Efficacy of low-level laser therapy on management of Bell's palsy: a systematic review

Laser therapy for Bell's palsy: a systematic review and meta-analysis of randomized trials

This meta-analysis investigated therapeautic effects of laser therapies in patients with Bell's palsy (BP). The authors performed the literature search in the PubMed, Embase, and Cochrane Library databases using the following search terms: (facial paralysis OR Bell's palsy OR facial palsy OR idiopathic facial paralysis) AND (laser OR low-level laser OR photobiomodulation OR phototherapy). Relevant studies published before October 29th 2024 were identified. Randomized trials comparing the outcomes of laser therapies with other interventions, including electrical stimulation and control or usual care in patients with BP were included. The mean difference (MD) was determined as the effect size for continuous outcomes, and outcome accuracy was determined using 95% confidence intervals (CIs). Twelve studies were included, with a total of 597 patients. Nine studies were further included in the quantitative analysis. Our meta-analysis revealed that laser therapy significantly improved disease severity (House-Brackmann facial paralysis scale) (MD = -1.51, 95% CI = -2.43 to -0.59), facial asymmetry (Sunnybrook facial grading system) (MD = 20.63, 95% CI = 10.33 to 30.94), and facial function and disability (Facial disability index) (MD = 17.91, 95% CI = 5.60 to 30.22) when compared with control care in adult patients. Moreover, laser therapy significantly improved facial severity (MD = 21.05, 95% CI = 16.77 to 25.33) when compared with electrical stimulation. In addition, no adverse effects of laser therapy were reported. Laser therapy has favorable effects on disease severity, facial asymmetry, and facial function and disability for patients with BP.

A case series of low-level laser therapy treatment in patients with peripheral facial palsy

BACKGROUND

Peripheral Facial Palsy (PFP) is a facial paralysis with various etiologies, including idiopathic causes (Bell's palsy), infections, trauma, and genetic factors. Traditional treatments involve antiviral medications, corticosteroids, and physiotherapy. However, new therapies, such as Low-Level Laser Therapy (LLLT), are emerging with promising results.

METHODS

This case series reports on two patients with PFP treated with LLLT combined with Vitamin B1, B6, and B12 supplementation. The first case involved a 52-year-old female with PFP due to a viral infection. The second case was a 33-year-old male who developed PFP following a traumatic brain injury. Both patients received LLLT sessions every two weeks, targeting 10 points along the facial nerve pathway from the facial notch across the face. The laser device used was the Theraphy EC (DMC, Sao Carlos, SP, Brazil), with each point receiving 4 Joules of energy applied perpendicular to the skin after cleaning the face with water and soap to remove lipids that could interfere. The administration of Vitamin B was done using NEUROBIONTA tablets (Vitamin B1 + Vitamin B6 + Vitamin B12; Procter & Gamble, Santiago, Chile) with one tablet taken daily for 30 days.

RESULTS

After six to seven sessions, both patients showed significant improvement in facial muscle function and overall facial symmetry. In the first case, improvements were noted in muscle tonicity and facial movements, with the patient reporting reduced facial disfigurement. In the second case, notable recovery in facial mobility and symmetry was observed, with the patient experiencing decreased paresthesia and restored muscle functionality.

CONCLUSION

These findings suggest that LLLT, combined with Vitamin B1, B6, and B12 supplementation, may effectively improve facial muscle function and symmetry in PFP patients. The non-invasive nature and ease of application make LLLT a viable option for PFP treatment. Further studies with larger sample sizes and standardized protocols are necessary to confirm these results and establish LLLT as a standard treatment for PFP.

