Cervicogenic headache: diagnostic evaluation and treatment strategies.

Cervicogenic headache is a chronic, hemicranial pain syndrome in which the source of pain is located in the cervical spine or soft tissues of the neck but the sensation of pain is referred to the head. The trigeminocervical nucleus is a region of the upper cervical spinal cord where sensory nerve fibers in the descending tract of the trigeminal nerve converge with sensory fibers from the upper cervical roots. This convergence of upper cervical and trigeminal nociceptive pathways allows the referral of pain signals from the neck to the trigeminal sensory receptive fields of the face and head. The clinical presentation of cervicogenic headache suggests that there is an activation of the trigeminovascular neuroinflammatory cascade, which is thought to be one of the important pathophysiologic mechanisms of migraine. Another convergence of sensorimotor fibers has been described involving intercommunication between the spinal accessory nerve (CN XI), the upper cervical nerve roots, and ultimately the descending tract of the trigeminal nerve. This neural network may be the basis for the well- recognized patterns of referred pain from the trapezius and sternocleidomastoid muscles to the face and head. Diagnostic criteria have been established for cervicogenic headache but its presenting characteristics may be difficult to distinguish from migraine, tension-type headache, or hemicrania continua. A multidisciplinary treatment program integrating pharmacologic, nonpharmacologic, anesthetic, and rehabilitative interventions is recommended. This article reviews the clinical presentation of cervicogenic headache, its diagnostic evaluation, and treatment strategies.