Multiple sclerosis (MS) is a disease that causes demyelination (disruption of the myelin that insulates and protects nerve cells) of spinal nerve and brain cells.

• Although the exact case is unknown, multiple sclerosis is considered to be an autoimmune disease.
• Risk factors for the disease include being between 15-45 years of age; women have about two to three times the risk for multiple sclerosis than men.
• Multiple sclerosis symptoms and signs depend on where the nerves are demyelinated and may include
  • visual changes,
  • numbness,
  • tingling or weakness (weakness may range from mild to severe),
  • paralysis,
  • vertigo,
  • erectile dysfunction (ED, impotence)
  • pregnancy problems,
  • incontinence (or conversely, urinary retention),
  • muscle spasticity,
  • painful involuntary muscle contractions.
• There are four types of multiple sclerosis:
  • relapsing-remitting multiple sclerosis (RRMS,
  • the most common type), secondary-progressive multiple sclerosis (SPMS),
  • primary-progressive multiple sclerosis (SPMS), and
  • progressive-relapsing multiple sclerosis (PRMS).
• Multiple sclerosis is diagnosed by a patient's history, physical exam, and tests such as MRI, lumbar puncture, and evoked potential testing (speed of nerve impulses); other tests may be done to rule out other diseases that may cause similar symptoms.
  • IV steroids,
  • interferon injections (Rebif),
  • glatiramer acetate (Copaxone),
  • dimethyl fumarate (Tecfidera), and
  • many others, depending on the patient's symptoms.Multiple sclerosis treatment options include
• Most multiple sclerosis patients have a normal life expectancy; untreated patients may develop mobility dysfunction while patients with the severe progressive forms may develop complications like pneumonia.
• Ways to prevent getting multiple sclerosis have not been discovered.
• Research is ongoing into developing new medications, immune system modifications, and other ways to identify potential multiple sclerosis causes.

Multiple sclerosis definition

Multiple sclerosis is a disease that involves an immune-mediated process that results in an abnormal response in the body's immune system that damages central nervous system tissues; the immune system attacks myelin, the substance that surrounds and insulate nerves fibers causing demyelination that leads to nerve damage. Because the exact antigen or target of the immune – mediated attack is not known, many experts prefer to label multiple sclerosis as "immune-mediated instead of an "autoimmune disease."

What is multiple sclerosis?

Multiple sclerosis is a disease which causes demyelination of the brain and spinal cord nerve cells. When this occurs, axons (the parts of the nerve cells which conduct impulses to other cells), don't work as well. Myelin acts like insulation on electrical wires. As more areas or nerves are affected by this loss of myelin, patients develop symptoms because the ability of axons to conduct impulses is diminished or lost. The specific symptom that someone experiences is related to the area that has been affected. As demyelination takes place, areas of inflammation and subsequent injury can be identified; these areas of injury are called lesions or plaques and are readily apparent on magnetic resonance imaging (MRI) studies.

Multiple sclerosis signs and symptoms may differ greatly from person to person and over the course of the disease depending on the location of affected nerve fibers. They may include:

• Numbness or Weakness in one or more limbs that typically occurs on one side of your body at a time, or the legs and trunk
• Partial or complete loss of vision, usually in one eye at a time, often with Pain during eye movement
• Prolonged double vision
• Tingling or Pain in parts of your body
• Electric-shock sensations that occur with certain neck movements, especially bending the neck forward (Lhermitte sign)
• Tremor, lack of coordination or unsteady gait
• Slurred speech
• Fatigue
• Dizziness
• Problems with bowel and bladder function

When to see a doctor

See a doctor if you experience any of the above symptoms for unknown reasons.

Disease course

Most people with MS have a relapsing-remitting disease course. They experience periods of new symptoms or relapses that develop over days or weeks and usually improve partially or completely. These relapses are followed by quiet periods of disease remission that can last months or even years.

Small increases in body temperature can temporarily worsen signs and symptoms of MS, but these aren't considered disease relapses.

About 60 to 70 percent of people with relapsing-remitting MS eventually develop a steady progression of symptoms, with or without periods of remission, known as secondary-progressive MS.

The worsening of symptoms usually includes problems with mobility and gait. The rate of disease progression varies greatly among people with secondary-progressive MS.

Some people with MS experience a gradual onset and steady progression of signs and symptoms without any relapses. This is known as primary-progressive MS.

The cause of multiple sclerosis is unknown. It's considered an autoimmune disease in which the body's immune system attacks its own tissues. In the case of MS, this immune system malfunction destroys myelin (the fatty substance that coats and protects nerve fibers in the brain and spinal cord).

