Multiple sclerosis is an autoimmune disease that affects the central nervous system. The disease disrupts the flow of information within the brain and between the brain and the body.
This article examines the different types of MS that can affect people and how their symptoms differ from each other.
Contents of this article:
Types of multiple sclerosis
The advice of a healthcare professional should be sought if any symptoms of MS are experienced.
There are five primary types, or disease courses, of MS. By determining the specific type of MS a person has, doctors and researchers can focus their treatments and studies to produce better results.
Clinically isolated syndrome (CIS)
This is considered the first of the MS types. To be diagnosed with CIS, the neurologic symptoms that are caused by inflammation or the loss of myelin must last 24 hours. CIS may lead to other types of MS, but some people with CIS never progress.
Relapsing-remitting MS (RRMS)
This is the most common form of MS, and it accounts for approximately 80 to 85 percent of initial diagnoses of MS. RRMS involves clear episodes of inflammatory activity and well-defined attacks of new or recurrent neurologic symptoms. A person with RRMS will typically experience full or partial recovery between episodes.
With RRMS, the disease does not progress between relapses.
Primary-progressive MS (PPMS)
This type of MS is less common, accounting for about 10 to 15 percent of all cases. With PPMS, neurological function is impaired and gets worse as the disease progresses. People with PPMS do experience occasional plateaus in progression of the disease. There may be temporary, minor improvements to the symptoms during progression, but there are no relapses.
Secondary-progressive MS (SPMS)
SPMS is normally seen as the next stage of the disease for people who already have RRMS. Around 50 percent of people with RRMS develop SPMS within 10 years, and nearly 90 percent do so after 25 years.
SPMS is similar to RRMS, but it may or may not involve occasional relapses, minor remissions, and plateaus.
Progressive-relapsing MS (PRMS)
PRMS is considered to be a progressive form of MS from the beginning. There are clear, acute relapses with or without full recovery between the relapses. But for people who have PRMS, the disease will continue to progress between relapses. Some doctors think that PRMS may be a subtype of PPMS as they share a similar history.
How do symptoms differ?
Symptoms of MS do vary but fatigue and weakness are common.
Symptoms vary from person to person. Even if people have the same type of MS, the symptoms may present differently.
However, some symptoms are commonly associated with all types of MS.
- Numbness and tingling
- Vision problems
- Dizziness or coordination problems
While people with different types of MS may show similar symptoms, people with a particular type of the disease are likely to present specific symptoms.
For example, people with RRMS often experience tingling or numbness, episodes of visual loss in one or the other eye, urinary urgency, double vision, fatigue, weakness, and balance problems.
By contrast, PPMS typically causes less damage to the brain but has more effect on the spinal cord. People with this type of the disease may have problems walking, stiff legs, and trouble with balance.
Unlike with RRMS, these symptoms get progressively worse and there are no periods of relapse between them. SPMS features less distinct periods of relapse. A person with SPMS may have symptoms, such as bowel and bladder problems, weakness and coordination issues, stiff and tight legs, depression, fatigue, and problems with thinking.
People who have PRMS are more likely to experience muscle spasms, weak muscles, chronic pain, decreased sexual arousal, vision changes, dizziness, and decreased bladder functions.
A person who has CIS may have similar symptoms as someone with MS, but they will have experienced the symptoms just once.
To be diagnosed with MS, a person must display evidence of damage in at least two separate areas of their CNS, such as the brain, the spinal cord, and the optic nerves. The problems must have occurred at least one month apart. Other conditions may have similar symptoms, so a doctor will need to rule out all other possible diagnoses.
How do treatments differ?
Studies suggest MS may be progressed by low levels of vitamin D.
The most common treatment is medication.
Medication regimens vary greatly between people and doses may be weekly or monthly.
The effectiveness of the treatment depends on the type of MS. For example, people with RRMS and PRMS are receptive to disease-modifying medications that reduce the number of relapses. These may also reduce disabilities and disease activity.
Some researchers have suggested that a lack of vitamin D may be a possible factor in the progression of MS.
By contrast, people with PPMS and SPMS are less responsive to medications.
Instead, treatment aims to control symptoms only partly with medications. Doctors recommend people with these types of MS take exercise, ensure they eat a healthful diet, and get some physical therapy. Research indicates that some progressive forms of MS may respond to high levels of biotin, a B vitamin.
People with MS may find that these alternative treatments can lessen symptoms and improve quality of life.
When to see a doctor
Anyone experiencing any of the symptoms of MS should seek medical advice.
An early diagnosis of MS can lead to a more effective management of symptoms. Catching the disease early may even slow the course of the disease.
How does the outlook differ for different types?
It is difficult to predict how each type of MS will directly affect a person or which type has the best outlook.
However, RRMS tends to have a better outlook as there may be years between flare-ups and the disease does not progress between episodes.
However, people with RRMS usually develop SPMS, which is progressive and is less responsive to medications.
PPMS and PRMS may be considered to have the worst outlooks because of the way they progress. They tend to be more debilitating, and the disease will progress even during a relapse, which may or may not occur.
Causes of MS
The causes of MS remain unknown, but certain environmental and genetic factors appear to trigger the disease.
Risk factors that increase the chance of developing MS include:
- Age: Symptoms of relapsing types of MS normally appear in people between of 20 and 50 years. Progressive forms tend to occur about 10 years later than relapsing forms.
- Gender: In relapsing forms, women are 2 to 3 times more likely to be affected than men. However, the progressive forms occur equally in men and women.
- Family history: A person with a close relative who has MS is at higher risk of developing it.
- Location: MS is more common in people who live in a temperate climate.
- Infections: A number of viruses have been identified as possible causes of MS.
- Personal history of autoimmune disorders: People with thyroid disease, type 1 diabetes, and inflammatory bowel disease are at higher risk of developing MS.