Greater 5-year Gray Matter Atrophy Is Associated with Newly Arising Paramagnetic Rim Lesions, but Not Disappearing or Persisting Rim Lesions
Jack Reeves1, Dejan Jakimovski1, Niels Bergsland1, Maryam Mohebbi1, Fahad Salman1, Ferdinand Schweser1, Bianca Weinstock-Guttman2, Michael Dwyer1, Robert Zivadinov1
1Buffalo Neuroimaging Analysis Center, University at Buffalo, 2Department of Neurology, University At Buffalo
Objective:
To investigate the associations between newly appearing, disappearing, and persisting paramagnetic rim lesions (PRLs) and longitudinal brain atrophy.
Background:
Previous studies have associated PRLs with increased brain atrophy in people with multiple sclerosis (pwMS), supporting the role of PRLs in MS progression. However, it remains unclear if PRLs maintain an association with long-term atrophy throughout their existence or only during specific phases, such as their initial appearance.
Design/Methods:
Clinical data and 3T MRI were acquired from 103 pwMS at baseline and 5-year follow-up. PRLs were identified on quantitative susceptibility maps and classified into three groups: “persisting” (present at both baseline and follow-up), “disappearing” (present at baseline but not at follow-up), and “newly appearing” (emerging at follow-up). Linear models were used to test associations between PRLs and percent brain volume changes. All analyses controlled for baseline volume, baseline age, sex, baseline disease duration, baseline MS disease course, time to follow-up, baseline total T2 lesion volume, and change in total T2 lesion volume.
Results:
At baseline, the average age was 47.7 ± 11.6 years, mean disease duration of 13.7 ± 10.4 years, and median expanded disability status scale was 2.5 (interquartile range 1.5 – 4.5). The mean follow-up time was 5.3 ± 0.5 years. On average, pwMS had 1.7 ± 3.1 PRLs, with 45.6% (47/103) having ≥ 1 PRL. 13.7% (14/103) of pwMS had at least one newly appearing PRL and 17.5% (18/103) had a disappearing PRL. The presence of at least one newly appearing PRL was associated with volume decreases in the whole brain, whole deep gray matter, thalamus, accumbens, pallidum, and putamen, along with an increase in lateral ventricular volume (p < 0.028 for all). No significant associations were seen with disappearing or persisting PRLs.
Conclusions:
PRLs are linked to longitudinal brain atrophy primarily in the early stages of their existence.