Paroxysmal hemicrania: an update.

Paroxysmal hemicrania (PH) is an underreported and underdiagnosed primary headache disorder. It usually begins in the third or fourth decade of life. The recent observations indicate that it is equally prevalent in both males and females. PH is characterized by severe, strictly unilateral head pain attacks that occur in association with ipsilateral autonomic features. The attacks in PH are shorter and more frequent compared with cluster headache (CH) but otherwise PH and CH have similar clinical features. The hallmark of PH is the absolute cessation of the headache with indomethacin. However, a range of drugs may show partial to complete relief in certain groups of patients. Neuromodulatory procedures, such as greater occipital nerve blockade, blockade of sphenopalatine ganglion and neurostimulation of the posterior hypothalamus, are reserved for refractory PH.