Brain atrophy in relapsing-remitting multiple sclerosis: relationship with 'black holes', disease duration and clinical disability.

Abstract

Recent MRI studies in multiple sclerosis have highlighted the potential role of brain atrophy evaluation as a putative marker of disease progression. In the present study, we evaluated the supratentorial and infratentorial brain volume in patients with relapsing remitting multiple sclerosis (RR MS) and in healthy subjects. Moreover, we determined whether brain volumes of MS patients are associated with different aspects of brain MRI abnormalities and clinical findings. Two-dimensional acquired MRI was performed on 52 relapsing-remitting multiple sclerosis and 30 healthy subjects. The volume of supratentorial and infratentorial structures was measured in selected representative slices. Gd-enhancement, T2 hyperintense, T1 hypointense (i.e. 'black holes') total lesion load, as well as the area of corpus callosum was calculated in the MS group and related to brain volume measures. Correlations between MRI parameters and clinical features were also considered. MS patients had significantly lower supratentorial, infratentorial brain volume and corpus callosum area than healthy subjects (P<0.01). Supratentorial brain volume was significantly related to corpus callosum area (r=0.58; P<0.01) and T1 hypointense lesion load (r=0.48; P<0.01), but not with T2 hyperintense lesion load. Infratentorial/supratentorial ratio was significantly associated with disease duration and EDSS score (r=-0.34; P=0.02 and r=-0.49; P<0.01, respectively). This study documents that brain atrophy is an early MRI finding in RR MS and it is closely related to 'black holes' burden. The use of relative values (infratentorial/supratentorial ratio) may increase the conspicuity of correlation between clinical and MRI findings.