丙酸睾酮对萃取神经修复大鼠坐骨神经缺损的促进作用

目的 观察丙酸睾酮对甘油萃取神经修复大鼠坐骨神经缺损的促进作用.方法 取SD大鼠60只,手术造成左侧坐骨神经1 cm缺损.每组20只.A组:甘油萃取的坐骨神经修复左侧缺损并注射丙酸睾酮(TP)50 g/L,0.1 ml,2次/周;B组仅以甘油萃取的坐骨神经修复缺损;C组以同种异体神经修复.术后16周,比较各组运动神经传导速度恢复率(RRMNCV)和腓肠肌复合动作电位波幅恢复率(RRCMAP);再生有髓神经纤维计数恢复率(RRMFP)及患侧小腿三头肌湿重/健侧小腿三头肌湿重率(ITSWW/UTSWW).结果 术后16周,A、B、c三组RRMNCV分别为(59.06±10.33)%、(45.80±9.05)%、(23.45±4.60)%;RRCMAP分别为(76.64±5.01)%、(64.55±4.20)%、(20.44 ±3.82)%;RRMFP分别为(79.11±2.55)%、(63.67±4.97)%、(29.76±5.68)%;ITSWW/UTSWW分别为(70.37±9.54)%、(56.77±6.08)%、(33.75±7.89)%,三组比较差异有统计学意义(P<0.05).结果 说明A组修复效果最好,B组次之,C最差.结论 丙酸睾酮对甘油萃取神经修复大鼠坐骨神经缺损具有促进作用.     

失神经支配红白肌肉早期运动神经营养活性研究

目的了解失神经支配后红白肌肉内脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)早期含量变化及相应运动神经传导功能恢复情况,探讨靶器官对损伤运动神经再生修复的作用. 方法 Wistar大鼠40只,平均分为5组,其中1组为对照,其余4组剪断双下肢坐骨神经制作肌肉失神经支配模型,分别于神经损伤后1、3、7和14天采用免疫组织化学方法检测肌肉内BDNF含量.另取15只Wistar大鼠,钳夹双下肢坐骨神经制作失神经支配肌肉神经再生模型,于伤后7天和14天采用神经电生理方法测定神经传导速度及肌电图. 结果比目鱼肌(soleus,SOL)失神经支配后1、3和7天BDNF含量较对照组大幅度升高,差异有统计学意义(P＜0.01),但随时间推移呈下降趋势,14天BDNF含量与对照组接近(P＞0.05);腓肠肌(gastrocnemius,GAS)失神经支配后1、3、7和14天BDNF含量与对照组均接近(P＞0.05).失神经支配肌肉神经再生模型中,伤后7天失神经支配SOL和GAS均未测到动作电位;伤后14天支配GAS和SOL的运动神经传导速度分别恢复至正常值的(36.60±7.40)%和(42.50±3.50)%,二者差异无统计学意义(P＞0.05);GAS M波波幅恢复至正常值的(19.9±6.4)%,而SOL M波波幅恢复至正常值的(13.7±4.0)%,二者差异无统计学意义(P＞0.05). 结论失神经支配红、白肌肉内早期运动神经营养因子含量在不同时间内发生不同的变化,但支配两种靶器官的损伤运动神经功能恢复相近.失神经支配后靶器官的运动神经营养活性是其内部各种运动神经营养因子综合作用的结果.     

神经束膜吻合术与神经外膜吻合术治疗尺神经损伤的效果比较

目的比较神经束膜吻合术和神经外膜吻合术治疗腕部尺神经损伤的效果。方法将80例腕部尺神经断裂伤患者按治疗方法分为神经束膜吻合组(42例)与神经外膜吻合组(38例)。比较两组患者术后尺神经传导速度、复合肌肉动作电位波幅和临床疗效。结果患者均获得12个月随访。术后3、6、12个月,尺神经传导速度、复合肌肉动作电位波幅神经束膜吻合组明显优于神经外膜吻合组(P 0.001)。术后12个月临床疗效优良率神经束膜吻合组(81.0%)高于神经外膜吻合组(47.4%)(P 0.05)。结论神经束膜吻合术治疗腕部尺神经损伤的效果优于神经外膜吻合术。     

