What is multiple sclerosis?

Multiple sclerosis (MS) is a central nervous system disorder-that is, it affects the brain and spinal cord and spares the nerves and muscles that leave the spinal cord. MS is an inflammatory disorder in which infection-fighting white blood cells enter the nervous system and cause injury. It is a demyelinating disorder because the myelin sheath that protects nerves is stripped off during inflammation. When this happens, the nerves cannot conduct electricity as well as they should, causing various symptoms. Symptoms may be the type that come and go over time (relapsing-remitting MS) or progress over time (progressive MS). MS can happen to just about anyone and is long-term.

Are there different types of MS?

MS varies from patient to patient so that each individual has their own set of symptoms, problems, and their own course. There are people who have MS so mildly that they never even know that they have it. Of course, there are also others that have it severely. It is really a spectrum that ranges from mild to severe. An international panel of experts developed a classification of MS in 1999 that most neurologists use today:

  • Relapsing-remitting: Patients have attacks of symptoms/signs, with or without recovery, but between attacks have no interval worsening.
  • Secondary progressive: This is often after a few years of relapsing-remitting MS. The pattern changes from a relapsing pattern to progressive in between attacks, usually with fewer attacks.
  • Primary progressive: This involves a gradual onset from the beginning and no attacks.
  • Progressive relapsing: This is a rare form, and begins with a progressive course, while later developing attacks.
  • Fulminant: This is a rare form, and is very severe, rapidly progressive MS.

Is there such a thing as benign MS?

The term, "benign MS," is not part of the international classification. It is used when people have had MS for many years without developing significant measurable disability. Recent studies have shown that it cannot be predicted early in the disease and so the term can only really be used retrospectively, after people have done very well with MS for many years.

Causes & Risk Factors

There has been extensive research about MS over the past 50 years. While we still do not know the cause of MS, we know that it is an inflammatory disorder of the central nervous system that occurs in people with a tendency to such a problem. We know that about 350,000 people in the United States have MS, about one in a 1,000 people. We know that it is more common further north and south of the equator, though we are still unsure why this is. Females tend to get MS about three times as often as males, a rate which is similar to other immune diseases. It is more common in Caucasians, but can occur in other populations. It is not contagious nor is it infectious. There may be a link with reduced vitamin D levels and perhaps with decreased sun exposure.

We know that there is a genetic component to MS. Having a mother or father with MS increases the risk of having MS to about 3-5% lifetime, and having an identical twin with MS increases the risk to about 30%. However, many people with MS have no close family members with the disease.

There is nothing that an individual with MS either did to cause the disease to happen, or can avoid to stop the disease from following its natural course. We know that emotional stress may increase the symptoms of MS. We also know that attacks of MS are more likely after infections. There does not seem to be any association with physical trauma or surgical procedures and MS, nor do these seem to make MS worse.

What do we know about multiple sclerosis?

There has been widespread research about MS over the past 50 years. We do not know the cause of MS, but do know that it is an inflammatory disorder of the central nervous system that occurs in people with a tendency to such a problem. We know that about 350,000 people in the United States have MS, about 1 in 1,000 people. We know that it is more common further north and south of the equator. Although we are still unsure exactly why this is. Females tend to get MS about three times as often as males, a rate similar to other immune diseases. MS is more common in Caucasians, but can occur in other populations. It is not contagious, nor is it infectious.

Did I do anything to bring on the MS or make it worse?

As far as we know there are no activities that specifically cause MS or make it worse. People with MS may not tolerate heat as well as they used to and may need to avoid particularly hot or humid situations. There is evidence that having infections makes having an exacerbation of MS more likely. There does not appear to be a link to trauma. However, emotional stress has been linked to a worsening of MS symptoms. Having MS is not the fault of people who have it; it can happen to anyone.

Is there anything new that we know about MS?

Multiple sclerosis is being studied actively in many research institutions around the world, and new knowledge is being added constantly. For example, we now know that even with early MS, the nerve fibers themselves (the axons) are affected more than we knew before. We know from MRI studies that new lesions (abnormal areas in the brain or spinal cord) occur about 5 to10 times as often as people with MS have new symptoms; that is, much of the disease occurs 'under the radar scope'. We know that myelin repair occurs in the central nervous system all the time. Some groups feel there are different types of immune or pathological processes going on that we call MS, and perhaps MS may be many different disorders that we have lumped together.

