Ultra-High-Resolution MRI Identifies Enlarged Perivascular Spaces in People with Migraines

Using ultra-high field 7T magnetic resonance imaging (MRI), researchers have identified enlarged perivascular spaces (EPVS) in the brains of individuals with migraine, according to emerging study findings presented at the Radiological Society of North America (RSNA) 2022 Annual Meeting.

"To our knowledge, this is the first study using ultra-high-resolution MRI to study microvascular changes in the brain due to migraine, particularly in perivascular spaces," said co-author Wilson Xu, an M.D. candidate at the Keck School of Medicine of the University of Southern California in Los Angeles. "Because 7T MRI is able to create images of the brain with much higher resolution and better quality than other MRI types, it can be used to demonstrate much smaller changes that happen in brain tissue after a migraine."

While migraine may be associated with vascular-related changes in the brain, such as white matter hyperintensities and cerebral microbleeds, the association with EPVS has not been thoroughly investigated.

"Perivascular spaces are part of a fluid clearance system in the brain," explained Xu. "Studying how they contribute to migraine could help us better understand the complexities of how migraines occur."

In the study, the researchers used ultra-high field 7T MRI to compare structural microvascular changes in 10 individuals with chronic migraine, 10 individuals with episodic migraine without aura and five age-matched headache-free healthy controls. Participants were aged 25 to 60 years. Exclusion criteria included overt cognitive impairment, brain tumor, prior intracranial surgery, MRI contraindications and claustrophobia.

Neuroimaging data were collected via 7T MRI scans using T1, T2, FLAIR and susceptibility-weighted imaging (SWI)/quantitative susceptibility mapping (QSM) sequences. The researchers calculated EPVS in the centrum semiovale and basal ganglia. White matter hyperintensities were measured using the Fazekas scale and cerebral microbleeds were rated using the microbleed anatomical rating scale. The researchers also recorded the duration and severity of disease, presence of aura, side of headache and symptoms at time of scan.

When compared with the healthy controls, the number of EPVS in the centrum semiovale, but not the basal ganglia, was significantly higher in participants with migraine. The frequency of white matter hyperintensities and cerebral microbleeds in participants with migraine did not differ significantly from that of healthy controls. However, EPVS quantity in the centrum semiovale significantly correlated with deep white matter hyperintensity severity in participants with migraine.

"Although we didn't find any significant changes in the severity of white matter lesions in patients with and without migraine, these white matter lesions were significantly linked to the presence of enlarged perivascular spaces. This suggests that changes in perivascular spaces could lead to future development of more white matter lesions," said Xu.

The authors concluded that significant differences in the EPVS in participants with migraine compared with healthy controls “might be suggestive of glymphatic disruption within the brain, but whether such changes affect migraine development or result from migraine is unknown.” They suggested that further study with larger populations and longitudinal follow-up is needed to better establish the relationship between structural changes and migraine development and type.

"The results of our study could help inspire future, larger-scale studies to continue investigating how changes in the brain's microscopic vessels and blood supply contribute to different migraine types," said Xu. "Eventually, this could help us develop new, personalized ways to diagnose and treat migraine."