扩张延长对周围神经影响的实验研究

目的 探讨三种不同容量组织扩张器（ｔｉｓｓｕｅ ｅｘｐａｎｄｅｒ，ＴＥ）扩张的神经及去扩张器神经松弛的后的神经长度、肌电图和组织学的变化及其变化机制。方法 ＳＤ大鼠３２只，分为４组，每组８只大鼠。第１～３组为实验组，用ＴＥ以不同容量（８天内分别注水２ｍｌ、４ｍｌ、８ｍｌ）延长大鼠右侧坐骨神经，１０ｄ后取向ＴＥ，测量神经长度，使神经处于松驰状态。３０ｄ后，左侧坐骨神经以同样方法进行延长。１０ｄ后取出左侧ＴＥ，测量右侧神经松驰后长度，对双侧进行肌电图和组织学检测，并与正常对照组（８只大鼠）的结果进行比较。结果 （１）神经长度，在延长期末各组均有延长，松驰期末又均有回缩。（２）运动神经传导速度（ＭＮＣＶ）、复合肌肉动作电位（ＧＭＡＰ）的波幅，在延长期末各组均有衰降，松驰期末均有回升。（３）２ｍｌ组延长期末神经组织学的     

几丁糖胶原复合膜及激活态雪旺细胞修复周围神经缺损的实验研究

目的研究几丁糖胶原复合膜、激活态雪旺细胞(activatedSchwanncell,ASC)促进周围神经再生的作用。方法将激活态雪旺细胞培养于几丁糖胶原复合膜后,将膜缝制成导管修复大鼠坐骨神经10mm的缺损(D组);并以自体神经移植(A组)、几丁糖胶原复合膜管(B组)及几丁糖胶原复合膜加脑源性神经营养因子[(brainderivedneurotrophicfactor,BDNF)C组]为对照。术后4、8、12周观察肢体运动,复合肌肉动作电位(CMAP)的波幅、潜伏期和运动神经传导速度(MNCV)。术后12周取材,样本染色观察神经轴突再生情况。结果几丁糖胶原复合膜加激活态雪旺细胞修复10mm神经缺损的效果优于几丁糖胶原复合膜加BDNF,与自体神经相似。结论几丁糖胶原复合膜加激活态雪旺细胞能有效地促进周围神经再生。     

兔坐骨神经高压电损伤后早期电生理改变的实验研究

目的 研究家兔坐骨神经高压电损伤后早期电生理的变化规律。方法 新西兰家兔48只,分成2组。实验组40只,以1万V高压电电击右下肢,于伤后即刻、3、7、14、21d共5个时间组检测实验兔右下肢的肌电图（EMG）、运动神经传导速度（MNCV）、复合肌肉电位（CMAP）和皮层体诱发电位（SEP）。正常对照组8只家兔不作任何处理。结果 20只兔右侧坐骨神经的MNCV、CMAP、SEP在伤后3d全部测不出,提示为完全损伤。20只兔随伤后时间的推移,坐骨神经的MNCV逐渐减慢;CMAP和SEP的潜伏期逐渐延长,波幅逐渐降低。提示为不全损伤。两者肌电图失神经电位的变化则相似。结论 家兔坐骨神经被高压电击伤后早期的肌电图神经电图改变呈进行性加重。     

犬化学去细胞神经同种异体移植的神经电生理研究

目的　以化学去细胞同种异体坐骨神经 ,移植修复犬坐骨神经的粗大和长段缺损 ,观察其近期神经电生理恢复。方法　12只犬随机分成去细胞神经移植组 (实验组 )和自体神经移植组 (对照组 )各 6只。右侧坐骨神经造成 5 0cm长缺损 ,以两种神经移植物桥接修复。术后 6个月行神经电生理观察 ,包括小腿三头肌运动诱发电位、神经移植段运动传导速度、感觉诱发电位等。结果　 (1)方波 (1 0mA～ 2 0mA ,0 1ms,1 0Hz)刺激移植段近侧神经 ,均在小腿三头肌上记录到运动诱发电位曲线。 (2 )神经移植段运动传导速度 ,实验组平均为 4 7 2m/s、对照组为 6 0 9m/s、正常值为 12 2 0m/s。 (3)方波 (5 0mA～ 10 0mA ,0 2ms,1 9Hz)刺激胫神经远端 ,均在颅顶部记录到感觉诱发电位曲线 ;两组动物的感觉恢复程度相似 ,但均不及正常侧。结论　化学去细胞神经同种异体移植修复犬坐骨神经长段缺损 ,术后 6个月近期感觉及运动传导功能恢复与自体神经移植相似     

