Photobiomodulation of Pain in Carpal Tunnel Syndrome: Review of Seven Laser Therapy Studies

Therapeutic efficacy and safety of home-based portable laser irradiation on patients with wrist pain: a single-blinded randomized controlled trial

The purpose of this study is to confirm the effect of small, portable low-level laser therapy (light sources in square configuration: 830 nm GaAs diode 3.2 mW at the center, 4 × 650 nm InGaAIP diodes over the corners) treatment in reducing and enhancing hand function in patients with wrist pain. This study was a prospective, randomized, sham-controlled, and home-based self-therapy trial. A total of thirty subjects with wrist pain were enrolled. All participants received low-level laser therapy on painful area at the wrist. The experimental group (n = 15) received laser stimulation, while the control group (n = 15) received sham stimulation using identical equipment that generated only a red light without the laser output. Both groups self-treated for 30 min a day, 5 days per week for 3 weeks, total of 15 sessions. The primary outcome was assessed using a visual analogue scale (VAS) for wrist pain from 0 (painless) to 10 (extreme pain). The secondary outcomes were measured with patient-rated wrist evaluation (PRWE), grip strength, lateral, palmar, and tip pinch strength. Measures were taken before and after treatment. A total of thirty participants provided outcome data. After the intervention, both groups showed a significant decrease in VAS score, from 4.93 to 3.67 in experimental group, from 5.53 to 4.00 in control group (the experiment group: p = 0.020, the control group: p = 0.003). The experimental group showed a significant improvement in function scale score (p = 0.012), the control group did not. Lateral and pinch strength was significantly improved in the experimental group (p = 0.017) and in the control group (p = 0.034) respectively. There were no side effects in the patients. Medical laser irradiation is a portable and easy-to-use laser irradiator without side effects. Clinical Trial Registration number: KCT0006604.

A comprehensive review on therapeutic potentials of photobiomodulation for neurodegenerative disorders

A series of experimental trials over the past two centuries has put forth Photobiomodulation (PBM) as a treatment modality that utilizes colored lights for various conditions. While in its cradle, PBM was used for treating simple conditions such as burns and wounds, advancements in recent years have extended the use of PBM for treating complex neurodegenerative diseases (NDDs). PBM has exhibited the potential to curb several symptoms and signs associated with NDDs. While several of the currently used therapeutics cause adverse side effects alongside being highly invasive, PBM on the contrary, seems to be broad-acting, less toxic, and non-invasive. Despite being projected as an ideal therapeutic for NDDs, PBM still isn't considered a mainstream treatment modality due to some of the challenges and knowledge gaps associated with it. Here, we review the advantages of PBM summarized above with an emphasis on the common mechanisms that underlie major NDDs and how PBM helps tackle them. We also discuss important questions such as whether PBM should be considered a mainstay treatment modality for these conditions and if PBM's properties can be harnessed to develop prophylactic therapies for high-risk individuals and also highlight important animal studies that underscore the importance of PBM and the challenges associated with it. Overall, this review is intended to bring the major advances made in the field to the spotlight alongside addressing the practicalities and caveats to develop PBM as a major therapeutic for NDDs.

Laser Acupuncture as a Treatment Option for Carpal Tunnel Syndrome Management: a Case Series

Carpal tunnel syndrome (CTS) is disease that gives burdens for many countries, with a few choices for the management such as drugs or surgery, each has side effects that decrease the quality of life. Acupuncture is proven to be an effective treatment for pain and can restore nerve functions, and laser acupuncture is one of the modalities. This study aims to assess the effectiveness of laser acupuncture with total sample of 3 patients (6 wrists) mostly with tingling sensations and the outcomes are Boston questionnaire (BCTQ), visual analogue scale (VAS), Tinel sign, Phalen sign, and parameters of nerve conduction study (NCS). Acupuncture points used here are PC6, PC7, EXUE9, and LI4. The results show a decrease in NCS grades for 3 wrists, all wrists have BCTQ score improvements, a decrease in VAS, but no significant improvement in Tinel and Phalen signs. It is concluded that laser acupuncture can be used as a treatment option for the management of carpal tunnel syndrome.

