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MS ExplainedThe cause of symptoms

In MS, only nerves in the brain or spinal cord are damaged. However, as these nerves control the functions of the whole body, symptoms can affect many different areas, although an individual with MS will only experience some of these. As well as the variety of symptoms, the severity and duration will also vary from person to person.

How MS affects an individual depends on where damage occurs and which nerve messages are interrupted or blocked.

Some people can have MRI scans that show a number of areas of scarring but in areas that have not caused them to experience noticeable symptoms. Conversely, a single scar that damages an area controlling bladder function, for instance, can have a serious impact on someone's life.

Similarly, the actual level of disease activity can remain constant with a consistent number of areas of scarring. However, if a new scar interrupts an important function, such as walking, it can seem to the individual as though the MS has accelerated.

Whilst the complexity of the brain and how it handles information are still far from fully understood, certain areas are associated with specific functions. This section gives a very broad overview of how damage caused by MS to these areas can lead to certain symptoms being experienced.

The following pages cover a range of symptoms that MS can cause, but it is important to stress that most people only experience a small number of these. Although there are no drugs to cure MS, there are treatments for many of the symptoms. Information on treatments can be found in other MS Trust publications or by contacting the MS Trust Information Service.

diagram of the brain
Site of damage Symptom
1 Spinal cord Spasticity
Bladder problems
Bowel problems
Weakness
2 Brainstem Visual problems
3 Optic nerve Optic neuritis
4 Cerebellum Balance and dizziness
Tremor and ataxia
5 Areas involved with thought and emotion Cognition
Depression
Mood swings
Symptoms not associated with a single area Fatigue
Speech and swallowing
Pain

Next page - The spinal cord