HeNe laser irradiation delivered transcutaneously: its effect on the sciatic nerve of rats

For our study of the effect of low energy laser irradiation (LELI) on living tissue we used HeNe laser on rats. The exponential absorption was reaffirmed in the living tissues overlying the sciatic nerve. An optimal range of energy between 3.5 and 7 J--associated with energy concentration of 4-10 J/cm2 delivered transcutaneously--was found to cause a significant increase in action potential in the sciatic nerve. The effect lasted for more than 8 months after the irradiation session.     

Electrophysiological effect of HeNe laser on normal and injured sciatic nerve in the rat

Summary The effect of low energy CW HeNe laser irradiation on normal and dissected nerves in the rat was examined. The methods are described. Results are compared to the laser effect on other living tissues. HeNe irradiation was found to increase significantly the action potentials of the nerves. It was found to be a long-lasting effect, keeping an increase in the nerves action potential for more than eight months after irradition has been stopped. A possible explanation for the way the irradiation acts on the nerve is suggested.This work was supported by a joint grant from the Ministry of Industry and Commerce and Tel-Aviv University, Israel.     

No effect of GA-AS (904 nm) laser irradiation on the intact skin of the injured rat sciatic nerve

We evaluated the electrophysiological and histopathological effects of low-energy gallium arsenide (904 nm) laser irradiation on the intact skin injured rat sciatic nerve. Twenty-four male Wistar rats were divided into three groups (n=8 each). At the level of proximal third of the femur the sciatic nerve was crushed bilaterally with an aneursym clip (Aesculap FE 751, Tuttingen, Germany) for half a second. A gallium arsenide laser (wavelength 904 nm, pulse duration 220 ns, peak power per pulse 27 W, spot size 0.28 cm², pulse repetition rate 16, 128 and 1000 Hz; total applied energy density 0.31, 2.48 and 19 J/cm²) was applied to the right sciatic nerve for 15 min daily at the same time on 7 consecutive days. The same procedure was performed on the left sciatic nerve of same animal, but without radiation emission, and this was accepted as control. Compound muscle action potentials were recorded from right and left sides in all three groups before surgery, just at the end of injury, at the 24th hour and on the 14th and 21st days of injury in all rats using a BIOPAC MP 100 Acquisition System Version 3.5.7 (Santa Barbara, USA). BIOPAC Acknowledge Analysis Software (ACK 100 W) was used to measure CMAP amplitude, area, proximal and distal latency, total duration and conduction velocity. Twenty-one days after injury, the rats were sacrificed. The sciatic nerves of the operated parts were harvested from the right and left sides. Histopathological evaluation was performed by light microscopy. Statistical evaluation was done using analysis of variance for two factors (right and left sides) repeated-measures (CMAP variables within groups) and the Tukey–Kramer Honestly Significant Difference test (CMAP variables between laser groups). The significance was set at p 0.05. No statistically significant difference (p 0.05) was found regarding the amplitude, area, duration and conduction velocity of CMAP for each applied dose (0.31, 2.48 and 19 J/cm²) on the irradiated (right) side and the control (left) side, or between irradiated groups. Twenty-one days after injury there were no qualitative differences in the morphological pattern of the regenerated nerve fibres in either irradiated (0.31, 2.48 and 19 J/cm²) or control nerves when evaluated by light microscopy. This study showed that low-energy GaAs irradiation did not have any effect on the injured rat sciatic nerve.     

Does low-Intensity helium-Neon laser irradiation alter sensory nerve active potentials or distal latencies?

The effect of 1 mW helium neon continuous-wave (0.633 microns) laser irradiation on superficial radical sensory and median sensory nerve function was examined in a double-blind, controlled study involving 40 volunteers. No differences in action potential amplitudes, distal latencies, or forearm skin temperatures were found between the treated and control groups either at the time of irradiation or at subsequent evaluations 15 and 30 minutes later. As a result, we are unable to confirm reports that low-energy lasers of this power and wavelength alter nerve function.     

