[Rare primary headache syndromes].

Primary headaches include common forms such as migraine, tension-type headache, and the less frequent cluster headache. Besides, several uncommon primary headaches were included in the section on 'Cluster headache and other trigeminal autonomic neuralgias' (section 3) and 'Other primary headaches' (section 4) in the second edition of the International Classification of Headache Disorders (ICHD-II, 2004). Since the prevalences of these uncommon headaches are quite low, datas related to clinical features, physiopathology and management are still controversial. While paroxysmal hemicrania, short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) are listed in the third section, hemicrania continua (HC) with not prominent autonomical signs are classified in the fourth section in the ICHD-II classification. The fourth section also includes other rare primary headache syndromes. In this review, some of the uncommon primary types of headache will be discussed. Even though these headaches are reported seldomly, the prevalences are possibly higher than known. It is of importance to recognize these uncommon disorders, since their management differs from common primary headaches.