Hyperperfusion of cerebral cortex, thalamus and basal ganglia during spontaneously occurring migraine headaches.

Color-coded, cross-sectional imaging of local cerebral blood flow (LCBF) was made in a prospective manner among 22 patients with well-established common or classic migraine utilizing the stable xenon-enhanced computed tomographic (Xe CT-CBF) method. LCBF in patients during spontaneously occurring headaches (N = 12) were significantly higher compared to patients without headache (N = 10) by 25-35%. The hyperperfusion involved not only cerebral cortex but also subcortical structures including thalamus, basal ganglia, and subcortical white matter. LCBF increases were not bilateral and sometimes asymmetrical, but LCBF increases were not consistently related to the preponderant side of headache. No significant differences were observed in the degree or pattern of cerebral hyperperfusion during headaches compared among common (N = 6) and classic (N = 6) migraineurs. Results suggest a common etiology for both common and classic migraine. Results are not consistent with spreading oligemia or spreading cortical depression as a cause of migraine. The cerebral hyperperfusion appears to be mediated by various neurogenic and chemical changes accompanying migraine. The unilateral nature of migraine head pain is more likely due to dilation of extracranial vessels.