| Objective: To analyze the dysfunction of large and small fibers of peripheral nerves in patients with diabetes mellitus according to the current perception threshold(CPT)combining with nerve conduction studies(NCS) and sympathetic skin response(SSR).In order to investigate the potential advantages of CPT.Methods: CPT was performed in 50 patients with diagnosed type 2 diabetes mellitus(T2DM)and 36 healthy subjects. Electrical stimulations of 2000 Hz、250 Hz and 5 Hz three different frequencies were delivered respectively to the first toe distal section, the bottom of the knee- patella middle line and the index finger distal section.The three parts belong to the same side of body. The NCS of limbs and SSR were performed in all patients,too.The NCS and SSR were used to evaluate the function of large and small fibers of peripheral nerves. The patients were divided into NCSN group and NCSA group according to the results of the nerve conduction. According to the results of SSR,the patients were divided into SSRN group and SSRA group,too.Results:1. Comparing the DM group with control group,the CPT increased significantly in three testing areas,which tested by the currents of 2000 hz and 250 hz,5 hz frequency. The CPT of first toes distal section(electrical stimulations of 2000 Hz,250 Hz and 5 Hz three different frequencies) in DM group and control group(x?s): 381.80?50.88vs287.35?32.50,194.60?26.51vs127.26?15.65,156.90?24.33vs70.87?16.66, the difference were statistically significant(P < 0.01). The CPT of bottom of the knee- patella middle line(electrical stimulations of 2000 Hz、250 Hz and 5 Hz three different frequencies)in DM group and control group(x?s): 210.80?30.57vs149.00?18.98,88.95?14.15vs52.70?7.86,74.25?9.39vs38.39?4.45,the difference were statistically significant(P < 0.01).The CPT of the index finger distal section(electrical stimulations of 2000 Hz,250 Hz and 5 Hz three different frequencies) in DM group and control group(x?s): 261.55?27.39vs230.35?26.96,105.15?13.45vs94.74?10.16,70.85?10.11vs48.30?5.54, the differences were statistically significant(P < 0.05).2. In DM group, the nerve conduction normal group(NCSN group) contained 20 cases, accounting for 40% of the total number in DM group. In DM group, nerve conduction abnormalities(NCSA group) contained 30 cases, accounting for 60% of the total number in DM group. In NCSA group, 14 cases of upper limb nerve conduction abnormality, DM group accounted for 28% of the total cases, 30 cases of lower limb nerve conduction abnormality, DM group accounted for 60% of the total cases, visible nerve conduction abnormality rate of lower extremity was greater than the upper limb, the difference was statistically significant(P=0.000); 14 cases of upper limb sensory nerve conduction abnormalities in DM group, accounting for 28% of the total cases, 2 cases of upper limb motor nerve conduction abnormality in DM group, accounted for 4% of the total cases, the sensory nerve conduction abnormalities rate of the upper limb was greater than the motor nerve conduction abnormalities rate of the upper limb, the difference was statistically significant(P=0.001); 30 cases of lower extremity sensory nerve conduction abnormality in DM group,accounted for 60% of the total cases, 4 cases of lower limb motor nerve conduction abnormality in DM group,accounted for 8% of the total cases, the sensory nerve conduction abnormality rate of the lower limb was greater than the motor nerve sensory nerve conduction abnormality rate of the lower limb, the difference was statistically significant(P=0.000).3. In DM group,the three testing areas were respectively test by the currents of 2000 hz,250 hz and 5 hz frequency. NCSN group compared with control group, there was no statistically significant difference(P > 0.05).Comparing the NCSA group with control group, CPT increased, and the differences were statistically significant(P < 0.05).Comparing the NCSA group with the NCSN group, CPT increased, and the differences were statistically significant(P < 0.05).4. In DM group, the SSR normal group(SSRN group) contained 16 cases, accounting for 32% of the total number of patients in DM group, SSR abnormal group(SSRA group) contained 34 cases, accounting for 68% of the total number in DM group. There were 34 cases of SSR abnormal in the lower limb(68% in DM group), 10 cases of SSR abnormal in the upper limb(20% in DM group), and the SSR abnormality rate of the lower limb was greater than the one of the upper limb, the difference was statistically significant(P=0.000).5. In DM group,the results were compared SSRN group with control group.CPT decreased in the first toes distal section,which tested by the currents of 250 hz and 5 hz frequency,and the differences were statistically significant(P< 0.05),however,there were no differences in both the index finger distal section and the knee- patella middle line(P > 0.05).CPT were no differences in three testing areas,which tested by the currents of 2000 hz(P > 0.05).Comparing SSRA group with control group,CPT increased significantly in three testing areas,which tested by the currents of 2000 hz and 250 hz, 5 hz frequency(P < 0.05).The results were compared SSRA group with SSRN group.CPT increased significantly in three testing areas,which tested by the currents of 250 hz and 5 hz frequency(P < 0.05). CPT increased significantly in the first toes distal section,which tested by the current of 2000 hz frequency(P = 0.000),however,there were no differences in both the index finger distal section and the knee- patella middle line(P > 0.05).Conclusion: CPT can be used to evaluate the dysfunction of large and small fibers of peripheral nerves in patients with diabetes mellitus.When SSR is normal, small fibers of diabetic peripheral nerves in the toe distal skin test area can be found in hypersensitivity.CPT maybe has the unique advantages in evaluating small fibers neuropathy.However,comparing CPT with NCS,there were no obvious advantages for evaluation of diabetic peripheral nerve large fiber damage. |
PDF Full Text Request