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Multiple Sclerosis (MS)

Multiple Sclerosis (MS) Overview

Multiple sclerosis (MS) is a chronic condition that develops when an abnormal response from the immune system is directed against the brain, spinal cord, and optic nerves—collectively known as the central nervous system.

This abnormal immune response damages nerve fibers and their protective myelin coating. This damaged myelin then forms scar tissue, or sclerosis, and disrupts the communication between the brain and the rest of the body, causing a host of complex symptoms.

Multiple sclerosis can be divided into three types, also known as disease courses. They are:

  • Relapsing-remitting MS (RRMS): The most common form of MS—85 percent of all cases—this type is characterized by periods of active inflammation or relapses, followed by periods of little to no discomfort.
  • Primary-progressive MS (PPMS): About 10 percent of people with MS are diagnosed with PPMS, which involves symptoms that worsen gradually. While there may be brief periods of improvement, the general course of the disease is marked by decreasing functionality.
  • Secondary-progressive MS (SPMS): This type of MS develops after the relapsing-remitting (RRMS) type. Most cases of RRMS will eventually evolve into SPMS.

What causes multiple sclerosis?

Although the exact cause of multiple sclerosis is unknown, what is known is that MS is a condition that combines elements from someone’s genetic makeup, lifestyle, environment, and exposure to infectious agents or viruses. In other words, MS appears when each of these factors collide simultaneously in an individual.

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Multiple Sclerosis Symptoms

Multiple sclerosis symptoms are famously unpredictable—they can range from mild to severe and progress or morph over time. The symptoms are caused by disrupted nerve signals and, depending on which nerves are damaged, can vary widely from person to person.

Symptoms you or someone you know with multiple sclerosis might notice include:

  • Fatigue: Regularly feeling extremely tired, even after rest.
  • Walking and coordination difficulties or changes in gait: Muscle tightness (spasticity), difficulty balancing, or numbness in the lower extremities.
  • Numbness or tingling: Sensations of pins and needles that often happen in the arms, legs, feet, or face.
  • Muscle spasms: This can feel like a sharp pain or a dull ache of stiff muscles.
  • Weakness: This can look like new or unusual effects involving muscle strength.
  • Dizziness and vertigo: This can include persistent sensations like light-headedness, spinning (vertigo), and loss of balance.
  • Vision problems: Blurred vision, double vision, or pain during eye movement.
  • Bladder or bowel problems: These can range from incontinence or constipation to more severe issues.
  • Sexual problems: Shared equally between men and women, this can include reduced libido, erectile dysfunction, and inability to orgasm.
  • Chronic pain: This is a persistent or habitual pain in muscles or joints.
  • Cognitive changes: Problems with memory, attention, and decision-making are the primary cognitive shifts.
  • Emotional changes: These changes can include an onset of mood swings, depression, or anxiety.

Less common symptoms of multiple sclerosis might include:

  • Seizure
  • Headache
  • Tremor, or only one part of the body that shakes
  • Speech problems
  • Swallowing problems
  • Itching

The average age of symptom onset is between 20 and 40 years old, although people over 50 can develop MS, and occasionally, children do as well. However, pediatric MS is quite rare and happens in only 3 to 5 percent of all multiple sclerosis cases.

Because multiple sclerosis symptoms vary so widely from person to person, it’s not a condition that’s diagnosed on symptoms alone. If you’re experiencing symptoms similar to these and are concerned, please work with your healthcare provider to seek a diagnosis.

Multiple Sclerosis Diagnosis

A multiple sclerosis diagnosis is often a complex process, as symptoms can overlap with other conditions, and there’s no single test to definitively confirm MS. The diagnostic process may involve multiple visits and tests to establish a clear picture of the condition—generally speaking, a diagnosis calls for evidence of at least two areas of damage in the central nervous system that have happened on separate occasions.

