Cluster headache is an intense and powerful, one-sided headache accompanied by involuntary symptoms such as red eye, droopy eyelids, flow of tears, small pupils and one-sided facial sweating. The headache is believed to be the most intense of all headaches and among many is totally disabling and of great personal and social consequences. For a small group of patients with episodic and most chronic form, drug therapy has little effect. For them, surgery can be a solution.

Neuroradiology has found evidence of a possible original activation of cluster headache from the portion of the brain called hypothalamus. Furthermore, an activation of the parasympathetic nervous system through the sphenopalatine ganglion, which may also explain some of the one-sided involuntary symptoms, is suspected in cluster headache. Injection of Botulinum toxin type A (BTA) inhibits secretion of synaptic acetylcholine resulting in nerve signals being blocked. The duration of such a blockade is believed to be 3-9 months.

The purpose of the present study is to develop and evaluate a new surgical procedure with injection of BTA for blocking of the sphenopalatine ganglion. The goal is to relieve the symptoms of refractory cluster headache with a minimal invasive procedure.

The main objective of the project is to determine the safety of BTA injection in the area of the sphenopalatine ganglion of refractory cluster headache and detect the adverse events. Secondary objectives are to identify the changes of headache attacks by the method used.

Inclusion Criteria:

• Informed and written consent
• Cluster headaches defined in ICHD-2 criteria, duration of periods of attacks normally more than 2 months and insufficient effect of available prophylactic treatment

Exclusion Criteria:

• Heart or lung disease
• Any kind of systematic or local disease or illness that may significantly increase the risk of complications for the procedure, related to injection or anesthesia
• Psychiatric illness that hinders participation in the study
• Known pregnancy or breast feeding
• Inadequate use of contraceptives
• Overuse or abuse of opioids
• Abuse of medications, narcotics or alcohol
• Allergy or any other hypersensitivity reactions against marcain, lidocaine, xylocain or adrenalin, botulinum toxin type A, Botox or any of it's constituents or any other related medication
• Treatment with medication that can interact with botulinum toxin type A