Background: MS is a chronic inflammatory disease of the central nervous system. MS lesions show a typical distribution pattern and primarily affect the white matter (WM) in the periventricular zone and in the centrum semiovale.
Objective: To track lesion development during disease progression, we compared the spatiotemporal distribution patterns of lesions in RRMS and SPMS.
Results: MS lesions clustered around the lateral ventricles (fluid filled space of the brain) and in the centrum semiovale (deep white matter of the brain). Cross-sectionally, compared to RRMSers, the SPMSers showed a significantly higher regional probability of T1 hypointense lesions (more damaging lesions, also called black holes) (p≤0.03) in the callosal body (structure linking the two halves of the brain), the corticospinal tract (motor pathways), and other tracts adjacent to the lateral ventricles, but not of T2 lesions (white blobs) (peak probabilities were RRMS: T1 9%, T2 18%; SPMS: T1 21%, T2 27%). No longitudinal changes of regional T1 and T2 lesion volumes between baseline and follow-up scan were found.