RESUMEN
BACKGROUND: Laser acupuncture is a proven non-invasive treatment with effects comparable to traditional acupuncture in different types of headaches, but there is still insufficient evidence for chronic migraine (CM) in adults. We aim to investigate the efficacy and safety of laser acupuncture (LA) as an add-on preventive therapy on CM. METHODS: A single-blind randomized controlled trial was conducted from January 2022 to November 2023. CM patients with unsatisfactory pharmacological effects were randomly assigned in a 1:1 ratio to receive either LA or sham treatment over a course of 8 sessions spanning 4 weeks. The co-primary outcomes were changes in monthly migraine days (MMD) and acute headache medications usage days per month from baseline. Evaluations were taken at baseline (12 weeks before randomization), at 4th week (treatment completed), 8th week and 12th week from baseline. RESULTS: A total of 60 patients (30 in each group) were included in the intention-to-treat analyses. Baseline headache characteristics between trial groups were similar. Compared with the sham group, the LA group had a significant reduction in MMD (5.2 vs. 1.5 days at 8th week, p = 0.015; 7.3 vs. 1.8 days at 12th week, p = 0.001), and acute headache medications usage days per month (3.1 vs. 0.4 days at 4th week, p = 0.007; 3.2 vs. 0.0 days at 8th week, p = 0.005; 3.9 vs. 0.0 days at 12th week, p < 0.001). No serious adverse event was observed in both groups. CONCLUSIONS: Laser acupuncture was effective in reducing MMD and acute headache medications usage with promising safety. Specifically, the efficacy of LA exhibited a progressively more pronounced effect within the follow-up period. We suggested that LA is a promising add-on preventive therapy for CM, and trials focused on investigating the mechanism of LA's effect and its long-term effects on CM prevention are justified. TRIAL REGISTRATION: The study was retrospectively registered at ISRCTN.org Identifier: ISRCTN11208146 ( https://doi.org/10.1186/ISRCTN11208146 ). The registration date: 19, January, 2024. The date of first participant registration: 04, May, 2022.