T2 lesion location really matters: a 10-year follow-up study in primary-progressive MS

International audienceObjectives: Prediction of long-term clinical outcome in patients with primary-progressive multiple sclerosis (PPMS) using imaging has important clinical implications, but remains challenging. We aimed to determine whether spatial location of T2 and T1 brain lesions predicts clinical progression during a 10-year follow-up in PPMS. Methods: Lesion probability maps of the T2 and T1 brain lesions were generated using the baseline scans of 80 patients with PPMS, who were clinically assessed at baseline and then after one, two, five and ten years. For each patient, the time (in years) taken before bilateral support was required to walk (time-to-event, TTE), was used as a measure of progression rate. The probability of each voxel being “lesional” was correlated with TTE, adjusting for age, gender, disease duration, centre, and spinal cord cross-sectional area, using a multiple linear regression model. To identify the best, independent predictor of progression, a Cox regression model was used. Results: A significant correlation between a shorter TTE and a higher probability of a voxel being lesional on T2 scans was found in the bilateral cortico-spinal tract and superior longitudinal fasciculus, and in the right inferior fronto-occipital fasciculus (p