Photobiomodulation for Alzheimer's Disease: Translating Basic Research to Clinical Application

One of the challenges in translating new therapeutic approaches to the patient bedside lies in bridging the gap between scientists who are conducting basic laboratory research and medical practitioners who are not exposed to highly specialized journals. This review covers the literature on photobiomodulation therapy as a novel approach to prevent and treat Alzheimer's disease, aiming to bridge that gap by gathering together the terms and technical specifications into a single concise suggestion for a treatment protocol. In light of the predicted doubling in the number of people affected by dementia and Alzheimer's disease within the next 30 years, a treatment option which has already shown promising results in cell culture studies and animal models, and whose safety has already been proven in humans, must not be left in the dark. This review covers the mechanistic action of photobiomodulation therapy against Alzheimer's disease at a cellular level. Safe and effective doses have been found in animal models, and the first human case studies have provided reasons to undertake large-scale clinical trials. A brief discussion of the minimally effective and maximum tolerated dose concludes this review, and provides the basis for a successful translation from bench to bedside.

The Effects of Nerve and Tendon Gliding Exercises Combined with Low-level Laser or Ultrasound Therapy in Carpal Tunnel Syndrome

BACKGROUND

Carpal tunnel syndrome (CTS) is a common medical condition that doctors and physiotherapists come across in clinical practice. There are no explicit recommendations concerning which physical therapy methods should be applied in its treatment; however, there have also been no studies on the effects of combining low-level laser therapy (LLLT) or ultrasound with nerve and tendon gliding exercises. The purpose of this study was to evaluate the therapeutic efficacy of ultrasound and LLLT combined with gliding exercises.

MATERIALS AND METHODS

A total of seventy patients with mild to moderate CTS, divided into two groups, were included in this study. Group 1 received ultrasound treatment, whereas Group 2 underwent LLLT. The treatment lasted 2 weeks (5 sessions/week). In addition, both groups were treated with nerve and tendon gliding exercises three times daily. The clinical evaluation involved an interview on subjective and objective sensory abnormalities, the intensity of pain, the measurement of grip strength, Phalen's test, Tinel's sign, and the Boston Carpal Tunnel Questionnaire. The assessment was performed before and after the treatment.

RESULTS

A decrease in sensory impairments, improvement in visual analog scale, hand grip strength and the Boston Questionnaire results were significant in all patients after therapy. No meaningful differences between groups were noted in any of the examined variables after treatment. No adverse effects were observed.

CONCLUSIONS

The results of this study may suggest the clinical efficacy of LLLT or ultrasound combined with gliding exercises in patients with mild to moderate CTS.

Treatment of mild to moderate carpal tunnel syndrome in patients with diabetic neuropathy using low level laser therapy versus ultrasound controlled comparative study

AIM

The aim of the present study was to investigate and compare between Low Level Laser Therapy (LLLT) and Ultrasound (US) in treatment of Carpal Tunnel Syndrome (CTS) using the advantage of application of treatment directly over the transverse carpal ligament, as well as over the course of the median nerve in the forearm simultaneously.

DESIGN

Fifty patients (25-55 years) with diabetic neuropathy, diagnosed as unilateral carpal tunnel syndrome participated in the study. They were equally divided and randomly assigned into two groups; each group consisted of 25 patients.

MATERIALS AND METHODS

Patients in group (A) received a program of IR Gallium Arsenide LLLT (wavelength 904 nm, average power 20 mW, laser probe 7 mm diameter), with a total application of 4.8 J, while patients in group (B) received a program of US (frequency 1 MHz, power 1.0 W/cm2, pulsed mode 1:5).

RESULTS & DISCUSSION

The results of our study showed that there were no statistical significance differences (P > 0.05) were observed between the two groups. It was concluded that both low level laser (20 mW power, 904 nm Wavelength) and ultrasound (1.0 w/cm2 power, 1 MHz frequency) are effective in the treatment of mild and moderate CTS patients.

