Both secondary progressive and relapsing progressive MS were referred to as chronic progressive in the past. The term chronic progressive is no longer used.
Primary progressive patients were also sometimes referred to as chronic progressive. Importantly, if an MS patient has never had an attack followed by a remission, they are diagnosed as having primary progressive MS. However, if an MS patient begins as a primary progressive but then has an onset of new problems followed by improvement, they then are rediagnosed as “relapsing progressive.”
Many neurologists in the past have concluded that there are many more types of MS, but these are not easily characterized or recognized clinically. Therefore, they are no help in determining prognosis or in evaluating the effects of therapy.