Comparative effect of photobiomodulation associated with dexamethasone after sciatic nerve injury model

Abstract

To analyze the effect of photobiomodulation and dexamethasone on nerve regeneration after a sciatic nerve crushing model. Twenty-six Swiss mice were divided into the following groups: naive; sham; injured, low-level laser therapy (LLLT) (660 nm, 10 J/cm, 0.6 J, 16.8 J total energy emitted during the 28 days of radiation, 20 s, for 28 days); dexamethasone (Dex) (local injection of 2 mg/kg for 10 consecutive days); and LLLT group associated with Dex (LLLT/Dex), with the same parameters of the other groups. For nerve injury, a portable adjustable pinch was used. The animals were evaluated using the Sciatic Functional Index (SFI) and Sciatic Static Index (SSI). The results obtained were evaluated with Image J™ and Kinovea™. Data and images were obtained at baseline and after 7, 14, 21, and 28 days after surgery. The evaluation of hyperalgesia, using Hargreaves, and behavior through the open field was also performed. In functional and static analysis, all groups presented significant differences when compared to the injured group. In the analysis of the SSI results, the group treated with both LLLT and dexamethasone was more effective in improving the values of this parameter, and in the SFI, the laser-treated group obtained better results. In the evaluation through the open field and the Hargreaves, there was no difference. The application of LLLT and dexamethasone was effective in nerve regeneration according to the results and was more effective when LLLT was associated with dexamethasone than in LLLT alone for the SSI.

Photobiomodulation in Sciatic Nerve Crush Injuries in Rodents: A Systematic Review of the Literature and Perspectives for Clinical Treatment

“…After the exclusion of articles published as systematic reviews, duplicated titles, inadequate titles, and abstracts, 30 articles were selected for a complete review, and only 19 articles fulfilled all the inclusion criteria. Among these articles, we highlight that the most used wavelengths were 660 nm 1,2,7,[18][19][20] and 830 nm, 2,12,21,22 the powers were 30 2,18,19,21,22 and 40 mW 5,7 and the energy densities were 4 1,3,5,23 and 10 2,5,7,13,16,19,21 J/cm 2 . Tables 1-3 describe the experimental design used in the studies selected for this review and the parameters of the LLLT and LED.…”

“…Table 4 shows the models of lesions of the sciatic nerve injury used by the authors in their studies; they are as follows: a deadweight machine, 2,5,13,19,21,22 calibrated adjustable tweezer, 12,24 homeostatic tweezer, 1,3,14,23,25,26 and non-serrated homeostatic tweezer. 8,7,20,27 The literary review showed consistent and significant results in favor of photobiomodulation about sciatic nerve regeneration after crush injury, as shown in Table 5.…”

Photobiomodulation Decreases Hyperalgesia in Complex Regional Pain Syndrome: An Experimental Mouse Model Subjected to Nicotine

“…To generate our experimental model, a 3‐hour IR in the mouse paw induced the disease‐causing hyperemia and edema, followed by neuropathic pain [23,26], with no signs of peripheral nerve injury at the tourniquet [27].…”

“…Moreover, patients suffering from this disease experience high medical and social costs related to loss of productivity and associated disability [10]. Although PBMT is a commonly used method to reduce pain, edema, and improve nerve regeneration [16,22,23]. Treatment protocol for CRPS, comparing different wavelengths, has not yet been performed, which justify the relevance of this study and analyze the effects of 660 and 830 nm wavelengths.…”

Effects of photobiomodulation on different application points and different phases of complex regional pain syndrome type I in the experimental model

“…Some studies [13,14,24,26,32,33,39,40] have evaluated the effects of different wavelengths including 660 and 830 nm on CRPS-I, and found a reported decrease in mechanical hyperalgesia [13], decreased temperature, and early functional recovery [33] in the groups treated with PBM Group 1: control (placebo), Group 2: photobiomodulation (PBM) applied to the paw with complex regional pain syndrome type I (CRPS-I) from the warm phase, Group 3: PBM applied to the paw with CRPS-I from the acute phase, Group 4: PBM applied close to the area of the region between L4 and L5 from the warm phase, Group 5: PBM applied close to the area of the region between L4 and L5 from the acute phase, Group 6: PBM applied at two points: right paw and region between L4 and L5 from the warm phase, Group 7: PBM applied at two points: right paw and region between L4 and L5 from the acute phase, 3rd: third evaluation day, 7th: seventh evaluation day, 14th: fourteenth evaluation day, 21st: twenty-first evaluation day. .…”