The Effect of High-Power and Low-Power Lasers on Symptoms and the Nerve Conduction Study in Patients With Carpal Tunnel Syndrome. A Prospective Randomized Single-Blind Clinical Trial

A systematic review and meta-analysis of the effectiveness of high-intensity laser therapy in patients with carpal tunnel syndrome

OBJECTIVES

This systematic review aimed to evaluate the effects of high-intensity laser therapy (HILT) on pain intensity, disability, and electrophysiological parameters in individuals diagnosed with carpal tunnel syndrome (CTS).

DATA SOURCES AND SYNTHESIS

A search of electronic databases, including PubMed, Web of Science, Scopus, CINAHL, Science Direct, Cochrane Library, the PEDro database, and Google Scholar (updated until February 18, 2025), was conducted for randomized controlled trials (RCTs).

DATA EXTRACTION AND QUALITY ASSESSMENT

Data were extracted independently by three researchers. The quality of RCTs was assessed using the Cochrane Risk of Bias (RoB) 2.0 tool, while evidence certainty was evaluated with the GRADE approach. Primary outcomes included pain intensity, with secondary outcomes comprising electrophysiological parameters and disability.

RESULTS

Nine RCTs met inclusion criteria. Most studies exhibited a low risk of bias across RoB2 domains, except for outcome measurement, resulting in an overall RoB of 44%. Meta-analyses demonstrated that HILT, alone or combined with interventions such as splinting, exercise, TENS, vitamin B supplements, or ergonomic modifications, significantly reduced pain (SMD = 0.7 to 1.6) and disability (SMD = 0.68). Electrophysiological improvements included enhanced distal motor latency (SMD = 0.98) and sensory conduction velocity (SMD = 0.8), particularly when combined with median nerve gliding or splinting.

CONCLUSION

This review confirms HILT's effectiveness in reducing pain and disability and improving electrophysiological parameters in CTS. However, evidence certainty remains moderate to low. Future RCTs should standardize outcome measures to evaluate HILT's clinical impact beyond statistical significance, and comparative studies with LLLT are needed to refine laser therapy protocols.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42023470170 (October 17, 2023). CONTRIBUTION OF THE PAPER.

Photobiomodulation in carpal tunnel syndrome with pain, strength, and functionality analysis: a systematic review and meta-analysis

BACKGROUND

Carpal tunnel syndrome (CTS) is characterized as a compressive neuropathy of the median nerve and has several treatments, including photobiomodulation, which can be performed with low-intensity laser therapy (LLLT) and light-emitting diodes (LEDs).

PURPOSE

To carry out a literature review on the effectiveness of low-intensity laser therapy (LLLT) in CTS.

METHODS

This study is characterized by being a systematic review with metaanalysis. The databases included were PubMed, Embase, Cochrane, the Physiotherapy Evidence Database (PEDro), Scopus and LILACS. Also, gray literature: Google Scholar, OpenGrey and CAPES Theses and Dissertations Catalog. The search was carried out in all databases on October 11, 2023 and updated on June 06, 2024. The risk of bias was assessed using the Cochrane tool, RoB 2, by two blinded reviewers and conflicts were resolved by consensus. The outcomes of interest were pain intensity (Visual analogue scale), strength (handgrip and pinch) and hand functionality (Boston questionnaire, Levine questionnaire, Purdue Pergboard Test). Statistical analysis was carried out using RevMan 5.4.1. Continuous results were expressed as standard mean differences (95% CI), with p-value of < 0.05 considered statistically significant. The value of the I2 statistical test was calculated to test for heterogeneity between studies. A random effects model was adopted.

RESULTS

13 randomized controlled trials were selected from 1.613 records. In the general bias analysis, two studies (15,4%) were considered to have some relevant problems that could interfere with the quality of the study, and three (23,1%) were identified as having a high risk of bias, eight studies (61,5%) were classified as having a low risk of bias. In the meta-analysis, it was possible to observe that there were no advantages of the laser for pain (p = 0.08), nor for handgrip strength (p = 0.11), but it did produce improvements in functionality.

