Multiple sclerosis (MS) is a disease that affects the central nervous system: the brain and the spinal cord. In MS, the body's immune system mistakenly attacks the myelin, the protective envelope surrounding the nerve fibers. The destruction of myelin leads to "multiple sclerosis" or the formation of scar tissue. It also impairs the ability of nerve cells to transmit signals in the form of electrical impulses.
MS is an autoimmune disease. This means that "for whatever reason, your immune system is acting badly and becoming intolerant to your own central nervous system," said Dr. Karen Blitz, director of the North Shore Multiple Sclerosis Treatment Center. LIJ in East Meadow, New York State.
We do not know what causes this disease, which can take an unpredictable and variable evolution depending on the patient. People with multiple sclerosis can have various neurological alterations related to the functioning of the brain and spinal cord. This includes vision problems, muscular control and sensory problems in the limbs, according to the National Library of Medicine of the United States.
Multiple sclerosis affects 400,000 Americans and about 2.5 million individuals worldwide, according to the National Center for Complementary and Integrative Health. Patients are usually diagnosed between the ages of 20 and 40 and the disease tends to affect women more than men.
The diagnosis of MS is often difficult and requires clinical detective work. "We get a patient story, we review it, and then we do tests," Blitz said. According to the National Multiple Sclerosis Society, examination of symptoms or test results per se does not conclusively conclude MS.
MS tests include neurological examinations (to test nerve function, sensations and reflexes) and magnetic resonance imaging (MRI).
An MRI identifies scars or lesions in the brain and spinal cord. One of the key aspects of diagnosing MS is to determine if nerve damage is present in more than one place and whether these lesions occurred at different times. In 2017, the international group on the diagnosis of multiple sclerosis published new guidelines – Revised Criteria of MacDonald – on the use of MRI and cerebrospinal fluid analysis for a rapid diagnosis of MS.
Blood tests can be performed to eliminate diseases that mimic MS. "There are many such diseases, but some examples include Lyme disease, vasculitis, thyroid dysfunction, vitamin B12 deficiency and migraine headaches," said Blitz. "Then you put all these pieces together to establish a clinical diagnosis."
Signs and symptoms
The symptoms of MS may differ from one patient to another, depending on the affected nerve fibers. According to the Mayo Clinic, symptoms include:
A numbness or weakness that can occur on one side of the body, legs and trunk.
The sensation of "electric shock" when moving the neck, also known as Lhermitte.
Lack of coordination or unstable market.
Blurred or double vision. Partial or total vision loss in one eye at a time, usually with pain during eye movements
Pain or tingling in different areas of the body.
Dizziness and fatigue.
Problems with the bowel, bladder or sexual function.
The symptoms of MS in each patient may evolve differently. According to the US National Library of Medicine, patients generally follow one of four treatments:
Relapse-Putting: Marked by attacks of MS symptoms (recurrence), followed by periods without symptoms (remissions). The attacks do not worsen with time. Approximately 80% of patients have been diagnosed with relapsing-remitting MS.
Progressive SecondaryAfter approximately 10 years of relapsing-remitting MS, the pattern may progress to secondary progressive MS. The attacks worsen progressively, without period of remission.
Progressive primary: This is the second most common form of MS. In the absence of relapse or remission, this type of symptom is characterized by a constant and constant worsening of symptoms. About 10 to 20% of patients have primary progressive MS.
Progressive-relapsing: Initially marked by more and more constant and similar symptoms, similar to those of primary progressive MS. However, this rare type also includes attacks of more severe symptoms.
According to Cedars-Sinai, although most patients with multiple sclerosis have one of the phases listed above, fulminant multiple sclerosis is another rare form of the disease, which primarily affects children and adults with multiple sclerosis. young adults. It looks like recurrent SP, but progresses very quickly.
Everyone can develop MS. Although there is no known cause, according to the Mayo Clinic, several factors can increase the risk of developing the disease. These included:
- Sex. Women are two to three times more likely to develop relapsing-remitting multiple sclerosis.