Myelin can be compared to the insulation coating on electrical wires. When the protective myelin is damaged and nerve fiber is exposed, the messages that travel along that nerve may be slowed or blocked. The nerve may also become damaged itself.

It isn't clear why MS develops in some people and not others. A combination of genetics and environmental factors appears to be responsible.

Many factors go into consideration for the treatment of a patient who has multiple sclerosis. During an acute exacerbation, steroids given through an IV are commonly prescribed, and often help patients recover more rapidly. If a patient cannot receive steroids, plasma exchange can be used.

Once a diagnosis of multiple sclerosis has been confirmed, disease-modifying therapy is often recommended. This therapy may decrease the number of exacerbations that a patient experiences or decrease the severity of an exacerbation. In addition, many of these therapies have been shown to decrease the potential for developing long-term disability.

Multiple sclerosis medications

Interferon therapies

Interferon therapies (Avonex, Betaseron, Extavia, Rebif, Plegridy) must be given by an injection. The frequency of injections ranges from every other day to every other week. Some patients develop flu-like symptoms or nodules under the skin following each injection; other patients may develop severe depression.

Glatiramer acetate (Copaxone) works along a different path than the interferons, but is still thought to modify the immune system and has been shown to reduce relapses. There are some oral medications which have been approved to treat multiple sclerosis, including fingolimod (Gilenya) and teriflunomide (Aubagio).

Although these medications are dosed orally, there is a risk of significant side effects:

• including heart disease (fingolimod), or
• severe liver injury (teriflunomide).

Another oral agent, dimethyl fumarate (Tecfidera), may function by preventing immune cells from attacking cells located in the central nervous system, and may have anti-inflammatory properties.

Dalfampridine (Ampyra), has been approved to specifically help with walking problems caused by multiple sclerosis. The specific way in which this medication works is unknown. There is a risk that this medication may cause seizures, even in patients without a history of seizure or epilepsy. As such, the use of this medication needs to be monitored carefully.

Natalizumab (Tysabri) is a monoclonal antibody, and has been approved for patients who have relapsing-remitting multiple sclerosis. Because of significant side effects, including the risk of severe brain infection, it is typically used for patients who have failed to respond to one of the interferon products or who have been diagnosed with very active disease.

Alemtuzumab (Lemtrada) can also decrease the relapse rate in relapsing-remitting multiple sclerosis. However, because of the risk of serious side effects, it is currently limited to use in patients who have failed other agents.

Mitoxantrone (Novantrone) is a chemotherapy agent for leukemia or prostate cancer, which has been shown to be of benefit in treating secondary-progressive multiple sclerosis, progressive-relapsing multiple sclerosis, and advanced relapsing-remitting multiple sclerosis.

Of note, mitoxantrone and Betaseron are the only medications identified to help patients with relapsing-primary multiple sclerosis.

These factors may increase your risk of developing multiple sclerosis:

• Age. MS can occur at any age, but most commonly affects people between the ages of 15 and 60.
• Sex. Women are about twice as likely as men are to develop MS.
• Family history. If one of your parents or siblings has had MS, you are at higher risk of developing the disease.
• Certain infections. A variety 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 highest risk of developing MS. People of Asian, African or Native American descent have the lowest risk.
• Climate. MS is far more common in countries with temperate climates, including Canada, the northern United States, New Zealand, southeastern Australia and Europe.
• Certain autoimmune diseases. You have a slightly higher risk of developing MS if you have thyroid disease, type 1 diabetes or inflammatory bowel disease.
• Smoking. Smokers who experience an initial event of symptoms that may signal MS are more likely than nonsmokers to develop a second event that confirms relapsing-remitting MS.

There’s no cure for MS, and the damage it causes can’t be reversed. However, certain medications can help you manage the condition.

Condition management focuses on medication that can treat relapses, as well as modify the disease to reduce damage and disability. It also involves other drugs that treat the symptoms or complications of MS.

There are several types of DMTs that work to help change the course of MS. The length of treatment with these medications can range from a few months to years, depending on how effective the medications are for you.

Your doctor may recommend switching between these drugs throughout the course of your treatment. This will depend on how effectively each drug manages your disease and how you tolerate the side effects.

If you switch to a different DMT, your doctor will take note of whether you develop new lesions.

Injections and infusions

The Food and Drug Administration (FDA) has approved 12 MS medications that are administered by injection or infusion.