CONCLUSION

It is concluded that LLLT is an effective therapeutic modality in the treatment of CTS, improving functionality; however, despite the studies pointing to advantages for the modality in reducing pain and improving grip strength, the meta-analysis did not show this result. Even so, there is a need for more clinical trials are needed to standardize dosimetry, mainly because the primary studies showed clinical advantages of PBM.

REGISTRATION

Open Science Framework (OSF)- https://doi.org/10.17605/OSF.IO/HQCRP .

Effect of High-Intensity Laser Therapy on Carpal Tunnel Syndrome Patients: A Systematic Review and Meta-analysis

OBJECTIVE

To provide a strong foundation for the use of high-intensity laser therapy in carpel tunnel syndrome, we conducted a systematic review and meta-analysis to investigate the outcomes of short- and long-term follow-up studies.

DESIGN

This is a systematic review and meta-analysis.

RESULTS

Sample sizes of included studies ranged from 16 to 98 patients ( N = 308). Overall, a significant difference between the treatment and control groups were found across majority of the measures. Studies using a 4-wk follow-up period, however, only found significantly greater benefits for high-intensity laser therapy in visual analog scale compared with placebo ( P = 0.0191), transcutaneous electrical nerve stimulation ( P = 0.0026), and low-intensity laser therapy 20 J/cm 2 ( P < 0.0002), and exercise ( P < 0.0001). For improvement in visual analog scale score over a long treatment period, high-intensity laser therapy was also preferred over control group ( P < 0.0071). Insufficient evidence exists to determine effect of high-intensity laser therapy on nerve conduction examinations. The only statistically significant differences observed in examinations were in relation to sensory nerve action potential ( P = 0.0083) and sensory nerve conduction velocity ( P = 0.0468).

CONCLUSIONS

Moderate evidence exists regarding efficacy of high-intensity laser therapy compared with placebo, high-intensity laser therapy + wrist splint, and exercise in a short period of follow-up time but evidence on long-term follow-up is limited.

A randomized clinical trial on the changing of median nerve cross-sectional area and pain after extracorporeal shock wave and low-level laser therapy added to conventional physical therapy in patients with mild-to-moderate carpal tunnel syndrome

BACKGROUND

Carpal tunnel syndrome (CTS) is the most common mononeuropathy in the upper limb. It remains uncertain whether adding extracorporeal shockwave therapy (ESWT) or low-level laser therapy (LLLT) to conventional treatment benefits CTS patients.

PURPOSE

This study aimed to compare the effectiveness of ESWT and LLLT in conjunction with conventional treatments (including carpal mobilization, transcutaneous electrical nerve stimulation, and ultrasound) on the cross-sectional area (CSA) of the median nerve and pain in mild-to-moderate CTS patients.

STUDY DESIGN

This was a single-blinded randomized clinical trial with registration number IRCT20220504054734N1.

METHODS

Thirty-six patients were randomly assigned using block balanced randomization to receive either four sessions of ESWT or 10 sessions of LLLT in addition to 10 sessions of conventional treatments over 2 weeks. Patients received numbered closed envelopes indicating their treatment group. CSA (primary) and pain (secondary) in 18 patients who completed the treatment were assessed at baseline and after 2 weeks by a blinded assessor. Paired and independent sample t-tests were used for analyses due to the normal distribution of data was checked by Kolmogorov-Smirnoff. Cohen's d effect size was used to assess the intervention's magnitude.

RESULTS

Both ESWT and LLLT groups showed significant improvements in CSA (p = 0.002) and pain (p < 0.001) from baseline to posttreatment. CSA improvement was moderate for ESWT (mean difference: 1.2, 95% CI 0.51-1.9) and mild for LLLT (mean difference: 0.76, 95% CI 0.4-1.14). Conversely, pain improvement was substantial in both groups (ESWT: mean difference 4.4, 95% CI 3.6-5.3; LLLT: mean difference 4.4, 95% CI 3.7-5.2). No substantial differences between ESWT and LLLT were observed, highlighting their comparable efficacy.

CONCLUSION

The addition of either LLLT or ESWT to conventional treatment effectively reduced pain and median nerve CSA in mild-to-moderate CTS. The absence of significant differences between ESWT and LLLT indicates their comparable efficacy in pain relief and CSA reduction.

