Ineficácia da laserterapia aplicada no trajeto do nervo e nas raízes medulares correspondentes Lack of effectiveness of laser therapy applied to the nerve course and the correspondent medullary roots (original) (raw)
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EFFECTS OF LASER THERAPy IN PERIPHERAL NERVE REGENERATION
Citation: Sene GAL, Sousa FFA, Fazan VS, Barbieri CH. Effects of laser therapy in peripheral nerve regeneration. Acta Ortop Bras. [online]. 2013;21(5): 266-70. Available from ABSTRACT Objective: The influence of dose of low power lasertherapy (AsGaAl, 830 nm) on the regeneration of the fibular nerve of rats after a crush injury was evaluated by means of the functional gait analysis and histomorphometric parameters. Methods: Controlled crush injury of the right common fibular nerve, immediately followed by increasing doses (G1: no irradiation; G2: simulated; G3: 5 J/cm 2 ; G4: 10 J/cm 2 ; G5: 20 J/cm 2) laser irradiation directly on the lesion site for 21 consecutive days. Functional gait analysis was carried out at weekly intervals by measuring the peroneal/fibular functional index (PFI). The animals were killed on the 21 st postoperative day for removal of
Previous studies have shown that low-level laser therapy (LLLT) promotes posttraumatic nerve regeneration. The objective of the present study was to assess the efficacy of 685-nm LLLT at the dosage of 3 J/cm 2 in the functional recovery of the sciatic nerve in rats following crushing injury. The left sciatic nerves of 20 male Wistar rats were subjected to controlled crush injury by a hemostatic tweezers, and the rats were randomly allocated into two experimental groups as follows: control group and laser group. Laser irradiation (685 nm wavelength; 15 mW, CW, 3 J/cm 2 , spot of 0.028 cm 2 ) was started on the postsurgical first day, above the site of injury, and was continued for 21 consecutive days. Functional recovery was evaluated at 3 weeks postoperatively by measuring the sciatic functional index (SFI) and sciatic static index (SSI) at weekly intervals. The treated rats showed improvement in motion pattern. The SFI and SSI results were significant when comparing two groups on the 14th and 21st postoperative days (p<0.05). There were intra-group differences detected in laser group in different periods (p<0.05). Low-level laser irradiation, with the parameters used in the present study, accelerated and improved sciatic nerve function in rats after crushing injury.
Journal of Hand and Microsurgery, 2013
Peripheral nerve lesions caused sensory and motor deficits along the distribution of the injured nerve. Numerous researches have been carried out to enhance and/or accelerate the recovery of such lesions. The objective of this study was to assess the functional recovery of sciatic nerve in rats subjected to different fluences of low-level laser therapy (LLLT). Thirty-six animals were randomly divided into four groups: one consisting of sham rats and three others irradiated with progressive fluencies of 10 J/cm 2 , 40 J/cm 2 and 80 J/cm 2 of laser AsGaAl (830 nm) for 21 consecutive days. They were evaluated by the Sciatic Functional Index (SFI) method. The crush injury was performed by using a portable device with dead weight of 5,000 g whose load was applied for 10 min. A digital camera was used to record the footprints left on the acrylic track, before surgery and after, on the 7th, 14th, and 21st days. The results also showed that on the 7th day, there was a difference between the groups irradiated with 40 J/cm 2 , when compared with the sham group (p<0.05). On the 14th day the groups irradiated with 40 J/cm 2 and 80 J/cm 2 also presented better results when compared with sham, however, on the 21st day, no inter-group difference was found (p>0.05). It was possible to observe that the LLLT at fluency of 40 J/cm 2 and 80 J/cm 2 had a positive influence on the acceleration of the functional nerve recovery.
2016
Aim of the work: The objective of study is to determine the effect of the low level laser therapy on nerves regeneration after a compression injury of rat sciatic nerve. Study design: The injury of the sciatic nerve was induced by using portable deadweight device with a load of 5000g applied over a length of 5 mm for 10 minutes was used in this study on the crushing of the sciatic nerve of rats. This device is characterized as being a faster, easier and more reliable crushing process, in relation to the load used. The animals were divided into three groups, the animals in group III received LLLT daily for 28 consecutive days we used A Semi-conductor Diode AlGaInP Laser, formed a control console and a handheld probe. The diameter of the probe is 18 mm and it was used to deliver the LLLT. Functional nerve assessment was done using the foot step forms and sciatic nerve was dissected for histological examination to evaluate the regeneration of the sciatic nerve. Results: Found that sign...
Lasers in Medical Science, 2010
Peripheral nerves are structures that, when damaged, can result in significant motor and sensory disabilities. Several studies have used therapeutic resources with the aim of promoting early nerve regeneration, such as the use of low-power laser. However, this laser therapy does not represent a consensus regarding the methodology, thus yielding controversial conclusions. The objective of our study was to investigate, by functional evaluation, the comparative effects of low-power laser (660 nm and 830 nm) on sciatic nerve regeneration following crushing injuries. Twenty-seven Wistar rats subjected to sciatic nerve injury were divided into three groups: group sham, consisting of rats undergoing simulated irradiation; a group consisting of rats subjected to gallium–aluminum–arsenide (GaAlAs) laser at 660 nm (10 J/cm2, 30 mW and 0.06 cm2 beam), and another one consisting of rats subjected to GaAlAs laser at 830 nm (10 J/cm2, 30 mW and 0.116 cm2). Laser was applied to the lesion for 21 days. A sciatic functional index (SFI) was used for functional evaluation prior to surgery and on days 7, 14, and 21 after surgery. Differences in SFI were found between group 660 nm and the other ones at the 14th day. One can observe that laser application at 660 nm with the parameters and methods utilised was effective in promoting early functional recovery, as indicated by the SFI, over the period evaluated.
