When MS causes a new lesion in the brain it leaves behind a scar ~80% of the time. The scar may become a black-hole which indicates loss of underlying tissues. The lesions that cause black holes are considered to be more destructive than lesions than don’t leave behind black-holes.
“This study shows that interferon-beta, is as likely as glatiramer acetate, to prevent lesions from turning into black holes. This would indicate that both these DMTs affect the evolution of lesions and reduce their effect on brain tissue; this data would support both these drugs as having some neuroprotective effect.”