Amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS) are both neurodegenerative diseases that affect the central nervous system (CNS). Each attacks different portions of the body’s nerves and affects muscle movements.
In a few ways, these two diseases are similar. However, their key differences determine a lot about their treatment and outlook:
|Amyotrophic lateral sclerosis (ALS)||Multiple sclerosis (MS)|
|affects the motor neurons of the central nervous system (CNS), near the spinal cord||affects the brain and spinal cord|
|often leaves people paralyzed in its later stages||can affect mobility in its later stages, but rarely leaves people completely debilitated|
|causes more physical difficulties||causes more cognitive impairment|
|not proven to be an autoimmune disease||an immune-mediated disease|
|more common in men||more common in women|
|most commonly diagnosed between 40 to 70 years old||most commonly diagnosed between 20 to 50 years old|
|no known cure||no known cure|
|often debilitating and ultimately fatal||rarely debilitating or fatal|
Basics about ALS
In a healthy body, motor neurons send signals throughout the body, telling muscles and body systems how to work. ALS rapidly destroys those neurons, preventing them from working correctly.
Eventually, ALS destroys the neurons completely. When this happens, the body can’t respond to commands from the brain, and individuals with late-stage ALS become paralyzed.
Basics about MS
MS is a CNS disorder that affects the brain and spinal cord. It destroys the protective coating on the CNS nerves. This slows the relay of instructions from the brain to the body, making motor functions difficult.
It also slows sensory signals to the brain, often impairing sensation.
MS is rarely completely debilitating or fatal. Some people with MS will experience mild symptoms for many years of their lives and might not become incapacitated because of it.
However, others may experience a progression of symptoms and become unable to care for themselves.
Both diseases attack certain nerves of the body, affecting muscle and nerve function. For that reason, they share many of the same symptoms, especially in the early stages.
Initial symptoms include:
However, the symptoms then become quite different as the conditions progress.
People with MS often experience cognitive problems, which is rare with ALS. People with ALS typically develop greater physical difficulties.
|Symptom of ALS?||Symptom of MS?|
|involuntary muscle spasms||✓||✓|
|numbness or tingling of the face or body||✓|
|tripping or falling tendencies||✓||✓|
|weakness or clumsiness in the hands||✓||✓|
|difficulty holding your head up or maintaining good posture||✓|
|dizziness or vertigo||✓|
|slurred speech or difficulty swallowing||✓||✓|
ALS commonly starts in the extremities such as the hands, feet, or arms and legs, and affects muscles that a person can control. This includes muscles in the throat.
It can also affect your vocal pitch when speaking. It eventually involves other parts of the body.
ALS has a rapid and consistently worsening onset that’s painless. Progressive muscle weakness is the most common symptom. Issues with thought processes or the five senses aren’t as common in ALS.
However, people in later stages have been known to develop dementia.
With MS, symptoms may come and go. MS can affect taste, vision, or bladder control. It can also cause temperature sensitivity as well as weakness to other muscles. Mood shifts are very common with MS too.
For people with ALS, symptoms remain largely physical. In fact, in many people with ALS, mental function remains intact even when most of their physical capabilities have been affected.
However, according to the ALS Foundation, it’s been estimated that up to 50 percent of people with ALS may experience some mild to moderate cognitive or behavioral changes due to the disease.
As it progresses, some people have gone on to develop dementia.
In MS, mental capabilities are usually more affected than in ALS.
People with MS can experience severe mental changes, including:
Flare-ups and remissions may increase mood shifts and the ability to focus.
MS is an immune-mediated condition. This means that the immune system is involved in the development of the disease.
MS is often considered an autoimmune disease. Autoimmune diseases occur when the immune system mistakenly attacks normal, healthy parts of the body as if they were foreign and dangerous.
ALS isn’t believed to be autoimmune disease. Its cause is largely unknown, but it’s considered a neurodegenerative disorder.
Some possible causes may include:
- gene mutation
- chemical toxicity
- a disorganized immune response
A small number of cases are linked to family history and may be inherited.
MS is estimated to affect over 2.3 million people worldwide, with approximately 1 million of them in the United States.
Around 30,000 people in the United States live with ALS, according to the Hospital for Special Surgery. Over 5,600 people in the country are diagnosed with ALS every year.
There are several risk factors that may affect who develops ALS and MS.
ALS is more common in men than women. The ALS Association estimates that 20 percent more men develop ALS than women.
Some researchers suggest that this estimate is actually higher, with women three or four times more likely to develop MS.
ALS is more commonly diagnosed in people between the ages of 40 to 70 years old, although it’s possible to be diagnosed at a younger age. The average age at time of diagnosis is 55 years old.