- Family history. Having a parent or sibling with multiple sclerosis increases the risk of developing the disease.
- Some infections. Many viral infections are linked to MS. This includes the Epstein-Barr virus, responsible for infectious mononucleosis.
- Race. Whites are the most exposed to MS. In particular, those of North European ancestry. The people most at risk are those of Asian, African or Native American descent.
- Climate. Multiple sclerosis is more common in countries further away from the equator, including southern Canada, the northern United States, New Zealand, southeastern Australia and the United States. 39; Europe. MS is less common in countries closer to the equator. Lower levels of vitamin D and low sun exposure are also risk factors.
- Some autoimmune diseases. Having a thyroid disease, type 1 diabetes, or inflammatory bowel disease can increase the risk of developing MS.
For people with MS, some lifestyle factors have also been associated with the course of the disease. For example, people with MS who smoke are more likely than non-smokers to develop a more serious form of the disease, Blitz said. In addition, "there is good data now that exercise is another piece of the puzzle," she said. Patients who exercise seem to do better than those who do not.
Treatment and drugs
The cause of MS is unknown and there is no cure for the disease. However, there are a number of treatments and medications available to treat the symptoms and progression of the disease. Several FDA-approved drugs can slow the course of MS, reduce the number of relapses, and help manage key symptoms. Here are the most commonly used.
corticosteroidsThese reduce inflammation associated with relapses and are the most common medications for MS, according to the Mayo Clinic. Oral prednisone and intravenous methylprednisolone are two corticosteroids used.
interferonsThese medications slow down the progression of MS symptoms, although they can lead to liver damage. Examples include Betaseron, Avonex and Rebif (none of which are in generic form).
glatiramer: Also known as Copaxone brand name, this intravenous drug can hinder the attack of the immune system against myelin. Side effects may include shortness of breath and hot flashes, according to the Mayo Clinic.
natalizumab: Also known as Tysabri, this medication is used if other drugs do not work or are not well tolerated. It prevents potentially damaging immune cells from migrating blood to the central nervous system.
mitoxantrone: Also known as Novantrone, this immunosuppressant is generally only used in advanced MS because of its cardiac risks.
For people with multiple sclerosis who have difficulty tolerating the side effects of injections or who wish to take the pill with ease, three FDA approved oral medications: Tecfidera (dimethyl fumarate), Aubagio (teriflunomide), and Gilenya ( fingolimod).
Other MS therapies can manage the symptoms or treat the disabilities caused by the disease. Physiotherapists and occupational therapists can demonstrate exercises in increasing flexibility and strength, as well as using adaptive devices that help patients perform their daily tasks, according to the Mayo Clinic.
According to the National Complementary and Integrative Health Center, some complementary health practices may help to reduce the symptoms of MS. For example, yoga and tai chi can help improve fatigue and mood. THC and cannabinoids can help relieve spasticity and pain. Marijuana-derived drugs are not approved by the FDA at this time. However, Canada and some European countries have approved Sativex, a prescription oral spray for muscle control.
Progress on Multiple Sclerosis Research
In 2018, the FDA approved the use of ocrelizumab to treat relapsing-remitting and primary progressive MS. In clinical trials, it has been shown that the progression of the disease was significantly slowed in both forms. In patients with multiple sclerosis, B cells (a type of white blood cell) have been shown to accumulate in lesions or scarred areas. The drug, which is an antibody, targets and destroys specific types of B cells in the body.
In January 2019, other promising drugs are in the final stages of clinical trials, according to a 2019 review published in Lancet magazine. Ibudilast is a drug for the treatment of progressive MS. In phase 2 trials, the rate of cerebral atrophy was reduced by about 48%. The researchers are also conducting clinical trials of pediatric patients with multiple sclerosis to test drugs approved for use in adults.
The review revealed that much of the current research on the treatment of MS is focused on identifying new biomarkers of the disease, particularly those that may indicate neuron degeneration.
This article is for informational purposes only and is not intended to offer medical advice. This article was last updated 24 May 2019 by Aparna Vidyasagar, Live Science Associate.