerve dysfunction in patients with abnormal glucose metabolism.MethodsA total of100patients with eDM and50patients with IGT,were consecutively enrolled into the study.50age-matched healthy subjects were also studied. NCS of median nerve,ulnar nerve,posterior tibial nerve and common peroneal nerve were performed in all enrolled subjects,respectively.SSR test and CHEP were also performed in all enrolled subjects.Thermal stimuli sites of CHEP:right forearm and right peroneal area. CHEP were recorded from Cz.N-P amplitude and N latency of CHEP were observed.ResultsThere was no difference between the IGT group and normal group when compared the SCV, SNAP, DML,CMAP of median nerve,ulnar nerve,posterior tibial nerve and common peroneal nerve(P>0.05). When compared with control group,the lower limb SSR amplitude of the IGT group was significantly decrease(P<0.05). There was no difference of the SSR latency between two groups(P>0.05).32cases of the eDM group was detected abnormal NCS,inrolled in the DM-NCN group.SSR latency had no difference(P>0.05). SSR amplitude of lower limb were significantly low in DM-NCN group when compared with control group(P<0.05),N latency were significantly long (P<0.05).. SSR amplitude and latency in forearm and in peroneal area of two groups had no difference(P>0.05).N-P amplitude in forearm and in peroneal area were significantly low in IGT group when compared with control group(P<0.05),N latency had no difference(P>0.05). N-P amplitude in forearm and in peroneal area were significantly low in DM-NCN group when compared with control group(P<0.05),N latency were significantly long (P＜0.05). N-P amplitude and N latency in forearm and peroneal area of two groups had no difference(P>0.05).Conclusions1.Patients with IGT presist peripheral nerve damage, characterized by small fiber involvement.2.1n patients with eDM large and small nerve fibers all can be involved, large fiber be involved first then small fiber involved. Dysfunction of nerve fiber areeorrelated with the length of nerve which is similar with IGT patients but server than IGT patients.3.Electrophysiological diagnostic methods have an important value for the discovery the peripheral nerve damage in IGT and diabetes, SSR and CHEP is in great value in discovery of a small fiber damage, CHEP is more sensitive than the SSR.