Laser acupuncture and photobiomodulation therapy in Bell's palsy with a duration of greater than 8 weeks: a randomized controlled trial

To investigate the efficacy of laser acupuncture and photobiomodulation therapy in alleviating symptoms among patients diagnosed with Bell's palsy with duration of greater than 8 weeks. The randomized controlled trial has been performed from May 2021 to April 2023. Patients were eligible who had Bell's palsy with duration of greater than 8 weeks on out-patient Department of Otorhinolaryngology in Beijing Tongren Hospital. The laser acupuncture group received class IV laser treatment for 3 times per weeks, a total of 72 times. The control group received the same treatment procedure except the laser parameter. The primary outcome measures comprised House-Brackmann facial nerve grading system and electroneurography. Secondary outcome measures comprised Sunnybrook facial grading system, electromyography, and the blink reflex. A total of 84 participants were included (42 control group, 42 laser acupuncture group). After treatment, House-Brackmann facial nerve grading system (OR, 0.11; 95% CI, 0.04-0.30; P < 0.001), and the pathologic numbers of electroneuronography were statistically different between the laser acupuncture group and control group, including orbicularis oculi (OR,0.08; 95% CI, 0.02-0.21; P < 0.001), Frontalis muscle (OR,0.14; 95% CI, 0.05-0.39; P < 0.001), Orbicularis oris (OR,0.13; 95% CI, 0.04-0.36; P < 0.001), Ala nasi muscle (OR,0.06; 95% CI, 0.02-0.18; P < 0.001). In secondary outcomes, Sunnybrook facial grading system, has significant difference between the two groups (20.26; 95% CI, 14.69 to 25.83; P < 0.01). Latency by ENoG, include orbicularis oculi (-0.61; 95% CI, -0.43 to -0.09; P < 0.001), frontalis muscle (-0.12; 95% CI, -0.21 to -0.03; P < 0.01), orbicularis oris (-0.28; 95% CI, -0.41 to -0.16; P < 0.001), and ala nasi muscle (-0.26; 95% CI, -0.38 to -0.16; P < 0.001). All amplitudes of MUAPs and durations by electromyography (EMG) showed statistically significant differences compared with the control group after treatment. For the frontalis muscle, the amplitude of MUAPs was -64.23 (95% CI, -80.89 to -47.56; P < 0.001) and duration was -1.18 (95% CI, -1.49 to -0.87; P < 0.001). For orbicularis oris, amplitude of MUAPs was -29.82 (95% CI, -55.03 to -4.62; P = 0.02) and duration was -0.57 (95% CI, -0.94 to -0.20; P < 0.001). For depressor angulli oris, amplitude of MUAPs was -47.06 (95% CI, -62.15 to -31.97; P < 0.001) and duration was -2.21 (95% CI, -2.69 to -1.72; P < 0.001). Blink reflex, including R1 (OR, 0.03; 95% CI, 0.01-0.16; P < .001), R2 (OR, 0.04; 95% CI, 0.004-0.29; P < .001), and R2 latency differences (OR, 0.15; 95% CI, 0.05-0.51; P < .001), have significant difference between the two groups, respectively. The findings suggest that laser acupuncture relieve symptoms for patients with Bell's palsy with a duration of greater than 8 weeks.Trial registration: ClinicalTrials.gov Identifier: NCT05846217.

Effects of low-level laser therapy on burning pain and quality of life in patients with burning mouth syndrome: a systematic review and meta-analysis

BACKGROUND

Burning mouth syndrome (BMS) is a complex chronic pain disorder that significantly impairs patients' quality of life. Low-level laser therapy (LLLT) uses infrared or near-infrared light to produce analgesic, anti-inflammatory, and biological stimulation effects. The aim of this systematic review is to evaluate the effect of LLLT on burning pain, quality of life, and negative emotions in patients with BMS.

METHODS

The PubMed, Embase, Cumulative Index of Nursing and Allied Health Literature (CINAHL), Cochrane Library, Web of Science, and Scopus databases were searched up January 2023 to identify relevant articles. All randomized controlled trials that were published in English and examined the use of LLLT treatment for BMS were included. The methodological quality of the included trials was assessed using the Cochrane risk of bias tool for randomized controlled trials (RCTs). A meta-analysis was performed to evaluate burning pain, quality of life, and negative emotions. Sensitivity, subgroup, and funnel plot analyses were also carried out.