Effects of laser irradiation on the spinal cord for the regeneration of crushed peripheral nerve in rats

BACKGROUND AND OBJECTIVE: The purpose of the present study was to examine the recovery of the crushed sciatic nerve of rats after low-power laser irradiation applied to the corresponding segments of the spinal cord. STUDY DESIGN/MATERIALS AND METHODS: After a crush injury to the sciatic nerve in rats, low-power laser irradiation was applied transcutaneously to corresponding segments of the spinal cord immediately after closing the wound by using 16 mW, 632 nm He-Ne laser. The laser treatment was repeated 30 minutes daily for 21 consecutive days. RESULTS: The electrophysiologic activity of the injured nerves (compound muscle action potentials--CMAPs) was found to be approximately 90% of the normal precrush value and remained so for up to a long period of time. In the control nonirradiated group, electrophysiologic activity dropped to 20% of the normal precrush value at day 21 and showed the first signs of slow recovery 30 days after surgery. The two groups were found to be significantly different during follow-up period (P < 0.001). CONCLUSION: This study suggests that low-power laser irradiation applied directly to the spinal cord can improve recovery of the corresponding insured peripheral nerve.     

Acute electrophysiologic effect of pulsed gallium-arsenide low energy laser irradiation on configuration of compound nerve action potential and nerve excitability

BACKGROUND AND OBJECTIVES: We evaluated the acute electrophysiologic effects of low-energy pulsed laser irradiation, measured by extracellular recording technique on compound action potential configuration and nerve excitability in the isolated frog sciatic nerve STUDY DESIGN/MATERIALS AND METHODS: A pulsed gallium-arsenide (GaAs) laser (wavelength, 904 nm; pulse duration, 220 nanoseconds; peak power per pulse, 27 W; spot size, 0.28 cm(2); total applied energy density, 0.005-2.5 J/cm(2)) was used for the experiment. Sixty isolated nerves were divided into six groups (n = 10), each of which received a different repetition frequency. In each group, action potentials were recorded, before laser irradiation, which served as the control data. The extracellular action potentials were recorded for each combination of 1, 3, 5, 7, 10, 13, and 15 minutes of irradiation time and 4, 8, 16, 32, 64, 128 repetition frequency by using a BIOPAC MP 100 Acquisition System Version 3.5.7 (Santa Barbara USA). Action potential latency, duration of depolarization and repolarization, and the stimulating voltage were measured. Statistical evaluation was performed using linear correlation analysis by SPSS 9.05. RESULTS: Although there was no correlation between applied energy density and action potential latency, the duration of depolarization and repolarization phases (P > 0.05), there was a weak correlation between applied energy density and stimulating voltage. CONCLUSIONS: The study showed that low-energy GaAs irradiation at 42 different energy density between 0.005 and 2.5 J/cm(2) generates no effect on action potential configuration and nerve excitability.     

中药治疗对大鼠坐骨神经损伤后mRNA^NGF表达的影响

目的研究中药党参、丹参、黄芪、生地和复方神肌再生冲剂对大鼠坐骨神经损伤后神经再生的影响。方法将大鼠分为党参组、丹参组、黄芪组、生地组、复方冲剂组和对照组，每组大鼠18只。麻醉下暴露右侧坐骨神经，在坐骨结节远侧0．8cm处造成坐骨神经挤压伤，根据分组，术后给予不同的中药喂养大鼠。术后不同时间，取紧邻挤压伤部位远侧神经干，应用原位杂交的方法和图像分析处理系统定量测定神经组织中神经生长因子mRNA（mRNA^NGF）的表达。结果丹参组和黄芪组大鼠坐骨神经挤压伤后第2周起，坐骨神经组织中mRNA^NGF表达明显增加，至伤后第4周达到高峰。党参治疗坐骨神经挤压伤，治疗后8周，mRNA^NGF表达较对照组明显增加，差异有显著性。在复方冲剂组，大鼠坐骨神经挤压伤后8周内，神经组织中mRNA^NGF表达始终处于高水平。各组大鼠坐骨神经mRNANG”表达与对照组之间的差异具有显著性（P〈0．05）。复方冲剂组大鼠坐骨神经mRNA^NGF表达与丹参和黄芪组之间的差异也具有显著性。结论中药党参、丹参和黄芪可以促进挤压伤后大鼠坐骨神经mRNA^NGF表达；这种作用在组成复方冲剂后，表现得更为明显。     

