Posterior femoral cutaneous nerve conduction

The posterior femoral cutaneous nerve is a sensory nerve comprised of fibers originating from the anterior and posterior divisions of the first three sacral segments. It exists the pelvis distal to the piriformis muscle and proceeds distally, superficial to and between the medial and lateral hamstring musculature. The nerve's major cutaneous distribution is the posterior aspect of the thigh and a variable area of the posterior calf. An electrophysiologic technique to assess the peripheral axons of the posterior femoral cutaneous nerve is described. A recording electrode is placed 6cm proximal to the midpopliteal fossa and the nerve is stimulated supramaximally 12cm proximally on a line between the active electrode and the ischial tuberosity. A ground electrode is placed just proximal to the active recording electrode. The lower extremities of 40 individuals with a mean age of 34 years (20 to 78 years) were examined. The mean peak latency of the response is 2.8 (2.3 to 3.4) msec +/- 0.2msec with a mean amplitude of 6.5 (4.1 to 12.0) microV +/- 1.5 microV. This technique may facilitate the proximal evaluation of lower extremity peripheral neuropathies, lesions of the posterior femoral cutaneous nerve, or the assessment of the peripheral nervous system in persons with lower extremity amputations.     

神经传导速度在多系统萎缩诊断中的实用价值探讨

目的:探讨周围神经运动传导功能电生理检测在诊断多系统萎缩中(MSA)的实用价值。方法:回顾性分析2004年11月至今本院神经科诊断明确的45例帕金森病(PD)患者和29例MSA患者的神经电生理检测结果,包括双上肢正中神经和双下肢腓神经的运动传导功能及肛门括约肌肌电图(EMG),研究周围神经传导功能评定与MSA及其亚型诊断、病程、首发症状间的关系。结果:与PD组相比,MSA组腓神经末梢潜伏期延长,神经传导速度减慢;而MSA组不同类型患者间比较,橄榄脑桥小脑萎缩(OPCA)组较Shy-Drager综合征(SDS)组正中神经传导速度减慢,腓神经潜伏期延长,纹状体黑质变性(SND)组正中神经远端潜伏期延长;联合肛门括约肌EMG检查后,MSA组电生理异常率增加27.6%;周围神经传导异常组的疾病病程较神经传导正常组短,以上差异均具统计学意义(P<0.05)。结论:MSA患者具有周围神经受损的亚临床电生理改变,不同亚型和不同病程累及程度有所不同,神经传导功能检测联合肛门括约肌EMG能提高临床诊断MSA的特异度。     

2型糖尿病患者运动及感觉神经传导速度变化与C肽的关系

目的:探讨2型糖尿病患者运动神经传导速度(motornerveconductionvelocity,MNCV)和感觉神经传导速度(sensorynerveconductionvelocity,SNCV)的变化与C肽水平的关系,为防治糖尿病周围神经病变提供理论依据。方法:回顾性分析73例2型糖尿病患者的MNCV和SNCV与C肽释放试验中糖负荷前及糖负荷120minC肽水平的关联性。结果:2型糖尿病患者的MNCV及SNCV正常者和异常者的下降与糖负荷120minC肽水平下降有关(t=23.15～35.46,P<0.01),与糖负荷前C肽水平下降无关(t=0.47～1.63,P>0.05)。结论:C肽水平下降可能会加速神经传导速度的下降,提示保持血中C肽水平,有可能延缓周围神经病变的进展。