Understanding cervicogenic headache.

The purported mechanism underlying the development and progression of cervicogenic headache (CEH) is the convergence of sensory inputs at the trigeminocervical nucleus. This mechanism explains the radiation of pain from the neck or the occipitonuchal area and its spread to the oculo-fronto-temporal region; it also explains the recurrent headaches caused by improper neck postures or external pressure to the structures in the neck and the occipital region. These neural connectivity mechanisms involving the trigeminal nucleus are also evident from the eyeblink reflex and findings of quantitative sensory testing (QST). Understanding the mechanisms underlying the development of CEH is important because it will not only provide a better treatment outcome but will also allow practitioners to appreciate the variability of symptomatic presentations in these patients.