Cervicogenic headache: criteria, classification and epidemiology.

The concept that headache might stem from the neck is old. The term "cervicogenic headache" was coined in 1983. A new content was then given to this concept: cervicogenic headache (CEH) is in principle a unilateral headache, generally starting in the neck and "spreading" forwards. A strict unilaterality--that is, absolutely no pain on the opposite side--is rather rare. Unilaterality in this context is defined as follows: the headache dominates on one side. When weak, the pain may be only on that side; when severe, it may also be felt on the contralateral side, but to a lesser extent. It never dominates on the contralateral side. These special features of CEH cannot be emphasised strongly enough. There are signs pertaining to the neck, such as reduced range of motion in the neck, mechanical precipitation mechanisms and ipsilateral shoulder/arm sensation (or even pain). Migraine without aura symptoms are less prominent than in migraine.