先天性马蹄内翻足的运动神经传导速度研究

目的采用对下肢运动神经传导速度的检测,研究先天性马蹄内翻足患者下肢神经和肌肉功能的变化,为有关该病病因学研究及其治疗方案的设计和疗效评价提供客观依据.方法用丹麦产维迪KEYPOINT 4C诱发电位仪,对53例,男39例,女14例,年龄0.5～15岁,平均(27.48±37.43)个月,临床确定为先天性马蹄内翻足的患者进行了运动神经传导速度检查.结果53例患儿75侧患肢运动神经传导速度检查发现,有47例68侧(88.7%)均有异常改变.只有6例7侧(11.3%)运动神经传导速度检查未发现明显异常.结论本研究发现支持有关先天性马蹄内翻足病因的神经肌肉学说,为该病诊断及治疗后效果评价提供了有价值的客观指标.     

不同年龄大鼠神经再生趋化性差异的研究

目的 比较不同年龄大鼠坐骨神经切断后，其神经再生趋化性在组织持异性和解剖特异性水平上的差异。方法 大鼠按年龄分幼年和成年组各40只，分别建立组织特异性(幼、成年组各20只)和解剖特异性(幼、成年组各20只)模型，术后3、6周分别采用神经电图、组织学检测神经再生。结果 术后3、6N，幼年组在神经传导速度恢复率、神经纤维再生准确率、胫腓神经传导速度比值和波幅比值、远端胫神经侧与腓总神经侧有髓轴索数的比值方面均低于成年组；但复合肌肉动作电位波幅恢复率两组无显著差异。结论 幼年大鼠周围神经再生趋化性的组织和解剖特异性较成年差，提示幼年大鼠较易发生主动肌与拮抗肌同步收缩的主要原因在于周围神经的错向生长。     

神经生长因子（NGF）促进挤压伤坐骨神经再生

作者就神经生长因子（ＮＧＦ）对挤压伤坐骨神经再生和作用进行了研究．３０只大鼠分为６组，每组各５只，双侧１０条坐骨神经．其中３组为对照组，３组为ＮＧＦ治疗组，观察期分别为１２、２８和５６天．结果显示ＮＧＦ治疗可使神经肌肉动作电位出现提早，运动神经传导速度加快，再生有髓神经纤维直径增粗及早期再生有髓神经纤维数量增加，表明ＮＧＦ可促进挤压伤坐骨神经再生．     

大鼠坐骨神经急性延长的实验研究

目的 探讨急性扩张延长周围神经的合理注水量与延长值。方法 使用组织扩张器对3组（每组8只）大鼠坐骨神经行一次性扩张延长,注水量分别为3ml、5ml、7ml。分别于注水前、注水后即刻、注水后保持5min、去水囊后15min,进行肌电测定;并在光镜、透射电镜下进行组织学观察。结果 （1）延长值（起始长度均为1．5cm）：分别为8．33％、14．7％、20．4％。（2）肌电结果：3ml、5ml组的运动神经传导速度与复合肌肉电位（CMAP）的潜伏期,神经扩张前和扩张后相比无明显差别。7ml组则比术前明显减慢及延长。（3）轴突密度：3ml、5ml组扩张部与正常段神经相比无明显差异。7ml组轴突的密度则明显降低。（4）形态学：3ml、5ml组的神经结构基本正常,7ml组束膜间有血管扩张、间质水肿、出血及脱髓鞘变化。（5）超微结构：3ml、5ml组神经髓鞘为圆形,排列规则;7ml组神经髓鞘明显皱缩变形。结论 大鼠坐骨神经一次性扩张延长的合理注水量为5ml,延长值为14．6％。     

Long-term results of peripheral nerve repair: a comparison of nerve anastomosis with ethyl-cyanoacrylate and epineural sutures.

