Migraine aura: new ideas about cause, classification, and clinical significance.

Abstract

The migraine aura is a dramatic spontaneous change in brain activity resulting in a variety of transient neurological symptoms. The purpose of this review is to address recent advances in the understanding of aura and its role in migraine. The formal classification of migraine aura is becoming both broader and more detailed. Traditionally viewed as a primary event that triggers a migraine attack, studies regarding the timing of aura relative to other symptoms of migraine indicate that it may not in fact play a primary role in initiating an attack. Careful recording and analysis of visual aura symptoms provides new insight into the initiation and propagation of the underlying brain phenomenon, and the different regions of visual cortex that produce different visual perceptions. Migraine with aura may have different responses to acute and preventive therapies. There has been significant evolution of concepts regarding the causes of migraine aura, how it is best defined, and how it fits into the picture of the migraine disorder as a whole. Regardless of its exact role in the genesis of migraine, an increased understanding of aura has the potential to provide important new insight into not only migraine but also fundamental mechanisms of brain physiology.