Conventional and non-conventional quantitative magnetic resonance imaging outcomes differ when comparing multiple definitions of benign multiple sclerosis

• Published in: Multiple sclerosis Vol. 14; p. S214
• Main Authors: Passanese, J, Kelemen, A, Weinstock-Guttman, B, Teter, B, Mihai, C, Hojnacki, D, Munschauer, F, Abdelrahman, N, Stosic, M, Zivadinov, R
• Format: Journal Article
• Language: English
• Published: 01.09.2008
• ISSN: 1352-4585

Background: Although benign multiple sclerosis (BMS) has been recognized for more than 50 years, a precise and reliable definition has yet to be elucidated. Objective: To investigate differences in quantitative magnetic resonance imaging (MRI) outcomes using four different definitions of BMS. Methods: A cohort of 730 consecutive multiple sclerosis (MS) patients enrolled at one site in the New York State Multiple Sclerosis Consortium (NYSMSC) were classified as BMS based on their Expanded Disability Status Scale (EDSS) score and disease duration in years (ddy) using four common literature definitions (number of BMS cases ranged from 184 to 78): BMS-1 (EDSS score less than or equal to 2, ddy greater than or equal to 10), BMS-2 (EDSS score less than or equal to 3, ddy greater than or equal to 10), BMS-3 (EDSS score less than or equal to 3, ddy greater than or equal to 15) and BMS-4 (EDSS score less than or equal to 2, ddy greater than or equal to 15). Primary MRI outcomes consisted of: T2-lesion volume (LV), T1-LV, gadolinium-LV, whole brain atrophy (NBV) and whole brain magnetization transfer ratio (MTR). Secondary MRI outcomes comprised a number of non-conventional MRI measures in gray matter (GM) and white matter (WM) tissue compartments. Differences in BMS vs. non-BMS groups for each definition were assessed using multivariate analysis of covariance procedure corrected for age, sex and total months of disease-modifying treatment. Results: NBV was significantly higher only in the BMS-2 definition. BMS-1,-2 and -4 definitions had significantly lower T2- and T1-LVs in comparison to non-BMS groups. BMS-3 was the only definition that did not reflect any significant differences for primary MRI outcomes. More robust differentiation of BMS vs. non-BMS groups was possible using non-conventional MRI measures. In particular, GM-based measures were significantly higher in all BMS definitions, except for BMS-4. Conclusions: Differences in primary and secondary MRI outcomes of BMS vs. non-BMS are affected by the particular definition used. Non-conventional MRI measures can contribute to better differentiation between BMS and non-BMS.