The morphological and functional recovery after repair of lesions to the sciatic nerve was studied in adult rats. We compared conventional microsuturing with a synthetic ethyl-cyanoacrylate adhesive. Six months after a unilateral lesion and subsequent repair the tibial branch to the lateral gastrocnemius muscle and the caudal sural cutaneous nerve were examined with electrophysiological measurements of motor and sensory conduction velocity, motor nerve action potentials, and quantitative histological examinations. There was functional reinnervation of motor and sensory nerves in both groups, as shown by equivalent recovery of motor and sensory conduction velocities, and motor nerve action potentials. Histological examination showed no significant difference in the mean diameter, fibre density or the number of regenerated myelinated motor and sensory axons distal to the repair site between the two groups. We conclude that anastomosis of the nerve with ethyl-cyanoacrylate adhesive supports morphological and functional recovery comparable to that of conventional epineural sutures after a unilateral lesion of the sciatic nerve in adult rats.     

Preferential block of small myelinated sensory and motor fibers by lidocaine: in vivo electrophysiology in the rat sciatic nerve.

BACKGROUND: Controversy still surrounds the differential susceptibility of nerve fibers to local anesthetics and its relation to selective functional deficits. In the current study we report features of conduction blockade in different classes of rat sciatic nerve fibers after injection of lidocaine by a percutaneous procedure that closely resembles clinical applications. METHODS: In 30 adult male Sprague-Dawley rats (weight, 300-400 g) during general anesthesia, impulses were recorded in different classes of sensory axons (large, Aalpha and beta fibers; small, Adelta myelinated fibers and unmyelinated C fibers) and motor axons (large, Aalpha fibers; small, Agamma myelinated fibers) classified by conduction velocity. The sciatic nerve was stimulated distally, and impulses were recorded from small filaments teased from L4-L5 dorsal (sensory) and ventral (motor) roots sectioned acutely from the spinal cord. Lidocaine at concentration of 0.05-1% was injected percutaneously in 0.1-ml solutions at the sciatic notch. Both tonic (stimulated at 0.5 Hz) and use-dependent (stimulated at 40 Hz for Adelta and Agamma fibers and at 5 Hz for C fibers) impulse inhibitions by lidocaine were assayed. RESULTS: Minimal effective (threshold) lidocaine concentrations (i.e., to block conduction in 10% of fibers) were, for sensory, 0.03% for Adelta, 0.07% for Aalphabeta, and 0.09-0.1% for C fibers, and for motor, 0.03% for Agamma and 0.05% for Aalpha fibers. The order of fiber susceptibility, ranked by concentrations that gave peak tonic fiber blockade of 50% (IC50s), was Agamma > Adelta = Aalpha > Aalphabeta > C. Faster-conducting C fibers (conduction velocity > 1 m/s) were more susceptible (IC50 = 0.13%) than slower ones (conduction velocity < 1 m/s; IC50 = 0.30%). At 1% lidocaine, all fibers were tonically blocked. Use-dependent effects accounted for only a modest potentiation of block (at a lidocaine concentration of 0.25%) in Adelta and Agamma fibers, and in C fibers phasic stimulation had even smaller effects and sometimes relieved tonic block. CONCLUSIONS: Susceptibility to lidocaine does not strictly follow the "size principle" that smaller (slower) axons are always blocked first. This order of fiber blockade is qualitatively consistent with previous reports of the order of functional deficits in the rat after percutaneous lidocaine, that is, motor = proprioception > nociception, if we assume that motor deficits first arise from conduction failure in Agamma fibers and that nociception relies on C fiber conduction.     

The endoneurial response to neurolytic agents is highly dependent on the mode of application.

