Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Multiple sclerosis ?
    ### Response:
    Multiple sclerosis (MS) is a degenerative disorder that affects the central nervous system, specifically the brain and the spinal cord. The disorder is characterized by destruction of the myelin, the fatty tissue that surrounds and protects the nerve fibers and promotes the transmission of nerve impulses, and damage to nerve cells.
    