Botulinum Toxin Type A Blockade of the Sphenopalatine Ganglion in Treatment-refractory Chronic Cluster Headache

Cluster headache is a primary headache condition characterized by clusters of one-sided, high-intensity pain attacks. The headache may be episodic or chronic. Treatment options are limited and their effects unsatisfactory. An important nerve pathway involved in the pain attacks has a switching station at the sphenopalatine ganglion (SPG) located in the depth of the facial bones. SPG is a known therapy target for cluster headache. The area can be identified on CT images, but is difficult to access due to its location. Thus, the Multiguide navigation system has been developed to enable precise delivery of the drugs that target SPG activity. In Trondheim, two phase 1 / Phase 2 study have been carried out using botulinum toxin A (Botox®) against SPG in patient with chronic cluster headache and chronic migraine. The results indicate that such a treatment strategy is safe and beneficial. The current study is a randomized, placebo-controlled, triple-blinded study to investigate whether precise single-injection of botulinum toxin A reduces the frequency of attacks in chronic cluster headache .