title: The natural history of secondary progressive multiple sclerosis: observations from the London study group.
authors.affiliation: University Hospital, Multiple Sclerosis Clinic, London, Ontario, Canada.
authors.forename: G P A
authors.initials: GP
authors.lastname: Rice
mesh_terms: D002986:Clinical Trials as Topic; D018450:Disease Progression; D005500:Follow-Up Studies; D006801:Humans; D008131:London; D020528:Multiple Sclerosis, Chronic Progressive / Q000503:physiopathology; D011379:Prognosis; D013997:Time Factors