High-intensity versus low-level laser in musculoskeletal disorders

PURPOSE

To evaluate the current evidence comparing low level to high level laser therapy to reveal any superiorities in the treatment of musculoskeletal disorders.

METHODS

Five databases were searched till September 2022 to obtain relevant RCTs comparing high intensity and low-level laser therapies in the management of musculoskeletal disorders. Two authors assessed the methodological quality of the included studies using the Physiotherapy Evidence Database scale and meta-analysis was conducted for studies that showed homogeneity.

RESULTS

Twelve articles were included in this systematic review with a total population of 704 participants across various musculoskeletal pathologies including tennis elbow, carpal tunnel syndrome, chronic non-specific low back pain, knee arthritis, plantar fasciitis, and subacromial impingement. There were no statistical differences between the two interventions in pain, electrophysiological parameters, level of disability, quality of life, postural sway or pressure algometer, however, Low level laser therapy showed superiority in increasing grip strength compared to high intensity laser therapy while results were significant in favour of high intensity laser therapy regarding long head of biceps diameter and cross sectional area, supraspinatus thickness and echogenicity and acromio-humeral distance.

CONCLUSION

The current literature suggests no superiority of both types of laser therapy in musculoskeletal disorders, however, more RCTs with larger sample size are required to reach a definitive conclusion regarding the superiority of either form of laser therapy in musculoskeletal disorders.

Effects of high-intensity laser therapy on pain, functional status, hand grip strength, and median nerve cross-sectional area by ultrasonography in patients with carpal tunnel syndrome

The aim of this study was to evaluate the effects of high intensity laser therapy (HILT) on pain, functional status, hand grip strength, and median nerve cross-sectional area by ultrasonography in patients with carpal tunnel syndrome. Sixty patients who were diagnosed with carpal tunnel syndrome were included in the study. The patients observed during the research were randomly divided into two groups with 30 patients in each group. Splint+ exercise and HILT (pulsed mode with a power of 8.0 W and energy density of 8 J/cm2 for 1.40 minutes for every 25 cm2, continuous mode with a power of 3.0 W and energy density of 80 J/cm2 for 11 minutes for each 25 cm2; total 10 sessions 5 days a week) were applied for 2 weeks for the first group, and splint+exercise and sham laser treatment were applied for 2 weeks for the second group. Randomization was undertaken with the assistance of a computer-generated random number table before beginning the treatment processes. The patients were evaluated with the determined scales before the treatment, at the end of the treatment, and at the 3rd month. Hydraulic hand dynamometer was used to measure hand grip strength, visual analog scale (VAS) for pain, Boston CTS Questionnaire to assess function, and ultrasonography to measure median nerve cross-sectional area. The impact of time on the change in VAS levels was found to be of statistical significance within each group of patients (p<0.001), but between-group comparisons did not yield significant results (p<0.454). The effects of time on variations in Boston CTS Questionnaire scores were found to have been of statistical significance for both groups (p<0.001), but significance was not subsequently observed when the results of the two groups were compared on a between-group basis (p=0.226 and p=0.973 for the FSS and SSS, respectively). While time had a statistically significant effect on the change in hand grip strength for both groups (p=0.000), between-group comparisons statistical significance finding in favor of HILT was found in the early period (p=0.012). The time-group association patterns of the groups showed significant difference (p=0.025). While time had a statistically significant effect on the changes in the median cross-sectional areas of the nerve for the patients of both treatment groups (p<0.001), between-group comparisons yielded no findings of statistical significance (p=0.438). The time-group relationship patterns of the groups were found to reflect statistical significance (p=0.001). In conclusion, the results of the research presented here have confirmed that hand grip strength may increase and the median nerve's cross-sectional area may decrease upon the application of high-intensity laser for individuals experiencing CTS. However, this effect was demonstrated here only in the short-term and the evidence was not maintained through the course of follow-up of a longer duration.

Splinting for carpal tunnel syndrome

BACKGROUND

Carpal tunnel syndrome (CTS) is a compression neuropathy of the median nerve causing pain and numbness and tingling typically in the thumb, index and middle finger. It sometimes results in muscle wasting, diminished sensitivity and loss of dexterity. Splinting the wrist (with or without the hand) using an orthosis is usually offered to people with mild-to-moderate findings, but its effectiveness remains unclear.

