Amyotrophic Lateral Sclerosis (ALS)

Amyotrophic lateral sclerosis is a progressive nervous system disease that affects nerve cells in the brain and spinal cord, leading to loss of muscle control. While there is currently no cure, treatments and supportive care can help manage symptoms and improve quality of life.

What is Amyotrophic Lateral Sclerosis?
Medical Classification Codes
Other Names for ALS
Types of ALS
Signs and Symptoms
What Causes ALS?
Who is More Likely to Get ALS?
How is ALS Diagnosed?
Disease Progression and Life Expectancy
Treatment and Management
Living with ALS

What is Amyotrophic Lateral Sclerosis?

Amyotrophic lateral sclerosis, commonly known as ALS, is a neurological disorder (a disease of the nervous system) that affects motor neurons, which are nerve cells in the brain and spinal cord that control voluntary muscle movement and breathing^[2]. The term “amyotrophic” means “no muscle nourishment,” which describes how the muscles weaken and waste away when they stop receiving signals from motor neurons^[4].

As motor neurons degenerate and die, they stop sending messages to the muscles. This causes the muscles to weaken, start to twitch, and waste away. Eventually, in people with ALS, the brain loses its ability to start and control voluntary movements such as walking, talking, chewing and other functions, as well as breathing^[2]. ALS is progressive, meaning symptoms get worse over time^[1].

An estimated 5,000 people in the United States receive an ALS diagnosis each year^[3]. Around 30,000 people in the United States have ALS at any given time, with about 5,000 people being told by their doctor that they have the disease each year^[6]. The lifetime risk of developing ALS is approximately 1 in 400^[5].

Medical Classification Codes

Lou Gehrig’s disease, Motor neuron disease, Motor neurone disease, Charcot’s disease

Types of ALS

There are two main types of ALS based on their cause^[3]:

Sporadic ALS: This is the most common type, making up about 90% of cases. It occurs randomly and is not inherited. About 85% of all ALS cases are sporadic, with no known family history of the disease^[5].
Familial ALS: This type makes up about 10% of cases and is caused by inherited gene changes passed down from a parent^[3]. About 70% of familial cases and 5% to 10% of sporadic cases involve gene changes, most often in the C9orf72, SOD1, TARDBP and FUS genes. There are more than 40 related genes^[3].

ALS can also be classified based on where symptoms first appear^[7]:

Limb-onset ALS: Affecting about two-thirds of patients, this type begins with weakness in the arms, hands, legs, or feet.
Bulbar-onset ALS: Seen in one-third of cases, this type initially impacts muscles controlling speech and swallowing.

Signs and Symptoms

Symptoms of ALS vary from person to person and depend on which nerve cells are affected^[1]. ALS generally begins with muscle weakness that spreads and gets worse over time.

Early Symptoms

Early symptoms of ALS may include^[2]:

Muscle twitches in the arm, leg, shoulder, or tongue
Muscle cramps
Tight and stiff muscles (spasticity, which means muscle stiffness)
Muscle weakness affecting an arm, a leg, or the neck
Slurred and nasal speech
Difficulty chewing or swallowing
Trouble walking or doing usual daily activities
Tripping and falling
Hand weakness or clumsiness

ALS often starts in the hands, feet, arms or legs, then spreads to other parts of the body. Early symptoms are usually muscle weakness or stiffness in the arms and legs, as well as trouble with speech and swallowing. These can make everyday tasks like writing or eating more challenging^[3].

Progressive Symptoms

As the disorder progresses, muscle weakness and atrophy (wasting away of muscle) spread to other parts of the body. People with ALS may develop problems with^[2]:

Chewing food and swallowing (dysphagia)
Drooling (sialorrhea)
Speaking or forming words (dysarthria)
Breathing (dyspnea)
Unintended crying, laughing, or other emotional displays (pseudobulbar symptoms)
Constipation
Maintaining a healthy weight and getting enough nutrients

Eventually, people with ALS become unable to stand or walk, get in or out of bed on their own, use their hands and arms, or breathe on their own^[2]. As symptoms get more severe, people may have trouble breathing, standing or walking, and might experience significant weight loss^[3].

What ALS Does Not Affect

There is generally no pain in the early stages of ALS, and pain is not common in the later stages. ALS does not usually affect bladder control^[1]. The senses, including hearing, sight, smell, taste, and touch, are not affected by ALS. In most cases of ALS, memory and thinking are not affected^[5].

Because people with ALS usually remain able to reason, remember, and understand, they are aware of their progressive loss of function. This can cause anxiety and depression in the person with ALS and their loved ones. Although not as common, people with ALS also may experience problems with language or decision-making. Some also develop a form of dementia known as FTD-ALS^[2].

What Causes ALS?

The exact cause of ALS is still not known^[1]. Researchers don’t know what causes amyotrophic lateral sclerosis, but they believe it’s a combination of several factors^[3].

Genetic Factors

About 70% of familial cases and 5% to 10% of sporadic cases involve gene changes. They’re most often in the C9orf72, SOD1, TARDBP and FUS genes. There are more than 40 related genes^[3]. The most common known genetic mutation in ALS is in the C9orf72 gene, which accounts for approximately 30 to 40% of all familial ALS cases^[5]. These mutations are also known to cause Frontotemporal Dementia (FTD), another neurodegenerative disease that primarily affects behavior and the ability to think and reason^[5].

Mutations in the SOD1 gene comprise around 20% of familial ALS, and TARDBP and FUS gene mutations each account for about five percent of familial cases^[5].

