Effects of linear-polarized near-infrared light irradiation on chronic pain

Effectiveness of polarized polychromatic light therapy on myofascial trigger points in chronic non-specific low back pain: a single blinded randomized controlled trial

Background

Phototherapy has been used for the treatment of chronic low back pain. However, the effect of linear polarized polychromatic light (PL) has not been examined on myofascial trigger points in patients with chronic non-specific low back pain (NSLBP).

Objectives

To investigate the effectiveness of PL on pain intensity, pain sensitivity of active myofascial trigger points (MTrPs) in gluteus medius (GM) and quadratus lamborum (QL) muscles, back disability, and lumbar range of motion in chronic NSLBP.

Methods

Forty-two participants of both genders with chronic NSLBP were randomly allocated into two equal groups: group A (Linear polarized polychromatic light (PL): 21 participants received polarized light therapy in the range of red and near-infrared rays on myofascial trigger points of bilateral GM and QL muscles for 5 min/point followed by stretching and strengthening exercises for 4 weeks. Group B (Sham PL): 21 participants received the same program but with sham linear polarized polychromatic light therapy. Numeric pain rating scale, pressure algometer, and Roland-Morris Disability Questionnaire were used to measure pain intensity, pain sensitivity (as represented by pain pressure threshold (PPT) of MTrPs of the target muscles and back disability respectively. Further, lumbar flexion, extension, and bilateral rotation were examined with a tape measure, while bilateral side bending were examined with a universal goniometer.

Results

After the intervention program, significant improvements (p < 0.05) in pain intensity, PPT of MTrPs of left GM (Effect Size (ES): 1.23) and bilateral QL muscles (ES Rt QL: 0.9; Lt QL: 1.56) were found in group A in comparison with group B. Nevertheless, the two groups displayed similar improvements (p > 0.05) in lumbar range of motion and back disability.

Conclusion

Linear polarized polychromatic light therapy in the range of red and near-infrared rays improves pain intensity and pain sensitivity of myofascial trigger points in chronic NSLBP.

Trial registration

PACTR, PACTR202111577053926. Registered 22 June 2019-Prospectively registered.

Analgesia for Sheep in Commercial Production: Where to Next?

Simple Summary

Increasing societal and customer pressure to provide animals with ‘a life worth living’ continues to apply pressure on industry to alleviate pain associated with husbandry practices, injury and illness. Although a number of analgesic solutions are now available for sheep, providing some amelioration of the acute pain responses, this review has highlighted a number of potential areas for further research.

Abstract

Increasing societal and customer pressure to provide animals with ‘a life worth living’ continues to apply pressure on livestock production industries to alleviate pain associated with husbandry practices, injury and illness. Over the past 15–20 years, there has been considerable research effort to understand and develop mitigation strategies for painful husbandry procedures in sheep, leading to the successful launch of analgesic approaches specific to sheep in a number of countries. However, even with multi-modal approaches to analgesia, using both local anaesthetic and non-steroidal anti-inflammatory drugs (NSAID), pain is not obliterated, and the challenge of pain mitigation and phasing out of painful husbandry practices remains. It is timely to review and reflect on progress to date in order to strategically focus on the most important challenges, and the avenues which offer the greatest potential to be incorporated into industry practice in a process of continuous improvement. A structured, systematic literature search was carried out, incorporating peer-reviewed scientific literature in the period 2000–2019. An enormous volume of research is underway, testament to the fact that we have not solved the pain and analgesia challenge for any species, including our own. This review has highlighted a number of potential areas for further research.

Thermographic follow-up of postherpetic neuralgia (PHN) subsequent to Ramsay Hunt syndrome with multicranial nerve (V, VII, VIII and IX) involvement: a case report

Background

Ramsay Hunt syndrome (RHS) is caused by a reactivation of varicella-zoster virus (VZV) infection, and it is characterized by the symptoms of facial paralysis, otalgia, auricular rash, and/or an oral lesion. Elderly patients or immunocompromised patients, deep pain at the initial visit and no prompt treatment are significant predictors of postherpetic neuralgia (PHN). When PHN occurs, especially involved cranial polyneuropathy, multiple modalities should be administered for patients with the intractable PHN. The use of thermography in the follow-up of PHN secondary to RHS with multicranial nerve involvement has not yet been described yet in the literature.

Case presentation

The patient was a 78-year-old man with the chief complaint of a 3-month history of PHN secondary to RHS with polycranial nerve (V, VII, VIII, and IX) involvement. Multimodality therapy with oral gabapentin, pulsed radiofrequency (PRF) application to the Gasserian ganglion for pain in the trigeminal nerve region, linear-polarized near-infrared light irradiation for pain in the facial nerve region, and 2% lidocaine spray for pain in the glossopharyngeal nerve region was used to the treat patient, and follow-up evaluations included thermography. This comprehensive treatment obviously improved the quality of life, resulting in considerable pain relief, as indicated by a decrease in the numerical rating scale (NRS) score from 9 to 3 and a decrease in thermal imaging temperature from higher to average temperature on the ipsilateral side compared with the contralateral side. Lidocaine spray on the tonsillar branches of the glossopharyngeal nerve resulted in an improvement in odynophagia, and the NRS score decreased from 9 to 0 for glossopharyngeal neuralgia after three applications.

