Timing and topography of cerebral blood flow, aura, and headache during migraine attacks

Recent research has improved our understanding of migraine with aura. In this study, 63 patients were observed to identify patterns in cerebral blood flow. The first change noted was a decrease in blood flow in one hemisphere. This decrease was linked to the onset of aura symptoms. After the aura, the headache phase began, with blood flow still low. Interestingly, during headaches, blood flow shifted from low to high. This change occurred without altering headache intensity. Some patients experienced headache relief while blood flow remained elevated. Most patients exhibited unilateral symptoms, but one-third reported bilateral headaches. Typically, headaches localized to the side where blood flow decreased. Aura symptoms were felt contralaterally but originated in the affected hemisphere. These findings propose a model for migraine attacks, where disturbances in one hemisphere lead to both aura and headache symptoms. Clinical relevance: This research highlights how migraine attacks involve complex changes in cerebral blood flow, potentially guiding better treatment strategies.