Progressive-relapsing MS (PRMS) is the least common of the four disease courses, occurring in approximately 5% or so of people with MS. Like those with primary-progressive MS (PPMS), people with PRMS experience disease progression from the very beginning — but they experience occasional relapses (also called attacks or exacerbations) as well .
Because PRMS is progressive from onset, the doctor may initially diagnose it as PPMS, subsequently changing the diagnosis to PRMS when a relapse occurs. Although this disease course is progressive from the outset, each person’s symptoms and rate of progression will be different.