An overview of Multiple Sclerosis

Multiple sclerosis (MS) is a disease of the central nervous system that affects the brain and spinal cord. It affects myelin – the sheath that surrounds and protects nerve fibers – whose progressive destruction slows down the transmission of nerve impulses. Multiple sclerosis can lead to sequelae and is one of the common causes of disability in young patients. Treatments for multiple sclerosis have made spectacular advances in recent years.

 

WHAT IS THE CENTRAL NERVOUS SYSTEM?

The central nervous system is made up of the brain and the spinal cord. It provides intellectual and sensory functions (vision, hearing, taste, etc.), controls and regulates movements and balance, and controls the functioning of muscles. Damage to the central nervous system can therefore result in an anomaly in each of these major functions.

The cells of the central nervous system can be divided into two main families: neurons, which transmit information, and glial cells, whose role is to nourish and maintain neurons. Among the latter, there are cells called oligodendrocytes, which are responsible for the formation of myelin in the central nervous system.

Myelin forms a segmented sheath along axons, extensions of neurons, and acts as an insulator that prevents “short circuits”. The spread of nerve impulses is discontinuous, skipping the myelinated segments, which speeds up transmission. When there is no or no more myelin, as in multiple sclerosis, the spread of nerve impulses is less well. New, thinner myelin sheaths may be reconstituted in some cases.

 

WHAT IS MULTIPLE SCLEROSIS?

Multiple sclerosis is a chronic disease of the brain and spinal cord. It is an autoimmune disease. The patient’s immune system attacks a protein essential for the propagation of nerve impulses, myelin, and the cells that produce it. For this reason, multiple sclerosis affects senses, movement, balance, etc. Most often, symptoms appear during periods of limited duration called flare-ups.

Autoimmune diseases are caused by an imbalance in the immune system that attacks certain constituents of the body. In multiple sclerosis, there is an inappropriate immune response that views myelin as a foreign body and causes inflammation. This inflammation plays a major role in the onset of relapses and in the progression of central nervous system involvement, leading to the destruction of myelin (demyelination) and sometimes oligodendrocytes.

Many chronic inflammatory diseases are said to be autoimmune: rheumatoid arthritis, spondylitis, Crohn’s disease, psoriasis, etc.

 

IS MULTIPLE SCLEROSIS A COMMON ILLNESS?

The number of cases of multiple sclerosis has been on the rise for twenty years, but the diagnosis is made earlier and easier than before; more often in women than in men. Globally, the frequency of multiple sclerosis would be greater than 100 cases per 100,000 inhabitants.

 

WHAT ARE THE SYMPTOMS OF MULTIPLE SCLEROSIS?

Multiple sclerosis manifests itself in a very variable way depending on the patient. Most often, symptoms appear during periods of limited duration, the flare-ups. Sensitivity disorders often reveal the disease: tingling, tingling, sensations of cold or runoff on the skin, numbness, pain, etc. Muscle weakness is sometimes seen in an arm or leg, with difficulty in walking. In 20 to 25% of cases, the disease is revealed by a decrease in vision. Dizziness is sometimes present.

 

MULTIPLE SCLEROSIS BETWEEN THROWS

Apart from relapses, the disease can manifest as fatigue. But other signs such as tremors, urinary disorders, or constipation can occur.

 

What do we call Uhthoff’s phenomenon?

Although the fever does not cause a flare per se, the rise in body temperature which characterizes it can, on the other hand, cause the reappearance of symptoms that appeared during a previous flare and be very badly tolerated by some patients (blockage of the conduction of nerve impulses within demyelinated fibers, known as the “Uhthoff phenomenon”). Some people sometimes experience a reactivation of old neurological symptoms, most often visual disturbances, which go away a few hours after the body temperature drops.

This reappearance of symptoms can also occur during or after exercise, due to the rise in body temperature, or while traveling in a country with a tropical climate. The threshold for triggering Uhthoff’s phenomenon varies from patient to patient.

 

THE MANAGEMENT OF MULTIPLE SCLEROSIS

WHAT ARE THE OBJECTIVES OF CARE?

