MS typically begins in the second or third decade of life but can be diagnosed as early as age 10 and as late as in the 60s. It is a chronic, inflammatory, demyelinating, and neurodegenerative disease of the central nervous system (CNS), believed to result from a genetic predisposition combined with an environmental trigger. The disease course is heterogeneous, with 85% of patients starting with a relapsing-remitting course, which, after 15 to 20 years evolves into a secondary progressive course. The remaining 15% of patients will have a chronic, primary progressive course from the onset.
Common presenting symptoms include visual loss, sensory loss in one or both lower extremities, weakness of a limb or loss of balance, walking difficulties.