Migraine is a common condition, involving a severe recurring headache but sometimes nausea, weakness and light sensitivity as well. According to the American Migraine Foundation, over 37 million people in the U.S. report being affected by migraine, though only 148 million people worldwide report suffering from it.

Perivascular spaces are fluid-filled spaces surrounding blood vessels in the brain. They are most commonly located in the basal ganglia and white matter of the cerebrum, and along the optic tract. Perivascular spaces are affected by several factors, including abnormalities at the blood-brain barrier and inflammation. Enlarged perivascular spaces can be a signal of underlying small vessel disease.

A new fMRI paper used ultra-high-field 7T MRI to compare structural microvascular changes in different types of migraine and note enlarged perivascular spaces in the brains of migraine sufferers. In people with chronic migraine and episodic migraine without aura, there are significant changes in the perivascular spaces of a brain region called the centrum semiovale.

Study participants included 10 with chronic migraine, 10 with episodic migraine without aura, and five age-matched healthy controls. All patients were between 25 and 60 years old. Patients with overt cognitive impairment, brain tumor, prior intracranial surgery, MRI contraindications and claustrophobia were excluded from the study.

The researchers calculated enlarged perivascular spaces in the centrum semiovale (central area of white matter) and basal ganglia areas of the brain. White matter hyperintensities—lesions that “light up” on MRI—were measured using the Fazekas scale. Cerebral microbleeds were rated with the microbleed anatomical rating scale. The researchers also collected clinical data such as disease duration and severity, symptoms at time of scan, presence of aura and side of headache.

Statistical analysis revealed that the number of enlarged perivascular spaces in the centrum semiovale was significantly higher in patients with migraine compared to healthy controls. In addition, enlarged perivascular space quantity in the centrum semiovale correlated with deep white matter hyperintensity severity in migraine patients.

The researchers speculate that significant differences in the perivascular spaces in patients with migraine compared to the healthy controls might be suggestive of glymphatic disruption within the brain. The glymphatic system is a waste clearance system that utilizes perivascular channels to help eliminate soluble proteins and metabolites from the central nervous system.