The central nervous system

To understand what happens in MS, you need to understand how the central nervous system works. Your central nervous system is made up of your brain and spinal cord. Your brain controls bodily activities, such as movement and thought, and your spinal cord is the central message pathway. Messages are sent from your brain to all parts of your body, controlling both conscious and unconscious actions.


 

What happens in MS?

Surrounding and protecting the nerve fibres of the central nervous system is an important substance called myelin, which helps messages travel quickly and smoothly between the brain and the rest of the body.

 

 

 

 

 

 

MS is an autoimmune condition. This means that your immune system, which normally helps to fight off infections, mistakes your body’s own tissue for a foreign body, such as infectious bacteria, and attacks it. In MS, the immune system attacks myelin. This damages the myelin and strips it off the nerve fibres, either partially or completely, leaving scars known as lesions or plaques. This myelin damage disrupts messages travelling along nerve fibres – they can slow down, become distorted, pass from one nerve fibre to another (short circuiting), or not get through at all.

As well as myelin loss, there can also sometimes be damage to the actual nerve fibres. It is this nerve damage that causes the accumulation of disability that can occur over time.

 

 

 

 

 

 

As the central nervous system links all bodily activities, many different types of symptoms can appear in MS. The specific symptoms that appear depend upon which part of your central nervous system is affected and the job of the damaged nerve.

 

Making it easier to understand

The simplest way to understand what happens in MS is to think of your nervous system as an electrical circuit, with your brain and spinal cord acting as the power source and the rest of your body being the lights, computers, TVs, etc. Your nerves are like the electrical cables linking all of the appliances together and the myelin is the plastic insulation surrounding these cables. If the insulation gets damaged, the electrical current to appliances can become faulty or temperamental and there may be a short circuit, preventing the appliances from working properly. 

Why is it called 'Multiple Sclerosis'?

The word sclerosis comes from the Greek 'skleros' meaning hard. In MS, hard areas called plaques, lesions or scars develop around the nerves. 'Multiple' refers to the many different areas of the central nervous system that may have damaged myelin.