Cervicogenic headache: the controversial headache.

Cervicogenic headache is characterized by unilaterality without sideshift, and the pain attack starts in the neck, in contradistinction to what is the case in common migraine. Signs of neck involvement (e.g. reduction of the range of motion; mechanical precipitation of attacks; ipsilateral, diffuse arm/shoulder pain) are typical in cervicogenic headache but not in common migraine. These and many other features aid in distinguishing these two headaches.