Table 1 Diagnostic criteria for cluster headache according to the International Classification of Headache Diseases II

A. At least five attacks fulfilling B through D

B. Severe or very severe unilateral orbital, supraorbital and/or temporal pain lasting 15 to 180 minutes if untreated

C. Headache is accompanied by at least one of the following:

   1. Ipsilateral conjunctival injection and/or lacrimation

   2. Ipsilateral nasal congestion and/or rhinorrhea

   3. Ipsilateral eyelid edema

   4. Ipsilateral forehead and facial sweating

   5. Ipsilateral miosis and/or ptosis

   6. A sense of restlessness or agitation

D. Attacks have a frequency from one every other day to eight per day

E. Not attributed to another disorder