Multiple sclerosis (MS) is the most common chronic neurological disorder in the central nervous system (CNS) for young adults in Europe. At least 10,000 residents in Belgium are estimated to suffer from this disease. MS can occur at any age but the first symptoms generally appear in people aged 20-40. Women are affected more commonly then men (2:1 ratio).
There are three different types of progression possible with MS. The majority of patients (85%) start with a relapsing-remitting pattern whereby there are relapses or relapses of neurological losses of function (usually developing over several days). The symptoms generally improve, if not fully, after a few weeks. Some of these patients, however, transition to a secondary progressive phase after some time. The relapses gradually disappear but there is a more gradual and constant neurological deterioration. A minority (15%) start with a primary progressive disease.
MS is a disorder of the central nervous system (CNS); this means the brain, spinal cord and optic nerves can be affected. No clear cause has yet been identified. It appears that various elements interact with each other and lead to MS. Environmental factors, genetic aspects and perhaps also a number of coincidences play a part in this. The interaction of these factors leads to a sequence of events which affect the immune system very severely (inflammation and recovery) and degenerative symptoms appear.
The name 'multiple sclerosis' refers to the presence of multiple sclerotic outbreaks in the white matter in the CNS, which consist of scar tissue (plaques) created after repeated and long-term inflammations of the myelin. These inflammations are paired with decomposition of the myelin – the insulating covers of nerve cells – caused by the body's own immune system. This result is that nerve conduction is threatened. The forming of new inflammatory lesions is the basis of clinical relapses of MS.
Neurodegeneration, with diffuse damage to the nerve fibres themselves, is therefore the driving force within the progressive phase of the disease. Inflammatory processes and the immune system seem to play a much smaller part here. The exact combination between inflammation on one hand and neurodegeneration on the other isn't yet fully understood for MS.
MS plaques can appear anywhere in the CNS so there is a wide range of possible symptoms. The disease starts with optic nerve inflammation for many patients. Other common symptoms are loss of strength in the limbs, diminished sensation, pain, coordination problems and difficulties controlling eyeball movement. Patients also often suffer from bladder or bowel problems, fatigue, depression and cognitive complaints. External factors such as heat, fever and infections can make old symptoms worse again temporarily.
The natural progression of MS varies greatly per individual and is relatively unpredictable. The following factors are associated with a less favourable prognosis: male, starts at older age, lots of relapses in the first 2 years, extensive neurological failure in the first relapse, significant worsening of disability within the first 5 years and progression of the disease.
It's important to note that MS is not a disorder from which people die prematurely, although life expectancy is slightly reduced globally. This is mainly because is of the premature death of severely affected people, often with complications caused by being bedridden (aspiration pneumonia, bladder infection, deep vein thrombosis, bedsores...).