. 2020 Jun 21;11(3):332–344. doi: 10.34172/jlms.2020.54

Table 5. Main Results and Analyzed Variables .

	Belchior et al., 2009¹	Barbosa et al., 2010²	Barbosa et al., 2010 ¹⁸	Gigo-benatto et al., 2010 ⁷	Gonçalves et al., 2010 ²⁴	Marcolino et al., 2010 ²¹	Câmara et al., 2011 ³
Main results	The SFI comparison showed that there was only P <0.05 between the pre-injury value of the LLLT group and after the 21st day in the control group.	LLLT group P <0.05 after 14 days P.O. about the control group.	LLLT group on the 14th day P.O. P <0.05 about the control.	SFI: there was no statistical difference between all groups. Histology and morphometry: muscle fiber atrophy in CR and CR780 10 J/cm², 60 J/cm² and 120 J/cm² compared to N and CR660 10 J/cm², 60J/cm² and 120 J/cm²; Mean cross-sectional area of anterior tibial mm: P <0.05 in CR groups CR780 10 J/cm², 60 J/cm² and 120 J/cm².	L14: lower amount of inflammatory infiltrate (P =0.001), higher amount of fibroblasts, (P =0.0001), lower myelin sheath degeneration (P =0.007). LLLT reduced the inflammatory process resulting from nerve damage.	(P <0.05) 7th and 14th day P.O between the control group and the LLLT group (P >0.05) 21st day of P.O. between the control group and LLLT group 21 days P.O.	In the groups submitted to low-intensity LLLT therapy, there was an increase in the number of all aspects with P <0.05.
Variables analyzed	SFI: functional gait analysis, pre-injury, 7th, 14th and 21st day P.O.	SFI: functional gait analysis, pre-injury, 7th, 14th and 21st day P.O.	SFI in the preoperative period and on the 7th, 14th and 21st P.O. days.	SFI: functional gait analysis. Histology and morphometry: anterior tibial muscle and sciatic nerve. Zymography: anterior tibial mm and sciatic nerve.	Presence of inflammatory infiltrate and fibroblasts, Degeneration of the myelin sheath, Axonal degeneration	SFI-Gait/footprint analysis (7, 14- and 21-days P.O.)	Histopathology: Schwann cells, myelin axons with large diameter and neurons.
	Tomazini et al, ²⁵ 2011	Gomes et al, ²⁶ 2012	Serafim et al, ²³ 2012	Alcântara et al, ²⁷ 2013	Marcolino et al, ²² 2013	Akgul et al, ¹³ 2014	-
Main results	The area and the number of sensory neurons found in the L5 spinal ganglion were statistically similar (P >0.05) in all groups, showing a positive LLLT effect. The number of myelin axons: no statistically significant difference was observed between the groups that suffered nerve crushing (P >0.05).	LLLT increased the mRNA expression of the BDNF and NGF factors after 14 days, with the maximum expression on the 21st day. No increase in NT-3 mRNA expression was observed. LLLT reduced the expression of iNOS, which played an important role in the inflammatory process.	Group 3 reduced the areas of edema, the number of mononuclear cells present in the inflammatory infiltration (P <0.05), and increased functional recovery (P <0.05) at 7, 14, and 21 days.	MMPs increased MMP-9 (P <0.05) and TNF-α (P <0.05) during the acute phase of nerve damage, modulating inflammation.	7th-day P.O. (P <0.04) when compared with Group 3; 14th-day P.O. (P <0.01 between the Sham group and groups 3 and 4 (P <0.04) between groups 2 and 3 21° day P.O. P >0.05 between all groups	SFI (P <0.05) after 21 days of treatment. Histology: LLLT treated groups (P <0.05), resulting in more dense fibers and less edema. Latency rate CAP: (P <0.05) control group and L14 and L7. Reduction of latency P <0.05 between experimental groups; velocity P <0.05.
Variables analyzed	Quantitative analysis of nerve fibers: number of myelin axons Quantitative analysis of sensory neurons: counting of neurons present in the spinal ganglion L5 Morphometry: counting neurons	Expression of mRNA of neurotrophic factors: BDNF, NGF, NT-3; Inflammatory markers: iNOS	SFI: functional gait analysis, preoperative and 7th, 14th and 21st day P.O. Edema; Mononuclear cell count.	PCR: pro-inflammatory (TWEA, Fn14, and TNF-α) and extracellular matrix remodeling and axonal growth markers (TIMP-1, MMP-2, and MMP-9) Zymography: activity levels of MMP-2 and MMP-9. Western Blot: assess the TNF-α protein content.	SFI: Footprints were analyzed before and after surgery on the 7th, 14th and 21st days.	SFI: 7, 14, and 21 days of P.O. Histology: analysis of mononuclear cells Speed and latency of compound action potential (CAP)
