TABLE 1.

CGH: Cervicogenic Headache International Study Group diagnostic criteria²³.

Major criteria
	I. Symptoms and signs of neck involvement a) Precipitation of comparable symptoms by: 1) neck movement and/or sustained, awkward head positioning, and/or 2) external pressure over the upper cervical or occipital region b) Restriction of range of motion in the neck c) Ipsilateral neck, shoulder or arm pain II. Confirmatory evidence by diagnostic anaesthetic block III. Unilaterality of the head pain, without sideshift
Head pain characteristics
	IV. Moderate-severe, non-throbbing pain, usually starting in the neck Episodes of varying duration, or f uctuating, continuous pain
Other characteristics of some importance
	V. Only marginal or lack of effect of indomethacin Only marginal or lack of ef ect of ergotamine and sumatriptan Female gender Not infrequent history of head or indirect neck trauma, usually of more than medium severity
Other features of lesser importance
	VI. Various attack-related phenomena, only occasionally present, and/or moderately expressed when present: a) nausea b) phono- and photophobia c) dizziness d) ipsilateral “blurred vision” e) difficulties swallowing f) ipsilateral oedema, mostly in the periocular area