Do any other diseases look like MS?

When neurologists evaluate MS they are also considering other diagnoses. While MS is the most likely cause of typical white matter changes and symptoms in an otherwise healthy young person, there are some other diseases that we consider and occasionally diagnose. These include a vitamin B12 deficiency that can cause an MS-like illness, and rarely, lupus, which may have symptoms that suggest MS. The MRI is very useful in ruling out many other disorders that could be confused with MS, and the blood tests and spinal fluid may also be helpful in diagnosing other diseases.

Why do people with multiple sclerosis (MS) have depression?

Depression is very common in people with multiple sclerosis (MS). In fact, symptoms of depression severe enough to require medical intervention affect up to half of all people with MS at some point during their illness.

Depression may be the result of a difficult situation or stress. It is easy to understand how having MS, with its potential for progressing to permanent disability, can bring on depression.

Depression might be actually caused by MS. MS may affect the insulating myelin that surrounds nerves which transmit signals affecting mood.

Depression is also a side effect of some drugs used to treat MS, such as steroids or interferon.

How does heat or humidity impact people with multiple sclerosis (MS)?

Heat or high humidity can cause many people with MS to experience a temporary worsening of their symptoms. Doctors believe that this occurs because heat causes nerves (whose myelin covering has been removed by MS) to conduct electrical signals even less efficiently.

For reasons that are not well understood, extremely cold temperatures and changes in temperature can also cause MS symptoms, usually spasticity (muscle stiffness), to flare.

Symptoms

What are some early symptoms of MS?

MS varies from person to person so there is no 'standard' set of symptoms for MS. However, we know that common symptoms of MS include:

  • Numbness or tingling in various parts of the body
  • Walking difficulties
  • Weakness of one or more body part
  • Fatigue
  • Visual blurring, and occasionally, double vision
  • Dizziness
  • Lhermitte's phenomenon, a symptom in which people feel electrical tingling or shocks down their back, arms, or legs when they bend their neck forwards
  • Urinary symptoms, such as hesitancy when trying to urinate, or a feeling of urgency (when you have to go, you have to go)

There is no way to predict which symptoms one person might develop.

MS varies from person to person so there is no ‘standard’ set of symptoms for MS. However we know that common symptoms of MS include numbness or tingling in various parts of the body, weakness of one or more parts of the body, walking difficulties, dizziness, fatigue, visual blurring, and occasionally double vision. Patients may also have a symptom called Lhermitte’s phenomenon, in which they feel electrical tingling or shocks down their back, arms or legs when they bend their neck forwards. Sometimes people notice hesitancy when they try to urinate or may find that 'when they have to go, they have to go’. There is no way to predict which symptoms one person might develop. The usual course of MS is to have periods of time where things are relatively stable, followed by times when, over a few days or weeks, new symptoms occur or old symptoms worsen. This relatively rapid worsening is known as an exacerbation (also known as an attack, or a relapse). In others with MS, there may be a tendency to progress in that symptoms gradually worsen over time (months to years).

Sensory Symptoms(changes in sensation)

  • Numbness
  • Tingling
  • Other abnormal sensations
  • (“pins & needles,” pain)
  • Visual disturbances
  • Dizziness

Motor Symptoms(changes in muscle function)

  • Weakness
  • Difficulty walking
  • Tremor
  • Bowel/Bladder problems
  • Poor coordination
  • Stiffness

Other Symptoms

  • Heat sensitivity
  • Fatigue
  • Emotional changes
  • Cognitive changes
  • Sexual symptoms

MS varies from patient to patient so that each individual has their own set of symptoms, problems, and their own course. There are people who have MS so mildly that they never even know that they have it. Of course, there are also others that have it severely. It is really a spectrum that ranges from mild to severe. An international panel of experts developed a classification of MS in 1999 that most neurologists use today.

  • Relapsing-remitting: Patients have attacks of symptoms/signs, with or without recovery, but between attacks have no interval worsening.
  • Secondary progressive: This is often after a few years of relapsing-remitting MS. The pattern changes from a relapsing pattern to progressive in between attacks, usually with fewer attacks.
  • Primary progressive: Gradual onset from the beginning, no attacks.
  • Progressive relapsing: This is a rare form, and begins with a progressive course, while later developing attacks.
  • Fulminant: Very severe, rapidly progressive MS. This is a rare form of MS.

Reviewed by a Cleveland Clinic medical professional.

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