Efficacy of low-level laser therapy in carpal tunnel syndrome management: a systematic review and meta-analysis

We performed this meta-analysis to investigate the efficacy of low-level laser therapy (LLLT), a physiotherapy modality with anti-inflammatory and analgesic effects, in the management of mild-to-moderate carpal tunnel syndrome (CTS). We searched PubMed, Web of Knowledge, Scopus, Cochrane Central, and Virtual Health Library for randomized controlled trials (RCTs) that compared the effects of LLLT with or without splinting versus placebo on functional and electromyographic outcomes in CTS. All outcomes were pooled as mean differences (MD) under the inverse variance or random effects model, using the statistical add-in (MetaXL, version 5.0). Eight RCTs (473 patients/631 wrists) were eligible for the final analysis. The overall effect estimates did not favor LLLT therapy group over placebo in all primary outcomes: visual analogue scale (MD -1.11, 95% CI [-2.58, 0.35]), symptom severity scale score (MD -1.41, 95% CI [-5.12, 2.29]), and functional status scale score (MD -1.33, 95% CI [-3.27, 0.61]). However, LLLT was superior to placebo in terms of grip strength (MD 2.19, 95% CI [1.63, 2.76]) and inferior to placebo in terms of sensory nerve action potential (MD -2.74, 95% CI [-3.66, -1.82]). Laser therapy is superior to placebo in terms of improving the grip strength; however, no significant difference was found between both groups in terms of functional status improvement, pain reduction, or motor electrodiagnostic evaluations. Further high-quality trials with longer follow-up periods are required to establish the efficacy of LLLT for CTS treatment.

Rehabilitation Principles of the Anterior Cruciate Ligament Reconstructed Knee: Twelve Steps for Successful Progression and Return to Play

The rehabilitation process begins immediately after injury to the anterior cruciate ligament (ACL). The goal of preoperative rehabilitation is to prepare the patient for surgery. Current rehabilitation programs focus on strengthening exercises and proprioceptive and neuromuscular control drills to provide a neurologic stimulus. It is also important to address preexisting factors, especially for the female athlete, that may predispose to future injury, such as hip and hamstring weakness. Our goal in the rehabilitation program is to restore full, unrestricted function and to assist the patient to return to 100% of the preinjury level while achieving excellent long-term outcomes.

Low-power laser therapy for carpal tunnel syndrome: effective optical power

Low-power laser therapy has been used for the non-surgical treatment of mild to moderate carpal tunnel syndrome, although its efficacy has been a long-standing controversy. The laser parameters in low-power laser therapy are closely related to the laser effect on human tissue. To evaluate the efficacy of low-power laser therapy, laser parameters should be accurately measured and controlled, which has been ignored in previous clinical trials. Here, we report the measurement of the effective optical power of low-power laser therapy for carpal tunnel syndrome. By monitoring the backside reflection and scattering laser power from human skin at the wrist, the effective laser power can be inferred. Using clinical measurements from 30 cases, we found that the effective laser power differed significantly among cases, with the measured laser reflection coefficient ranging from 1.8% to 54%. The reflection coefficient for 36.7% of these 30 cases was in the range of 10-20%, but for 16.7% of cases, it was higher than 40%. Consequently, monitoring the effective optical power during laser irradiation is necessary for the laser therapy of carpal tunnel syndrome.

Red LED photobiomodulation reduces pain hypersensitivity and improves sensorimotor function following mild T10 hemicontusion spinal cord injury

Background

The development of hypersensitivity following spinal cord injury can result in incurable persistent neuropathic pain. Our objective was to examine the effect of red light therapy on the development of hypersensitivity and sensorimotor function, as well as on microglia/macrophage subpopulations following spinal cord injury.

Methods

Wistar rats were treated (or sham treated) daily for 30 min with an LED red (670 nm) light source (35 mW/cm²), transcutaneously applied to the dorsal surface, following a mild T10 hemicontusion injury (or sham injury). The development of hypersensitivity was assessed and sensorimotor function established using locomotor recovery and electrophysiology of dorsal column pathways. Immunohistochemistry and TUNEL were performed to examine cellular changes in the spinal cord.

