Chronic migraine (CM) is a severe enervate disorder which affects about 2% of the general population. Only two approaches have displayed the efficacy in treating CM, one is OnabotulinumtoxinA, and the other is Topiramate. As compared to the conventional treatment, OnabotulinumtoxinA shows some difficulties for headache specialists who have not practiced injecting toxins before. As no European Guidelines were present regarding the method to use OnabotulinumtoxinA and therefore the European Headache Federation present with this guideline which aimed to deliver recommendations for the use of OnabotulinumtoxinA in the treatment of CM.

According to the expert panel, the administration of OnabotulinumtoxinA should be as per the PREEMPT injection rules, i.e. injecting 155 U–195 U to 31–39 sites each 12-weeks. The patients with less than 30% reduction in headache days per month while the OnabotulinumtoxinA treatment was defined as non-responders. However, while assessing response, other factors like disability, patient preferences, and headache intensity should also be considered. The patients who do not respond at the first two or three treatment cycles, the treatment should be stopped in those patients. The evaluation four weeks before with the four weeks following each treatment cycle should be conducted to determine the OnabotulinumtoxinA response.

Further, the patients who acquired a reduction to less than ten headache days per month for three months should stop taking the OnabotulinumtoxinA treatment and re-analysed 4–5 months after closing the OnabotulinumtoxinA treatment to observe that the sufferer has not repeated CM. Questions associating OnabotulinumtoxinA tolerability and efficacy could be explained based on scientific evidence. The other recommendations principally relied on expert evaluation. More analysis of the management of CM with OnabotulinumtoxinA needs to be conducted.