Multiple sclerosis and amyotrophic lateral sclerosis are both progressive diseases that affect the central nervous system and impact a person's ability to carry out their daily tasks.
The effects and symptoms of both conditions can be similar, but the treatment and outlook are different.
In MS, the body's immune system mistakenly attacks myelin, the substance that protects the nerves in the central nervous system (CNS). This results in damage and scarring of the myelin sheath.
This can lead to a disruption or distortion of nerve impulses as they travel between the brain and the spinal cord. These changes can result in a wide range of symptoms.
The impact of these symptoms may vary. In remitting-relapsing MS (RRMS), a person will experience a worsening of symptoms for a while, then make a partial or full recovery.
However, the symptoms tend to return.
In progressive forms of MS, the symptoms do not go away but gradually worsen.
Symptoms may be mild, moderate, or severe. Some people will eventually lose their ability to walk and talk, but this is rare. MS does not usually affect life expectancy.
In time, damage to the nerves results in muscle weakness and eventually paralysis.
In its late stages, ALS affects breathing, and this can make it life-threatening.
Both MS and ALS are neurodegenerative diseases that affect the CNS. MS is more common, affecting nearly 1 million adults in the United States, according to the National Multiple Sclerosis Society.
The National Institute of Neurological Disorders and Stroke (NINDS) suggest that it affects around 250,000–350,000 people, but they note that it is difficult to know the exact number.
Around 14,000–15,000 U.S. individuals may be living with ALS, according to the NINDS.
Overlapping symptoms include muscle weakness and paralysis. There is currently no cure for either condition, but it is possible to manage the symptoms of both. In the case of MS, treatments now exist that can prevent flares and slow the progress of the disease.
However, MS and ALS differ in some important ways.
Who do MS and ALS affect?
MS is more common in women and typically appears at the age of 20–50 years, but it can also occur at any age.
Other basic differences include:
- ALS often causes paralysis. This is rare with MS.
- ALS mainly affects physical functions, while MS can lead to problems with memory and thinking.
- ALS is not an autoimmune disease, but MS probably results from a faulty immune reaction.
The following table summarizes some of the other differences between the two conditions.
|Most affected gender||Female||Male|
|May lead to death||No||Yes|
|Has a cure||No||No|
MS and ALS appear to have different causes, which we cover in more detail in the following sections.
Experts do not know exactly why MS develops. Some people may have genetic factors that increase the risk of it appearing when certain environmental factors are also present.
The following may play a role:
- Immunological factors: There may be a link with other autoimmune conditions.
- Environmental triggers: Smoking, having low vitamin D levels, and living in a colder climate are common factors.
- Infectious diseases: Certain viral infections may play a role.
- Genetic factors: These might increase the risk.
Most cases of ALS have no clear cause, but genetic factors appear to play a role. Experts believe that around 60% of people with ALS have a genetic feature that results in the development of symptoms.
Veterans appear to have a higher chance of developing ALS, suggesting that environmental triggers may also play a role.
ALS does not seem to involve unusual immunological activity.
The symptoms of MS and ALS can be similar, but there are some important differences to note.
MS symptoms vary widely from person to person. They can also be unpredictable and can change over time. One person may live with mild symptoms for many years, while another may experience a loss of mobility.
Symptoms of MS include:
- fatigue and weakness
- difficulties with walking and balance
- vision problems
- pain, numbness, or tingling
- bladder or bowel problems
- changes in thinking and memory
- sexual problems
- dizziness and vertigo
In RRMS, the most common type of MS, symptoms will come and go during periods of flare and recovery.
ALS symptoms can also vary widely. With ALS, muscles weaken gradually and without pain. Once ALS starts, however, it can take as little as 3 years to have a significant impact on a person's life.
Symptoms of ALS can begin in the muscles that control speech and swallowing. For some people, symptoms may start in the hands, arms, legs, or feet. However, over time, progressive muscle weakness and paralysis affect almost everyone with ALS.
Other symptoms of ALS include:
- tripping when walking
- abnormal fatigue of the arms, legs, or both
- slurred speech
- uncontrollable laughing or crying
- dropping objects
- muscle cramps and twitches
As ALS advances, it can affect the respiratory muscles, making it difficult to breathe. For this reason, a person may need to use a ventilator.
It is rare for a person with ALS to experience remission.
There is currently no cure for either MS or ALS, but treatment is available to slow progression and manage symptoms.
MS treatment options
For MS, guidelines from the American Academy of Neurology recommend starting to use a disease-modifying therapy from the early stages. The drugs are for regular use, whether symptoms are present or not.
These can reduce the risk of flares and may slow the progression of the condition. A person should speak to their doctor about the best drug for their situation.
Other treatment options can help manage flares and treat symptoms.
- Corticosteroid injections: These reduce nerve inflammation, can reduce the impact of a flare, and help manage severe symptoms. A doctor will give these only when necessary.
- Plasma exchange: This involves taking blood from the person's body, removing certain substances from it, and returning it to the body. This is suitable for people with severe symptoms and when other medications do not help.
- Lifestyle remedies: Exercising when possible, avoiding smoking, eating a healthful diet, and taking doctor-recommended supplements may help.
- Physical therapy: Various types of therapy can help a person maintain strength and flexibility and find new ways to carry out tasks as their abilities change.
- Other treatments: A doctor can recommend a variety of treatments for symptoms such as depression, constipation, pain, and itching, among others.
ALS treatment options
Several types of drug are available to slow disease progression and help a person manage their symptoms. A person may also wish to try different therapy types or make some lifestyle changes:
- Riluzole and Edaravone: Riluzole (Rilutek or Tiglutik) is a drug that may reduce damage to the muscles and nerves, but it cannot reverse the damage. Edaravone (Radicava) may slow the progression of ALS.
- Other medications: Medications are available that can help reduce symptoms such as fatigue and pain, muscle cramps, spasms and involuntary displays of emotion, and excess saliva and phlegm.
- Condition management strategies: Trying physical and speech therapies, assistive technology, feeding tubes, ventilators, and occupational therapy can help improve quality of life. Counseling may help with depression and sleep issues.
MS and ALS have symptoms that can appear similar, but there are also key differences. One major difference between the conditions is the outlook.
Both are degenerative diseases that can progress over time.
However, it is possible for a person with MS to live for many years with only mild symptoms. According to the NINDS, a person with MS will have roughly the same life expectancy as a person without MS.
ALS, on the other hand, is more likely to progress rapidly and become life-threatening due to the respiratory failure that accompanies it. According to the ALS Association, the life expectancy of a person with ALS is 2–5 years following diagnosis.
However, 50% of people with ALS will live for at least another 3 years after diagnosis, while 5% will live for 20 years longer or more.
Many treatment options and lifestyle strategies can help improve the quality of life of a person with either MS or ALS, and ongoing research may help improve the outlook in the future.
Some scientists believe that in time, regenerative therapies such as stem cell therapy may be able to reverse or repair neurological damage. This could mean a cure for conditions such as MS and ALS.