Results

We demonstrate that red light penetrates through the entire rat spinal cord and significantly reduces signs of hypersensitivity following a mild T10 hemicontusion spinal cord injury. This is accompanied with improved dorsal column pathway functional integrity and locomotor recovery. The functional improvements were preceded by a significant reduction of dying (TUNEL⁺) cells and activated microglia/macrophages (ED1⁺) in the spinal cord. The remaining activated microglia/macrophages were predominantly of the anti-inflammatory/wound-healing subpopulation (Arginase1⁺ED1⁺) which were expressed early, and up to sevenfold greater than that found in sham-treated animals.

Conclusions

These findings demonstrate that a simple yet inexpensive treatment regime of red light reduces the development of hypersensitivity along with sensorimotor improvements following spinal cord injury and may therefore offer new hope for a currently treatment-resistant pain condition.

Placebo-controlled investigation of low-level laser therapy to treat carpal tunnel syndrome

OBJECTIVE

This study investigated the short-term efficacy of low-level laser therapy (LLLT) in patients with mild to moderate carpal tunnel syndrome (CTS), lasting for <1 year.

METHODS

Seventy-nine patients with CTS were included in this double-blind, placebo-controlled study, and randomly divided in two treatment groups: Experimental group (EG), active laser group (40 patients); and control group (CG), placebo (sham) laser group (39 patients). A GaAlAs diode laser [780 nm, 30 mW continuous wave (CW), 0.785 cm(2), 38.2 mW/cm(2)] was applied in contact with four points perpendicularly to the skin over the carpal tunnel area for 90 sec per point (2.7 J, 3.4 J/cm(2)/point). Both groups were treated five times per week, once a day over 2 weeks, followed by 10 treatments every other day for 3 weeks, that is, for a total of 20 treatments. Clinical assessment, including visual analogue scale (VAS) pain rating, Tinel's sign, and median nerve conduction studies (NCSs) were evaluated before, and 3 weeks after, the last LLLT treatment.

RESULTS

Significant reduction in pain, reduction in the percentage of patients with a positive Tinel's sign, and shortening of sensory and motor latency time in the NCS examination was observed in the experimental LLLT group (but not in the control group).

CONCLUSIONS

This study has observed and documented the statistically significant short-term effects of LLLT on CTS patients in comparison with a placebo group. The results support this conclusion, especially if the LLLT is applied in the earlier stages of CTS, and with mild to moderate cases.

Electrophysiological effects of single point transcutaneous 650 and 808 nm laser irradiation of rat sciatic nerve: a study of relevance for low-level laser therapy and laser acupuncture

OBJECTIVE

The purpose of this study was to evaluate effects of transcutaneous 650 and 808 nm laser irradiation (LI) to a single point overlying rat sciatic nerve; a comparison to four point LI and relevance to the clinical application of low-level laser therapy (LLLT) and laser acupuncture (LA).

BACKGROUND DATA

Transcutaneous LI inhibits somatosensory and motor conduction when delivered to four points overlying sciatic nerve; however, effects of the same total energy delivered to a single point over the nerve, equating to laser acupuncture, are undefined.

METHODS

Transcutaneous 808 nm, 450 mW, (13.5 or 54 J) continuous wave (cw) mode or 650 nm, 35 mW, (1.1 or 4.4 J), cw LI or sham LI, was applied for 30 or 120 sec to a single point overlying the midpoint of rat sciatic nerve. Somatosensory evoked potentials (SSEPs) and compound muscle action potentials (CMAPs) were then recorded after 10 and 20 min, and after 24 and 48 h.

RESULTS

120 sec of 808 nm LI increased SSEP amplitudes only at 10 min, with no effect of 30 or 120 sec at other time points on SSEPs or on CMAPs. LI 650 nm for 30 or 120 sec did not alter SSEPs or CMAPs at any time point.

