TITLE : Periventricular magnetisation transfer ratio abnormalities in multiple sclerosis improve after alemtuzumab RUNNING TITLE : Effect of alemtuzumab on MTR gradients

Background In relapse-onset multiple sclerosis (MS), tissue abnormality – as assessed with magnetisation transfer ratio (MTR) imaging is greater in the outer cortical and inner periventricular layers. The cause of this remains unknown but meningeal inflammation has been implicated, particularly lymphoid follicles, which are seen in secondary progressive (SP) but not primary progressive (PP) MS. Cortical and periventricular MTR gradients might therefore differ in PPMS and SPMS if these follicles are responsible.