	Wang et al, ⁸ 2014	Takhtfooladi et al, ¹⁴ 2015	Andraus et al, ¹² 2017	Ziago et al, ⁵ 2017	de Souza et al, ¹⁹ 2018	Mangueira et al, ²⁰ 2018
Main results	SFI P <0.05 in GL3 and GL8 J/cm² groups ROM P <0.05 only in the GL8 J/cm² group; The myelin sheath thickness and GAP43 expression levels significantly increased (P <0.05) in the GL3 and GL8 J/cm² groups	SFI / SSI (P <0.05) between GC and GL on day 14 and 21 P.O. GL: SFI/SSI (P <0.05) between the 7th and 14th days. There were intra-group differences detected in GL in different periods (P <0.05).	The irradiated groups showed a significant decrease in SFI and a significant increase in mechanical resistance when compared to the untreated injured group (P <0.05), with no significant difference between the energy densities used.	Groups L0, L4, L10, and L50 exhibited decreased values of all quantitative and morphometric parameters compared to the control group. Morphological, quantitative and morphometric data showed an improvement after lesion in groups L4, L10, and L50 (irradiated groups) compared to the only injured group (L0); the best results, in general, were observed in the L10 group after 15 days of nerve damage.	The AsGaAl (660 nm) and dexamethasone were found to be effective in the early functional recovery of the sciatic nerve of mice. However, the variables used showed that in the SFI, the group treated with LLLT alone obtained better results when compared to the other groups. In the SSI, the group treated with LLLT/Dex obtained better results in the intergroup comparison.	The Raman spectra (RS) of the sciatic nerve fragments showed the peaks of the major biochemical components of the nerve. They increased in the groups treated with LLLT, mainly lipids (sphingo and phospholipids) and proteins (collagen) - constituents of the myelin sheath. The RS was useful in identifying the biochemical differences in the SN after the crush injury, and LLLT 660 nm was more efficient in cell proliferation and repair of the injured SN.
Variables analyzed	SFI SSI Transmission electron microscopy (TEM): evaluation of myelin sheath Western blotting analysis: to detect the expression of GAP43 Immunofluorescence: for the detection of GAP43 and neurofilament	SFI: functional gait analysis, preoperative and 7th, 14th and 21st days P.O. SSI: footprint analysis, preoperative and 7th, 14th, and 21st days P.O.	SFI: 7th, 14th and 21st days Maximum mechanical resistance of gastrocnemius muscle with the load cell. Zimographic: anterior tibial muscle	Histology: myelin density and capillary density. Morphology: nerve fiber Morphometry: maximum and minimum diameter of the nerve fiber, axonal diameter, and myelin thickness.	SFI SSI Hyperalgesia (Hargreaves) Behavior through the open field.	Spectroscopy: Raman Spectra To estimate the biochemical changes in the SN associated with LLLT, the PCA was applied. PCA is a statistical technique that transforms original correlated variables into new uncorrelated variables called principal components loading vectors, based on the maximum variance and the corresponding scores.

Abbreviations: P.O. (post-operative), SFI (sciatic functional index), CR (crush group), TNF-α (tumor necrosis factor-alpha), TWEAK (tumor necrosis factor-like weak inducer of apoptosis), Metallopeptidase matrix 9 (MMP-9), Metallopeptidase matrix 2 (MMP-2), BDNF (neurotrophic factor derived from the brain), full power capacity (CAP), NGF (nerve growth factor), NT-3 (neurotrophin 3), iNOS (induced nitric oxide syntheses), TIMP-1 (metallopeptidase inhibitor 1), mRNA (RNA messenger), tumor necrosis factor as a weak inducer of apoptosis), Fn14 (inducible factor of fibroblast growth 14), LLLT (Low-Level Laser Therapy), ROM (range of motion), SSI (static sciatic index), GL (laser group), GAP43 (growth-associated protein 43), Transmission electronic microscopy (TEM), SN (Sciatic Nerve), PCA (Principal Component Analysis), PCR (protein c reactive), MMPs (mainly matrix metalloproteinases).