BACKGROUND AND OBJECTIVES: The variability and predictability of neurolytic neural blocks were studied using an experimental rat sciatic nerve model. The goal of the study was to compare endoneurial and clinical responses to commonly used neurolytic agents. METHODS: The sciatic nerves of 80 rats were treated either with intra- or perineural injections of 7% phenol-aqua, anhydrous glycerol, or 5% phenol-glycerol. Lidocaine and saline injections were used as controls. Muscle function and trophic changes of the hind limbs were evaluated, and samples for morphologic analysis were taken 1, 2, 4, and 8 weeks after the injections. RESULTS: Intra- and perineural injections of 7% phenol-aqua resulted in gross endoneural damage of the sciatic nerve and hind limb paresis. Perineural 5% phenol-glycerol and anhydrous glycerol injections caused subperineural damage with slight paresis; gross endoneural damage and noticeable paresis were present only after intraneural injections. When 7% phenol-aqua was compared to other neurolytic agents, the differences in the lesion size (P < .0001) were statistically significant after perineural injections. Regeneration occurred in a stereotypic fashion in all neurolytic groups. Axonal sprouts were noted at the injured area 2 weeks after intraneural and 1 week after perineural injections. Motor function had partially recovered at 8 weeks. CONCLUSION: There were no differences in the effects of clinically used neurolytic agents after intraneural injections. Although the perineurally applied 7% phenol-aqua induced marked endoneural damage, the destructive effect of glycerol and phenol-glycerol injections seemed to be prevented by the perineurium; phenol-glycerol and glycerol treatments induced subperineural damage only after perineural injections. The ability to penetrate the perineurium favors the use of 7% phenol-aqua in peripheral perineural blocks when complete neurolysis is the goal.     

108例腕管综合征正中神经传导测定结果分析

分析１０８例腕管综合征正中神经传导测定结果，以求最敏感的电诊断指标。比较１０８例正中神经复合肌肉动作电位，肘至腕的运动传导速度测定及指至腕部的感觉神经动作电位三项。指标异常检测率，表明拇指至腕段的感觉传导速度减慢是最敏感的电诊断参量。１０８例中伴有前臂段运动传导速度减慢的占１０．５％。同组病例无症状上肢出现电生理异常者为２０％，指示有亚临床的腕管部神经卡压存在的可能。     

银杏叶提取物对坐骨神经再生的影响

目的：研究银杏叶提取物局部应用对坐骨神经再生的影响。方法：选Wistar大鼠32只，随机分为银杏叶提取物组和对照组。在双目放大镜下切断两组大鼠右侧坐骨神经，于神经损伤处和周围肌肉间隙内注射药物后立即行缝合术。2周后进行坐骨神经功能指数、电生理学和组织形态学观测评定。结果：银杏叶提取物组各项指标均优于对照组，其坐骨神经功能指数的恢复、神经纤维的生长速度及数量明显优于对照组。结论：银杏叶提取物局部应用可有效促进大鼠坐骨神经损伤的早期再生，加快神经再生速度与神经功能恢复。     

Functional assessment of sciatic nerve recovery: biodegradable poly (DLLA-epsilon-CL) nerve guide filled with fresh skeletal muscle

The aim of this study was to compare functional peripheral nerve recovery in the rat sciatic nerve model after reconstruction of a 10-mm gap with a biodegradable poly (DLLA-epsilon-CL) nerve guide, as filled with either fresh skeletal muscle or phosphate-buffered saline (PBS). During 24 weeks of recovery, motor and sensory functional evaluation was tested by extensor postural thrust (EPT) and withdrawal reflex latency (WRL), respectively. At the end of the experiment, anesthetized animals were prepared for motor nerve conduction velocity (MNCV) studies, followed by gastrocnemius and soleus muscle weight measurement. Motor functional recovery was greater in the muscle-grafted group, and reached a significant difference from weeks 8-12 (P < 0.05). The results of this investigation suggest that filling a nerve guide with fresh skeletal muscle induces faster maturation of regenerated nerve fibers in comparison with traditional tubular repair.     

N-Butyl Tetracaine as a Neurolytic Agent for Ultralong Sciatic Nerve Block

Background: Neurolytic agents such as phenol (5% to 10%) and absolute alcohol have long been used clinically to destroy the pathogenic nerve regions that manifest pain. Both phenol and alcohol are highly destructive to nerve fibers. However, these agents exert only weak local anesthetic effects and therefore are difficult to administer to alert patients without pain. This report describes a tetracaine derivative that displays both local anesthetic and neurolytic properties. Studies with such a compound may lead to the design of neurolytic agents that are more effective and more easily administered than phenol and alcohol.

