On-Site Laser Photobiomodulation Treatment of Crushed Muscle Due to Prolonged Pressure in Rats.

BACKGROUND AND OBJECTIVES: Crush injuries and prolonged pressure on muscles lead to bruises and sprains and, in most of the cases, cause distraction of the muscle and release of particles into the blood stream, causing renal and systemic complications in severe cases. Laser photobiomodulation treatment (i.e., laser phototherapy) is a method suggested to decrease the pressure damage in the first 24-48 hours after muscle injury, allowing a faster and more complete physical rehabilitation. We studied the efficacy of non-invasive laser photobiomodulation treatment as an on-site treatment for crush-injured gastrocnemius muscles, developing a moderate muscle crush injury model and aiming at decreasing damage extent while regaining physical competence faster. STUDY DESIGN/MATERIALS AND METHODS: Muscle crush injury was performed on 30 female Wistar rats using direct pressure for 10 minutes on the gastrocnemius muscle in both left and right hindlimbs. Immediately after the injury, only the left hindlimb were irradiated for 16 minutes (with 780 nm laser with a power of 250 mW, the energy at the target was 240 J, and the fluence was 1019 J/cm2 ) for 1, 3, or 7 consecutive days, and sacrificed accordingly. During the follow-up period, 1, 3, or 7 days, both gastrocnemius muscles (of the treated and untreated hindlimbs) were evaluated for electrophysiology and functionality. RESULTS: The laser photobiomodulation treatment showed a significant electrophysiological and functional recovery of the gastrocnemius muscle during the first 3 days after injury, in comparison with the untreated hindlimb. CONCLUSIONS: These preliminary results are promising, showing a significant effect of the laser photobiomodulation treatment during the first 3 days after the induction of the muscle crush injury, which is the most critical period in the clinical aspect. These findings suggest a therapeutic approach, which may help restore the muscle after crush injury.

Comparison of results between chitosan hollow tube and autologous nerve graft in reconstruction of peripheral nerve defect: An experimental study.

OBJECT: This study evaluated a chitosan tube for regeneration of the injured peripheral nerve in a rodent transected sciatic nerve model in comparison to autologous nerve graft repair. METHODS: Chitosan hollow tube was used to bridge a 10-mm gap between the proximal and distal ends in 11 rats. In the control group, an end-to-end coaptation of 10-mm long autologous nerve graft was performed in 10 rats for nerve reconstruction. RESULTS: SFI showed an insignificant advantage to the autologous group both at 30 days (P = 0.177) and at 90 days post procedure (P = 0.486). Somato-sensory evoked potentials (SSEP) and compound muscle action potentials (CMAP) tests showed similar results between chitosan tube (group 1) and autologous (group 2) groups with no statistically significant differences. Both groups presented the same pattern of recovery with 45% in group 1 and 44% in group 2 (P = 0.96) showing SSEP activity at 30 days. At 90 days most rats showed SSEP activity (91% vs.80% respectively, P = 0.46). The CMAP also demonstrated no statistically significant differences in latency (1.39 ms in group 1 vs. 1.63 ms in group 2; P = 0.48) and amplitude (6.28 mv vs. 6.43 mv respectively; P = 0.8). Ultrasonography demonstrated tissue growth inside the chitosan tube. Gastrocnemius muscle weight showed no statistically significant difference. Histomorphometry of the distal sciatic nerve, 90 days post reconstructive procedure, showed similar number of myelinated fibers and size parameters in both groups (P ≥ 0.05). CONCLUSIONS: Chitosan hollow tube used for peripheral nerve reconstruction of rat sciatic nerve showed similar results in comparison to autologous nerve grafting. © 2015 Wiley Periodicals, Inc. Microsurgery 36:664-671, 2016.

Laser phototherapy (780 nm), a new modality in treatment of long-term incomplete peripheral nerve injury: a randomized double-blind placebo-controlled study.