RESULTS

Fourteen RCTs involving a total of 550 patients with BMS met the inclusion criteria. The results showed that LLLT (measured by the Visual Analog Scale; SMD: -0.87, 95% CI: -1.29 to -0.45, P < 0.001) was more effective for reducing burning pain than placebo LLLT or clonazepam. LLLT improved quality of life (evaluated by the Oral Health Impact Profile-14; SMD: 0.01, 95% CI: -0.58 to 0.60, P = 0.97) and negative emotions (evaluated by the Hospital Anxiety and Depression Scale; SMD: -0.12, 95% CI: -0.54 to 0.30, P = 0.59), but these effects were not statistically significant.

CONCLUSIONS

The meta-analysis revealed that LLLT may be an effective therapy for improving burning pain in patients with BMS, and producing a positive influence on quality of life and negative emotions. A long-term course of intervention, a larger sample size, and a multidisciplinary intervention design are urgently needed in future research.

TRIAL REGISTRATION

PROSPERO registration number: CRD42022308770.

Efficacy of 1064 nm Photobiomodulation Dosimetry Delivered with a Collimated Flat-Top Handpiece in the Management of Peripheral Facial Paralysis in Patients Unresponsive to Standard Treatment Care: A Case Series

Peripheral facial paralysis (PFP) is a common condition where oxidative stress (OS) is involved in the pathophysiology of facial paralysis, inhibiting peripheral nerve regeneration, which can be featured in Bell's palsy, Ramsay Hunt syndrome and Lyme disease. The current standard care treatments lack consensus and clear guidelines. Hence, the utilization of the antioxidant immunomodulator photobiomodulation (PBM) can optimize clinical outcomes in patients who are unresponsive to standard care treatments. Our study describes three unique cases of chronic PFP of various origins that were unresponsive to standard care treatments, but achieved a significant and complete recovery of facial paralysis following PBM therapy. Case presentations: Case #1: a 30-year-old male who presented with a history of 12 years of left-side facial paralysis and tingling as a result of Bell's palsy, where all the standard care treatments failed to restore the facial muscles' paralysis. Eleven trigger and affected points were irradiated with 1064 nm with an irradiance of ~0.5 W/cm2 delivered with a collimated prototype flat-top (6 cm2) in a pulsed mode, with a 100 µs pulse duration at a frequency of 10 Hz for 60 s (s) per point. Each point received a fluence of 30 J/cm2 according to the following treatment protocol: three times a week for the first three months, then twice a week for another three weeks, and finally once a week for the following three months. The results showed an improvement in facial muscles' functionality (FMF) by week two, whereas significant improvement was observed after 11 weeks of PBM, after which the House-Brackmann grading scale (HBGS) of facial nerve palsy dropped to 8 from 13 prior to the treatment. Six months after PBM commencement, electromyography (EMG) showed sustainability of the FMF. Case #2: A five-year-old female who presented with a 6-month history of severe facial paralysis due to Lyme disease. The same PBM parameters were utilized, but the treatment protocol was as follows: three times a week for one month (12 consecutive treatment sessions), then the patient received seven more sessions twice a week. During the same time period, the physiotherapy of the face muscles was also delivered intensively twice a week (10 consecutive treatments in five weeks). Significant improvements in FMF and sustainability over a 6-month follow-up were observed. Case #3: A 52-year-old male who presented with severe facial palsy (Grade 6 on HBGS) and was diagnosed with Ramsay Hunt syndrome. The same laser parameters were employed, but the treatment protocol was as follows: three times a week for three weeks, then reduced to twice a week for another three weeks, then weekly for the next three months. By week 12, the patient showed a significant FMF improvement, and by week 20, complete FMF had been restored. Our results, for the first time, showed pulsed 1064 nm PBM delivered with a flat-top handpiece protocol is a valid and its treatment protocol modified, depending on the origin and severity of the condition, which is fundamental in optimizing facial paralysis recovery and alleviating neurological symptoms. Further extensive studies with large data are warranted to validate our PBM dosimetry and treatment protocols.

