Multiple sclerosis

Multiple sclerosis or SEP is a chronic autoimmune inflammatory disease, which attacks the central nervous system. The disease worsens slowly in most cases and this worsening depends on, among other things, the frequency and severity of the relapses.

La multiple sclerosis touch it central nervous system, especially the brain, nerves and spinal cord. It alters the transmission of nerve impulses because the myelin, which forms a protective sheath around the nerve extensions, is affected.  

The symptoms vary depending on the location where the myelin is affected: numbness of a limb, visual disturbances, sensations of electric shock in a limb or in the back, movement disorders, etc.

Read more about the symptoms of multiple sclerosis 

Most often, multiple sclerosis progresses by spurts, during which symptoms reappear or new symptoms arise. These symptoms often resolve after relapses, but after a few years the relapses still leave sequelae (permanent symptoms), more or less disabling. The disease can indeed affect many functions: movement control, sensory perception, memory, speech, etc. However, thanks to therapeutic advances, having multiple sclerosis is no longer synonymous with a wheelchair. The biggest problem described by people with this disease is often fatigue, also called “invisible disability” because it is not visible but is nonetheless annoying and requires adaptations in his daily life.

There is also a progressive form of multiple sclerosis, which does not progress in flares, but develops gradually.

La multiple sclerosis is a chronic autoimmune disease, the severity and course of which vary widely. It was first described in 1868 by the French neurologist Jean Martin Charcot.

The disease is characterized by inflammatory reactions which in places lead to the destruction of the myelin (demyelination). Myelin is a sheath that surrounds nerve fibers (see diagram below). Its role is to protect these fibers and accelerate the transmission of messages or nerve impulses. The immune system of affected people destroys myelin by considering it foreign to the body (autoimmune reaction). Thus, in certain places of the nervous system, the impulses are slower or blocked, which causes the various symptoms. Apart from the flare-ups, the inflammation subsides and part of the myelin is reformed around the fibers, which leads to a complete or partial regression of the symptoms. However, in cases of repeated and prolonged demyelination, the nerve impulse may no longer flow, resulting in permanent disability.

The parts of the nervous system affected by the disease look like plates that can be seen during magnetic resonance imaging (MRI), hence the term multiple sclerosis.

Multiple sclerosis diagram

What are the causes of multiple sclerosis? 

  • La multiple sclerosis  occurs in the presence of a combination of environmental factors, in people whose heredity predisposes to the disease. .
  • The further one moves away from the Equator, the more frequent the disease is: for this reason, researchers believe that the lack of sunlight during childhood and adolescence could play a role.
  • Passive smoking in children and smoking in adolescents may also play a role.
  • Viruses that would cause an inappropriate immune reaction could be involved: in any case, this is a line of study taken seriously.
  • On the other hand, several studies have exonerated the vaccines (against hepatitis B or against the papillomavirus), a time suspected of playing a supporting role.
  • As to genetic factors predisposing, they are also numerous. Several potentially involved genes have been identified in recent years and could increase the risk of multiple sclerosis. And besides, the risk increases when other family members are already affected by the disease.

See also the People at Risk and Risk Factors for Multiple Sclerosis sections

Diagnosis: how do you recognize multiple sclerosis? 

There is no test that can diagnose with certainty a multiple sclerosis. Moreover, diagnostic errors remain frequent, because many diseases can manifest themselves by symptoms resembling those of multiple sclerosis.

In general, the diagnostic based on :

  • There is no test that can diagnose with certainty a multiple sclerosis. Moreover, diagnostic errors remain frequent at the beginning, because many diseases can initially manifest themselves with symptoms resembling those of multiple sclerosis.

In general, the diagnostic based on :

  • A medical history, with a questionnaire that establishes the history of problems related to the disorder and identifies, if applicable, previous neurological manifestations.
  • A physical exam that assesses vision, muscle strength, muscle tone, reflexes, coordination, sensory functions, balance and the ability to move.
  • Magnetic resonance imaging (MRI) of the brain and spinal cord which allows you to visualize the lesions in the white matter (which contains myelin): this is the most telling examination. Cerebrospinal fluid (CSF) in the lumbar region is not routine but it can help spot signs of inflammation.
  • Depending on the symptoms and before prescribing treatments, other examinations may still be requested: for example, a fundus, a recording of electrical activity to measure the time it takes for visual information to reach the brain, an EKG, etc.

    • La multiple sclerosis is difficult to diagnose and usually requires 2 or more relapses, with at least partial remission, to confirm the diagnosis.

    To establish a definitive diagnosis of multiple sclerosis, the neurologist must be convinced that there is damage to myelin in two different places which cannot be the consequence of other diseases (spatial criterion). In addition, he must also demonstrate that these infringements occurred at two different periods (criterion of a temporal nature). The medical questionnaire is therefore crucial so that we can fully understand the symptoms and check whether there have been neurological manifestations in the past.

