Brain atrophy in relapsing-remitting multiple sclerosis and secondary progressive multiple sclerosis: Longitudinal quantitative analysis

PURPOSE: To determine annual rates of volumetric changes in the whole-brain parenchyma of patients with relapsing-remitting and secondary progressive multiple sclerosis (MS) and test the hypothesis that these changes correlat e with clinical disability. MATERIALS AND METHODS: A computer-assisted segmentation technique with thin -section magnetic resonance (MR) imaging was used in 36 patients with MS (2 7 relapsing-remitting, nine secondary progressive) and in 20 control subjec ts to quantify brain and cerebrospinal fluid volumes. To determine the degr ee of brain atrophy, the percentage brain parenchyma volume (PBV) relative to that of intracranial contents was calculated. RESULTS: At the beginning of the study, the PBV was smaller in the MS group than in the control group (P = .007); brain parenchyma volumes were simila r. The median rate of brain volume loss was 17.3 mL per year in patients wi th relapsing-remitting MS and 23.6 mL per year in those with secondary prog ressive MS. There was a negative correlation between brain atrophy and Expa nded Disability Status Scale (EDSS) score in patients with secondary progre ssive MS (r = -0.69, P = .004) and no correlation in patients with relapsin g-remitting MS. T2 lesion volume did not correlate with brain atrophy in ei ther group. CONCLUSION: The correlation between brain atrophy and EDSS score was better in patients with secondary progressive MS than in those with relapsing-rem itting MS.