Lesion analysis
The Lesion Segmentation Toolbox of Statistical Parametric Mapping (SPM; Wellcome Centre for Human Neuroimaging; UCL Queen Square Institute of Neurology; London, United Kingdom) was used to measure total lesion volume and number of lesions within the MS sample. This toolbox segments T2 hyperintense lesions by combining information from T1 and FLAIR structural images to generate lesion probability maps. All lesion masks were quality assured. Lesion characteristics of the MS sample are provided in 