股神经联合坐骨神经阻滞应用在踝关节镜手术中的效果评价

目的 比较两种不同的麻醉方式在踝关节镜手术中的应用效果。方法 选择2018年1月至2019年12月在中山大学孙逸仙纪念医院行踝关节镜手术的患者60例,随机分为股神经组和腰丛组,每组各30例,股神经组实施股神经联合坐骨神经阻滞,腰丛组实施腰丛联合坐骨神经阻滞。比较两组患者术中和术后的麻醉和镇痛效果、麻醉操作时间、不同时间的心率及平均血压和麻醉并发症及不良反应。结果 两组患者术中额外使用局麻药和麻醉性镇痛药人数、术后24小时内静息或运动的VAS评分及额外使用镇痛药的人数和使用时间差异均无统计学意义;股神经组麻醉操作时间显著少于腰丛组;股神经组在麻醉操作过程中的心率和平均血压显著低于腰丛组;两组患者术后不良反应比较差异无统计学意义。结论 股神经联合坐骨神经阻滞与腰丛联合坐骨神经阻滞在踝关节镜手术中的麻醉和术后镇痛效果无显著差别,但前者麻醉操作时间更短,围术期生命体征更平稳。     

Systemic effects of low-power laser irradiation on the peripheral and central nervous system, cutaneous wounds, and burns

In this paper, we direct attention to the systemic effect of low-power helium-neon (HeNe) laser irradiation on the recovery of the injured peripheral and central nervous system, as well as healing of cutaneous wounds and burns. Laser irradiation on only the right side in bilaterally inflicted cutaneous wounds enhanced recovery in both sides compared to the nonirradiated control group (P less than .01). Similar results were obtained in bilateral burns: irradiating one of the burned sites also caused accelerated healing in the nonirradiated site (P less than .01). However, in the nonirradiated control group, all rats suffered advanced necrosis of the feet and bilateral gangrene. Low-power HeNe laser irradiation applied to a crushed injured sciatic nerve in the right leg in a bilaterally inflicted crush injury, significantly increased the compound action potential in the left nonirradiated leg as well. The statistical analysis shows a highly significant difference between the laser-treated group and the control nonirradiated group (P less than .001). Finally, the systemic effect was found in the spinal cord segments corresponding to the crushed sciatic nerves. The bilateral retrograde degeneration of the motor neurons of the spinal cord expected after the bilateral crush injury of the peripheral nerves was greatly reduced in the laser treated group. The systemic effects reported here are relevant in terms of the clinical application of low-power laser irradiation as well as for basic research into the possible mechanisms involved.     

Effects of 830 nm continuous wave laser diode irradiation on median nerve function in normal subjects

