How MS affects nerve cells

Multiple sclerosis is an immune-mediated condition that causes lesions to form in the brain and spine, which result in changing physical and cognitive symptoms over time.

The exact reason why MS begins is unknown, but the condition is classified as an autoimmune disease because the body’s immune system attacks the central nervous system (CNS).

During these attacks, the myelin sheath (a fatty substance that protects the nerve fibers) is worn down, causing lesions to form and symptoms to start.

Get the information and support you need

Sign up to receive information about OCREVUS, along with additional information that may be helpful throughout the course of your treatment.

Talk to your doctor about OCREVUS

Discover information and resources that can help you make the most of your next doctor's appointment.