OBJECTIVES

To assess the effects (benefits and harms) of splinting for people with CTS.

SEARCH METHODS

On 12 December 2021, we searched the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, Embase, AMED, CINAHL, ClinicalTrials.gov, and WHO ICTRP with no limitations. We checked the reference lists of included studies and relevant systematic reviews for studies.

SELECTION CRITERIA

Randomised trials were included if the effect of splinting could be isolated from other treatment modalities. The comparisons included splinting versus no active treatment (or placebo), splinting versus another disease-modifying non-surgical treatment, and comparisons of different splint-wearing regimens. We excluded studies comparing splinting with surgery or one splint design with another. We excluded participants if they had previously undergone surgical release.

DATA COLLECTION AND ANALYSIS

Review authors independently selected trials for inclusion, extracted data, assessed study risk of bias and the certainty in the body of evidence for primary outcomes using the GRADE approach, according to standard Cochrane methodology.

MAIN RESULTS

We included 29 trials randomising 1937 adults with CTS. The trials ranged from 21 to 234 participants, with mean ages between 42 and 60 years. The mean duration of CTS symptoms was seven weeks to five years. Eight studies with 523 hands compared splinting with no active intervention (no treatment, sham-kinesiology tape or sham-laser); 20 studies compared splinting (or splinting delivered along with another non-surgical intervention) with another non-surgical intervention; and three studies compared different splinting regimens (e.g. night-time only versus full time). Trials were generally at high risk of bias for one or more domains, including lack of blinding (all included studies) and lack of information about randomisation or allocation concealment in 23 studies. For the primary comparison, splinting compared to no active treatment, splinting may provide little or no benefits in symptoms in the short term (< 3 months). The mean Boston Carpal Tunnel Questionnaire (BCTQ) Symptom Severity Scale (SSS) (scale 1 to 5, higher is worse; minimal clinically important difference (MCID) 1 point) was 0.37 points better with splint (95% confidence interval (CI) 0.82 better to 0.08 worse; 6 studies, 306 participants; low-certainty evidence) compared with no active treatment. Removing studies with high or unclear risk of bias due to lack of randomisation or allocation concealment supported our conclusion of no important effect (mean difference (MD) 0.01 points worse with splint; 95% CI 0.20 better to 0.22 worse; 3 studies, 124 participants). In the long term (> 3 months), we are uncertain about the effect of splinting on symptoms (mean BCTQ SSS 0.64 better with splinting; 95% CI 1.2 better to 0.08 better; 2 studies, 144 participants; very low-certainty evidence). Splinting probably does not improve hand function in the short term and may not improve hand function in the long term. In the short term, the mean BCTQ Functional Status Scale (FSS) (1 to 5, higher is worse; MCID 0.7 points) was 0.24 points better (95% CI 0.44 better to 0.03 better; 6 studies, 306 participants; moderate-certainty evidence) with splinting compared with no active treatment. In the long term, the mean BCTQ FSS was 0.25 points better (95% CI 0.68 better to 0.18 worse; 1 study, 34 participants; low-certainty evidence) with splinting compared with no active treatment. Night-time splinting may result in a higher rate of overall improvement in the short term (risk ratio (RR) 3.86, 95% CI 2.29 to 6.51; 1 study, 80 participants; number needed to treat for an additional beneficial outcome (NNTB) 2, 95% CI 2 to 2; low-certainty evidence).  We are uncertain if splinting decreases referral to surgery, RR 0.47 (95% CI 0.14 to 1.58; 3 studies, 243 participants; very low-certainty evidence).  None of the trials reported health-related quality of life. Low-certainty evidence from one study suggests that splinting may have a higher rate of adverse events, which were transient, but the 95% CIs included no effect. Seven of 40 participants (18%) reported adverse effects in the splinting group and 0 of 40 participants (0%) in the no active treatment group (RR 15.0, 95% CI 0.89 to 254.13; 1 study, 80 participants).  There was low- to moderate-certainty evidence for the other comparisons: splinting may not provide additional benefits in symptoms or hand function when given together with corticosteroid injection (moderate-certainty evidence) or with rehabilitation (low-certainty evidence); nor when compared with corticosteroid (injection or oral; low certainty), exercises (low certainty), kinesiology taping (low certainty), rigid taping (low certainty), platelet-rich plasma (moderate certainty), or extracorporeal shock wave treatment (moderate certainty). Splinting for 12 weeks may not be better than six weeks, but six months of splinting may be better than six weeks of splinting in improving symptoms and function (low-certainty evidence).

