Background: There is growing evidence for the concept of multiple sclerosis (MS) as an inflammatory-neurodegenerative disease, with a different pattern of atrophy evolution in gray matter (GM) and white matter (WM) tissue compartments.
Objective: We aimed to investigate the evolution of different MRI measures in early relapsing-remitting (RR) MS patients and in normal controls (NC) over 2 years. We also evaluated the progression of these MRI measures in a subset of patients who were followed for up to 5 years.
Methods: Included in this study were one hundred forty-seven (147) patients who participated in the combination ASA (Avonex Steroids Azathioprine) study and completed full treatment, clinical and MRI assessment at 0, 12 and 24 months. A subgroup of 66 patients was followed for 36 months, 51 for 48 months and 43 for 60 months, respectively. Mean age at baseline was 30.7 years, mean disease duration was 5.5 years, mean EDSS was 1.8 and mean annualized relapse rate before study entry was 1.7. MRI scans were performed on a 1.5T scanner every 2 months for the first 2 years and thereafter once yearly for up to 5 years. In addition to the MS group, 27 NC were examined at months 0, 12 and 24 using the same MRI protocol. Percent brain volume change (PBVC), GM volume (GMV), WM volume (WMV) and peripheral gray volume (PGV) were measured annually using SIENA/X software. T2-hyperintense lesion volume (LV), lateral ventricle volume (LVV), and third ventricle width (3VW) were also assessed annually.
Results: Over the period of 0-24 months, MS patients lost significantly more GMV (-2.6% vs. –0.72%, p<0.0001), PGV (-2.4% vs. -1.03%, p<0.0001) and PBVC (-1.2% vs. -0.22%, p<0.0001), and increased in LVV (+16.6% vs. +0.55%, p<0.003) and 3VW (+9.3% vs. 0, p=0.003), when compared to NC. Within-person change in MRI measures for MS patients over 5 years was -4.2% for PBVC, -6.2% for GMV, -5.8% for PGV, -0.5% for WMV (all p<0.0001), +68.7 for LVV (p<0.00001), +4% for 3VW (p<0.00001) and +42% for T2-LV (p<0.0001).
Conclusions: Our study confirmed a different pattern of GM, WM and central atrophy progression over 2 years between MS patients and NC. The study showed a different evolution of tissue compartment atrophy measures in MS patients, with faster decline in cortical and deep GM regions, as well as periventricular WM regions over a 5-year period.
- brain atrophy
- gray matter
- multiple sclerosis
- normal controls
- white matter