MS vs. ALS

Amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS) are both neurodegenerative diseases that affect the central nervous system. Both attack the body’s nerves and muscles. In many ways, these two diseases are similar. However, their key differences determine a lot about their treatment and outlook:

affects the brain and central nervous systemaffects the brain and spinal cord
late stage often leaves people paralyzedlate stage can affect mobility, but rarely leaves people completely debilitated
more physical difficultiesmore mental impairment
not an autoimmune diseasean autoimmune disease
more common in menmore common in women
most commonly diagnosed between 40-70 years oldmost commonly diagnosed between 20-50 years old
no known cureno known cure
often debilitating and ultimately fatalrarely debilitating or fatal

What is ALS?

ALS, also known as Lou Gehrig’s disease, is a chronic, progressive disease. ALS greatly affects the brain and central nervous system. In a healthy body, motor neurons in the brain send signals throughout the body, telling muscles and body systems how to work. ALS slowly destroys those neurons, preventing them from working correctly.

Eventually, ALS destroys the neurons completely. When this happens, the brain can no longer give commands to the body, and individuals with late-stage ALS become paralyzed.

What is MS?

Multiple sclerosis is a central nervous system disorder that affects the brain and spinal cord. It destroys the protective coating on nerves. This slows the relay of instructions from the brain to the body, making motor functions difficult.

MS is rarely completely debilitating or fatal. Some people with MS will experience mild symptoms for many years of their lives but never become incapacitated because of it. However, others may experience a rapid progression of symptoms and quickly become unable to care for themselves.

Both diseases attack and destroy 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. People with MS often experience greater mental problems than people with ALS. People with ALS typically develop greater physical difficulties.

Symptom of ALS?Symptom of MS?
difficulty walking
involuntary muscle spasms
muscle cramps
muscle weakness
numbness or tingling of the face or body
tripping or falling tendencies
hand weakness or clumsiness
difficulty holding your head up or maintaining good posture
dizziness or vertigo
vision problems
slurred speech or difficulty swallowing
sexual dysfunction
bowel problems

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, and it can also affect vocal pitch when speaking. It then spreads to other parts of the body.

ALS has a gradual onset that’s painless. Progressive muscle weakness is the most common symptom. Issues with thought processes or the senses of sight, touch, hearing, taste, or smell, aren’t as common in ALS. However, people in later stages have been found to develop dementia.

With MS, symptoms are more difficult to define because they 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 swings are very common with MS.

People with MS and ALS may both face memory problems and cognitive impairment. In MS, mental capabilities are usually more affected than in ALS.

People with MS can experience severe mental changes, including:

Flare-ups or remissions may increase mood swings and the ability to focus.

For people with ALS, symptoms do 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, 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 ALS. As the disease progresses, some people have gone on to develop dementia.

MS is 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. In the case of MS, the body mistakes myelin for an invader and tries to destroy it.

ALS isn’t an autoimmune disease, but a nervous system disorder. Its cause is largely unknown. Some possible causes may include:

  • gene mutation
  • chemical imbalance
  • disorganized immune response

A small number of cases are linked to family history and may be inherited.

MS is estimated to affect about 2.1 million people worldwide, approximately 400,000 of them in the United States.

In 2014, almost 16,000 U.S. people were reported to be living with ALS. The Centers for Disease Control and Prevention (CDC) estimates that about 5,000 people 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 in women. The ALS Association estimates that 20 percent more men develop ALS than women.

On the other hand, MS is more commonly seen in women. Women may be two to three times more likely to develop MS than men. But 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, although it’s possible to be diagnosed at a younger age. The average age at time of diagnosis is 55.

MS is often diagnosed in people a little younger, with the typical age range for diagnosis between 20 to 50 years old. As with ALS, it’s possible to be diagnosed with MS at a younger age.

Additional risk factors

Family history seems to increase your risk for both conditions. There’s no ethnic or socioeconomic risk factor for ALS or MS. For unknown reasons, military veterans are about twice as likely to develop ALS as the general public.

More research is needed to better understand the causes of both conditions.

It’s very difficult to diagnose either ALS or MS, especially early in the disease. To make a diagnosis, your doctor will ask for detailed information about your symptoms and your health history. There are also tests they can do to help make a diagnosis.

