Cerebral atrophy and disability in relapsing-remitting and secondary progressive multiple sclerosis over four years

Pathology and magnetic resonance imaging (MRI) studies have provided evidence of widespread axonal loss and reductions of cerebral and spinal cord volume in multiple sclerosis (MS). Atrophy measures on MRI may be a useful surrogate marker of worsening disability in MS, but the published studies are of relatively short duration. Change in brain volume (atrophy) was measured over a four-year period in 20 patients with relapsing-remitting (RR) and 18 with secondary progressive (SP) MS using three-dimensional (3D) MRI acquired during treatment trials of interferon-beta-1a (Rebif). Brain parenchymal and lateral ventricle volume changes were determined and correlated with clinical measures. Over four years, brain parenchymal volume (BPV) decreased in RRMS and SPMS patients by 0.9% (P = 0.006) and 0.3% (P = 0.118), respectively, and the lateral ventricle volumes increased by 15% (P < 0.0001) and 13% (P < 0.0001), respectively. In RRMS patients both lateral ventricle volume (r = 0.63, P = 0.004) and BPV change (r = -0.47, P = 0.037) were related to disability change, as measured by the Expanded Disability Status Scale. Even though a small study and despite the possible confounding effects of interferon treatment, this study demonstrated an association between measures of cerebral atrophy and worsening disability. The data also provides evidence that brain atrophy can be detected early in the disease course and central white matter atrophy as reflected by ventricle enlargement appears to be a continuous process.