So-called background drug treatment is prescribed to reduce the duration and intensity of relapses; it is suitable for the form of multiple sclerosis. Beyond this basic treatment, the medical management of this disease also passes:

• relief of relapse-related symptoms with treatments that are not specific to multiple sclerosis.
• functional rehabilitation to maintain autonomy as long as possible and limit complications related to immobilization.
• psychological support.
• a therapeutic education program.

 

WHO ARE THE HEALTHCARE PROFESSIONALS INVOLVED IN THE CARE?

As with many chronic diseases, the care of people with multiple sclerosis is the responsibility of a multidisciplinary team that brings together health professionals in hospitals and in the city:

• a neurologist for the initial prescription and renewal of basic medical treatment and jointly the general practitioner for the monitoring, management of adverse effects and symptomatic treatments,
• a psychologist specially trained for psychological support,
• a physiotherapist, a speech therapist, an occupational therapist for functional rehabilitation,
• a nurse for patient care and therapeutic education.

Other medical specialists (urologist, ophthalmologist, etc.) and medico-social professionals can intervene as needed. The coordinated action of these various professionals is essential to ensure optimal monitoring of people with multiple sclerosis.

 

WHAT PLACE FOR ADAPTED PHYSICAL ACTIVITY IN THE MANAGEMENT OF MULTIPLE SCLEROSIS?

Adapted physical activity (APA) is part of the non-drug treatment for multiple sclerosis. Indeed, regular physical activity helps to maintain muscle strength and motor coordination, to fight against social isolation or depression and to preserve balance.

Many sports practices have adapted to be practiced by people suffering from multiple sclerosis: for example, athletics and taïchi chuan and qi gong.

 

THE TREATMENT OF MULTIPLE SCLEROSIS

The considerable therapeutic progress made in recent years has not yet made it possible to cure multiple sclerosis. DMARDs are those that have benefited the most from recent therapeutic advances. They aim to prevent the progression of the disease. They include so-called immunomodulatory treatments and so-called immunosuppressive treatments.

 

WHAT ARE THE TREATMENTS FOR MULTIPLE SCLEROSIS?

The long-term treatment of multiple sclerosis uses immunomodulators and immunosuppressants which reduce the frequency of relapses and slow the progression of the disability. The treatment of relapses is based on intravenous infusions of corticosteroids, strong anti-inflammatory drugs, over a short period of time. Other, non-specific treatments relieve pain, abnormal tremors and movements, muscle stiffness, and incontinence. Psychological support and functional rehabilitation are also prescribed.

Since 1993, immunomodulatory and immunosuppressive drugs have shown significant benefit in relapsing forms of multiple sclerosis, as well as in some cases of progressive forms of the disease.

 

IMMUNOMODULATORS IN THE SUBSTANTIVE TREATMENT OF MULTIPLE SCLEROSIS

Medicines called “immunomodulators” work by regulating the activity of the immune system and reducing inflammation and damage caused by its activity against the myelin sheath. The immunomodulators used in multiple sclerosis are interferons and peginterferons (beta-1a and beta-1b) and glatiramer acetate. The products differ according to their method of administration (subcutaneous or intramuscular injection) and the frequency of injections.

Flu-like symptoms are common with beta interferons at the start of treatment: fever, headache, sweating, body aches, painful joints. They do not usually justify stopping treatment. Potentially serious side effects in the blood and kidneys are rarely seen. They can occur after several years of treatment with beta interferon. Blood tests make sure there are no abnormalities.

 

FUTURE TREATMENTS FOR MULTIPLE SCLEROSIS

Today, research is targeting different stages of the disease in order to propose new drugs with complementary mechanisms of action. Two types of strategy are currently being developed: on the one hand an immunosuppression strategy, i.e. drugs aimed at reducing the abnormal immune response developed against the nervous system, and on the other hand a neuroprotection strategy aimed at reducing irreversible damage to neurons.

In addition, there is a capacity for spontaneous repair of lesions linked to multiple sclerosis in the central nervous system, but these are often insufficient. In some patients, this remyelination capacity is very weak or even absent. Understanding the mechanisms of repair and the reason for its insufficiency is one of the avenues of research towards new treatments for multiple sclerosis.

Currently, more than fifty therapeutic trials are underway with various new drugs.