AUTHORS' CONCLUSIONS

There is insufficient evidence to conclude whether splinting benefits people with CTS. Limited evidence does not exclude small improvements in CTS symptoms and hand function, but they may not be clinically important, and the clinical relevance of small differences with splinting is unclear. Low-certainty evidence suggests that people may have a greater chance of experiencing overall improvement with night-time splints than no treatment. As splinting is a relatively inexpensive intervention with no plausible long-term harms, small effects could justify its use, particularly when patients are not interested in having surgery or injections. It is unclear if a splint is optimally worn full time or at night-time only and whether long-term use is better than short-term use, but low-certainty evidence suggests that the benefits may manifest in the long term.

High-Intensity Laser Therapy for Musculoskeletal Disorders: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

High-intensity laser therapy (HILT) is one of the therapeutic approaches used in the treatment of musculoskeletal disorders (MSD). The main objective of this study was to examine the effectiveness of HILT for reducing pain and improving functionality in people with MSD. Ten databases were systematically searched for randomized trials published up to 28 February 2022. Randomized clinical trials (RCTs) assessing the effectiveness of HILT on MSD were included. The main outcome measures were pain and functionality. In total, 48 RCTs were included in the qualitative synthesis and 44 RCTs in the quantitative analysis. HILT showed a decrease on the pain VAS (mean difference (MD) = -1.3 cm; confidence interval (CI) 95%: -1.6 to -1.0) and an improvement in functionality (standardized mean difference (SMD) = -1.0; CI95%: -1.4 to -0.7), with low and moderate quality of evidence, respectively. A greater effect was observed when compared with control than with other conservative treatments, both on pain (χ2 = 20.6; p < 0.001) and functionality (χ2 = 5.1; p = 0.02). Differences in the effectiveness of HILT were found depending on the location (χ2 = 40.1 p < 0.001), with further improved functionality in MSD of the knee and shoulder. HILT is an effective treatment for improving pain, functionality, range of motion, and quality of life in people with MSD, although these findings must be treated with caution due to the high risk of bias in the studies. Further clinical trials should be well designed to lower the risk of bias.

Diagnostic Value of Ultrasound for Detecting Carpal Tunnel Syndrome in Patients With Rheumatoid Arthritis: A Three-Arm Cross-Sectional Study

Objective:

This study was conducted to assess the diagnostic value of sonography in detecting carpal tunnel syndrome (CTS) in patients with rheumatoid arthritis (RA) and to compare the results with a normal control group.

Materials and Methods:

In this three-arm cross-sectional study, the sonographically measured median nerve cross-sectional area (MNCSA) was compared in three groups: RA patients with CTS, RA patients without CTS, and normal subjects (no RA, no CTS). A nerve conduction study (NCS) was performed for all enrolled participants, across the three study arms.

Results:

In this study, 38 RA patients (17 in CTS group and 21 in no CTS group) and 19 healthy subjects were recruited. The MNCSAs were 11.86 (±1.87) mm2 in RA patients with CTS, 10.16 (±1.71) mm2 in RA patients without CTS, and 9.42 (±1.46) mm² in healthy control patients. The accuracy of sonography in detecting CTS was 0.79 (95% confidence interval, 0.67–0.91), with a sensitivity and specificity of 88% and 57%, respectively. The MNCSA in CTS group was significantly higher than the control group ( P = .02).

Conclusion:

In this cohort, the sonographic measurement of MNCSA was an accurate and sensitive method for the diagnosis of CTS, especially in its early stages. In addition, in this cohort, RA without CTS did not increase the MNCSA.