Abstract
INTRODUCTION: Randomized controlled trials have established onabotulinumtoxinA as an effective prophylactic treatment for chronic migraine. However, real-world evidence in the Saudi population remains limited. This study aimed to evaluate the clinical effectiveness of onabotulinumtoxinA injections in patients with chronic migraine treated at a tertiary care center in Jeddah, Saudi Arabia between 2016 and 2024. METHODS: A retrospective analysis was conducted at King Abdulaziz Medical City in Jeddah, Saudi Arabia. Migraine Disability Assessment Test (MIDAS) was used. Data on patients' demographics, number of onabotulinumtoxinA doses (155 U for each dose), pain level, days of headache in the 3 months following the last injection, and side effects experienced after each injection session were gathered. RESULTS: Among 133 patients studied, 85% were female, 56.4% were aged ≤ 40 years, and 66.9% had ≤ 14 headache days in the 3 months following the last injection. The median MIDAS score decreased from 28 (severe disability) to 8 (mild disability). Median headache days were reduced from 60 to 10 days. Patients with MIDAS Grade I had a significant higher number of onabotulinumtoxinA doses. A significant negative correlation was found between number of onabotulinumtoxinA doses and the MIDAS grade, pain level, and days of headache in the 3 months post injection. Side effects were experienced by 13.5% of patients, with ptosis being the most common. CONCLUSION: OnabotulinumtoxinA resulted in meaningful reductions in migraine-related disability, headache frequency, and pain intensity in patients with chronic migraine treated in a tertiary care center. These findings reinforce its role as an effective long-term preventive therapy and highlight the importance of maintaining consistent treatment cycles to sustain clinical benefit.