See below. Secondary progressive MS is a more advanced stage of relapsing remitting ms. In this stage, individuals experience fewer recognized neurological relapses, and betwen such attacks begin to accumulate measureable worsening of physical or cognitive disability. It is not a distinct form of disease, but part of the spectrum of relapsing ms.
Usually worsening. 85% of all MS cases begin with the relapsing/remitting form, and if not successfully managed, by ten years, 50% become secondary progressive, and by 20 years, 90%. Relapses become less frequent and progressive disability fails to reverse. So, the key factor is to use potent medication from the beginning.
MS. Secondary would signify that it is another a primary disease but rather the disease was initiated by another process or disease. Progressive means that the ms itself is progressively worsening beyond current therapy.