The extracranial vascular theory of migraine: an artificial controversy.

Over the years there has been a considerable amount of controversy over whether the vascular component of migraine pain arises from the intracranial or the extracranial vessels, or both. Some have even questioned whether vasodilatation actually plays a significant role in migraine pain, and have described it as an unimportant epiphenomenon. The controversy is an artificial one though, which has been generated as a consequence of misrepresentation of the facts in the headache literature. In this review, some of the more blatant distortions in the literature are exposed.