Cerebral blood flow changes in migraine: methods, observations and hypotheses.

A number of basically different methods have been used in studies of the cerebrovascular changes which occur in migraine and each individual set of findings seems to be dependent on which method is used. One method on its own can only disclose a part of all the pathophysiological events. This review is an attempt to consider the capabilities of each method and to bring together the results from different studies on migraine in order to create a complete picture of the cerebrovascular changes which occur during the course of a migraine attack.