Multiple sclerosis is one of the most common disorders of the central nervous system
Multiple sclerosis (MS) is in these parts one of the most common disorders of the central nervous system. It affects mainly younger people, women more often than men, and can lead to temporary or even permanent disability. To those affected, who are often in the prime of life, the diagnosis of "MS" can pose a serious challenge and possibly affect one's professional, family and personal life as well as damaging one's physical and mental stability and independence.
The progression of multiple sclerosis can be influenced
The possibility of a cure, in the same way for instance as antibiotics permanently eradicating a particular infection, has not yet been found for multiple sclerosis. However, the choice of medications for favourably influencing the progression of multiple sclerosis has been clearly broadened in recent years, and a number of additional substances are currently "in the pipeline" i.e. they are currently undergoing clinical testing and offer the promise of improvement in the near future. In addition, treatment methods have become established which aim to alleviate the symptoms and improve the quality of life. Unlike almost any other disease, self-help groups and societies have been formed at various levels, with the German Multiple Sclerosis Society (Deutsche Multiple Sklerose Gesellschaft (DMSG)) being the main body in Germany for providing MS sufferers with political representation as well as support in a number of other ways.
Multiple sclerosis can progress in different ways
The diagnosis of multiple sclerosis does not, by any means, always imply disability. The disease progresses in very different ways. Some of those affected develop only temporary symptoms and can go about their everyday activities without any impediment. Others suffer increasing disability within a few years until they are bound to a wheelchair. As yet it is not possible, with certainty, to predict the exact course of the disease from the outset. But improved diagnostic methods and an improvement in therapeutic possibilities currently go hand in hand.
Multiple Sclerosis. Information A-Z
Definition. What exactly is multiple sclerosis?
As yet, nobody has been able to properly answer this question. But a lot is known about the processes involved in this disease. And a lot of factors are known to increase the risk of suffering from multiple sclerosis.
Immune system dysfunction in multiple sclerosis
There is no doubt that at least part – perhaps even the major part – of the underlying disease process in multiple sclerosis is attributable to inflammation. Thereby, the immune system misguidedly attacks some of the endogenous neurons in the brain and spinal cord (autoimmune disease). The myelin sheaths in particular, which form the coating for the projections of the neurons (axons) and thus improve conductivity, are targeted by the uncontrollable inflammation. The processes of such an inflammatory reaction are highly complex and incorporate various immune cells (T and B lymphocytes) and numerous mediators. Normally, the central nervous system is fairly well insulated from the immune cells by the so-called blood-brain barrier. In the case of multiple sclerosis, however, there is a temporary breakdown in this barrier, leaving the door open to a blind attack on the neurons.
Episodic process of multiple sclerosis
In those affected, this can often lead to a relatively rapid onset of certain neurological symptoms. This is known as an "attack". Depending on which parts of the brain and spinal cord are inflamed at the time, symptoms such as paralysis, impaired vision or a loss of sensitivity in certain parts of the body may result. Healthy parts of the immune system, however, recognise that something is wrong. They attempt to stem the acute inflammation and reseal the blood-brain barrier. Depending on how well the inflammation can be stopped before it causes irreparable damage to the neurons, the deficits may be either partly or totally reversed following an attack. In the best case scenario, the protective myelin sheaths at the site of destruction can be reconstructed (remyelination), otherwise long-term defects remain with permanent scarring (gliosis) or simply defined holes called "black holes" on MRI.
The inflammation can appear in other areas of the nervous system
But the matter is only resolved momentarily. For the immune system has a fairly good memory, in fact in many ways it is better than the brain. Which is good, since an unwelcome visitor that returns after a long time, having previously attempted to make its way in, is quickly identified and thrown out. A problem only arises when the immune system becomes paranoid and imagines that the intruder is still in the house. As a result self-destructive, supposed purges are repeatedly enacted. Consequently, with multiple sclerosis the inflammation may reappear in new areas of the nervous system at varying time intervals. This pattern, affecting the brain and spinal cord at different times and in different areas, is very typical of multiple sclerosis. This is considered by the diagnostic criteria. Similarly, the term "multiple sclerosis" was deduced from the fact that long-term pathological examinations revealed numerous (multiple) sites of hardened scar tissue (sclerosis) in the brain and spinal cord.
Secondary Progression of Multiple Sclerosis
85% of all multiple sclerosis cases are sudden to begin with, and the extent of regression of the symptoms and interim relief can vary. After several years, however, half of the patients who suffered a sudden attack to start with undergo gradual deterioration without, as a rule, any considerable interim improvements. This is called "secondary progression". In 15% of multiple sclerosis sufferers the condition gradually progresses from the very beginning ("primary progressive multiple sclerosis") without any identifiable attacks. In such cases, a pathological process other than the inflammation is evidently at work. The neurons and their projections are continually destroyed ("axonal loss"). This disintegration process in certain cells is possibly triggered by the original inflammation, but then keeps going on its own. This aspect of the disease has not yet been fully explained. Perhaps what we diagnose today as multiple sclerosis is made up of different individual diseases, more precise knowledge of which could enable us to design more individual treatment concepts.
