Chronic cluster headache: new and emerging treatment options.

Cluster headache (CH) is a primary headache syndrome characterized by short-lasting unilateral head pain attacks accompanied by ipsilateral oculofacial autonomic phenomena. Approximately 20% of CH patients have the chronic form and need continuous medical care. In the chronic form, attacks continue unabated for years, often on a daily basis, resulting in severe debilitation. It is a common experience that drug treatments are able to control or prevent the attacks in approximately 80% of chronic CH patients. In the remaining 20% of chronic cases, drugs are ineffective. Until recently, the etiology of CH was poorly understood and this hampered the development of new therapies. However, we have now gained a much improved understanding of the peripheral and central mechanisms giving rise to the pain in CH and this has inspired the development of new treatment approaches, which, although still in the initial phases of validation, appear to be very promising. Among these, the novel approach based on hypothalamic deep brain stimulation is one of the most promising.