Abstract
Context: Nowadays, botulinum toxin is used for migraine prophylaxis, and a wide range of adverse effects (AEs) are reported after administration. Objectives: The present study was conducted to evaluate the safety profile of botulinum toxin for migraine headache prophylaxis. Methods: Migraine Disorder, Disorder AND Migraine, Headache AND Sick, Headache AND Migraine, Migraine, Migrainosus, Migraine Headache, Migraines, Sick Headaches, Botulinum, Toxins AND Botulinum, Botulinum AND Neurotoxins, Toxins AND Clostridium Botulinum Neurotoxins, Botulinum Toxin, Botulinum Neurotoxin, Clostridium Botulinum Toxins, and Botulin were searched in PubMed, Scopus, EMBASE, Web of Science, and Google Scholar databases, and gray literature, including references of the studies published before April 2023. Results: We found 3081 articles by literature search; after deleting duplicates, 1711 remained. Thirty-five articles remained for meta-analysis. The pooled prevalence of musculoskeletal weakness in the head and neck regions was 4% (95% CI: 2-5%) (I2 = 92.2%, P < 0.001). The pooled prevalence of neck pain was 6% (95% CI: 4-7%) (I2 = 95.8%, P < 0.001). The pooled prevalence of blepharoptosis was 2% (95% CI: 2-3%) (I2 = 91.1%, P < 0.001). The pooled prevalence of facial paralysis was 2% (95% CI: 1-4%) (I2 = 94.1%, P < 0.001). The pooled prevalence of injection site pain was 4% (95% CI: 2-5%) (I2 = 93.5%, P < 0.001). Conclusions: The results of this systematic review and meta-analysis show that the most common AEs following botulinum toxin injection for migraine headache prophylaxis are neck pain, followed by musculoskeletal weakness and injection site pain.