Abnormal blood-brain barrier permeability in normal appearing white matter in multiple sclerosis investigated by MRI
Abstract
Objectives: To investigate whether blood–brain barrier (BBB) permeability is disrupted in normal appearing
white matter in MS patients, when compared to healthy controls and whether it is correlated with MS clinical
characteristics.
Methods: Dynamic contrast-enhanced MRI was used to measure BBB permeability in 27 patients with MS and
compared to 24 matched healthy controls.
Results: Permeability measured as Ktrans was significantly higher in periventricular normal appearingwhite matter
(NAWM) and thalamic gray matter in MS patients when compared to healthy controls, with periventricular
NAWMshowing the most pronounced difference. Recent relapse coincided with significantly higher permeability
in periventricular NAWM, thalamic gray matter, and MS lesions. Immunomodulatory treatment and recent
relapsewere significant predictors of permeability inMS lesions and periventricular NAWM. Our results suggest
that after an MS relapse permeability gradually decreases, possibly an effect of immunomodulatory treatment.
Conclusions: Our results emphasize the importance of BBB pathology in MS, which we find to be most prominent
in the periventricular NAWM, an area prone to development of MS lesions. Both the facts that recent relapse
appears to cause widespread BBB disruption and that immunomodulatory treatment seems to attenuate this
effect indicate that BBB permeability is intricately linked to the presence of MS relapse activity. This may reveal
further insights into the pathophysiology of MS.