A Nonrandomized Trial of the Effects of Near-Infrared Photobiomodulation Therapy on Bell's Palsy with a Duration of Greater Than 8 Weeks

Objective: To determine whether photobiomodulation therapy (PBMT) by class IV Multiwave Locked System laser treatment as an adjunctive therapy could relieve symptoms in patients with Bell's palsy with a duration of greater than 8 weeks. Materials and methods: This nonrandomized controlled trial was conducted from January 2020 to December 2022. Patients were eligible if they had Bell's palsy with a duration of greater than 8 weeks at the out-patient department of otorhinolaryngology in Beijing Tongren Hospital. The control group consisted of patients recruited between January 1, 2020, and December 31, 2020. The PBMT group consisted of patients recruited between January 1, 2021, and December 31, 2022. In this study, the PBM used has a wavelength of 808 and 905 nm, 1.2 W power (808 nm is 1 W, 905 nm is 200 mW), continuous mode emission (808 nm) and pulsed mode emission (905 nm), 8.35 J/cm2 dosimetry, administered 3 times per week, 72 times of total treatment. The primary outcome measures included the House-Brackmann facial nerve grading system, the Sunnybrook facial grading system, and the Facial Clinimetric Evaluation Scale (FaCE). Secondary outcome measures comprised electroneurography, electromyography, and the blink reflex. Results: A total of 54 participants were included (27 in the control group and 27 in the photobiomodulation group). After 6 months, the House-Brackmann grading system [risk difference, -0.59, confidence interval (95% CI), -0.81 to -0.38, relative risk, 0.27, 95% CI, 0.13-0.56, p < 0.001], Sunnybrook facial grading system (21.14, 95% CI, 11.71-30.58; p < 0.001), and FaCE (-0.20, 95% CI, 0.41-0.02; p = 0.07) had significant difference between the two groups. Latency of ala nasi muscle (10.92, 95% CI, 5.58-16.27; p < 0.001) was not statistically significant after treatment compared with the control group; however, most of the electrophysiological examinations have significant difference between the two groups, respectively. Conclusions: The results of this study suggest that PBMT may relieve symptoms for patients with Bell's palsy with a duration of greater than 8 weeks. Trial Registration: ClinicalTrials.gov Identifier: NCT05585333.

Efficacy of Laser Therapy on Paralysis and Disability in Patients with Facial Palsy: A Systematic Review of Randomized Controlled Trials

(1) Background: Facial palsy is a common health issue which leads to sequelae and disability. This systematic review aimed to assess the efficacy of laser therapy for the treatment of facial palsy. (2) Methods: Only randomized controlled trials comparing the effectiveness of laser therapy to non-laser intervention, no intervention, or placebo were searched for. Relevant studies were searched in seven electronic databases. Studies that examined the use of laser modalities for facial palsy management, with or without acupuncture, were also included. Two authors independently read and scored the methodological quality of the selected texts, and any disagreement was resolved by discussion or by intervention from the third author. (3) Results and conclusions: With five full-text articles, a methodological quality for each included study was assessed (kappa coefficient = 0.75). The laser therapy group in the mean difference measuring FDI showed an effect size of 8.15 compared to the control group; while measuring the paralysis score, an advantage was disclosed with an effect size of 0.22 compared to the control group.

Kabat Rehabilitation in Facial Nerve Palsy after Parotid Gland Tumor Surgery: A Case-Control Study

Temporary facial nerve palsy after parotid tumor surgery ranges from 14 to 65%, depending on surgery, tumor type, and subsite. The study aimed to evaluate the role of Kabat physical rehabilitation in the outcomes of patients affected by severe facial nerve palsy following parotid gland surgery. The results and clinical data of two groups, Kabat and non-Kabat (control), were statistically compared. Descriptive statistics, the multiple linear regression model, difference in difference approach, and the generalized linear model were used. F-Test, Chi-square test, McFadden R-squared, and adjusted R-squared were used to assess the significance. The results showed that the House–Brackmann (HB) stage of patients who had physiotherapy performed were lower than the control group. The decrease of HB staging in the Kabat group at 3 months was −0.71 on average, thus the probability of having a high HB stage decreased by about 13% using Kabat therapy. The results are statistically significant, and indicated that when the Kabat rehabilitation protocol is performed, mainly in the cases of a high-grade HB score, the patients showed a better and faster improvement in postoperative facial nerve palsy.

