Multiple sclerosis, a slow degenerative disease

What is multiple sclerosis or MS?

Mentioned for the first time by the French neurologist Jean-Martin Charcot in the 19th century, multiple sclerosis or MS is an autoimmune disease (incurable), which mainly affects young adults (mostly women 20-40 years old). The patient’s own immune system (via auto-antibodies) will damage the central nervous system by targeting and destroying the myelin (especially the cells responsible for the synthesis of this myelin). It is called demyelination. This inflammatory reaction in flare-ups, which affects over 2 million people in the world, will have an impact on the quality of the nerve impulses (the electrical activity allows each of us to move, to communicate …) and therefore causes a lot of neurological symptoms. In fact, myelin’s role is to physically protect the nerve fibers by creating a sheath around them; it also plays a role in the speed of propagation of information (nerve impulses). Therefore, by demyelinating, the nerve message is sent more slowly and less efficiently, hence the symptoms resulting from it. Prolonged demyelination leads to a final destruction of neurons and thus to the occurrence of a real and life-long handicap. We talk about sclerosis for the hardening of tissues affected by the disease and the formation of lesions in the form of plaques in places where myelin has been attacked (plaques visible by MRI), hence the term multiple sclerosis.

Causes of MS

If the cause of the disease onset has not yet been formally identified, clues to disease onset tip the balance towards not only a factor but certainly to a combination of factors. What is certain is that the hereditary factor must be ruled out, as well as vaccination against hepatitis B. In fact, after the complaint of some vaccinated patients that have developed MS, an international study was performed (a study analyzing the rate of MS in vaccinated and unvaccinated individuals), that ruled out the connection between vaccination and incidence of MS. Therefore, we might think that MS would have:

• A genetic origin; a study enabled a link between the presence of certain genes (29 exactly) and the presence of the disease, the gene HLA DRB1 (Human Leukocyte Antigen) being one of them.
• An infectious origin, MS having similarities with infectious diseases such as subacute encephalopathy or progressive multifocal leukoencephalopathy (two viral diseases). Doubt still persists.
• An environmental link, including lower sun exposure. In fact, we find that the people living in high latitude areas are more likely to be affected by MS, with a vitamin D deficiency playing a role. Smoking and a high-animal fat diet are also included in these environmental factors.
• An origin linked to other diseases. Studies have found an increased risk of developing MS after having contracting infectious mononucleosis (Epstein-Barr virus), if the patient is affected by an auto-immune thyroid disorder or has developed type 1 diabetes.

Symptoms of MS

There is not just one but several types of MS

There are several types of MS characterized by a chronological change in symptoms in most cases (a progression of the disease). Even if each patient is unique, the course of MS is often slow but unpredictable: * Relapsing MS that affects nearly 3/4 of patients when the disease begins, this stage alternating between flare-ups (time of onset of old or new symptoms lasting between 24 hours to several days and even a lot more) and remission periods. In some patients we can even see a total absence of symptoms even for several years.

• The secondary progressive MS, that could be called the second stage of the disease and which occurs in a longer or shorter period according to the patients (5 to 15 years after the onset of the disease), neurological sequelae get worse and worse irreversibly, flare-ups and remissions disappear, being replaced by a real handicap.
• The primary progressive MS, (rare, 10% of patients especially after 40 years old) the disease occurs and gets worse rapidly without passing through the relapsing and secondary progressive stage.

The most common symptoms

There are several recurring symptoms in many patients:

• Motor disorders such as muscle weakness, loss of balance, tremors, problems with speech, trouble in walking (spasticity) characterized by stiffness, spasms and muscle contractures
• Sensory disturbances such as tingling in the limbs, loss of sensation (numbness) in the hands, arms, legs …
• Vision problems (failing sight, blurry sight, double sight)
• Cognitive impairment (memory loss, mood swings …)
• Partial even total paralysis of certain parts of the body
• Digestive (constipation …) and sexual (erection problems) disorders
• Urinary incontinence
• Unexplained fatigue

The diagnosis of MS

Alerted by the clinical signs as mentioned previously, the doctor will confirm the presence of the disease by using several complementary tests (unfortunately, there is not yet one unique test for disease detection):

• A blood test to rule out other conditions similar to MS such as lupus or Lyme disease
• MRI (magnetic resonance imaging) to detect sclerosis lesions caused by the disease in the brain and spinal cord
• Lumbar puncture in order to carry out an analysis of the cerebrospinal fluid that surrounds the spinal cord in order to detect certain antibodies specific to inflammation

A positive diagnosis will allow the patient to begin the treatment especially in order to :

• Treat the strength and duration of flare-ups with corticosteroids (in high doses)
• Tackle demyelination (inflammation) by immunomodulators administrated to the patient (interferon), immunosuppressants and inhibitors.
• Improve the patient’s quality of life by addressing various motor disorders through physical therapy, speech therapy …