If you’ve been told that you have primary-progressive MS (PPMS), you probably have questions about what it is, how it differs from other forms of MS, and what can be done to treat it. And you may be wondering what research is being done on this form of MS.

PPMS is a disease course that is characterized by steady worsening of neurologic functioning, without any distinct relapses (also called attacks or exacerbations) or periods of remission. A person’s rate of progression may vary over time — with occasional plateaus or temporary improvements — but the progression is continuous.