Multiple sclerosis is a neurological disease that affects the central nervous system. It’s a chronic illness with varying circumstances, so each case evolves in a different way.
It occurs with the appearance of plaque – or areas where the myelin disappears – in the central nervous system. Myelin is the substance that covers and protects the axons of neurons. Its principal function is to increase the speed of the transmission of nerve impulses. Its elimination explains the risks most characteristic of this disease.
Who does multiple sclerosis affect?
This disease affects more women than men and it has a greater impact on Caucasians. It tends to begin between the ages of 20 and 40 and it follows a geographical distribution.
The incidence of the disease is greater in countries far from the equator. Thus, it’s especially prevalent in Nordic countries. In fact, it was the Vikings who facilitated its expansion with their voyages.
The latest evidence points to an interesting environmental influence. Vitamin D and heat are protecting factors. This can partially explain the geographical distribution of the illness.
How does it occur?
As far as genetics, it has been shown to be associated with human leukocyte antigens HLA – DR2 and HLA – DQ. Also, the illness is more frequent in families who have direct family members with the illness than in the rest of the population.
Clinical manifestations of multiple sclerosis
The most frequent (61%) symptoms are sensitivity. Among these may be paresthesias, (the sensation of ants crawling on you) or hyposthesia, lessening sensibility in an area.
Frequently, in young patients, the illness begins as optic neuritis. In these cases, the vision becomes blurry and it’s painful to move the eyes from their normal position. In fact, in a young person this may lead to unilateral loss. If this is the case, multiple sclerosis should never be ruled out. Another symptom may be double vision.
Weakness and motor symptoms appear as frequently as optic neuritis. They’re a consequence of the lesion of the pyramidal path.
Meanwhile, in the medular lesions, other symptoms frequently appear. They may be impotence and urgency to urinate. In cervical lesions, it can be a sign of Lhermitte, which is a feeling of painful electric shock when moving the neck.
Plus, if there’s a cerebral lesion, it may be difficult to articulate words. There may also be a lack of coordination, nystagmus, and tremors.
In advanced cases, it’s fairly common to experience neurological dysfunction that manifests itself in loss of memory. As a result, there may also be a change of behavior, bouts of euphoria and displays of inhibition.
Patients frequently experience depression, especially when they first receive the diagnosis. The depression is reactive, however, and is not provoked by the disease itself.
Patterns that evolve
Multiple sclerosis can evolve following one or more of the following patterns:
- Recurring pattern – 85% of cases follow this pattern. This pattern produces spikes without aftermaths that then return to the initial situation.
- Secondary progressive pattern – In some cases, after a period of spikes, the symptoms begin to progress.
- Primarily progressive pattern – 10% of cases follow a progressive curve from the very beginning, without the experience of spikes. Unfortunately, this has a poor prognosis.
- Progressive pattern recurrent – This only occurs in 5% of the cases of this illness. In this case, the illness takes a progressive path from the very beginning. There are also spikes and the symptoms are exacerbated by spikes.
The diagnosis of multiple sclerosis is basically done in a clinic. In addition, there are two fundamental requirements:
- There should have been 2 or more episodes of symptoms separated by at least a month without symptoms (temporal dissemination).
- The symptoms and signs should include at least two different lesions (spacial dissemination). For example, paralysis in one leg and blurry vision in one eye.
A series of tests supports the diagnosis.
Analysis of cerebrospinal fluid (CSF)
Normal CSF is totally transparent and acellular. The CSF of a person with multiple sclerosis shows the following:
- An elevation of the lymphocites and of the complete proteins,
- An elevation of the lg G in almost 80% of the patients.
By using this technique, one can determine the velocity of the sensory paths. The detection of a slowing down of the electric conduction in the neural transmission suggests that there is a demyelinated lesion.
Fortunately, a physician can diagnosis this in the absence of a clinic. Today, they measure it almost exclusively by visual evoked potentials.
MRI (magnetic resonance)
This is the test with the best results for diagnosing. In just one study, experts can determine the following:
- The number of lesions
- The Spacial dissemination
- The temporal dissemination (the most recent lesions are most visible)
In an MRI, one can observe “Dawson’s fingers.”. These are lesions that are oval (like fingers). They’re perpendicular to the cerebral ventricles and are lesions that are very characteristic of this disease.
At this time, there is still not a cure for this disease. However, the current treatments go in two directions:
- On one hand, they calm the symptoms of the spike.
- On the other hand, they modify the course of the disease.
Additionally, there are drugs aimed at treating the symptoms.
- Treatment of the severe spikes are with mega doses of corticosteriods. The pattern and the method of administration depend on the severity of the spike.
- Immunomodulators are used to adjust the course of the illness. Glatiramer acetate and beta interferon are the primary drugs. These are the most effective that exist. The secondary drugs of defense are natalizumab and fingolimod.
The high rate of depression in these patients explains the need for a good, supportive psychologist.