Your healthcare provider may use the following to rule out other possible causes of symptoms and reach a diagnosis:

  • Detailed medical history: MS symptoms can vary widely, from vision problems, muscle weakness, balance issues, numbness, or tingling to fatigue and cognitive difficulties. Your healthcare provider will also inquire about any family history of MS or other autoimmune diseases.
  • Neurological exam: A neurological exam is generally done to assess functions controlled by the central nervous system, or the brain and spinal cord. This can include testing reflexes, coordination, muscle strength, sensation, and vision.
  • Magnetic resonance imaging (MRI): MRI is a crucial tool in diagnosing MS because it allows for visualization of the brain and spinal cord to identify areas of inflammation, demyelination (damage to myelin, the protective covering of nerve fibers), and scarring.
  • Lumbar puncture (spinal tap): In some cases, a lumbar puncture may be done to analyze cerebrospinal fluid for abnormalities, like elevated levels of specific proteins and the presence of immune system cells called oligoclonal bands. These findings can also support a diagnosis of MS.
  • Evoked potential tests: These tests measure electrical activity in the brain in response to stimuli, like visual or auditory signals. Abnormal results can indicate damage to nerves caused by MS.
  • Blood tests: Blood tests may be done to rule out other conditions that can mimic MS, as well as to assess overall health.

Once diagnosed, it’s vital for your healthcare team to develop a treatment plan specific to your multiple sclerosis. With a plethora of treatments and support systems to help manage the condition, many individuals diagnosed with MS go on to live fulfilling lives.

one hand with pills and the other hand holding a glass of water

Treatments for Multiple Sclerosis

While there’s currently no cure for multiple sclerosis, it’s a very treatable condition, thanks to decades of MS-specific research. Treatment will focus on managing your symptoms, slowing the progression of the disease, and improving your overall quality of life.

Typically, treatments are broken down into three categories, all of which are FDA-approved: injectable medications, oral medications, and IV-infused medications.

Injectable Medications

Injectable medications are administered using a needle and a syringe, similar to a vaccine. In many cases, your MS care team can teach you to administer these medications yourself at home. Commonly used injectable medications include:

  • Avonex (interferon beta-1a)
  • Betaseron (interferon beta-1b)
  • Copaxone (glatiramer acetate)
  • Extavia (interferon beta-1b)
  • Glatopa (glatiramer acetate)
  • Kesimpta (ofatumumab)
  • Plegridy (peginterferon beta-1a)
  • Rebif (interferon beta-1a)

Oral Medications

Oral medications are considered to have moderate efficacy, except Mavenclad, which has been proven to have high efficacy. Each of these medications aids in recovery after an attack while slowing the progression of the disease. Commonly prescribed oral medications include:

  • Aubagio (teriflunomide)
  • Bafiertam (monomethyl fumarate)
  • Gilenya (fingolimod)
  • Mayzent (siponimod)
  • Mavenclad (cladribine)
  • Ponvory (ponesimod)
  • Tascenso ODT (dimethyl fumarate)
  • Tecfidera (dimethyl fumarate)
  • Vumerity (diroximel fumarate)
  • Zeposia (ozanimod)

Intravenous (IV) Infused Medications

IV-infused medications are considered to be highly effective in stopping the immune response against the brain. IV infusions are much less disruptive overall because they can be given once a month or even once every six months. What’s more, an infusion typically takes between two and six hours at an infusion center, so people often return to work the same day.

Commonly prescribed IV-infused medications include:

  • Briumvi (ublituximab-xiiy)
  • Lemtrada (alemtuzumab)
  • Novantrone (mitoxantrone)
  • Ocrevus (ocrelizumab)
  • Tysabri (natalizumab)
  • Tyruko (natalizumab-sztn)

Physical therapy, occupational therapy, and other rehabilitative approaches can also be helpful in symptom management.

In Phoenix, Arizona, Barrow Neurological Institute is home to a robust Multiple Sclerosis Program with a team of specialists who work tirelessly to empower patients through extensive clinical knowledge, state-of-the-art facilities, and access to clinical trials.

