The association of white matter (WM) lesions and grey matter (GM) atrophy is a feature in relapsing‐remitting multiple sclerosis (RRMS). The spatiotemporal distribution pattern of WM lesions, their relations to regional GM changes and the underlying dynamics are unclear. Here we combined parametric and non‐parametric voxel‐based morphometry (VBM) to clarify these issues. MRI data from RRMS patients with progressive (PLV, n = 45) and non‐progressive WM lesion volumes (NPLV, n = 44) followed up for 12 months were analysed. Cross‐sectionally, the spatial WM lesion distribution was compared using lesion probability maps (LPMs). Longitudinally, WM lesions and GM volumes were studied using FSL‐VBM and SPM5‐VBM, respectively. WM lesions clustered around the lateral ventricles and in the centrum semiovale with a more widespread pattern in the PLV than in the NPLV group. The maximum local probabilities were similar in both groups and higher for T2 lesions (PLV: 27%, NPLV: 25%) than for T1 lesions (PLV: 15%, NPLV 14%). Significant WM lesion changes accompanied by cortical GM volume reductions occured in the corpus callosum and optic radiations ( P = 0.01 corrected), and more liberally tested (uncorrected P < 0.01) in the inferior fronto‐occipital and longitudinal fasciculi, and corona radiata in the PLV group. Not any WM or GM changes were found in the NPLV group. In the PLV group, WM lesion distribution and development in fibres, was associated with regional GM volume loss. The different spatiotemporal distribution patterns of patients with progressive compared to patients with non‐progressive WM lesions suggest differences in the dynamics of pathogenesis. Hum Brain Mapp, 2010. © 2010 Wiley‐Liss, Inc.

Prevention of global gray matter (GM) volume changes in multiple sclerosis (MS) are an objective in clinical trials, but the effect of immunomodulatory medication on regional GM atrophy progression is unclear. MRIs from 86 patients with relapsing-remitting MS (RRMS) followed up for 24 months were analyzed using voxel-based morphometry. An analysis of covariance model (cluster threshold, corrected p<0.05) was used to compare GM volumes between baseline and follow-up while stratified by immunomodulatory medication (IM): Interferone INF-beta-1a (n=34), INF-beta-1b (n=16), glatiramer acetate (GA) (n=15), and no-immunomodulatory treatment (n=21). In the INF-beta-1a/1b group (n=50), significant GM volume reductions were observed during follow-up in fronto-temporal, cingulate and cerebellar cortical brain regions, without significant differences between the INF-beta-1a and INF-beta-1b patients. In the GA group and in unmedicated patients, no significant regional GM volume reductions were observed. In contrast to GA, INF-beta-1a/1b treatment was associated with GM volume reductions in hippocampal/parahippocampal and anterior ungulate cortex. This is the first longitudinal study investigating the effects of IMs on GM in RRMS. Results suggest differences in the dynamics of regional GM volume atrophy in differentially treated or untreated RRMS patients. (C) 2010 Elsevier B.V. All rights reserved.