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An overview of multiple sclerosis

What is MS?

Multiple sclerosis (MS) is a disease that causes the body’s immune system to attack the central nervous system (CNS). The CNS includes the brain and the spinal cord.

Central nervous system scheme

How MS damages the CNS

Nerve cells in the CNS communicate with each other by way of axons (which work like wires connecting one nerve cell to the next).

Axons have a protective coating around them called myelin.

MS causes the immune system to “attack” the myelin, creating damaging lesions within the CNS. This damage keeps the nerve cells from communicating as they are meant to. Therefore, the CNS can’t function properly.

Process of nerve cell damage by MS

Lesion activity leads to communication breakdowns in the brain

Chain break icon

Lesions limit the brain’s ability to function properly. It becomes difficult for signals to be sent from one part of the brain to another—and from the brain to the rest of the body. This “communication breakdown” can lead to both cognitive and physical changes.

Learn more about the impact of MS on the brain