What is MS?
Multiple sclerosis (MS) is a lifelong condition that affects the central nervous system (CNS). Cells of the immune system attack the nerves of the CNS and they become inflamed and damaged. These areas become scarred and hard – ‘sclerosis’ means hardening.
MS can affect any part of the CNS, damaging the nerves in that area. This damage to the nerves can affect different parts of the body, which explains why MS can have such a wide range of symptoms. Understanding the effect that MS has on the body is important for understanding both:
the nature of MS and the course of the condition (as discussed in Symptoms of MS and Types of MS)
the effects of available treatments (as discussed in Treatment options)
Disease animation
This short animation should help explain the effect MS has on the body.
What happens in MS?
The CNS is made up of the brain and spinal cord. The brain controls bodily activities, such as movement and thought, and the spinal cord is the central message pathway.
Messages are sent from the brain to all parts of the body via nerves. These messages are transported in the form of electrical pulses that travel along the nerve fibres.
Surrounding and protecting nerve fibres is a substance called myelin. Myelin acts as an insulator, a bit like the plastic coating around electric wires, helping the electrical messages travel quickly and smoothly between the brain and the rest of the body.
In MS, it is believed that the body’s immune system attacks and destroys the myelin sheath, this is a process known as demyelination.
As a result of demyelination, the passage of electrical messages along the affected nerve fibres is disrupted and this results in the characteristic Symptoms of MS.
Without the myelin sheath, nerve fibres are vulnerable to damage. It is this nerve damage that is believed to cause the increase in disability that can occur over time in MS, as discussed in Types of MS.
Loading content...