2. Cluster Headache

Cluster headache is a strictly unilateral headache that is associated with ipsilateral cranial autonomic symptoms and usually has a circadian and circannual pattern. Prevalence is estimated at 0.5 to 1.0/1,000. The diagnosis of cluster headache is made based on the patient's case history. There are two main clinical patterns of cluster headache: the episodic and the chronic. Episodic is the most common pattern of cluster headache. It occurs in periods lasting 7 days to 1 year and is separated by at least a 1-month pain-free interval. The attacks in the chronic form occur for more than 1 year without remission periods or with remission periods lasting less than 1 month. Conservative therapy consists of abortive and preventative remedies. Ergotamines and sumatriptan injections, sublingual ergotamine tartrate administration, and oxygen inhalation are effective abortive therapies. Verapamil is an effective and the safest prophylactic remedy. When pharmacological and oxygen therapies fail, interventional pain treatment may be considered. The effectiveness of radiofrequency treatment of the ganglion pterygopalatinum and of occipital nerve stimulation is only evaluated in observational studies, resulting in a 2 C+ recommendation. In conclusion, the primary treatment is medication. Radiofrequency treatment of the ganglion pterygopalatinum should be considered in patients who are resistant to conservative pain therapy. In patients with cluster headache refractory to all other treatments, occipital nerve stimulation may be considered, preferably within the context of a clinical study.