CONCLUSIONS

Localized transcutaneous 808 LI to a single point overlying sciatic nerve increases SSEP amplitudes when compared with delivery of the same total energy to four points, which causes decreased SSEP amplitudes and conduction block. Therefore, the area and duration of delivery are important, independent variables with implications for clinical delivery of both LLLT and LA.

Recent advances in the rehabilitation of anterior cruciate ligament injuries

Rehabilitation following anterior cruciate ligament surgery continues to change, with the current emphasis being on immediate weight bearing and range of motion, and progressive muscular strengthening, proprioception, dynamic stability, and neuromuscular control drills. The rehabilitation program should be based on scientific and clinical research and focus on specific drills and exercises designed to return the patient to the desired functional goals. The goal is to return the patient's knee to homeostasis and the patient to his or her sport or activity as safely as possible. Unique rehabilitation techniques and special considerations for the female athlete will also be discussed. The purpose of this article is to provide the reader with a thorough scientific basis for anterior cruciate ligament rehabilitation based on graft selection, patient population, and concomitant injuries.

Therapeutic modalities--an updated review for the hand surgeon

The number of therapeutic modalities available to the hand surgeon has greatly increased over the past several decades. A field once predicated only on heat, massage, and cold therapy now uses electrical stimulators, ultrasound, biofeedback, iontophoresis, phonophoresis, mirror therapy, lasers, and a number of other modalities. With this expansion in choices, there has been a concurrent effort to better define which modalities are truly effective. In this review, we aim to characterize the commonly used modalities and provide the evidence available that supports their continued use.

Biophoton detection and low-intensity light therapy: a potential clinical partnership

Low-intensity light therapy (LILT) is showing promise in the treatment of a wide variety of medical conditions. Concurrently, our knowledge of LILT mechanisms continues to expand. We are now aware of LILT's potential to induce cellular effects through, for example, accelerated ATP production and the mitigation of oxidative stress. In clinical use, however, it is often difficult to predict patient response to LILT. It appears that cellular reduction/oxidation (redox) state may play a central role in determining sensitivity to LILT and may help explain variability in patient responsiveness. In LILT, conditions associated with elevated reactive oxygen species (ROS) production, e.g. diabetic hyperglycemia, demonstrate increased sensitivity to LILT. Consequently, assessment of tissue redox conditions in vivo may prove helpful in identifying responsive tissues. A noninvasive redox measure may be useful in advancing investigation in LILT and may one day be helpful in better identifying responsive patients. The detection of biophotons, the production of which is associated with cellular redox state and the generation of ROS, represents just such an opportunity. In this review, we will present the case for pursuing further investigation into the potential clinical partnership between biophoton detection and LILT.

Low-Level Laser Therapy Effectiveness for Reducing Pain after Breast Augmentation

Introduction:

The purpose of this Institutional Review Board (IRB)-approved, placebo-controlled, randomized, double-blinded parallel-grouped, multicenter trial was to determine the effectiveness of low-level laser therapy (LLLT) in decreasing patients' postoperative pain 24 hours post breast augmentation surgery.

Materials and Methods:

The Erchonia EML, 630–640 nm, (Erchonia Medicial, Inc., McKinney, Texas) with 2 7-mw laser-emitting diodes was used within 10 minutes of the start of the procedure over each breast for 4 minutes at a distance of 6 inches. This was repeated within 10 minutes of completion of the procedure with the same methodology. One hundred and four (104) patients participated in the study, 50 test subjects and 54 controls. Primary investigator and patient were blinded with respect to treatment group.

Results:

The success criteria for this study using the standardized Visual Analogue Scale (VAS) was a self-reported degree-of-pain rating of less than 30 at 24 hours after the implant procedure. At this time the patient had not taken pain medication for 4 hours. Overall study success criteria were defined as at least 30% difference between treatment groups with respect to proportion of successes. At the 24-hour time interval 37 (74%) of the test subjects and 20 (37%) of the control subjects met the success criteria, a difference of 37% (p<.0002). The amount of pain medication used over the first 7 days post operatively was measured as a covariant. The test subjects used less medication 848 versus 932 total doses (p<.01).

