Key Points ÎCluster headache (CH) is a rare and disabling primary headache disorder.
ÎCH attacks are unilateral, short, severe headaches associated with ipsilateral autonomic symptoms, restlessness, or agitation that occur in a periodic fashion.
ÎThe International Classification of Headache Disorders, 2nd edition, defines CH as at least 5 severe to very severe unilateral headache attacks, lasting 15 to 180 minutes untreated.
ÎAttack frequency ranges from 1 every other day to 8 per day.
ÎThere are 2 types of CH: > Episodic CH occurs in series lasting weeks or months separated by remission periods usually lasting months or years.
> A total of 10% to 15% of patients with CH have chronic CH.
> Chronic CH occurs for more than 1 year without remission or with remissions lasting less than 1 month.
ÎWhen patients present with a new cluster bout, it is appropriate to initiate both acute symptomatic therapy and preventive therapy.
Cluster Headache – Symptoms
ÎThe symptoms of a CH include stabbing pain behind or above one eye or in the temple, tearing of that eye, congestion in the associated nostril, pupil changes, and eyelid drooping.