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

Abstract

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.