This prospective, observational pilot study included 7 patients who suffered from chronic cluster headache and who were given injections of onabotulinumtoxinA. The participants were evaluated at 18 and 24 months after the initial injection with headache diaries to assess the frequency, duration, and intensity of headaches as well as with questionnaires to assess qualify of life, satisfaction with treatments, and any adverse events. Additional injections were possible in 3-month intervals if needed.
The frequency of headaches decreased from a baseline level of 14.3 per week to 3.1 per week at 18 months and 6.1 per week at 24 months (P =.018, for both). There was a headache frequency reduction greater than 50% for 71.4% of the cohort at 18 months and 57.1% of the cohort at 24 months. Headache-free days increased from a baseline level of 4.2 days per month to 19.1 days per month at 18 months (P =.027) and 12.9 days per month at 24 months (P =.018). In regards to follow-up injections, 2 patients did not receive additional injections (1 patient was a non-responder), 1 patient received 1 additional injection, 2 patients received 2 additional injections, and 2 patients received 6 additional injections.
The mean pain score describing the injection was 3.2 on the visual analog scale for pain, which was less painful than one cluster headache. Only 2 mild to moderate adverse events were noted and both were temporary. Overall, 4 patients reported being satisfied or completely satisfied, and 3 patients were moderately or a little satisfied.
Future studies need to increase sample size, include a placebo-control arm, and create a standard protocol for injections and evaluating the headache data from the headache diaries.
In conclusion, onabotulinumtoxinA injections at the sphenopalatine ganglion reduced the frequency of cluster headaches and provided more headache-free days for patients suffering from chronic cluster headaches.
Aschehoug I, Bratbak DF, Tronvik EA. Long-term outcome of patients with intractable chronic cluster headache treated with injection of onabotulinum toxin A toward the sphenopalatine ganglion – an observational study [published online September 14, 2018]. Headache. doi: 10.1111/head.13398
This article originally appeared on Neurology Advisor