White matter lesion burden in migraine with aura may be associated with reduced cerebral blood flow

Objective: The objective of this study was to determine whether white matter hyperintensities (WMHs) in subjects with migraine are related to alterations in resting cerebral blood flow (CBF). Methods: Migraine with aura (MWA), migraine without aura (MwoA), and control subjects were enrolled in a 1:1:1 ratio. WMH load was scored based on fluid-attenuated inversion recovery/T2-weighted magnetic resonance imaging (MRI) using a previously established semi-quantitative scale. Global and regional CBFs were quantified using arterial spin labelled perfusion MRI. Integrity of the circle of Willis was assessed with magnetic resonance angiography (MRA). Results: A total of 170 subjects were enrolled (54 controls, 56 MWA, and 60 MwoA). There was no significant difference in subjects with 1 WMH across groups (22% controls, 29% MWA, 35% MwoA; p=NS). Similarly, high WMH load was not significantly different across groups (16.7% controls, 21.4% MWA, 25.0% MwoA; p=NS). High WMH load was strongly associated with increasing age (odds ratio: 1.08 per year, 95% confidence interval: 1.02-1.13, p=0.01). Resting CBF was similar across groups, but was significantly higher in women. In MWA subjects with high WMH load, CBF was substantially lower (p=0.03). No association between WMH load and CBF was seen in control or MwoA subjects. Conclusions: WHMs in MWA may be related to alterations in resting CBF.