Onabotulinumtoxin A in chronic migraine: predictors of response. A prospective multicentre descriptive study

Chronic migraine (CM) usually appears as a result of the increased in frequency and intensity of pain in an episodic migraine (EM) patients. OnabotulinumtoxinA is a treatment specifically approved for the prevention of chronic migraine in adults. Its efficacy has been studied in two large multicenter randomized clinical trials, but the results were controversial. Therefore in this multicentre study, the author significantly improved the chronic migraine patient's outcomes by starting treatment in the first 12 months.

The OnabotulinumtoxinA is particularly recommended for treating chronic migraines in adults. This study aimed to evaluate the efficacy of OnabotulinumtoxinA in a chronic migraine following one year postoperatively in a real-life setting and to determine clinical predictors of outcome.  

The researchers conducted a prospective multicentre study among the 13 hospitals of Spain. Patients went through a complete medical examination and history analysis and then treated with OnabotulinumtoxinA every 12 weeks for 12 months. Information associated with results, adverse events, emergency room use, disability and abortive medication use were measured at three months and one year.  

The study was completed by 725 individuals. A total of 79.3% obtained >50% reduction in the incidence of headache per month and 94.9% found to have no adverse events. The excellent outcome showed association with lesser disability days per month, milder headache at baseline, and unilaterality of pain. Duration of disease <12 months enhanced the chances of response to the OnabotulinumtoxinA treatment.

The study proved the OnabotulinumtoxinA efficacy after 12 months of treatment. The probability of good results raised if treatment starts in the first 12 months following chronic migraine diagnosis.