MRI Detects MS Progression Markers in White Matter

Magnetic resonance imaging shows the combined presence of astrogliosis and axonal damage in white matter, which has cardinal importance in multiple sclerosis (MS) severity, according to an article published in JAMA Neurology.

Researchers from the U.S. and Spain performed a study to evaluate the potential of MR markers of central nervous system injury to predict brain-volume loss and clinical disability among patients with MS.

A total of 59 patients with MS and 43 healthy controls participated in the study. There was also a confirmatory data set that included 220 patients from an independent, large genotype-phenotype research project. Participants were assessed annually over four years for outcomes, which were based on baseline N-acetylaspartate (NAA) level, myo-inositol (mI) in normal-appearing white and gray matter, myelin water fraction in normal-appearing white matter, markers of axonal damage, astrogliosis, and demyelination.

The results showed that mI:NAA could be used as a predictor, based on NAA and mI having significant effects on brain volume. “The ratio was a predictor of brain-volume change in both cohorts (annual slope in the percentage of brain-volume change/unit of increase in the ratio: −1.68; 95 percent CI, −3.05 to −0.30; P = .02 in the preliminary study cohort and −1.08; 95 percent CI, −1.95 to −0.20; P = .02 in the confirmatory study cohort),” the authors wrote.

The mI:NAA ratio predicted clinical disability in the preliminary data set as well, they noted. Also predicted were Multiple Sclerosis Functional Composite evolution, Expanded Disability Status Scale evolution, and Expanded Disability Status Scale sustained progression in the confirmatory data set. However, there was no predictive value shown with myelin water fraction.

The authors concluded that “the mI:NAA ratio in normal-appearing white matter has consistent predictive power on brain atrophy and neurological disability evolution. The combined presence of astrogliosis and axonal damage in white matter has cardinal importance in disease severity.”