Additional risk factors
Family history increases your risk for both conditions. Both conditions are more prevalent among people of Western European descent and who live in the Northern Hemisphere, although each of the conditions has been diagnosed in every region of the world.
For unknown reasons, U.S. military veterans are up to twice as likely to be diagnosed with ALS or ALS-like conditions as the general public.
Veterans of the Gulf War and members of the Air Force are particularly affected, according to a 2020 study on people who received care from the Veterans Health Administration between 2002 and 2015.
More research is needed to better understand the causes of both conditions.
To make a diagnosis, your doctor will ask for detailed information about your symptoms and your health history. There are also tests they can perform to help make a diagnosis.
These tests provide information on the transmission of nerve signals to your muscles and can show certain patterns that are consistent with a diagnosis of ALS.
Your doctor may also order blood and urine samples, or perform a lumbar puncture to examine your spinal fluid.
MRI scans or X-rays may be ordered as well. If you have an MRI scan, you may have special images ordered to increase visualization of demyelinating areas in the brain and spine.
Doctors can use MRI results to distinguish between MS and ALS. MS targets and attacks myelin in a process called demyelination.
Demyelination prevents the nerves from performing as well as they once did, and it can be detected by an MRI scan.
On the other hand, ALS attacks the motor neurons, which doesn’t appear on brain or spine MRIs.
There’s no cure for either condition, but treatments are available.
ALS treatments are used to help slow symptoms and prevent some complications.
Riluzole (Rilutek) and edaravone (Radicava) are approved by the Food and Drug Administration (FDA) for treatment of ALS. They’re both available as pills.
Tiglutik, which is riluzole in the form of an oral suspension, is also available.
Occupational, physical, and speech therapy can help manage some effects of ALS. When breathing becomes difficult, you can get devices to assist. Psychological support is also important to help emotionally.
Recent research efforts have been put into finding more treatments and medications, such as ocrelizumab (Ocrevus), for the progressive forms of the disease. Researchers are also working hard to find a cure.
Treatment plans for MS focus on slowing down the progression of the disease and managing symptoms.
Anti-inflammatory drugs such as cortisone may help block the immune response and are used short term for treatment of MS flare-ups.
Disease-modifying therapies (DMTs) are available in both injectable and oral forms. These are used on a regular basis to prevent a relapse and can be effective in improving outcomes for relapsing forms of MS.
Lifestyle remedies and alternative treatments for MS are also important, especially those focusing primarily on stress reduction.
Chronic stress is believed to worsen the neurological symptoms of MS and may even increase the number of brain lesions.
MS relapses can come without warning and your physical and cognitive abilities can fluctuate in between relapses, so it’s important to be willing to adapt your activities to how you feel on a given day.
However, staying as active as possible and continuing to socialize can help you feel better about your disease and improve your quality of life.
Each condition has a different long-term outlook.
Outlook for ALS
ALS symptoms usually develop very quickly, and it’s considered a terminal condition.
The 5-year survival rate, or the number of people still living 5 years after being diagnosed, is 20 percent, according to the ALS Association. The average survival rate is 3 years after diagnosis.
Around 10 percent of people with ALS survive more than 10 years.
According to the National Institute of Neurological Disorders and Stroke, all people with ALS will eventually become unable to walk, stand, or move about without help.
They also may develop great difficulty swallowing and chewing.
Outlook for MS
MS symptoms usually develop slowly, and people with MS usually live lives that are moderately affected by the disease.
Symptoms of MS may come and go, depending on the type of MS.
You may experience a flare-up, and then symptoms almost completely resolve for days, weeks, or even years.
Usually, there are some residual symptoms in between flare-ups, and often there’s an overall permanent decline in cognitive or physical function after each flare-up.
The progression of MS differs from person to person. Most people with MS fall into one of these four categories of the disease:
- Clinically isolated syndrome (CIS): CIS is a single episode of neurological symptoms. It’s caused by inflammation and damage to the myelin covering on nerves in the brain or spinal cord. CIS can, but doesn’t always, evolve into MS.
- Relapsing-remitting MS (RRMS): RRMS is the most common form of MS. Relapses are followed by almost full recovery. There’s little progression of the disease after flare-ups.
- Secondary progressive MS (SPMS): Sometimes RRMS can become SPMS when the disease significantly progresses after flare-ups or relapses.
- Primary progressive MS (PPMS): Neurologic function begins to worsen from the very beginning of PPMS. Disease progression varies and levels off from time to time, but there are no remissions.
Though both diseases appear to have a few features in common during the earliest stages, the progression, treatments, and outlook for ALS and MS are very different.
However, in both cases, treatment paves the path toward a healthier, more fulfilling life for as long as possible.
People with either condition should talk with their doctor about developing a treatment plan. Your doctor can also prescribe medications that can help you manage your symptoms.