Other Neuroinflammatory Conditions

Although multiple sclerosis makes up a large percentage of diagnoses, it’s not the only neuroinflammatory condition in need of treatment. At our Multiple Sclerosis Program, we can also diagnose and treat:

  • Acute Disseminated Encephalomyelitis (ADEM): This is a rare demyelinating disease of the central nervous system. In ADEM, damage occurs due to a brief but intense attack of inflammation (swelling) in the brain and spinal cord.
  • Anti-MOG Syndrome: This syndrome is an autoimmune disorder in which the immune system mistakenly attacks myelin oligodendrocyte glycoprotein (MOG) and produces antibodies to the protein.
  • Autoimmune Encephalitis: Inflammation that occurs when the body’s immune system attacks the brain, this condition impairs brain function and, in severe cases, can be life-threatening.
  • IgG4 Related Neurological Disease (IgG4): The most common type of antibody found in the blood, IgG4 occurs when immune cells malfunction and attack normal, healthy tissue in the nervous system.
  • Neuromyelitis Optica (NMO): With NMO, Immune system cells and antibodies attack and destroy myelin cells in the optic nerves and spinal cord.
  • Neurosarcoidosis: Sarcoidosis is an inflammatory disease that occurs when the immune system goes into overdrive for an unknown reason. It affects the brain, spinal cord, and/or peripheral nerves.
  • Optic Neuritis: This condition, which is an inflammation of the optic nerves, can damage the myelin surrounding the nerve fibers and the nerve fibers and cause pain and vision loss.
  • Susac’s Syndrome: Susac syndrome is an autoimmune endotheliopathy, meaning the body’s immune system mistakenly attacks the endothelium, or the thin layer of cells that lines the inner walls of blood vessels.
  • Transverse Myelitis: This condition is caused by inflammation of the spinal cord; damaging myelin and interrupting communications between nerves in the spinal cord and the rest of the body.

Common Questions about Multiple Sclerosis

How common is multiple sclerosis?

Multiple sclerosis affects 2.8 million people worldwide. The average person has about a one in 750 chance of developing MS. However, the actual number of people with MS may be higher, due to incorrect or missed diagnoses.

Who gets multiple sclerosis?

People are most often diagnosed with multiple sclerosis between the ages of 20 and 40, but the condition does occur in both older adults and children. While we see MS in most ethnic groups, it’s most common in white people of Northern European descent. Women are two to three times more likely than men to develop MS.

It’s important to note that MS is not a genetic disease. However, there is a risk that can be inherited from family members that contributes to the abnormal immune response. For example, if you have no inherited risk of developing MS, your chances of developing the condition are one in 1,000. If you have a first-degree relative—a mom or dad with MS—the odds of developing MS are one in 200. In the event you were to have an identical twin with MS, the odds of developing the condition would be one in four.

What is the prognosis for those with multiple sclerosis?

Multiple sclerosis isn’t a fatal condition in a majority of cases—most people with MS enjoy a close-to-normal life expectancy. That said, it can be difficult for healthcare providers to predict whether someone’s condition will improve or worsen because the course of the disease can vary so much from person to person.

Can multiple sclerosis be prevented?

The answer to this question is quite nuanced. MS is not directly caused by an environmental factor, like an infectious agent or virus, and it does not spread from one person to another. However, certain viruses, like the Epstein-Barr virus, can lead to molecular mimicking. This is when the immune system attacks parts of your own body—your nervous system in the case of MS—after it attacks the virus.

Another element that appears to influence MS is your distance from the equator—as in, the further away you live from the equator, the greater the odds you develop MS (although this is not universally true). Studies have also shown that when young people move from an area of low MS prevalence to an area of high MS prevalence, they also have a greater chance of developing MS.

Multiple sclerosis isn’t a lifestyle-based disease, either. However, there are lifestyle factors, like obesity or cigarette smoking, that can increase the odds of developing MS. For example, if someone who smoked was also classified as obese and had an exposure to a virus, or was born or raised in a particular part of the world, with certain genetic makeup, it could increase the likelihood of that person developing an autoimmune disease like MS.

Medically Reviewed by Aimee Borazanci, MD on April 29, 2024

Information and Resources about MS

National Multiple Sclerosis Society

Multiple Sclerosis Association of America

MS Focus: Multiple Sclerosis Foundation

Group 49
Multiple sclerosis affects 2.8 million people worldwide

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