Effects of Laser Acupuncture Therapy for Patients With Inadequate Recovery From Bell's Palsy: Preliminary Results From Randomized, Double-Blind, Sham-Controlled Study

Introduction: Inadequate recovery from Bell's palsy exists in a third of patients and results in physical and social impairments. The controversial nature of existing medical treatment options means that novel, alternative approaches are needed. In basic and clinical studies, low-level laser therapy (LLLT) has proven successful in regenerating peripheral nerves. Laser acupuncture therapy (LAT) is a rapidly growing treatment modality; however, its effectiveness for treating chronic Bell's palsy is unknown. The feasibility of this innovative approach is the focus of this pilot study. Methods: A two-armed, parallel, randomized, investigator-subject-assessor-blinded, sham-controlled pilot study was conducted, and 17 eligible subjects were randomly allocated to either LAT (n=8) or sham LAT (n=9). The LAT group received three treatments each week for six weeks (18 sessions), while the sham LAT group received the same procedure but with a sham laser device. The change from baseline to week 6 in the social subscale of the Facial Disability Index (FDI) was the primary outcome. Secondary outcomes were changes in the House-Brackmann facial paralysis scale (HB), the Sunnybrook facial grading system (SB) and a stiffness scale at weeks 3 and 6. Results: A significant difference was shown in the HB score (P=0.0438) between baseline and week 3 and borderline significance was observed in both SB and stiffness scores from baseline to week 6 (P=0.0598 and P=0.0980 respectively). There was no significant difference in the FDI score between baseline and week 6. Conclusion: To the best of our knowledge, this clinical trial is the first such investigation on this topic. Our findings suggest that using LAT may have clinical effects on long-term complications of Bell's palsy and justify further large-scale studies.

"At-Home" Photobiomodulation: A New Approach for Bell's Palsy Treatment

Objective

This report is the first one to describe the possibility to use “self‐administered” photobiomodulation (PBM) for Bell's palsy (BP) treatment.

Background

BP is a peripheral disorder of the facial nerve causing sudden paralysis of unilateral facial muscles, and PBM has been successfully suggested for its treatment without any side effect. This is the first case report where a laser device was successfully used at home by the patient herself to treat BP opening new perspectives on the therapy of this disease.

Methods

This report describes the “at-home PBM” treatment performed on a 15-year-old girl who presented BP consisting of acute pain on the right side of her face, difficulty in biting and dripping saliva from the right side of her lips. The treatment was performed twice a day by cutaneous applications, each of 15 minutes (total fluence 48 J/cm²) in an area corresponding to the parotid gland by a device emitting at 808 nm at 250 mW output power.

Results

Two weeks after PBM treatment, performed at home twice a day by the patient herself without any kind of pharmacological therapy, the complete disappearing of the disease was noticed with no side effects.

Conclusion

With the limitations due to a single case report and with the need of further clinical trials to confirm it, “at-home PBM” seems to represent a good and safe approach to the treatment of BP.

Recovery from Idiopathic Facial Paralysis (Bell’s Palsy) Using Photobiomodulation in Patients Non-Responsive to Standard Treatment: A Case Series Study