The presence, magnitude, and nature of the effect that low intensity laser irradiation has on nerve function, growth, and repair constitute a contentious area of research. We have addressed one aspect of this controversy by systematically examining the influence of 830 nm laser radiation on median nerve function. In particular, we investigated median nerve motor and sensory distal latencies, action potential amplitudes, action potential areas, and conduction velocities as well as dorsal hand skin temperatures in 33 normal subjects in a double-blinded, randomized controlled study. All subjects received identical treatment: 30 seconds of “irradiation” at 10 points over the course of the right median nerve (five sites on the forearm and five sites distal to the wrist crease) with either an active (1.2 J/point) or inactive (0 J/point) 40 mW 830 nm continuous wave IR laser diode. Latencies, conduction velocities, amplitudes, areas, and skin temperatures were collected bilaterally at a baseline immediately prior to irradiation and at intervals of 1, 5, 10, 15, 20, and 30 minutes following treatment. Analysis of the results reveals that motor and sensory distal latencies were decreased in the treated limbs of the lasertreated group relative to the control group by 3–4% (P <.016 and.046, respectively, rank sum test). No significant differences in these quantities were found between the limbs within either group. Similarly, no alterations of action potential amplitudes, action potential areas, forearm conduction velocities, or skin temperatures were detected within or between the groups. Thus on the basis of this experiment, percutaneous 830 nm continuous wave laser irradiation can affect median nerve function, but the effects are quite limited and appear to be limited to the distal portion of the nerve. © 1993 Wiley-Liss, Inc.     

Electrophysiologic effect of gallium arsenide laser on frog gastrocnemius muscle

BACKGROUND AND OBJECTIVE: In this study, the effect of low energy Gallium arsenide (GaAs) laser irradiation on the compound action potential of frog gastrocnemius muscle were investigated. STUDY DESIGN/MATERIALS AND METHODS: Sixty frogs were divided into different six dose groups: laser 1 (1 Hz), laser 2 ( 4 Hz), laser 3 (16 Hz), laser 4 (64 Hz), laser 5 (128 Hz), and laser 6 (1,000 Hz, DC, continue) (in each group n=10). Low energy GaAs laser (wavelenght: 904 nm, pulsed duration: 220 nanoseconds, peak power per pulse: 27 W, total applied energy density: 0.001-25.7 J/cm2) was used for the experiment. Compound muscle action potentials were recorded before laser irradiation and these data were accepted as control group. After recording the control data, each muscle was irradiated by the laser. Action potentials were recorded at 1, 5, 10, 15, and 20 minutes of irradiation time in each group by using standartized needle electromyography and nerve conduction study techniques. Distal motor latency, peak to peak amplitude, area, and total duration of action potential were measured. Repeated measures analysis of variance were used for the statistical evaluation. RESULTS: No significant differences were detected between control and laser dose groups in muscle action potential parameters. CONCLUSIONS: This study revealed that at the different repetition rate and exposure time, low energy GaAs laser does not have any significant effect on frog gastrocnemius action potential.     

SD大鼠坐骨神经对腺样囊性癌细胞系ACC-M体外增殖能力的影响

目的：研究SD大鼠坐骨神经对腺样囊性癌ACC-M细胞体外增殖能力的影响。方法：将人腺样囊性癌细胞系（ACC-M）分别与条件培养液和坐骨神经培养液共培养24、48、72h。应用MTT比色法研究SD大鼠坐骨神经对腺样囊性癌ACC-M细胞体外增殖能力的影响。结果：坐骨神经培养液对ACC-M作用48和72h后,ACC-M细胞的增殖明显高于其它组别,而共培养液则对ACC-M细胞的增殖没有明显影响。结论：SD大鼠坐骨神经培养液作用于腺样囊性癌细胞,能有效促进腺样囊性癌细胞的增殖,这可能是腺样囊性癌嗜神经侵袭的基础。     

External iliac artery thrombus masquerading as sciatic nerve palsy in anterior column fracture of the acetabulum

We report a case of ischemic neuropathy of the sciatic nerve in a patient with an anterior column fracture of the acetabulum operated by ilioinguinal approach. It resulted from occlusion of the blood supply to the sciatic nerve. There were no signs of a vascular insult until ischemic changes ensued on the 6^th postoperative day on the lateral part of great toe. The patient underwent crossover femoro-femoral bypass grafting and there was a complete reversal of the ischemic changes at 6 months. The sciatic nerve palsy continued to recover until the end of 1 year; by which time the only deficit was a Grade 4 power in the extensor hallucis longus (EHL) and the extensor digitorum longus (EDL). There was no further recovery at 2 years followup.     