If ALS is suspected, your doctor may order electrodiagnostic tests, such as an electromyography or a nerve conduction velocity test. These tests provide information on the transmission of nerve signals to your muscles.

Your doctor may also order blood and urine samples, or perform a spinal tap to examine spinal fluid. MRI scans or X-rays may be ordered. If you have an MRI scan or X-ray, your doctor may inject a dye into you to increase visualization of damaged areas. A muscle or nerve biopsy may also be recommended.

Doctors can use MRI results to distinguish between MS and ALS. MS targets and attacks myelin in a process called demyelination, which an MRI scan can detect. This prevents the nerves from performing as well as they once did. On the other hand, ALS attacks the nerves first. In ALS, the demyelination process begins later, after the nerves have begun to die.

Treating MS:

Most drugs approved by the FDA for MS are effective for those who have a relapsing form of the disease. Recent research efforts have been put into finding more treatments and drugs for the progressive forms of the disease. Researchers are also working hard to find a cure.

Developing a treatment plan for MS focuses on slowing down the progression of the disease and managing symptoms. Anti-inflammatory drugs such as cortisone may help block the autoimmune response. Disease-modifying drugs are available in both injectable and oral forms. These seem to be effective in improving outcomes for relapsing forms of MS.

Lifestyle and alternative treatments for MS are also important, focusing primarily on stress reduction. Chronic stress is believed to worsen the neurological symptoms and increase the number of brain lesions. Lifestyle treatments include exercising and relaxation techniques, such as practicing mindfulness. Mindfulness reduces stress and allows for better coping methods in stressful situations.

MS attacks or relapses can come without warning, 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 with symptoms.

Treating ALS:

As with MS, there’s no cure for ALS. Treatments are used to slow symptoms and prevent some complications.

For many years, the only FDA-approved drug to treat ALS was riluzole (Rilutek). However, researchers are hard at work to find new treatments and drugs, and one was approved in May 2017. For some people, these drugs seem to slow the disease’s progression. There are other drugs that can help manage symptoms like constipation, fatigue, and pain.

Physical, occupational, 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.

Each condition has a different long-term outlook.

Outlook for MS

MS symptoms usually develop slowly. People with MS may go on to live relatively unaffected lives. Symptoms of MS may come and go, depending on the type of MS you have. You may experience an attack, and then symptoms disappear for days, weeks, or even years.

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: This is the first episode of symptoms caused by inflammation and damage to the myelin covering on nerves in the brain or spinal cord.
  • Relapsing-remitting MS (RRMS): RRMS is the most common form of MS. Relapses are followed by full or almost full recovery. There’s little or no progression of the disease after attacks.
  • Secondary-progressive MS (SPMS): SPMS is the second stage of RRMS. The disease begins to progress after attacks or relapses.
  • Primary-progressive MS (PPMS): Neurologic function begins to worsen from the very beginning of PPMS. Progression varies and levels off from time to time but there are no remissions.

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. The average survival rate is 3 years after diagnosis. Up to 10 percent survive more than 10 years.

According to the National Institute of Neurological Disorders and Stroke, eventually all people with ALS will become unable to walk, stand, or move about without help. They also may develop great difficulty swallowing and chewing.

Though both diseases appear to have much 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 as long as possible.

People with either condition should talk to their doctor about developing a treatment plan. Your doctor can also prescribe medications that can help manage symptoms.


I have initial symptoms of both MS and ALS. What tests or procedures are done to determine diagnosis?

Anonymous patient


MRI is often used to distinguish between MS and ALS. In MS, demyelination of the nerves begins and results in nerve changes. In other words, the loss of myelin coating of the nerve occurs first in MS, and then a loss of nerve function. In ALS, nerves are damaged by an unknown cause, and then the damaged nerves lose their coating or myelin. By looking for demyelination using an MRI, a doctor can often tell the difference between the two diseases, as signs of demyelination often occur well after symptoms have progressed in ALS. Finally, there’s no single definitive test to distinguish between the two, but signs, symptoms, and imaging are often used to come to a conclusion.

George Krucik, MD, MBAAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.