Brain atrophy and lesion load in a large population of patients with multiple sclerosis

Abstract—Objective: To measure white matter (WM) and gray matter (GM) atrophy and lesion load in a large populationof patients with multiple sclerosis (MS) using a fully automated, operator-independent, multiparametric segmentationmethod. Methods: The study population consisted of 597 patients with MS and 104 control subjects. The MRI parameterswere abnormal WM fraction (AWM-f), global WM-f (gWM-f), and GM fraction (GM-f). Results: Significant differencesbetween patients with MS and control subjects included higher AWM-f and reduced gWM-f and GM-f. MRI data showedsignificant differences between patients with relapsing–remitting and secondary progressive forms of MS. Significantcorrelations between MRI parameters and between MRI and clinical data were found. Conclusions: Patients with multiplesclerosis have significant atrophy of both white matter (WM) and gray matter (GM); secondary progressive patients havesignificantly more atrophy of both WM and GM than do relapsing–remitting patients and a significantly higher lesion load(abnormal WM fraction); lesion load is related to both WM and even more to GM atrophy; lesion load and WM and GMatrophy are significantly related to Expanded Disability Status Scale score and age at onset (suggesting that the youngerthe age at disease onset, the worse the lesion load and brain atrophy); and GM atrophy is the most significant MRIvariable in determining the final disability.