There are multiple definitions:
Stichting Pensioenfonds Medische Specialisten(Dutch)
secondary-progressive multiple sclerosis(English)
- in MS follows an initial relapsing-remitting course. Some people will eventually transition to a secondary progressive course in which there is a progressive worsening of neurologic function (accumulation of disability) over time
- CIS, MS, RRMS
- Neuropathy, Disability
- https://www.nat…-progressive-MS