Multiple Sclerosis



  • Pathophysiology: Recurrent episodes of CNS demyelination:
    • Signs and symptoms depend on location of lesions and timing of demyelination
  • Multiple sclerosis (MS) occurs in distinct patterns:
    • Relapsing recurring MS: 2 or more episodes lasting ≥24 hr separated by ≥1 mo
    • Primary progressive MS: Slow or stepwise progression over at least 6 mo
    • Secondary progressive MS: Initial exacerbations and remissions followed by slow progression over at least 6 mo
    • Stable MS: No progression (without treatment) over at least 18 mo


  • MS is a chronic demyelinating disease of CNS:
    • Etiology is not well understood
  • Presumed to be T cell–mediated autoimmune disease
  • There is evidence for a viral trigger
  • Plaques in white matter:
    • Characterized by infiltrate of T cells and macrophages
  • Persons of northern European origin most often affected (in the U.S.)
  • Increased prevalence is seen moving away from equator

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