New lesions might occur in patients with progressive MS and adjusting therapy can be considered. Patients with untreated CIS should be scanned every 1–3 months for the initial 6 months and if stable repeating MRIs every 6–12 months is recommended, unless new clinical symptoms occur.

How long does an MS lesion stay active?

Most symptoms develop abruptly, within hours or days. These attacks or relapses of MS typically reach their peak within a few days at most and then resolve slowly over the next several days or weeks so that a typical relapse will be symptomatic for about eight weeks from onset to recovery.

How many lesions is alot for MS?

According to the team, patients with a combination of more than 13 lesions, with a maximal lesion diameter greater than 0.75 cm, and lesions perpendicular to the corpus callosum, had a 19 times greater chance of progressing to MS during the following year.