Cluster headache (CH) is the most common type of the trigeminal autonomic cephalalgias and is considered one of the most severe and debilitating pain syndromes in humans. This paper describes the clinical features, pathophysiology, acute treatment of cluster headache attacks, and prophylactic treatment.
The clinical features of CH attacks are orbital and periorbital unilateral pain with very high intensity. The pain is maximal in around or behind the eye and may radiate into ipsilateral temple, jaw, upper teeth, and neck.
The headache is associated with one or more autonomic symptoms and signs ipsilateral to the pain: ptosis, miosis, conjunctival injection, tearing, facial and frontal sweating, nasal obstruction, and rhinorhea. The most common presentation of CH is the episodic form in 85-90 % of patients.
In 10-15 % of patients the episode does not remit within 12 months, then the disease is classified as chronic CH. In pathophysiology both the peripheral hypothesis including the role of the trigeminal-autonomic reflex and the central hypothesis with the activation in the inferior posterior hypothalamus are mentioned.
Inhalation of pure oxygen or subcutaneous sumatriptan are the most effective treatment of CH attacks. Prophylactic treatment consists of transitional bridging therapy and traditional maintenance therapy.
Transitional medications are usually administered initially together with traditional maintenance therapy until traditional prophylactic treatment effectiveness begins. Transitional therapies include corticosteroids, ergot derivatives or occipital nerve block.
Traditional maintenance therapy includes verapamil, lithium, topiramate, valproic acid, melatonin or in some countries methysergide. In refractory chronic CH, if all alternative therapies have failed, noninvasive or invasive neuromodulation techniques should be considered.