    How does multiple sclerosis progress?

    THEevolution of multiple sclerosis is unpredictable. Each case is unique. Neither the number of relapses, nor the type of attack, nor the age of the diagnosis make it possible to predict or envisage the future of the person who is affected. There are benign forms which do not cause any physical difficulty, even after 20 or 30 years of illness. Other forms can evolve quickly and be more invalidating. Finally, some people have only one flare in their entire life.

    Today, thanks to existing treatments, many people with multiple sclerosis are able to lead very satisfying social, family (including pregnancy for women) and professional lives, at the cost of certain adjustments because the fatigue is often pervasive.

    What are the different forms of multiple sclerosis?

    In general, we distinguish 3 shapes main causes of multiple sclerosis, depending on how the disease progresses over time.

    • Remitting form. In 85% of cases, the disease begins with the relapsing-remitting form (also called “relapsing-remitting”), characterized by spurts interspersed with remissions. A single push is not enough to make the diagnosis in most cases, doctors sometimes speak of “isolated clinical syndrome” while waiting to see how it evolves. A flare is defined as a period of onset of new neurological signs or of reappearance of old symptoms lasting at least 24 hours, separated from the previous flare by at least 1 month. Usually flare-ups last a few days to 1 month and then gradually go away. In the majority of cases, after several years, this form of the disease can progress to a secondarily progressive form.
    • Primary progressive form (or progressive from the outset). This form is characterized by a slow and constant course of the disease, upon diagnosis, with worsening of symptoms for at least six months. It concerns 15% of cases6. Unlike the relapsing-remitting form, there are no real relapses, although the disease can get worse at times. This form usually appears later in life, around the age of 40. It is often more severe.
    • Secondarily progressive form. After an initial relapsing-remitting form, the disease may worsen continuously. We then speak of a secondarily progressive form. Flare-ups can occur, but they are not followed by clear remissions and the handicap gradually worsens.

    How many people are affected by multiple sclerosis? 

    It is estimated that on average 1 in 1 people have multiple sclerosis, but this prevalence varies by country. 

    According to Arsep, in France, 100 people are affected by multiple sclerosis (about 000 new cases diagnosed each year) for 5000 million patients worldwide.  

    The countries of the North are more affected than the countries close to the equator. In Canada, the rate is said to be among the highest in the world (1/500), making it the most common chronic neurological disease in young adults. According to estimates, around 100 French people have it, while Canada has the highest rate of multiple sclerosis in the world with an equivalent number of cases. As yet unexplained, there are twice as many women as there are. men with multiple sclerosis. The disease is diagnosed most of the time in people aged 000 to 2 years, but it can also, in rare cases, affect children (less than 20% of cases).

    As part of its quality approach, Passeportsanté.net invites you to discover the opinion of a health professional. Dr Jacques Allard, general practitioner, gives you his opinion on the multiple sclerosis : It is estimated that, on average, 1 in 1 people have multiple sclerosis, but this prevalence varies by country. 

    In France, there are 100.000 people affected by multiple sclerosis and 2.000 to 3.000 new cases are diagnosed each year.

    Women are three times more affected than men.

    The average age at the onset of symptoms is 30 years. However, minors can also be affected: the disease affects around 700 children in our country.

    Northern countries are more affected than countries close to the equator. In Canada, the rate is said to be among the highest in the world (1/500), making it the most common chronic neurological disease in young adults.

    Our Doctor’s Opinion on Multiple Sclerosis 

    As part of its quality approach, Passeportsanté.net invites you to discover the opinion of a health professional. Dr Nathalie Szapiro, general practitioner, gives you her opinion on the multiple sclerosis :

     

    Like any long-term illness that affects a person who is still young, multiple sclerosis can call into question a life that seemed well mapped out: a professional path, a love life, frequent travel, etc. In addition, its uncertain nature – will there be other outbreaks, in how long, with what consequences – further complicates any projections that one can have of his future.

    This is why it is very important to surround yourself well medically (with a team allowing exchanges in all confidence) and to be helped by associations of patients, for example.

    Having multiple sclerosis requires you to make certain choices that may not have been planned at the start, but does not prevent you from leading a rich family, social and professional life and therefore, from having projects.

    Medicine has progressed and the image of the person with multiple sclerosis who was bound to end up in a wheelchair twenty years later is obsolete. The problem most often put forward by patients is that of fatigue which means not to overwork, to listen to your body and to take your time. Fatigue is part of what is called the “invisible disability”.

     

    Dr Nathalie Szapiro 

    Can multiple sclerosis be prevented?

    There is currently no sure way to prevent multiple sclerosis, since it is a multifactorial disease.

    It is nevertheless possible to avoid certain risk factors such as passive smoking in children (and smoking in adolescents and young adults).

    Encouraging outdoor activities for young people rather than staying locked between four walls is also a good idea to make the most of the sunshine in winter. Taking vitamin D supplements could also be beneficial.

     

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