Conclusion

Although the use of thermography in the follow-up of RHS with multiple cranial nerve (V, VII, VIII, and IX) involvement is very rare, in this patient, thermal imaging showed the efficacy of combination therapy (oral gabapentin, 2% lidocaine sprayed, PRF application and linear-polarized near-infrared light irradiation) and that is a good option for treatment.

Determining the Effectivity of Infrared Distance to Eliminate Dental Pain Due to Pulpitis and Periodontitis

OBJECTIVE

 The infrared rays is one of the treatments to relief of dental pain due to pulpitis or periodontitis. The ability of infrared to increase the pain threshold which make eliminating P substance on the inflammation area and inducing Aβ and Aδ fibers to activate γ-aminobutyrate (GABA) and neuropeptides to decrease the pain. Hence, reducing or eliminating dental pain. This study to get information about effectively distance between patients and infrared rays which can reduce or eliminate dental pain.

MATERIALS AND METHODS

 The explorative experimental research to determine the effectivity of the infrared rays' distance: 45, 55, and 55 cm in reducing or eliminating dental pain. The material of infrared was tungsten with luminous light and the time for the lighting was 15 minutes.

STATISTICAL ANALYSIS

 The data were obtained and analyzed using Wilcoxon's signed rank test and Kruskal-Wallis test (α= 0.05).

RESULTS

  There were influenced of the infrared rays to reduce the dental pain as follow, distance 45 cm (p = 0.007), distance 55 cm (p = 0.026), and distance 65 cm (p = 0.007). The average scale reduction for distance 45 cm was 2.23 ± 0.83, the distance 55 cm was 3.33 ± 0.87, and the distance 65 cm was (1.78 ± 0.83). Therefore, according to Kruskal-Wallis test with p = 0.004 (p < 0.05) showed the significant difference between the scale to decrease of dental pain was the distance of 55.

CONCLUSION

 Infrared rays located at a distance of 55 cm from patients might be more effective in relieving dental pain, compared with other distances tested.

Robotic therapy for the hemiplegic shoulder pain: a pilot study

Backgrounds

Exoskeletons development arises with a leading role in neurorehabilitation technologies; however, very few prototypes for upper limbs have been tested, contrasted and duly certified in terms of their effectiveness in clinical environments in order to incorporate into the health system. The purpose of this pilot study was to determine if robotic therapy of Hemiplegic Shoulder Pain (HSP) could lead to functional improvement in terms of diminishing of pain, spasticity, subluxation, the increasing of tone and muscle strength, and the satisfaction degree.

Methods

An experimental study was conducted in 16 patients with painful shoulder post- ischemic stroke in two experimental groups: conventional and robotic therapy. At different stages of its evolution, the robotic therapy effectiveness applied with anti-gravitational movements was evaluated. Clinical trial was developed at the Physical Medicine and Rehabilitation Department of the Surgical Clinical Hospital “Dr. Juan Bruno Zayas Alfonso” in Santiago de Cuba, from September 2016 - March 2018. Among other variables: the presence of humeral scapular subluxation (HSS), pain, spasticity, mobility, tone and muscle strength, and the satisfaction degree were recorded. Results with 95% reliability were compared between admission and third months of treatment. The Mann-Whitney U-Test, Chi-Square and Fisher’s Exact Tests were used as comparison criteria.

Results

Robotic therapy positively influenced in the decrease and annulment of pain and the spasticity degree, reaching a range increase of joint movement and the improvement of muscle tone.

The Effectiveness of the Polarized Low-Level Laser in the Treatment of Patients With Myofascial Trigger Points in the Trapezius Muscles

Introduction: This study assessed the effect of polarized low-level laser therapy (PLLLT) on the treatment of myofascial trigger points (MTrPs) in the trapezius muscles. Its effectiveness in pain reduction was compared to low-level laser therapy (LLLT). Methods: Sixty-four patients with MTrPs were randomly divided into 2 groups, namely PLLLT and LLLT. Each patient received treatment for a period of 2 weeks, 5 sessions a week. The intensity of laser irradiation to the skin surface was 6 J/cm² . The system exit power was 160 mw at a 755 nm wavelength. The visual analog scale (VAS) for the 1st, 5th and 10th sessions was analyzed through two-way repeated measures ANOVA. Results: Increasing the number of treatment sessions was effective in reducing pain intensity (P>0.05). The effect of LLLT on pain reduction was significantly greater than that of PLLLT (P>0.05). Referred pain (RP), the limitation of neck movement (LNM), the presence of muscular taut band (PMTB) and the sensitivity of muscular taut band (SMTB) were reduced significantly by the end of the 10th session, compared with participants' condition at the beginning of the 1st session in both groups. Conclusion: PLLLT and LLLT can effectively treat MTrPs in the trapezius muscles and they reduce RP, LNM, PMTB, and SMTB in particular. However, the effect of the LLLT was significantly greater than that of PLLLT. In accordance with the observed results, LLLT is recommended as an effective method for treating MTrPs.

