[Cervicogenic headache. An over- or underdiagnosed headache syndrome?].

"Cervicogenic headache" (CEH) is a strictly unilateral constant dull, dragging, boring background pain of varying intensity which does not alternate sides and persists for a few hours to several days. It is triggered or intensified by head movements, and typically radiates from the neck to the fronto-temporal region. Occasionally, the ipsilateral shoulder and arm are also affected, with no definite radicular pattern. There is overall restriction of head movements. Ipsilateral accompanying symptoms may include conjunctival injection, lacrimation and lid edema. Migraine-like symptoms such as nausea, vomiting, sound and light sensitivity, and ipsilateral visual blurring may occur, as well as dizziness and difficulties in swallowing. A C2-blockade always leads to temporary pain relief. The possible pathophysiology of CEH, and its differential diagnosis are discussed.