title: Mechanisms of disability progression in primary progressive multiple sclerosis: are they different from secondary progressive multiple sclerosis?
authors.affiliation: Mellen Center for Multiple Sclerosis, Area U10, Departmentof Neurology, Cleveland Clinic Foundation, Cleveland, OH, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Rudick
mesh_terms: D004185:Disability Evaluation; D018450:Disease Progression; D006801:Humans; D020528:Multiple Sclerosis, Chronic Progressive / Q000503:physiopathology*