Evaluation Of The Value Of The Clinical Diagnosis Methods In Diabetic Peripheral Neuropathy

Objective There are many different diagnosis methods of diabetic peripheral neuropathy which with very complex clinical manifestation, however, in the clinical application aspect, they can't reach coincidence. Using the results of the nerve conduction velocity examination as golden criteria, assess the efficacy of neuropathy symptom score/neuropathy disability score (NSS/NDS), Michigan Neuropathy screening instrument (MNSI), Toronto clinical scoring system (TCSS) in the diagnosis of diabetic peripheral neuropathy.Methods 188 patients, with type 2 diabetes mellitus, were examined by NSS/NDS, MNSI, TCSS. Using the results of the nerve conduction velocity examination as golden criteria, the sensitivity, specificity, the ROC curve and accuracy of these examinations were analyzed among the scales or scores mentioned above. All of patients finished the laboratory examinations of blood routine,blood pressure, blood fat, glucated hemoglobin, liver and kidney function, then body mass index(BMI) were measured, an urite color ultrasonic diagram, electrocardiogram and Cranial Computed tomography were carried out. Group t test was made to all data, as well as Wilcoxon signed rank test,χ2 test.Results 1.Among the 188 patients with type 2 diabetes mellirus,111 cases are in the DPN group and the 77 cases are in the group without DPN. Compared with the group without DPN, the DPN group had significantly higher age, course of diabetes, contractive blood pressure, diastolic blood pressure, glucated hemoglobin, triglyceride, cholesterol, scores in NSS/NDS,MNSI and TCSS(P<0.01), but they had significantly lower motor nerve conduction velocity of median nerve, ulnar nerve, peroneus nerve, tibial nerve,as well as sensory nerve conduction velocity of median nerve, ulnar nerve, sural nerve (P<0.01), except body mass index(BMI)(P>0.05).2.The scores in NSS/NDS,MNSI and TCSS were significant negatively associated with the motor nerve conduction velocity of median nerve, ulnar nerve, peroneus nerve, tibial nerve,as well as sensory nerve conduction velocity of median nerve, ulnar nerve, sural nerve(P<0.01);choosing 2,.2.5 or 3 as the cut-off point of MNSI,MNSI score that over or equal to 2.5 had a moderate correlation with the nerve conduction velocity examination(P<0.01); when TCSS score over or equal to 5, TCSS had the best correlation with the nerve conduction velocity examination(P<0.01).3.MNSI, TCSS had higher consistency with the nerve conduction velocity examination than NSS/NDS(kappa were 0.524,0.547,0.534, respectively).Compared with the diagnosis between MNSI score that over or equal to2,5 and TCSS score that over or equal to 5 or 6, the difference ad not reach stathistical significance(P>0.05). 4. The area under the ROC curve of NSS/NDS, MNSI, TCSS were 0.579,0.794,0.814, respectively, and 95%CI were 0.523～0.654,0.728～0.861, 0.751～0.876(P<0.05).the accuracy for diagnosis in MNSI and TCSS were moderate, however, NSS/NDS was lower. Using the formula to compare the area under the ROC curve between MNSI and TCSS, there is no significant difference(z=1.521, P>0.05).5.The average time for completing three scoring methods:NSS/NDS,MNSI, TCSS score needed 11.37±0.86 minutes,5.51±0.92 minutes,16.23±1.01 minutes, respectively, which implied that it need shorter time to complete MNSI, and longest time to complete TCSS.6. According to the patients with or without clinical symptom, all the patients were divided into two groups:asymptomatic group(81 cases, account for 43.1%) and symptomatic group(107 cases, account for 56.9%).In the asymptomatic group, the positive rate in the diagnosis of DPN was different between MNSI and NSS/NDS, the same as TCSS and NSS/NDS, NCV and NSS/NDS(P<0.05), but others were not significant different(P>0.05).In other words, in the diabetic patients without clinical symptom, the positive rate in the diagnosis of DPN in MNSI,TCSS,NCV were higher than NSS/NDS. In the symptomatic group, there was no obvious statistic difference (P>0.05).Conclusions 1. NSS/NDS, MNSI, TCSS had a better correlation with the nerve conduction velocity examination, but among the three scoring methods, TCSS score is the best. MNSI, TCSS had a higher consistency with the nerve conduction velocity examination and higher accuracy than NSS/NDS. 2 To compare MNSI with TCSS, the two value of the diagnosis had no obvious difference. However, the advantage of MNSI score lie in that it was relatively simple to operate, and need short time to finish. Relatively, TCSS was tedious to operate, and need longer time to finish.3.MNSI score over or equal to 2.5 had a better correlation, consistency with the nerve conduction velocity examination, and the sensitivity, specificity, positive predictive values, negative predictive values, Youden index and correct rate in diagnosis of DPN were comparatively ideal. the sensitivity, correct rate, Youden index and kappa value of TCSS score over or equal to 5 for diagnosis of DPN were better.