The presence of enhancing lesions affecting the cortex and adjacent white matter, although transient and not frequent, suggests that at least some cortical lesions are related to blood–brain barrier disruption in multiple sclerosis (MS), according to a recent study. Researchers performed a retrospective, observational, longitudinal analysis of MRI scans collected as part of the study. 75 patients with early-stage MS were scanned monthly, over a period of 12–24 months, using 3T MRI after administration of triple-dose gadolinium. A total of 1,188 scans were included; 139 were selected using an image pipeline algorithm that integrated the image information from cortical gray matter masks and gadolinium-enhancing lesion masks. Researchers found:

• The total number of gadolinium-enhancing lesions was 2,044.
• The number of gadolinium-enhancing lesions affecting the cortex was 120 (6%), 95% of which were leukocortical.
• The number of patients who showed gadolinium-enhancing lesions affecting the cortex was 27 (36%).
• The number of gadolinium-enhancing lesions affecting the cortex at baseline was 25 (21%) and the number of new lesions that developed in follow-up scans was 49 (41%).