| Objective:To study the features of the diabetic neuropathy(DN) according to the contact heat evoked potential (CHEP), and analyze the function of cranial nerve, spinal nerve, large and small fibres in patients with diabetes mellitus(DM) combine with general electroneurogram. In order to investigate the probably ascendency of CHEP.Methods:Heat stimuli was delivered to four body sites of 50 diabetic patients and 40 healthy subjects:right peroneal area, forearm, the lower perioral skin and above the eyebrow. The N-P amplitudes and N wave latencies of CHEP was recorded at the vertex (Cz). Meanwhile BR and direct electrical stimulation of the facial nerve were performed. The visual analog scale(VAS), SSR, sensory and motor nerve conduction of limbs were performed in all patients too.The BR, NCS, CHEP were used to evaluate the function of large and small fibers of cranial and spinal nerves respectively, we calculate the ratio of R/D(the latency of R1/the latency of direct electrical stimulation).The nerve conduction velocity, distal latency and amplitude of action potential were also recorded. The patients were divided into the NCSN group and the NCSA group, the SSRN group and the SSRA group according to the results of the nerve conduction and SSR.Results:1. The N wave latencies of CHEP in diabetic group and the control group were (x±s):372.62±32.11 vs 354.26±25.58ms,381.59±31.84 vs 343.10±18.23ms(all P<0.01); The N-P amplitudes were [M(Q)]:42.85(34) vs 59.00(25)μv,42.51(12.8) vs 65.40(39.3)μv in the perioral and the eyebow we detected(all P<0.01).The visual analog scale(VAS) of the two sites were [M(Q)]:4.56(1) vs 5.67(1); 4.82(2) vs 6.03(2) (Z=3.078, P=0.002). The CHEP latency ratio of eyrbow/perioral in DM group and that in control group were 1.03(0.09),0.97(0.08) (Z=3.078, P=0.002).There were no statistical differences between the abnormal rates of BR, the latencies of R1, R2, R2', numerical value of D and R/D ratio in two groups (P>0.05).2. The N wave latencies of CHEP in diabetic group and the control group were 474.68±42.74 vs 447.03±11.51 ms,424.28±46.34 vs 405.45±8.91 ms(all P<0.01); The N-P amplitudes were 42.85(34) vs 59.00(25)μv,42.51(12.8) vs 65.40(39.3)μv in the forearm and the peroneal (all P<0.01).The VAS of the two sites in diabetic group were:2.92(2),3.93(1), the control group were 4.38(1),5.28(1) (all P=0.000). The CHEP amplitude ratio of upper limb/lower limb in DM group and that in control group were 1.03(0.09),0.97(0.08) (Z=2.021, P=0.043).3. Compared with the control group, the NCSA group has a longer latency and a smaller logarithm of amplitude at the forearm, the logarithm of amplitude of the NCSN group was diminished too (P<0.05).At the peroneal area, the latency of the NCSA and the NCSN group was longer, the logarithm of amplitude was smaller.The logarithm of the NCSA group was smaller than the NCSN group (P<0.05).4. The CHEP of cranial nerve compared with the NCS of the spinal nerve:The NCSA group has a longer latency and a smaller logarithm of amplitude than the control group at the perioral skin(all P<0.01). Compared with the control group, the latency of the NCSA group at the eyebow was longer and the logarithm of amplitude was smaller,as soon as the latency of the NCSN group (all P<0.01).5. In all stimulate sites, the latency of the SSRA group was longer than the control group, the logarithm of amplitude was smaller (all P<0.01). At the eyebow and peroneal, the SSRN group has a longer latency and a smaller logarithm than the control group.When stimulate the eyebow, the latency of the SSRA group was longer than the SSN (P<0.05). Compared with the SSRN group, SSRA group had a smaller logarithm of amplitude at the forearm and the peroneal(P<0.01 or P<0.05).Conclusion:DN can involved cranial, spinal nervs, large and small fibres. DM small fibre dysfunction of cranial and spinal nerves may happened before the electrophysiological evidence of the large fibre or sympathetic C fibre was foud. CHEP maybe has special dominances relative to BR, NCV, SSR in evaluating DN. |
PDF Full Text Request