THERAPEUTIC EFFICACY OF DIFFERENT WAVELENGTHS OF LOW-LEVEL LASER THERAPY IN THE TREATMENT OF CERVICOGENIC HEADACHE: A DOUBLE-BLINDED RANDOMIZED CLINICAL TRIAL

Abstract

Background: Cervicogenic headache is a disabling secondary headache disorder associated with cervical musculoskeletal dysfunction, reduced quality of life, and limited long-term comparative evidence for wavelength-specific photobiomodulation strategies. Objective: To compare the therapeutic efficacy of 820-nm near-infrared laser photobiomodulation, 675-nm red-spectrum laser photobiomodulation, and multiwavelength LED-based photobiomodulation, each combined with standardized physiotherapy, in adults with cervicogenic headache. Methods: This single-centre, three-arm, parallel-group randomized clinical trial enrolled 150 adults with ICHD-3-confirmed cervicogenic headache at a tertiary care hospital in Lahore, Pakistan. Participants were randomized equally to 675-nm laser photobiomodulation plus routine physiotherapy, 820-nm laser photobiomodulation plus routine physiotherapy, or multiwavelength LED-based photobiomodulation plus routine physiotherapy. Treatment was delivered three times weekly for 6 weeks. The prespecified co-primary outcomes were change in visual analogue scale pain intensity and headache frequency at 6 weeks. Secondary outcomes included neck disability, cervical mobility, craniovertebral angle, and health-related quality of life. Analyses were performed according to the intention-to-treat principle. Results: Of 198 individuals screened, 150 were randomized and 130 completed 6-month follow-up. At 6 weeks, mean VAS pain intensity was 37.8 mm in the 675-nm group, 21.6 mm in the 820-nm group, and 46.2 mm in the multiwavelength group. Adjusted analyses showed significantly greater pain reduction with 820 nm versus 675 nm (adjusted mean difference, -16.2 mm; 95% CI, -21.2 to -11.2) and versus multiwavelength therapy (-24.6 mm; 95% CI, -29.6 to -19.6), with a significant overall group effect (F[2,146] = 48.3; p < 0.001). Mean headache frequency at 6 weeks was 6.4, 3.8, and 8.6 days per 4 weeks, respectively, with significant adjusted differences favoring 820 nm (F[2,146] = 42.1; p < 0.001). Improvements in disability, cervical flexion, craniovertebral angle, and SF-36 physical health scores also favored 820 nm. No serious adverse events occurred. Conclusion: In adults with cervicogenic headache receiving standardized physiotherapy, 820-nm near-infrared photobiomodulation was associated with greater reductions in headache frequency and pain intensity than 675-nm laser photobiomodulation or multiwavelength LED-based photobiomodulation.