OBJECTIVE: The authors conducted this pilot study to prospectively investigate the effectiveness of low-power laser irradiation (780 nm) in the treatment of patients suffering from incomplete peripheral nerve and brachial plexus injuries for 6 months up to several years. BACKGROUND DATA: Injury of a major nerve trunk frequently results in considerable disability associated with loss of sensory and motor functions. Spontaneous recovery of long-term severe incomplete peripheral nerve injury is often unsatisfactory. METHODS: A randomized, double-blind, placebo-controlled trial was performed on 18 patients who were randomly assigned placebo (non-active light: diffused LED lamp) or low-power laser irradiation (wavelength, 780 nm; power, 250 mW). Twenty-one consecutive daily sessions of laser or placebo irradiation were applied transcutaneously for 3 h to the injured peripheral nerve (energy density, 450 J/mm(2)) and for 2 h to the corresponding segments of the spinal cord (energy density, 300 J/mm(2)). Clinical and electrophysiological assessments were done at baseline, at the end of the 21 days of treatment, and 3 and 6 months thereafter. RESULTS: The laser-irradiated and placebo groups were in clinically similar conditions at baseline. The analysis of motor function during the 6-month follow-up period compared to baseline showed statistically significant improvement (p = 0.0001) in the laser-treated group compared to the placebo group. No statistically significant difference was found in sensory function. Electrophysiological analysis also showed statistically significant improvement in recruitment of voluntary muscle activity in the laser-irradiated group (p = 0.006), compared to the placebo group. CONCLUSION: This pilot study suggests that in patients with long-term peripheral nerve injury noninvasive 780-nm laser phototherapy can progressively improve nerve function, which leads to significant functional recovery.

Efficacy of 780-nm laser phototherapy on peripheral nerve regeneration after neurotube reconstruction procedure (double-blind randomized study).

OBJECTIVE: This pilot double-blind randomized study evaluated the efficacy of 780-nm laser phototherapy on the acceleration of axonal growth and regeneration after peripheral nerve reconstruction by polyglycolic acid (PGA) neurotube. BACKGROUND DATA: The use of a guiding tube for the reconstruction of segmental loss of injured peripheral nerve has some advantages over the regular nerve grafting procedure. Experimental studies have shown that laser phototherapy is effective in influencing nerve regeneration. METHODS: The right sciatic nerve was transected, and a 0.5-cm nerve segment was removed in 20 rats. A neurotube was placed between the proximal and the distal parts of the nerve for reconnection of nerve defect. Ten of 20 rats received post-operative, transcutaneous, 200-mW, 780-nm laser irradiation for 14 consecutive days to the corresponding segments of the spinal cord (15 min) and to the reconstructed nerve (15 min). RESULTS: At 3 months after surgery, positive somato-sensory evoked responses were found in 70% of the irradiated rats (p = 0.015), compared to 30% of the non-irradiated rats. The Sciatic Functional Index in the irradiated group was higher than in the non-irradiated group (p < 0.05). Morphologically, the nerves were completely reconnected in both groups, but the laser-treated group showed an increased total number of myelinated axons. CONCLUSION: The results of this study suggest that postoperative 780-nm laser phototherapy enhances the regenerative process of the peripheral nerve after reconnection of the nerve defect using a PGA neurotube.

Photobiomodulation Triple Treatment in Peripheral Nerve Injury: Nerve and Muscle Response.

BACKGROUND: Muscle preservation or decrease in muscle degeneration and progressive atrophy are major challenges in patients with severe peripheral nerve injury (PNI). Considerable interest exists in the potential therapeutic value of laser phototherapy (photobiomodulation) for restoring denervated muscle atrophy and for enhancing regeneration of severely injured peripheral nerves. As previously published, the laser phototherapy has a protective and immediate effect in PNI. Laser phototherapy in the early stages of muscle atrophy may preserve the denervated muscle by maintaining creatinine kinase (CK) activity and the amount of acetylcholine receptor (AChR). OBJECTIVE AND METHODS: In the present study, the effectiveness of triple treatment laser phototherapy, namely, applied simultaneously at three areas: injured area of the peripheral nerve, corresponding segments of the spinal cord, and corresponding denervated muscle (triple treatment), was evaluated for the treatment of incomplete PNI in rats with the ultimate goal of achieving improved limb function. RESULTS: Forty-five days after the sciatic nerve insult, all rats regained normal walking (functional sciatic index values returned to baseline); however, the long laser irradiation (7 min) group presented the fastest recovery as opposed to short laser irradiation (3 min). A histological evaluation of the nerves revealed that long laser irradiation led to a higher amount of neuronal fibers that were larger than 4 µm (543 ± 76.8, p < 0.01) than short irradiation (283 ± 35.36). A histological evaluation of muscular atrophy showed that long laser irradiation evolved with significantly less muscle atrophy (8.06% ± 1.23%, p < 0.05) than short irradiation (24.44% ± 7.26%). CONCLUSIONS: The present study and our previous investigations showed that the laser phototherapy increases biochemical activity and improves morphological recovery in muscle and, thus, could have direct therapeutic applications on muscle, especially during progressive atrophy resulting from PNI.