Interferon beta products

Injectable drugs include:

• interferon beta-1a (Avonex, Rebif)
• peginterferon beta-1a (Plegridy)
• interferon beta-1b (Betaseron, Extavia)

They help modify relapsing-remitting MS (RRMS) and secondary progressive MS (SPMS) in cases of active disease — that is, a relapse has occurred or new lesions have appeared on an MRI scan.

They also treat clinically isolated syndrome (CIS), a one-off episode of neurological symptoms. CIS can progress to MS and is sometimes categorized as a type of MS.

These drugs are made up of proteins that keep certain white blood cells (WBCs) from entering your brain and spinal cord. These WBCs are thought to damage the myelin that forms a protective coating over your nerve fibers.

Therefore, preventing these WBCs from moving into your brain and spinal cord can help slow their damage and reduce the number of relapses you have.

You inject these drugs yourself. Your healthcare provider will show you how to do this. The number of injections depends on the drug:

• Rebif: three times per week
• Betaseron: every other day
• Extavia: every other day
• Avonex: once per week
• Plegridy: every 2 weeks

Glatiramer acetate (Copaxone)

Glatiramer acetate (Copaxone) is a manufactured substance that resembles a basic protein of natural myelin. It’s thought to work by prompting the WBCs to attack the substance instead of the myelin cells.

It’s used to treat RRMS and SPMS in cases of active disease — that is, a relapse has occurred or new lesions have appeared on an MRI scan. It can also treat CIS.

You inject this drug yourself once per day or three times per week, depending on your dosage. Your healthcare provider will show you how.

People who receive injections three times per week should ensure that at least 48 hours elapses between their injections.

The FDA has also approved Glatopa, a generic form of Copaxone.

Natalizumab (Tysabri)

Natalizumab (Tysabri) is an antibody that may block damaged T lymphocytes from moving into your brain and spinal cord.

It’s used to treat RRMS and SPMS in cases of active disease — that is, a relapse has occurred or new lesions have appeared on an MRI scan. It can also treat CIS.

A healthcare provider gives you this drug as an intravenous (IV) infusion. The infusion takes about an hour, and you’ll get it every 4 weeks.

Mitoxantrone hydrochloride

Mitoxantrone hydrochloride was originally used to treat cancer. Now it’s also prescribed to treat people with MS. It suppresses the immune system cells that are thought to attack myelin cells. This medication is only available as a generic drug.

It’s used to treat SPMS or worsening RRMS in instances where other drugs haven’t worked. It has a high risk of serious side effects, so it’s only appropriate for people with these more severe forms of MS.

A healthcare provider gives you this drug as a short IV infusion once every 3 months. The infusion should only take 5 to 15 minutes.

Alemtuzumab (Lemtrada)

Alemtuzumab (Lemtrada) is approved for people with relapsing forms of MS, including RRMS and active SPMS. It’s intended for people who’ve tried at least two other MS medications but found that treatment was unsuccessful or caused intolerable side effects.

It works by reducing the number of specific B and T lymphocytes in your body. This action may decrease the inflammation of and damage to nerve cells.

Alemtuzumab is given as a 4-hour IV infusion. To start, you receive this drug once per day for 5 days. Then 12 months after your first treatment course, you receive it once per day for 3 more days.

Ocrelizumab (Ocrevus)

Ocrelizumab (Ocrevus) is the newest infusion treatment for MS. It was approved by the FDA in 2017.

It’s the first drug used to treat primary progressive MS (PPMS). It’s also used to treat CIS and relapsing forms of MS.

Ocrelizumab appears to work by targeting and ultimately reducing the number of B lymphocytes. B lymphocytes are responsible for damage and repair of the myelin sheath.

Ocrelizumab is given as an IV infusion. To begin, you’ll receive it in two 300-milligram (mg) infusions, separated by 2 weeks. After that, you’ll receive it in 600-mg infusions every 6 months.

You’ll also receive a corticosteroid and an antihistamine on the day of each infusion to reduce the risk of reaction to the medication.

Ofatumumab (Kesimpta)

Ofatumumab (Kesimpta) was approved by the FDA in August 2020 and is the newest treatment for MS.

It’s used to treat RRMS and SPMS in cases of active disease — that is, a relapse has occurred or new lesions have appeared on an MRI scan. It can also treat CIS.

Like ocrelizumab (Ocrevus), it also works by targeting harmful B lymphocytes and reducing their overall number.

Ofatumumab is given as an injection once per week for the first 3 weeks. After a 1-week break, the drug is given as a monthly injection.