Relapsing-remitting MS is defined by inflammatory attacks on myelin (the layers of insulating membranes surrounding nerve fibers in the central nervous system (CNS)), as well as the nerve fibers themselves. During these inflammatory attacks, activated immune cells cause small, localized areas of damage which produce the symptoms of MS. Because the location of the damage is so variable, no two people have exactly the same symptoms.
How does RRMS differ from progressive types of MS?
While RRMS is defined by attacks of inflammation (relapses) in the CNS, progressive forms of MS involve much less of this type of inflammation.