Research Points to a Potential Imaging Biomarker for Migraine
Further studies, larger cohort needed to confirm findings of researchers
Migraine is a diagnosis of exclusion — a determination that is made through process of elimination since there is no test or biomarker to identify the condition. Research has shown, however, that there is a possible association between alterations in permeability of the blood brain barrier (BBB) and chronic pain.
In a recent study in Radiology, researchers from the Republic of Korea determined that this association in BBB permeability points to the location in the brain associated with pathological changes in the BBB during migraine.
Researchers, led by Yeon Soo Kim, MD, of the Department of Radiology, Seoul National University Hospital, Republic of Korea, recruited 56 patients (35 with migraine and 21 as a healthy control group) to undergo dynamic contrast-enhanced MRI to determine the contrast agent kinetics in the brains of migraine patients.
Dr. Kim and colleagues found that the mean fractional plasma volume (Vp) in the left amygdala was lower in the migraine group (median, 0.27 mL/100 g; interquartile range, 0.21–0.41 mL/100 g) than in the healthy control group (median, 0.39 mL/100 g; interquartile range, 0.28–0.63 mL/100 g) (P = .04).
“Thus, participants with migraine exhibited lower local blood plasma volume fraction in alleged migraine-associated regions compared with healthy control participants,” Dr. Kim said.
In an accompanying Radiology editorial, Timothy Carroll, PhD, and Daniel Thomas Ginat, MD, both of the Department of Radiology, University of Chicago, wrote that the study provides what appears to be the first observation of a potential biomarker for migraine.
“The identification of a quantifiable metric (Vp) of the left amygdala and specific area of the brain are a great first step,” Dr. Carroll said. “This is particularly useful as many migraine sufferers are subjected to MRI scans to rule out other possible diagnoses, such as aneurysms or tumors. So the quantification of Vp be easily implemented in standard screening protocols.”
Nevertheless, Drs. Carroll and Ginat suggest proceeding with caution. The single-center study with a low number of participants should be confirmed in a larger cohort, they said.
“And while this study was carried out at a prestigious, high-end research institute, the use of such a biomarker has to be easily implemented in every type of radiology department,” they wrote. “To move such a biomarker toward widespread use, there are clear metrics of success that must be met.”
Validating Vp as a diagnostic biomarker first means establishing its clinical performance characteristics, such as sensitivity, specificity, accuracy and precision, said Dr. Carroll, adding that further research will need to establish test-retest repeatability, reliability and whether Vp values can be harmonized across imaging systems and post-processing software.
Episodic and Chronic Migraine
In a January 2020 online study in the Journal of Headache and Pain, researchers led by Álvaro Planchuelo-Gómez, MSc, Universidad de Valladolid, Valladolid, Spain, studied potential migraine biomarkers as well as biomarkers for episodic and chronic migraine.
Researchers compared white matter of the brain in patients with episodic migraine, chronic migraine and healthy controls, using data from diffusion MRI. Planchuelo-Gómez and colleagues detected widespread white matter structural differences between patients with episodic (less than 15 headache days per month) and chronic migraine (15 or more headache days per month, with at least eight of these days showing migraine characteristics for at least three months). Planchuelo-Gómez and colleagues also found changes in episodic and chronic migraine with respect to healthy controls.
“In a nutshell, our study suggests that it is not only important to develop migraine biomarkers, but also biomarkers for episodic and chronic migraine, taking into account different measures that model diverse pathophysiological processes such as fiber packaging density or axonal impairment,” Planchuelo-Gómez said.
Longitudinal studies to confirm hypotheses about temporal changes in chronic migraine and to better understand migraine progression are needed, he said.
For More Information
Access the Radiology study, “Altered Vascular Permeability in Migraine-associated Brain Regions: Evaluation with Dynamic Contrast-enhanced MRI,” and the Radiology editorial, “Using Dynamic Contrast-enhanced MRI as an Imaging Biomarker for Migraine: Proceed with Caution.”Access the study, “White matter changes in chronic and episodic migraine: a diffusion tensor imaging study,” in Journal of Headache and Pain,” at journalofheadacheandpain.biomedcentral.com