Advances in the understanding of headache.

Primary headache disorders account for a substantial part of the morbidity seen in medical practice and so advances in their understanding and management are of general importance. The classification of headache disorders has recently been revised, and the importance of frequent migraine, chronic (transformed) migraine and some important, albeit rarer, conditions that were previously not included has been recognized. Identification of the first genes for a migraine syndrome, namely familial hemiplegic migraine, and their classification as channelopathies opens up new understanding of these disorders and their possible pathophysiology. Functional brain imaging of migraine and cluster headache has placed the pathophysiology of these disorders firmly and clearly in the brain. As our understanding of migraine and related syndromes has increased, new therapies have been developed which reduce the significant disability associated with these important neurological disorders.