Symptoms. What are the symptoms of multiple sclerosis?
Just as multiple sclerosis can lead to pathological changes in various parts of the brain and spinal cord, as described above, so the symptoms are very varied and diverse. They may develop within hours or days and abate either completely or partially, like an attack, or they may appear gradually over the course of weeks and months. Some multiple sclerosis sufferers notice that symptoms which already exist may temporarily worsen due to the heat or increased body temperature (Uthoff phenomenon). Feverish infections, therefore, can cause transient deteriorations but are not an indication of an attack or advancement of the disease.
Common symptoms with a relatively specific correlation to certain regions of the central nervous system are:
- Paralysis on one side of the body, the extremities or the face. Often associated with "spastic" convulsions of the muscles.
- Impaired vision: often with inflammation of the visual nerve, then affecting one eye with clouded vision as far as a clear loss of the vision, sometimes accompanied by motion dependent pain behind the eyes.
- Impaired sensitivity in various regions of the body (formication, tingling, numbness). Electrical sensations in the extremities when flexing the neck (Lhermitte's sign).
- Imbalance, uncertain gait, vertigo, impaired coordination including clumsiness when gripping or writing.
- Bladder/rectal disorders with a sudden urge to urinate, incontinence or constipation
- Ocular movement disorders: double vision, involuntary rapid eye movements (nystagmus).
- Speech disorders with unclear, slurred speech
- Swallowing difficulties
Diffuse problems often occur with multiple sclerosis
Multiple sclerosis can often involve nonspecific or diffuse symptoms which may go unrecognised when the disease first appears. It should be acknowledged, however, that such problems do not only occur with multiple sclerosis and also are sometimes quite common in the general population. They should be taken seriously, however, and be diagnosed by a specialist. Last but not least, they may have a very negative impact on the quality of life of multiple sclerosis sufferers, which may be underestimated in the long term:
- Fatigue: increased exhaustion, fatigue, weakness, lack of concentration, lack of relaxation
- Depression: lack of drive, listlessness, sleep disorders, apathy, melancholy, suicidal thoughts
- Cognitive disorders: concentration and attention difficulties, impaired retentiveness, slow reactions
- Pain: sometimes difficult to localise, diffuse, burning, searing, convulsive. Occasionally sudden, shooting, electrical such as trigeminal neuralgia.
Causes. Why does multiple sclerosis develop?
The exact causes of multiple sclerosis are not yet known today. Perhaps there is no "one cause" at all, but rather an interaction of various factors which triggers the disease. Hitherto, several such risk factors were identified which, if they exist, increase the likelihood of a person contracting MS. Both genetics and the environment are influential factors.
Multiple sclerosis. Genetic disposition
It has been known for a long time that multiple sclerosis can be partly caused by genetic modifications and can occur more often in one family. If an identical twin suffers from multiple sclerosis, the probability of his or her twin also contracting the disease is 30%. Even in unidentical twins, the risk of the disease – at 2% – is much higher than that in the normal population of 0.1%. Recently, a gene locus could be identified specifically on chromosome 6 which is important in controlling immunological processes and in which modifications could be identified in the case of multiple sclerosis.
Multiple sclerosis. Environmental factors
On the other hand, it has also been known for many years that certain environmental factors clearly increase the risk of multiple sclerosis. Surprisingly, geographical aspects are amongst them. The closer to the equator an individual lives when growing up, the smaller his chances of contracting the disease. The further away, either north or south of the equator, that a person lives during childhood, the greater the chances of developing multiple sclerosis. Northern Europe and North America are the regions with the highest rates of multiple sclerosis. According to earlier studies, migrations following puberty have no further influence and the risk according to where an individual has grown up is retained. More recent studies question this age limit, however. One consideration is that there is a link to sun exposure during a critical, influential phase in the immune system. UV rays promote the creation of vitamin D in the body. Recent research findings prove that vitamin D is important not only for bone metabolism, but also to the immune system. Studies were able in fact to identify a connection between the vitamin D levels in the blood and the risk of contracting multiple sclerosis. The higher the levels, the lower the risk.
Do viruses trigger multiple sclerosis?
The apparently occasional, epidemic occurrence of multiple sclerosis cases has often led to discussions of whether there is a correlation to certain pathogens, particularly viruses. One example is the epidemic on the Faroe Islands. There was no known case of multiple sclerosis there prior to 1943. During its occupation in the Second World War by British troops, however, 21 cases of multiple sclerosis occurred in island inhabitants within two years. It was presumed that the disease had been "introduced" by the troops. No proof could ever be furnished, however, that the multiple sclerosis had been caused by a specific infectious organism. In light of present knowledge, it is highly unlikely. But there are clear indications that long-term contact with certain pathogens may cause the immune system to adopt self-aggressive behavioural patterns. Studies most recently have shown that an increase in antibodies against the Epstein-Barr virus in the blood, as an indication of an earlier and successful confrontation of the immune system with this bacteria, is associated with a 9-fold increase in the risk of multiple sclerosis.
Multiple sclerosis (MS) is in these parts one of the most common disorders of the central nervous system.