Cervicogenic headache.

Chronic headache is a significant medical and socioeconomic problem resulting in severe disability and impairment. The term "cervicogenic headache" was coined by Sjaastad in 1983, who also proposed criteria for its diagnosis. Cervicogenic headache as described by Sjaastad et al is characterized as recurrent, long lasting, severe unilateral headache arising from the neck. Exact pathoanatomic and pathophysiologic basis for cervicogenic headache is unclear. Numerous authors have proposed various theories ranging from neurophysiologic basis involving ascending fibers from the C1 and C2 nerve roots to multiple pain generators in pain-sensitive structures involved in head movement. Thus, cervicogenic headache should be considered as a descriptive term rather than a final diagnosis. Because of the numerous potential pain generators, neither uniform clinical findings, nor a pathophysiology has been defined for the entity known as cervicogenic headache. Sequential diagnostic injections may elucidate pain generators and differentiate it from other types of headaches. This review describes the epidemiological and clinical aspects of cervicogenic headache, pathophysiology, diagnostic strategies to differentiate it from other common headaches and describes various non-operative treatment strategies.