Diminished facial movement and marked facial asymmetry can lead to a consistent psychological burden. Bell′s palsy (BP) is one of the most common causes of facial nerve illness, which comes with unilateral acute facial paresis. Nowadays, no clear guidelines for treating BP are available. We carried out a case series study to test the efficacy of photobiomodulation (PBM) therapy in patients with BP non-responsive to standard treatment. The study was experimentally performed at the Department of Surgical and Diagnostic Sciences, University of Genoa (Genoa, Italy), in accordance with case report guidelines. Patients were referred to our department by colleagues for evaluation to be included in the case series because no consistent improvement was observed at least 3 months from the diagnosis of BP. All the patients interrupted their pharmacological therapy before the initiation of PBM therapy. PBM therapy (808 nm, 1 W irradiated in continuous-wave for 60 s on spot-size 1 cm2; 1 W/cm2; 60 J/cm2; and 60 J) was administered every 2 days until complete resolution. Evaluation of the House-Brackmann scale was performed before and after treatments. Fourteen patients were screened as eligible for the study. Patients were Caucasians (36% females and 64% males) with a mean age ± standard deviation of 56.07 ± 15.21 years. Eleven patients out of 14, who experienced BP a maximum of 6 months, completely recovered through PBM. The three patients that did not show improvement were those who had experienced BP for years. PBM could be a supportive therapy for the management of BP in patients non-responsive to standard treatment. However, randomized controlled trials are necessary to sustain our encouraging results, exclude bias, and better explain the boundary between the time from diagnosis and the recovery of BP through PBM therapy.

A bibliometric analysis of research on the treatment of facial nerve palsy

BACKGROUND

There are various treatments for facial nerve palsy, and research into this topic is ongoing. In the present study, we carried out bibliometric and visualized analyses to identify the trends of research into facial nerve palsy treatment.

METHODS

To identify articles, the SCOPUS database was searched for articles published from its inception to December 27, 2020. The search was conducted twice, with Search 1 investigating general treatment trends and Search 2 narrowing the scope to complementary and alternative treatment. The extracted keywords were analyzed using the Visualization Of Similarities (VOS) viewer. Through analysis of keywords, research hotspots in the treatment of facial nerve palsy were identified.

RESULTS

A total of 1609 and 223 articles were identified in Searches 1 and 2, respectively. The number of articles published each year showed a tendency to increase, and most of the studies were only conducted in a few countries. In terms of subject area, "medicine" was overwhelmingly the most common(77.6%). Based on the analysis of 316 keywords in Search1, "medication treatment," and "complementary and alternative treatment" were the hotspots of research.

CONCLUSION

This study provides the overall trends of facial nerve palsy treatment. To date, research on medication treatment has been main focus, and antiviral use among medication treatment and complementary and alternative treatment has emerged in recent years.

The effectiveness of low-level laser therapy combined with facial expression exercises in patients with moderate-to-severe Bell's palsy: A study protocol for a randomised controlled trial

BACKGROUND

Even though corticosteroid therapy and facial expression exercises were found to be effective, still 30% of participants with bell's palsy achieve incomplete recovery from the facial paralysis. The study objective was to evaluate the effectiveness of low-level laser therapy (LLLT) combined with progressive facial expression exercises in participants with moderate to severe bell's palsy.

METHODOLOGY

A total of 120 participants with idiopathic bell's palsy to be equally allocated in three groups. LLLT, electrical stimulation and corticosteroid/antiviral therapy will be performed respectively in the group I, group II and Group III and facial expression exercises as a common intervention. First two groups to be treated with respective interventions weekly 3 days for 6 consecutive weeks and third group will receive prescribed doses of medications and facial expression exercise for 6 weeks. The functional recovery will be assessed at baseline, 3 weeks, 6 weeks, and 12 weeks using the Facial Disability Index and House-Brackmann Scale. The overall within and between group differences in the clinical outcomes to be reported based on the Friedman Repeated Measures ANOVA and Kruskal-Wallis test. Whereas Wilcoxon Signed Rank and Mann-Whitney-U tests will be performed to report the within and between groups timeline differences.

DISCUSSION

Based on the dearth of evidence for the effective treatment of moderate to severe bell's palsy, we framed a most appropriate LLLT dosage along with facial expression exercises. Our study's intervention protocol designed with equal duration and number of interventions for all three groups. Even the comparator groups such as electrical muscle stimulation and Corticosteroids therapy will be receiving similar facial expression exercises. We believe that this intervention protocol would benefit by promoting the complete facial function recovery in patients with moderate to severe bell's palsy.

DISSEMINATION

We plan to publish this review in a peer-reviewed journal. We may also present this review at local and/or national conferences.