神经干细胞移植量对PST大鼠神经病理性疼痛的影响

目的 观察不同数量神经干细胞(NSCs)鞘内注射对坐骨神经半切断(PST)大鼠神经病理性疼痛及脊髓背角、背根神经节(DRG)胶质源性神经营养因子(GDNF)表达的影响.方法 84只成年雄性SD大鼠随机均分为七组:假手术组(Ⅰ组)、PST组(Ⅱ组)、PST+NSCs 1×10<'3>组(Ⅲ组)、PST+NSCs 1×10<'4>组(Ⅳ组)、PST+NSCs 1×10<'5>组(Ⅴ组)、PST+NSCs 1×10<'6>组(Ⅵ组)、PST+NSCs 1×10<'7>组(Ⅶ组).NSCs于术后3 d鞘内注射.记录术前1 d、术后1、3、7、14、21 d机械痛及热痛阈;术后7、21 d免疫组织化学与RT-PCR检测同侧脊髓背角及DRG GDNF表达.结果 与Ⅰ组比较,Ⅱ～Ⅶ组术后1 d痛阈下降,术后7、14 d最低(P<0.05);与Ⅱ组比较,术后7 d Ⅳ、Ⅴ、Ⅵ、Ⅶ组随着NSCs量的增加,痛阈逐渐升高,脊髓背角及DRG GDNF表达逐渐上调(P<0.05);术后21d,Ⅴ、Ⅵ、Ⅶ组痛阈均与术前差异无统计学意义,但其GDNF表达Ⅴ组最高(P<0.05).结论 鞘内注射1×10<'5>NSCs能最有效缓解PST大鼠神经病理性疼痛.     

Inclusion of lignocaine base into a polar lipid formulation--in vitro release, duration of peripheral nerve block and arterial blood concentrations in the rat

BACKGROUND: Slow-release formulations of local anaesthetics may produce nerve blocks of long duration. The present study aimed at investigating the in vitro and in vivo properties of a polar lipid formulation for slow release of lignocaine and the effects on nerve block duration by inclusion of dexamethasone into the system. METHODS: In vitro release of lignocaine from the lipid formulation was studied in a US Pharmacopoeia rotating apparatus. Sciatic nerve blocks were induced in rats by 0.1 ml of test formulations containing lignocaine HCl 20 mg. ml-1 in aqueous solution, lignocaine base 20, 100 or 200 mg. ml-1 in lipid formulation or the last formulation with dexamethasone 0.05, 0.5 or 5 mg. ml-1. The durations of sensory and motor block and the arterial blood concentrations of lignocaine were investigated. RESULTS: In vitro there was a sustained release of lignocaine from the lipid formulation, with 50% release at around 48 h. In vivo lignocaine base 20 mg. ml-1 in lipid formulation produced sciatic nerve blocks of significantly shorter duration than lignocaine HCl 20 mg. ml-1 in aqueous solution, while lignocaine base 100 and 200 mg. ml-1 in lipid formulation produced blocks lasting two and three times longer, respectively, than the lignocaine HCl solution. Addition of dexamethasone did not affect the duration of nerve block. Following administration of lignocaine base 200 mg. ml-1 in lipid formulation, as compared to lignocaine HCl 20 mg. ml-1 in aqueous solution, the maximal blood concentration of lignocaine was only three times higher in spite of the ten-fold difference in dose, and the mean terminal half-life was three times longer, reflecting the slow release from the formulation. CONCLUSIONS: Our findings indicate that lignocaine base in polar lipids acts as a slow-release preparation of local anaesthetic both in vitro and in vivo.     

