Multiple sclerosis usually begins at 30 years old.
 The course of symptoms occurs in two main patterns initially: either as episodes of sudden worsening that last a few days to months (called relapses, exacerbations, bouts, attacks, or flare-ups) followed by improvement (85% of cases) or as a gradual worsening over time without periods of recovery (1015% of cases)
 It is similar to the age that secondary progressive usually begins in RRMS, around 40 years of age