Conclusion:

Low-level laser therapy is effective at significantly decreasing postoperative pain and the amount of pain medication needed after breast augmentation at 1 day and 1 week respectfully. All other covariants studied including, implant type, implant size, incision size, implant location, test site location, amount of swelling measurements, hydration level, and adverse events were found to be neglible.

Low-level laser irradiation inhibits abdominal aortic aneurysm progression in apolipoprotein E-deficient mice

AIMS

Increased early detection of abdominal aortic aneurysm (AAA) and the severe complications of its current treatment have emphasized the need for alternative therapeutic strategies that target pathogenetic mechanisms of progression and rupture. Recent in vitro studies from our laboratory have shown that low-level laser irradiation (LLLI) (780 nm) modifies cellular processes fundamental to aneurysm progression. The present study was designed to determine whether LLLI retards the progression of suprarenal AAA in vivo.

METHODS AND RESULTS

High-frequency ultrasonography (0.01 mm resolution) was used to quantify the effect of LLLI on aneurysmatic aortic dilatation from baseline to 4 weeks after subcutaneous infusion of angiotensin II by osmotic minipumps in the apolipoprotein E-deficient mouse. At 4 weeks, seven of 15 non-irradiated, but none of the 13 LLLI, mice had aneurysmal dilatation in the suprarenal aneurysm-prone segments that had progressed to >or=50% increase in maximal cross-sectional diameter (CSD) over baseline (P = 0.005 by Fisher's exact test). The mean CSD of the suprarenal segments (normalized individually to inter-renal control segments) was also significantly lower in irradiated animals (LLLI vs. non-irradiated: 1.32 +/- 0.14 vs. 1.82 +/- 0.39, P = 0.0002 by unpaired, two-tailed t-test) with a 94% reduction in CSD at 4 weeks compared with baseline. M-mode ultrasound data showed that reduced radial wall velocity seen in non-treated was significantly attenuated in the LLLI mice, suggesting a substantial effect on arterial wall elasticity.

CONCLUSION

These in vivo studies, together with previous in vitro studies from this laboratory, appear to provide strong evidence in support of a role for LLLI in the attenuation of aneurysm progression. Further studies in large animals would appear to be the next step towards testing the applicability of this technology to the human interventional setting.

Carpal tunnel syndrome treated with a diode laser: a controlled treatment of the transverse carpal ligament

OBJECTIVE

The purpose of this placebo-controlled study was to investigate the therapeutic effects of the 830-nm diode laser on carpal tunnel syndrome (CTS).

BACKGROUND DATA

Many articles in the literature have demonstrated that low-level laser therapy (LLLT) may help to alleviate various types of nerve pain, especially for CTS treatment. We placed an 830-nm laser directly above the transverse carpal ligament, which is between the pisiform and navicular bones of the tested patients, to determine the therapeutic effect of LLLT.

MATERIALS AND METHODS

Thirty-six patients with mild to moderate degree of CTS were randomly divided into two groups. The laser group received laser treatment (10 Hz, 50% duty cycle, 60 mW, 9.7 J/cm(2), at 830 nm), and the placebo group received sham laser treatment. Both groups received treatment for 2 wk consisting of a 10-min laser irradiation session each day, 5 d a week. The therapeutic effects were assessed on symptoms and functional changes, and with nerve conduction studies (NCS), grip strength assessment, and with a visual analogue scale (VAS), soon after treatment and at 2-wk follow-up.

RESULTS

Before treatment, there were no significant differences between the two groups for all assessments (p > 0.05). The VAS scores were significantly lower in the laser group than the placebo group after treatment and at follow-up (p < 0.05). After 2 wk of treatment, no significant differences were found in grip strengths or for symptoms and functional assessments (p > 0.05). However, there were statistically significant differences in these variables at 2-wk follow-up (p < 0.05). Regarding the findings of NCS, there was no statistically significant difference between groups after treatment and at 2-wk follow-up.

CONCLUSIONS

LLLT was effective in alleviating pain and symptoms, and in improving functional ability and finger and hand strength for mild and moderate CTS patients with no side effects.