Effect of low intensity laser (830 nm) irradiation on skin temperature and antidromic conduction latencies in the human median nerve: Relevance of radiant exposure

The effects of low intensity near-infrared laser radiation (830 nm; 1.5–12 J/cm²; continuous wave) on peripheral neurophysiology and skin temperature were investigated using antidromic conduction studies in the human median nerve in vivo. Healthy human volunteers (n = 80) were recruited and randomly allocated to one of two control (n = 30) or five laser groups (1.5, 3.0, 6.0, 9.0, and 12 J/cm²; n = 10 per group). Analysis of variance (ANOVA) in negative peak latency difference scores (NPLDs) and skin temperature over a 20 min period post-irradiation demonstrated a significant decrease in skin temperature following irradiation at the lowest radiant exposure (1.5 J/cm²) coupled with a significant increase in NPLDs (P < 0.05). While no such (significant) changes were found in the other laser groups, it was found that observed changes (increases and decreases) in NPLDs were inversely related to changes in skin temperature. These findings demonstrate measurable peripheral neurophysiological effects of laser radiation concomitant with changes in skin temperature; however, further studies are indicated to establish the precise relationship between the observed effects on skin temperature and nerve Conduction. © 1994 Wiley-Liss, Inc.     

Large-area irradiated low-level laser effect in a biodegradable nerve guide conduit on neural regeneration of peripheral nerve injury in rats

This study used a biodegradable composite containing genipin-cross-linked gelatin annexed with β-tricalcium phosphate ceramic particles (genipin-gelatin-tricalcium phosphate, GGT), developed in a previous study, as a nerve guide conduit. The aim of this study was to analyse the influence of a large-area irradiated aluminium-gallium-indium phosphide (AlGaInP) diode laser (660 nm) on the neural regeneration of the transected sciatic nerve after bridging the GGT nerve guide conduit in rats. The animals were divided into two groups: group 1 comprised sham-irradiated controls and group 2 rats underwent low-level laser (LLL) therapy. A compact multi-cluster laser system with 20 AlGaInP laser diodes (output power, 50 mW) was applied transcutaneously to the injured peripheral nerve immediately after closing the wound, which was repeated daily for 5 min for 21 consecutive days. Eight weeks after implantation, walking track analysis showed a significantly higher sciatic function index (SFI) score (P < 0.05) and better toe spreading development in the laser-treated group than in the sham-irradiated control group. For electrophysiological measurement, both the mean peak amplitude and nerve conduction velocity of compound muscle action potentials (CMAPs) were higher in the laser-treated group than in the sham-irradiated group. The two groups were found to be significantly different during the experimental period (P < 0.005). Histomorphometric assessments revealed that the qualitative observation and quantitative analysis of the regenerated nerve tissue in the laser-treated group were superior to those of the sham-irradiated group. Thus, the motor functional, electrophysiologic and histomorphometric assessments demonstrate that LLL therapy can accelerate neural repair of the corresponding transected peripheral nerve after bridging the GGT nerve guide conduit in rats.     

超激光对家兔坐骨神经损伤后再生的作用

目的探讨超激光照射疗法对坐骨神经钳夹伤后神经再生的作用.方法45只成年雄性家免随机分为3组,对照组根据是否钳夹坐骨神经分为两组(A组和B组),C组为钳夹后超激光治疗组.钳夹前、钳夹后24h、超激光治疗10d、20d、30d时测运动神经传导速度(MNCV),治疗30d后行坐骨神经神经纤维单丝制备、Bielschowsky染色、Loyez染色、电镜超薄切片观察坐骨神经再生和修复情况.结果超激光治疗20d、30d时,C组MNCV明显快于B组(P＜0.01),但仍慢于术前(P＜0.01).治疗30d后光镜和电镜下观察,C组损伤处神经纤维有大量轴突和髓鞘形成,郎飞氏结清晰,结间距变短,髓鞘板层样结构清楚,轴浆内线粒体结构正常且数目增多,雪旺氏细胞胞浆丰富,胞浆内线粒体数目增多.结论超激光照射疗法对神经钳夹损伤后再生修复有明显的促进作用.