Hasegawa Osamu
Department of General Medicine, Yokohama City University Medical Center, 4-57 Urafune-cho, Minami-ku, Yokohama 232-0024, Japan.
Brain Nerve. 2009 Mar;61(3):255-62.
The use of microneurography for recording of the compound nerve action potentials enables a more accurate evaluation of even severe cases of diabetic polyneuropathy. A tungsten microelectrode with a tip diameter of approximately 1 microm is percutaneously inserted into the median nerve trunk in the elbow without the administration of anesthesia. The median nerve in the wrist is subiected to supramaximal electric stimulation, and the largest compound nerve action potential is recorded by the microelectrode. In healthy controls, the median nerve action potential appeared as a large triphasic wave (positive-negative-positive; average amplitude, 400 microV) followed by small multiphasic waves. In diabetic patients, the maximal nerve conduction velocity (NCV) and the amplitude of the triphasic wave (Amp) were decreased, and the multiphasic waves were more prominent. The reproducibility of the compound nerve action potentials in the same subject was acceptable. Diminution of Amp appeared to be associated with temporal dispersion due to segmental demyelination. In diabetic polyneuropathy, NCV and Amp decrease with disease progression. In patients with advanced disease and subjective symptoms, low Amp and prominent multiphasic waves were apparent. Because a recording microelectrode is directly inserted into the nerve trunk, this method has many advantages: large potentials measuring several hundred microvolts can be obtained, averaging is not required, and quantitative analysis of the nerve action potential and evaluation of slow fibers are possible. This compound nerve action potential is considered to represent the density of large myelinated fibers (7 microm), especially sensory fibers, around the electrode. This technique may evaluate nerve function more accurately than that of "near-nerve recording of action potentials", a technique reported by Buchthal et al. This method can be a valuable tool for evaluating the function of large myelinated fibers without the use of time-consuming averaging procedures or computer analysis.
使用微神经ography记录复合神经动作电位能够更准确地评估甚至是严重的糖尿病性多发性神经病病例。将尖端直径约为1微米的钨微电极经皮插入肘部的正中神经干，无需麻醉。对腕部的正中神经施加超强电刺激，并用微电极记录最大复合神经动作电位。在健康对照者中，正中神经动作电位表现为一个大的三相波（正-负-正；平均振幅，400微伏），随后是小的多相波。在糖尿病患者中，最大神经传导速度（NCV）和三相波的振幅（Amp）降低，多相波更明显。同一受试者复合神经动作电位的可重复性是可以接受的。Amp的降低似乎与节段性脱髓鞘导致的时间离散有关。在糖尿病性多发性神经病中，NCV和Amp随疾病进展而降低。在疾病晚期和有主观症状的患者中，低Amp和明显的多相波很明显。由于记录微电极直接插入神经干，这种方法有许多优点：可以获得几百微伏的大电位，无需平均，并且可以对神经动作电位进行定量分析以及评估慢纤维。这种复合神经动作电位被认为代表电极周围大的有髓纤维（7微米）的密度，尤其是感觉纤维。与Buchthal等人报道的“动作电位的近神经记录”技术相比，这种技术可能更准确地评估神经功能。这种方法可以成为评估大的有髓纤维功能的有价值工具，而无需使用耗时的平均程序或计算机分析。