Effects of Laser Therapy (680 nm) on Recovery of the Sciatic Nerve in Rabbits
2012
Peripheral nerve injuries are common, and there is no easily available formula for successful treatment. Incomplete injuries are most frequent. After complete axonal transection, the neuron undergoes a number of degenerative processes, followed by attempts at regeneration. Unfortunately, results of nerve repair to date have been no better than fair. Many evidence lines have shown that peripheral nerves regeneration may be accelerated by physical agents. Laser irradiation is one of the therapeutic methods for the recovery of degenerated peripheral nerves. The objective of this study was to investigate whether laser therapy (680 nm) could stimulate the healing process in the sciatic nerve regeneration in rabbits submitted to complete transection through histological analysis. Twenty adult white New Zealand male rabbits were used, where the injury of the type neurotmesis of the right sciatic nerve under general anesthesia (intramuscular ketamine/xylazine) was approximated using prolene...
Local Low Power Laser Irradiation Accelerates the Regeneration of the Fibular Nerve in Rats
2010
In spite of adequate surgical treatment and rehabilitation, traumatic injuries of the peripheral nerves do not always evolve satisfactorily, with return of motor and sensation functions to useful levels. Physical resources, such as electricity,1 electromagnetism, therapeutic ultrasound2 and laser,3 have been employed to stimulate the regeneration of the peripheral nerves, with results that are still controversial, but tending positive. Of these resources, laser is perhaps the least well known, as regards its effects on the biological tissue4,5 and the parameters of use, such as dose, wavelength, continuous or pulsed mode,4-6 treatment duration3 and application site. Gigo-Benato et al.7 applied lower power laser irradiation (wavelengths of 808 NM and 905 NM, and doses of 29 J/cm2 and 40 J/cm2, respectively) directly on the median nerve, sectioned and repaired by lateral terminal neuroraphy of the distal segment in the intact ulnar nerve, in rats; the treatment was performed over thre...
PLoS ONE, 2014
The development of noninvasive approaches to facilitate the regeneration of post-traumatic nerve injury is important for clinical rehabilitation. In this study, we investigated the effective dose of noninvasive 808-nm low-level laser therapy (LLLT) on sciatic nerve crush rat injury model. Thirty-six male Sprague Dawley rats were divided into 6 experimental groups: a normal group with or without 808-nm LLLT at 8 J/cm 2 and a sciatic nerve crush injury group with or without 808-nm LLLT at 3, 8 or 15 J/cm 2 . Rats were given consecutive transcutaneous LLLT at the crush site and sacrificed 20 days after the crush injury. Functional assessments of nerve regeneration were analyzed using the sciatic functional index (SFI) and hindlimb range of motion (ROM). Nerve regeneration was investigated by measuring the myelin sheath thickness of the sciatic nerve using transmission electron microscopy (TEM) and by analyzing the expression of growth-associated protein 43 (GAP43) in sciatic nerve using western blot and immunofluorescence staining. We found that sciatic-injured rats that were irradiated with LLLT at both 3 and 8 J/cm 2 had significantly improved SFI but that a significant improvement of ROM was only found in rats with LLLT at 8 J/cm 2 . Furthermore, the myelin sheath thickness and GAP43 expression levels were significantly enhanced in sciatic nerve-crushed rats receiving 808-nm LLLT at 3 and 8 J/cm 2 . Taken together, these results suggest that 808-nm LLLT at a low energy density (3 J/cm 2 and 8 J/cm 2 ) is capable of enhancing sciatic nerve regeneration following a crush injury.
Stimulation Effect of Low Level Laser Therapy on Sciatic Nerve Regeneration in Rat
Journal of lasers in medical sciences, 2017
Introduction: Recent studies showed that low-level laser therapy (LLLT) accelerates the regeneration process of injured peripheral nerve tissue. The objective of this study was investigate the effect of LLLT (780 nm) on regeneration of injured right sciatic nerve of male Wistar rat. Methods: In this research work, the effect of LLLT (780 nm) on the regeneration process and reconstruction of injured peripheral right side sciatic nerve was investigated. Twelve adult male Wistar rats underwent surgery in aseptic conditions under general anesthesia to induce a lesion to their right side sciatic nerve according to standard protocol. Before suturing the location, only the experimental group was treated by laser. The damaged nerve was directly irradiated with (2 J, 100 mW, 40 seconds). The irradiation procedure was terminated in 21 days with little improvement (4 J, 200 mW, 40 seconds) across the skin surface of experimental group. Rats were selected randomly from each group to be sacrific...