What is multiple sclerosis?
Multiple sclerosis is a chronic disease that moves the dominant nervous system, especially the brain, spinal cord, and optic nerves. This can cause a wide range of symptoms throughout the body. It is not likely to forecast how multiple sclerosis (MS) will progress in any individual. Some people have mild symptoms, such as blurred vision and numbness, and tingling in the extremities.
In severe cases, a person can experience paralysis, vision loss, and mobility problems. However, this is rare. It is difficult to know exactly how many people have MS. According to the National Institute of Neurological Disorders and Stroke (NINDS), between 250,000 and 350,000 people in the United States are living with MS.
The National Multiple Sclerosis Society (NMSS) estimates that the number could be closer to 1 million. However, new treatments are proving effective in curbing the disease.
Symptoms of multiple sclerosis
Multiple sclerosis (MS) causes a wide variety of symptoms and can affect any part of the body. Each person with the condition is affected differently. The symptoms are unpredictable. Some symptoms develop and get worse over time, while others develop. Periods of exacerbation of symptoms are called relapses. Remissions are periods when symptoms improve or disappear.
The most common characteristics are:
- Eyesight problems
- Numbness and tingling
- Muscle aches, stiffness, and weakness
- Mobility problems
- Trouble thinking, learning, and planning
- Depression and anxiety
- Sexual problems
- Bladder problems
- Intestinal problems
- Difficulties speaking and swallowing
Most people with MS have only some of these symptoms.
Check with your doctor if you are concerned that you may have early signs of MS. Symptoms are similar to many other conditions, so they are not necessarily caused by MS.
Types of multiple sclerosis
There are four types of multiple sclerosis (MS), named after the way the disease acts on the body over time:
Recurrent-remitting MS (RRMS): This is the most common form of numerous sclerosis. About 75% to 85% of people with MS are originally diagnosed with RRMS. People with RRMS have provisional periods called relapses, flare-ups, or exacerbations when new symptoms look. Relapses usually last a few days or weeks. At other times, the symptoms seem to go away and this is called remission; however, MS is still active and can progress. Nerve damage can still occur even if there are no symptoms.
Progressive secondary MS (SPMS): In SPMS, symptoms worsen more consistently over time, with or without relapses and remissions. Beforehand disease-modifying therapies were available, historical studies indicated that approximately 50% of people with RRMS progressed to EMPR approximately 10 years after their first diagnosis. Long-term data are not yet available to determine whether treatment significantly delays this transition.
Primary progressive MS (PPMS): This type of MS is not very common and occurs in about 10% of people with MS. PPMS is characterized by a slow worsening of symptoms from the start, without relapses or remissions2.
Progressive relapsing MS (PRMS): A rare form of MS (5%), PRMS is categorized by a constantly worsening disease state from the start, with acute relapses but no reductions, with or without recovery
Causes of multiple sclerosis
If you have MS, the protective layer of myelin that surrounds nerve fibers is damaged. The damage is believed to be the result of an attack by the immune system. The researchers believe that there could be an environmental trigger, such as a virus or toxin, that triggers the immune system attack.
As your immune system attacks myelin, it causes inflammation. This leads to scar tissue or injury. Inflammation and scar tissue interrupt signals between your brain and other parts of your body. MS is not inherited, but having a parent or sibling with MS increases your risk slightly. Scientists have identified some genes that appear to increase susceptibility to developing MS.
Risk factors of multiple sclerosis
These factors can increase your risk of developing multiple sclerosis:
Years: Multiple sclerosis can occur at any age, but onset usually occurs around the ages of 20 and 40. However, younger and older people can be affected.
Sex: Women are two to three times more likely than men to have relapsing-remitting multiple sclerosis.
Family history: If one of your parents or siblings has had MS, you are at a higher risk of developing the disease.
Certain infections: A diversity of viruses have been linked to MS, including Epstein-Barr, the virus that causes infectious mononucleosis.
Race: White people, particularly those of Northern European descent, are at higher risk of developing MS. People of Asian, African, or Native American descent are at the lowest risk.
Weather: MS is much more common in countries with temperate climates, such as Canada, the northern United States, New Zealand, southeastern Australia, and Europe.
Vitamin D: Having low levels of vitamin D and little exposure to sunlight is associated with an increased risk of MS.
Certain autoimmune diseases: You are at slightly advanced risk of developing multiple sclerosis if you have other autoimmune disorders such as thyroid disease, pernicious anemia, psoriasis, type 1 diabetes, or inflammatory bowel disease.
Smoking: Smokers who experience an initial episode of symptoms that may indicate MS are more likely than non-smokers to develop a second episode confirming relapsing-remitting MS.
Diagnosis of multiple sclerosis
The diagnosis of multiple sclerosis is typically based on the presenting signs and symptoms, in combination with supporting laboratory tests and medical imaging. It can be difficult to confirm, especially in the beginning, as the signs and symptoms can be similar to those of other medical problems. The McDonald criteria, which focuses on clinical, laboratory, and radiological evidence of lesions at different times and in different areas, is the most widely used diagnostic method.
Clinical data alone may be sufficient for a diagnosis of multiple sclerosis if an individual has had separate episodes of characteristic neurological symptoms of the disease. In those seeking medical attention after a single attack, other tests are needed for diagnosis. The most commonly used tools for the diagnosis of multiple sclerosis are neuroimaging, analysis of cerebrospinal fluid, and evoked potentials. MRI scans of the brain and spine can show areas of demyelination (lesions or plaques).
Treatment of multiple sclerosis
There is currently no cure available for MS, but there are multiple treatment options.
Disease-modifying therapies (DMT): Disease-modifying therapies are designed to slow the progression of the disease and reduce the rate of relapse.
Self-injectable disease-modifying medications: Self-injectable disease-modifying medications for RRMS include glatiramer acetate (Copaxone) and beta interferons, such as:
Oral medications for RRMS include:
- Dimethyl fumarate (Tecfidera)
- Fingolimod (Gilenya)
- Teriflunomide (Aubagio)
- Cladribine (Mavenclad)
- Diroximel fumarate (Vumerity)
- Siponimod (Mayzent)
Intravenous infusion treatments for RRMS include:
- Alemtuzumab (Lemtrada)
- Natalizumab (Tysabri)
- Mitoxantrone (Novantrone)
- Ocrelizumab (Ocrevus)
In 2017, the Food and Drug Administration (FDA) approved the first DMT for people with PPMS. This infusion medicine is called ocrelizumab (Ocrevus) and can also be used to treat RRMS.
Another drug, ozanimod (Zeposia), has recently been approved for the treatment of CIS, RRMS, and SPMS, but is not yet commercialized due to the COVID-19 pandemic.
Not all MS medications will be available or appropriate for everyone. Talk to your doctor about which medications are best for you and the risks and benefits of each.
Complications of multiple sclerosis
People with multiple sclerosis can also develop:
- Muscle stiffness or spasms
- Paralysis, typically in the legs.
- Problems with sexual, bowel, or bladder function
- Mental changes, such as amnesia or mood swings.