Regeneration of the transected rat sciatic nerve after suturing or adhesion with cyanoacrylate glue.

OBJECT: Traditional treatment of transected peripheral nerves has been by suturing the nerve ends to each other. Because this approach is not widely available and is technically demanding, the authors evaluated an easier method for end-to-end anastomosis using cyanoacrylate-based glue. METHODS: The authors used a rat sciatic nerve model. The sciatic nerve was transected in one hind limb in each of 40 rats. In 20 rats, end-to-end anastomosis was performed with suturing, while in the other 20 it was performed using only cyanoacrylate glue. The outcome variables were incapacitance test results; the functional sciatic index; somatosensory evoked potentials; axon counts and sizes at the proximal, anastomotic, and distal levels; local adhesions; and automutilation injuries. Outcomes were measured in a manner blinded to the anastomotic technique. RESULTS: Only the somatosensory evoked potentials and degree of local adhesions were significantly better in the Suture Group than in the Glue Group. With respect to the remaining outcomes (automutilation injuries, counts of large and medium axons combined, and counts of small axons), either the results were significantly better in the Glue Group or the between-groups difference was not statistically significant. There were no consistent significant correlations between the various outcome measures. CONCLUSIONS: Using cyanoacrylate-based glue for microanastomosis of cut nerves appears to be as effective as microsuturing the nerve ends. Despite more local adhesions in the glued nerves, most functional outcomes were not influenced by the anastomotic technique. Validation of these findings awaits studies of larger groups of animals.

Whiplash injury: is there a role for electromyographic studies?

INTRODUCTION: This retrospective study was undertaken to assess the value of carrying out baseline and follow-up electromyography (EMG) for patients with whiplash-associated disorders (WAD, grades I and II) after they had undergone rear-end car collisions, and to determine if there is any agreement with clinical and imaging (CT and MRI) findings. MATERIALS AND METHODS: We carried out a retrospective review of 330 patients seeking compensation after rear-end car collisions. The treating physician referred all patients for EMG studies in the post-injury follow-up period and for additional CT scans and MRIs. All patients underwent physical and X-ray examination by the senior author (SD), and 75 patients with persistent radicular complaints were referred again for EMG studies. The results of the association between patient complaints, clinical examination, and EMG, CT and MRI studies are reported. RESULTS: We sought but failed to find any correlations between 354 EMG results with those of 278 CT scans and 75 MRIs. Both subjective complaints and early vs late EMG abnormalities showed statistical agreement and persistency of findings only at disc level C7/D1. CONCLUSIONS: Our data indicate that follow-up EMG studies for patients with WAD do not contribute any useful information for patient management.

Whiplash injury--a retrospective study on patients seeking compensation.

The purpose of this cohort study is to evaluate the objective long-term findings and the final outcome of a population suffering from whiplash-associated disorders (WAD) after rear-end car collision and claiming legal compensation. Eight hundred and sixty-six patients after whiplash injury were followed up on average 32 months post-trauma. All patients had clinical examination and radiographs performed on the day of the accident and at follow up. MRI, CT scan, bone scan, electromyographic (EMG) tests were performed upon request of the treating physician and correlated by the authors with the clinical findings. Cervical pain was the most common complaint (96%). Radiating pain to one side of the upper limbs or the shoulder was also very common (36 and 24%, respectively). Chin to chest test was found to be a strong indicator in differentiating between the less severe (grades 1 and 2) to more severe (grades 3 and 4) WAD patients. In 10% of the patients with normal radiographic findings, degenerative changes were found at follow up. CT scan and MRI did not add to patient diagnosis, except for those patients suffering from degenerative changes and decreased range of motion (RoM). Based on our findings the initial radiograph taken in the emergency room was the best imaging modality and probably the only one needed routinely following whiplash injury. Although this is a special subgroup of patient seeking compensation, the overall prognosis is favorable in all grades of WAD injury and there is no need for further diagnostic expenditures.