Methods: A tetracaine derivative, N-butyl tetracaine quaternary ammonium bromide, was synthesized, and its ability to elicit sciatic nerve block of sensory and motor functions in vivo was tested in rats. A single dose of 0.1 ml N-butyl tetracaine at 37 mM was injected into the sciatic notch. Transverse sections of treated sciatic nerves were subsequently examined to determine the neurolytic effect of this drug. Finally, the local anesthetic properties of N-butyl tetracaine were studied in vitro; both tonic inhibition and use-dependent inhibition of Sodium sup + currents in neuronal GH3 cells were characterized under whole-cell voltage-clamp conditions.

Results: N-butyl tetracaine at 37 mM (equivalent to 1.11% tetracaine-hydrochloric acid concentration) elicited prolonged sciatic nerve block of the withdrawal response to noxious pinch in rats for more than 2 weeks. The withdrawal response was fully restored after 9 weeks. Parallel to sensory block, motor functions of the hind legs were similarly blocked by this drug. Morphologic examinations 3 and 5 weeks after a single injection of drug revealed degeneration of many sciatic nerve fibers, consistent with the results of functional tests. Finally, N-butyl tetracaine was found to be a potent Sodium sup + channel blocker in vitro. It produced strong tonic and use-dependent inhibition of Sodium sup + currents with a potency comparable to that of tetracaine.     

Effects of nerve growth factor on crushed sciatic nerve regeneration in rats

The effects of nerve growth factor (NGF) on crushed sciatic nerve regeneration were studied in 30 rats, with 60 bilateral nerves. The nerves were crushed at a site 6 mm distal to the sciatic notch by the standard technique and 3 mm wide crush injuries were created. Then 2.1 μl of normal saline in the control groups and an equal volume of NGF solution (containing 1 μg of NGF) in the NGF-treated groups was injected into the crush sites and followed for 12, 28, and 56 days, respectively. At the end of the observation, electrophysiological evaluation was carried out; then samples 10 mm distal to the crush site were removed and prepared for histological and morphometric studies. Evoked muscle action potential (MAP) was recorded in 50% of the NGF-treated group at 12 days but not in the control group; the difference was statistically significant (P<0.05). The motor nerve conduction velocity (MNCV) was increased in NGF-treated groups compared with control groups at 28 and 56 days (P<0.05). Morphometrically, significantly more regenerated myelinated fibers (RMFs) were seen at 12 days, and larger diameter RMFs were found at 12, 28, and 56 days in NGF-treated groups than in control groups. These results indicate that topically applied NGF stimulates nerve regeneration and promotes function recovery in crushed rat sciatic nerves. © 1995 Wiley-Liss, Inc.     

Comparative electrophysiologic evaluation of nerve grafts and autogenous vein grafts as nerve conduits: an experimental study

This study was carried out to compare electrophysiologically the efficacy of autogenous vein grafts, with autogenous nerve grafts as conduits for nerve regeneration. A 0.75-cm segment of sciatic nerve was resected in two groups of Sprague-Dawley rats of equivalent maturity. The nerve gaps were bridged with an autogenous vein graft in the first group (31 rats), and an autogenous nerve graft in the second group (24 rats). Serial in vivo nerve conduction velocity studies and terminal in vitro nerve conduction velocity and nerve action potential measurements were performed. An additional group of 21 animals who had undergone no surgical procedures, were similarly studied to establish an age-adjusted baseline for comparison. Twelve animals in the first group, 14 in the second group, and 13 in the baseline group survived the full year of study. In vivo conduction velocities between the two experimental groups compared favorably. Nerve conduction velocity determined by in vitro technique confirmed this finding and measured similarly at about 78 percent of the baseline. Nerve action potential amplitude in the vein-grafted group was 12.0 percent of the baseline, while the nerve-grafted group was 23.9 percent of the baseline. This study demonstrated that the vein graft compares well with the nerve graft in nerve conduction velocity, but only one-half as well in nerve action potential.