What is the primary characteristic of multiple sclerosis?

The primary characteristic of multiple sclerosis (MS) is that it is a chronic central nervous system disease caused by the destruction of myelin. Myelin is the protective sheath that surrounds nerve fibers, and its damage disrupts the transmission of electrical impulses along the nerves. This disruption is what leads to the various neurological symptoms associated with MS, such as fatigue, difficulty with coordination and balance, vision problems, and cognitive changes.

Unlike other options that describe different conditions or aspects of neurological health, the hallmark of multiple sclerosis is indeed the autoimmune process that targets myelin. Patients with MS experience periods of relapse and remission, but the underlying mechanism of myelin degeneration is foundational to understanding the disease. This demyelination leads to the formation of scar tissue (sclerosis) in the central nervous system, which is where the name "multiple sclerosis" comes from.