Blood brain barrier permeability changes in the left amygdala in patients with migraine may be a detectable migraine imaging marker, according to a recent article published in Radiology.
Researchers sought to evaluate the permeability of the blood brain barrier and its potential diagnostic relationship with migraine-associated brain regions using dynamic contrast material-enhanced (DCE) magnetic resonance imaging (MRI). Each of the 56 study participants (n=35 with a migraine diagnosis and n=21 controls) was given gadobutrol prior to undergoing a DCE MRI and the T1-weighted images that were formed created fractional plasma volume maps, which were used to measure the permeability of the blood brain barrier in the migraine-associated brain region masks. Clinical characteristics, such as migraine duration, and headache characteristics, such as the intensity of the migraine attacks, were evaluated for each participant of the migraine group. The researchers then compared the result of 2 groups to assess differences, in addition to looking into the correlation of brain differences to clinical characteristics of the migraine group.
The researchers found that the fractional plasma volume was significantly lower in the left amygdala in the migraine group compared with the control group (P =.04). Thus, those in the study with migraine presented with lower local blood plasma volume fraction in migraine-associated brain regions. Furthermore, when comparing the lower fractional plasma volume in the left amygdala with the clinical and headache characteristics, the researchers found that the mean value of fractional plasma volume in the left amygdala was inversely correlated with the intensity of migraine attack of those with migraine (r=-0.34; P =.04). This suggests that “[blood brain barrier] BBB impairment in the amygdala may relate to pathophysiologic change in individuals with migraine.”
In addition to the small sample size, the researchers mention a few study limitations. The researchers measured the blood brain barrier integrity and not the perfusion of metabolic demand, which is pathophysiologically different from blood brain barrier integrity. Thus their results cannot directly conclude that the groups’ differences are entirely caused by migraine. DCE MRI has low contrast for poorly vascularized tissue, which could have also affected their results.
The researchers concluded from their results that “the lower fractional plasma volume in the left amygdala is observed in participants with migraine, which can be used as a migraine-associated imaging marker on dynamic contrast-enhanced MRI.” Additionally, due to the subtleness of blood brain barrier change in migraines, “additional evaluation is required for confirmation in larger numbers of patients and with a matched control group.”
Kim YS, Kim M, Choi SH, et al. Altered vascular permeability in migraine-associated brain regions: evaluation with dynamic contrast-enhanced MRI [published online July 2, 2019]. Radiology. doi:10.1148/radiol.2019182566