Efficacy of Stellate Ganglion Blockade Applied with Light Irradiation: A Systemic Review and Meta-analysis

OBJECTIVE

Stellate ganglion block has mostly been used to relieve symptoms of neuropathic pain; several potential complications have been reported. Noninvasive stellate ganglion block application using light irradiation (SG-LI) can be used as an alternative to conventional injection blockades. Based on the variety of application protocols among previous studies, it was needed to further identify the clinical efficacy of SG-LI in managing neuropathic pain or other disorders associated with sympathetic hyperactivity.

DESIGN

A comprehensive search of online databases was performed to identify experimental or observational studies reporting the efficacy of SG-LI in treating patients with disorders requiring sympatholytic management. The included studies were subjected to a meta-analysis and risk-of-bias assessment.

RESULTS

Twenty-one experimental studies with a Physiotherapy Evidence Database score of 6/10 and 5 observational studies with a Newcastle-Ottawa scale score of 7/9 were included in the analysis. A significant effect on pain relief favoring SG-LI was identified at a standard mean difference (SMD) of -2.05 [95% confidence interval (CI), -2.49 to -1.61; P < 0.00001]. Similar effects favoring SG-LI were found in peripheral blood flow (SMD, 1.26; 95% CI, 0.26-2.25; P = 0.01) and skin temperature (SMD, 1.31; 95% CI, 0.55, 2.08; P = 0.0007).

CONCLUSIONS

Stellate ganglion block application using light irradiation effectively relieves pain of various etiologies and successfully induces a sympatholytic response. Stellate ganglion block application using light irradiation may be a valuable addition to the contemporary pain management armamentarium.

Efficacy of Noninvasive Stellate Ganglion Blockade Performed Using Physical Agent Modalities in Patients with Sympathetic Hyperactivity-Associated Disorders: A Systematic Review and Meta-Analysis

BACKGROUND

Stellate ganglion blockade (SGB) is mainly used to relieve symptoms of neuropathic pain in conditions such as complex regional pain syndrome and has several potential complications. Noninvasive SGB performed using physical agent modalities (PAMs), such as light irradiation and electrical stimulation, can be clinically used as an alternative to conventional invasive SGB. However, its application protocols vary and its clinical efficacy remains controversial. This study investigated the use of noninvasive SGB for managing neuropathic pain or other disorders associated with sympathetic hyperactivity.

MATERIALS AND METHODS

We performed a comprehensive search of the following online databases: Medline, PubMed, Excerpta Medica Database, Cochrane Library Database, Ovid MEDLINE, Europe PubMed Central, EBSCOhost Research Databases, CINAHL, ProQuest Research Library, Physiotherapy Evidence Database, WorldWideScience, BIOSIS, and Google Scholar. We identified and included quasi-randomized or randomized controlled trials reporting the efficacy of SGB performed using therapeutic ultrasound, transcutaneous electrical nerve stimulation, light irradiation using low-level laser therapy, or xenon light or linearly polarized near-infrared light irradiation near or over the stellate ganglion region in treating complex regional pain syndrome or disorders requiring sympatholytic management. The included articles were subjected to a meta-analysis and risk of bias assessment.

RESULTS

Nine randomized and four quasi-randomized controlled trials were included. Eleven trials had good methodological quality with a Physiotherapy Evidence Database (PEDro) score of ≥6, whereas the remaining two trials had a PEDro score of <6. The meta-analysis results revealed that the efficacy of noninvasive SGB on 100-mm visual analog pain score is higher than that of a placebo or active control (weighted mean difference, -21.59 mm; 95% CI, -34.25, -8.94; p = 0.0008).

CONCLUSIONS

Noninvasive SGB performed using PAMs effectively relieves pain of various etiologies, making it a valuable addition to the contemporary pain management armamentarium. However, this evidence is limited by the potential risk of bias.

Effect of high-intensity pulse irradiation with linear polarized near-infrared rays on muscle tone in patients with cerebrovascular disease: a randomized controlled trial

[Purpose] This study evaluated effects of a high-intensity linear polarized near-infrared ray irradiation for mitigation of muscle hypertonia. [Subjects] The subjects were 20 patients with cerebrovascular disease. [Methods] Subjects were randomly allocated to an intervention or control group. The intervention group received irradiation of the triceps surae. Passive range of motion and passive resistive joint torque of ankle dorsiflexion were measured before and after the intervention in knee extended and flexed positions. [Results] In the knee extended position, the mean changes in passive range of motion were 2.70° and -0.50° in the intervention and control groups, respectively, and the mean changes in passive resistive joint torque were -1.42 and -0.26 N·m in the intervention and control groups, respectively. In the knee flexed position, the mean changes in passive range of motion were 3.70° and 0.70° in the intervention and control groups, respectively, and the mean changes in passive resistive joint torque were -2.38 and -0.31 N·m in the intervention and control groups, respectively. In both knee positions, the mean changes in the two indices were greater in the intervention group than in the control group. [Conclusion] High-intensity linear polarized near-infrared ray irradiation increases passive range of motion and decreases passive resistive joint torque.