MS is a disease of the central nervous system or CNS, i.e. the brain and spinal cord. While the precise cause of MS is not known, a few comments may be made in this connection. MS is not really a hereditary disease, but genetic factors do
play a role. A combination of a number of factors probably determines whether someone is going to get MS. There are indications, for example, that virus infections or dietary habits play a role, but the precise details are as yet unknown.

Origin of the symptoms

Inflamed areas, generally a few millimeters to a centimeter in size, arise in the brain and spinal cord. This can damage the myelin (the insulating layer round the nerves), so that the nerves no longer transmit signals properly. The nerves themselves may also be damaged in the long run. As a result of this damage to the myelin and the nerves, vital signals may fail to reach their destination in the body. If for example a muscle does not receive a signal to contract it will remain motionless and will thus in effect be paralyzed even though there is functionally nothing wrong with it. In other words, MS is not a muscle disease even though it may affect the working of the muscles. Similar problems may arise in
connection with vision (due to damage to the ocular nerve; there is nothing wrong with the eye itself) and the sense of touch. The nature of the complaints produced will depend on the site of the inflamed areas, which can vary widely from person to person. Frequently occurring complaints associated with MS are poor vision or double vision, dizziness, lack of feeling or pins and needles, paralysis or loss of bodily control. Fatigue is also a common symptom.

Course of the disease

In most cases, the body can initially repair the damage caused by the inflammation and the complaints will clear up for a while. The disease thus seems to consist of a series of attacks, also known as ‘exacerbations’ or ‘relapses’. The medical name for this condition, which occurs in about 85% of the people with MS, is ‘relapsing remitting MS’. In the long run, however, it becomes increasingly difficult for the body to repair the damage caused by the inflammations. As a result, a relapse is not followed by recovery and the condition of the person concerned may even deteriorate gradually. The medical name for this is ‘secondary progressive MS’. Some people may enter this phase a few years after the first complaints are observed, others may take 20 years or more to reach it and in some cases this phase never occurs at all.

About 10-15% of MS patients show a gradual deterioration right from the start, without an alternation of attacks and remissions. This condition is known as ‘primary progressive MS’.

When a person is first diagnosed with MS, it is usually difficult to predict how the disease will progress in the future. This generally causes a great deal of worry and uncertainty; there is little we can do to alleviate this. It should be noted, however, that while no cure exists for MS it is not a fatal disease. People with MS usually live as long as those without it.