Comparative effects of wavelengths of low-power laser in regeneration of sciatic nerve in rats following crushing lesion

Abstract

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/cm(2), 30 mW and 0.06 cm(2) beam), and another one consisting of rats subjected to GaAlAs laser at 830 nm (10 J/cm(2), 30 mW and 0.116 cm(2)). 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.

Stimulation Effect of Low Level Laser Therapy on Sciatic Nerve Regeneration in Rat

“…19 Since then, many other studies on the effect of different wavelengths of LLLT on slight and mild peripheral nerve lesion have been reported. 14,[20][21][22][23][24][25] In addition, combination of laser therapy with entubulation to reconstruct massive segmental loss of peripheral nerve has shown very promising outcomes. [26][27][28] Most reports on the effect of LLLT on PNS injury are in cases of axonotmesis.…”

“…[26][27][28] Most reports on the effect of LLLT on PNS injury are in cases of axonotmesis. [13][14][15][18][19][20][21]25,[29][30][31][32] However, promising results have been obtained in severe cases of neurotmesis when LLLT is used in combination with or Gore-Tex tubes. 27 The cutaneous branch consisted of 400 myelinated and 1800 unmyelinated afferent axons.…”

Análisis Comparativo del Número de Neurofilamentos en Nervios Isquiáticos de Rata Sometidos a Neuropraxia Tratadas con Láser de Baja Intensidad y Ultrasonido Terapéutico

“…Estos autores observaron que en el grupo sometido a la irradiación por LBI hubo aumento del número total de axones y mejor calidad en el proceso de regeneración en comparación al grupo control, siendo la recuperación de los nervios más rápida y eficiente. Barbosa et al (2010) compararon dos tipos de LBI: GaAlAs 660 nm (10 J/cm 2 , 30 mW y 0,06 cm 2 , 20 s, modo continuo) y de 830 nm (10 J/cm 2 , 30 mW y 0,116 cm 2 , 38,66 s, modo continuo), en la regeneración del nervio isquiático tras compresión. Ellos encontraron recuperación funcional temprana utilizando el LBI de 660 nm.…”

Low-Level Laser Therapy (LLLT) Improves the Repair Process of Peripheral Nerve Injuries: A Mini Review

“…This new vascularization aids in the process of tissue regeneration [26]. The PBMT is classified as a differential in the process of tissue regeneration and recovery, also relating its anti-inflammatory and anti-edematous effects, besides providing analgesia and circulatory normalization [17][18][19][20][21]27]. The literature also demonstrates the relation of the laser in the morphological and functional recovery of the nervous system, but there is still no consolidation of the PBMT application protocols [28][29][30].…”