Environmental and Other Factors

Exposure to toxins (like lead or mercury), viruses or trauma may also play a role^[3]. Health studies have not found definite environmental factors that are linked with either ALS or other motor neuron diseases. Some studies suggested a possible link with exposure to heavy metals (like lead and mercury), trace elements, solvents, radiation, and agricultural chemicals, but no confirmed link was found^[6].

There are many theories outlining potential causes of ALS including oxidative stress, mitochondrial dysfunction, immune system overactivity, glutamate toxicity, and exposure to toxic substances^[5].

How ALS Affects the Body

What researchers do know is that the disease targets motor neurons, which regulate voluntary movements like talking, chewing, moving limbs and breathing. Motor neurons communicate with muscles to tell them to move. ALS disrupts this communication, like bad phone reception. The messages sent from neurons to muscles break up and don’t get through clearly. This eventually causes the call to end. As a result, neurons can’t take any new calls, causing symptoms to appear^[3].

Who is More Likely to Get ALS?

Risk factors for amyotrophic lateral sclerosis include^[3]:

Age: You’re most likely to develop symptoms between the ages of 55 and 75 years^[6].
Sex: ALS is slightly more common in men than women, but recent studies suggest that this difference is decreasing over time^[6].
Military service: Studies have shown that people who have served in the military are almost 2 times as likely to develop ALS^[5].
Race and ethnicity: Ethnicity-based differences in prevalence have been noted, with European-Americans showing more than double the prevalence compared to African-Americans in the United States^[7].

Familial ALS is found equally among men and women. People with familial ALS usually do not fare as well as a person with ALS who are not related, and typically live only one to two years after symptoms appear^[6].

How is ALS Diagnosed?

Amyotrophic lateral sclerosis can be hard to diagnose early because it can have symptoms similar to other diseases^[8]. Tests to rule out other conditions or help diagnose ALS might include:

Electromyogram (EMG)

A needle is inserted through the skin into various muscles. The test records the electrical activity of the muscles when they contract and when they’re at rest. This can determine if there is a problem with the muscles or nerves^[8].

Nerve Conduction Study

This study measures your nerves’ ability to send impulses to muscles in different areas of the body. This test can determine if you have nerve damage. EMG and nerve conduction studies are almost always done together^[8].

MRI

Using radio waves and a powerful magnetic field, an MRI produces detailed images of the brain and spinal cord. An MRI can reveal spinal cord tumors, herniated disks in the neck or other conditions that might be causing your symptoms. The highest resolution cameras may sometimes see ALS changes themselves^[8].

Blood and Urine Tests

Analyzing samples of your blood and urine in the laboratory might help eliminate other possible causes of your symptoms. Serum neurofilament light levels, which are measured from blood samples, are generally high in people with ALS. The test can help make a diagnosis early in the disease^[8].

Spinal Tap (Lumbar Puncture)

This involves removing a sample of spinal fluid for laboratory testing. Spinal fluid is removed using a small needle inserted between two bones in the lower back. The spinal fluid appears typical in people with ALS but may uncover another cause of symptoms^[8].

Muscle Biopsy

If your health care provider believes you may have a muscle disease rather than ALS, a muscle biopsy may be performed^[8].

Disease Progression and Life Expectancy

ALS is progressive, meaning symptoms get worse over time^[1]. The speed at which symptoms progress varies from person to person^[3].

Most people with ALS die from being unable to breathe on their own (known as respiratory failure), usually within three to five years of symptoms first appearing. But about 1 in 10 people survive for 10 years or more^[2]. Most people live from 2 to 5 years after symptoms develop. How long a person lives with ALS seems to be related to age; people who are younger when the illness starts live slightly longer^[6].

It is important to note that familial ALS and sporadic ALS appear to be clinically indistinguishable from one another^[5], meaning they progress in similar ways regardless of whether the disease is inherited or occurs randomly.

Treatment and Management

There is no cure for ALS. However, the U.S. Food and Drug Administration (FDA) has approved several drugs for ALS that may prolong survival, reduce the rate of decline, or help manage symptoms. But there’s currently no known treatment that stops or reverses the progression of ALS^[2].

Disease-Slowing Medications

The drug riluzole (Rilutek) was approved by the FDA to treat ALS in December 1995. It is an oral medication that may reduce motor neuron damage by decreasing levels of glutamate (a molecule involved in signaling between nerve cells and motor neurons). Rilutek has a modest effect on slowing disease progression and prolonging life. In clinical trials, Rilutek prolonged survival in people with ALS by three to six months^[11].

Symptom Management

Managing the symptoms is the mainstay treatment for ALS; multidisciplinary care may improve quality of life^[11]. Medical interventions and technology have vastly improved the quality of life for people with ALS by assisting with breathing, nutrition, mobility, and communication. Proper management of symptoms and proactive use of medical interventions and equipment can make a positive difference in day-to-day living and potentially may lengthen life^[11].

Breathing Support

As ALS progresses, breathing difficulties become a major concern. Non-invasive ventilation and, in some cases, invasive ventilation may be needed to help with breathing^[11].

Nutrition Support

Difficulty swallowing can lead to weight loss and malnutrition. Speech therapists and nutrition experts can teach safe ways to eat. Special cups, utensils and tools can help. Feeding tubes may be necessary as the disease progresses^[16].

Multidisciplinary Care

ALS treatment includes therapies and medications to manage symptoms and slow the progression of the disease^[3]. Although there’s no cure, treatments are constantly improving. The right combination may slow the progression of the disease and improve quality of life^[3].

Living with ALS

Being diagnosed with ALS changes life in many ways. ALS affects muscles, making it harder to move, speak, eat or even breathe. But living with ALS is more than dealing with symptoms. It’s about finding new ways to cope, getting support and protecting quality of life^[16].

Daily Living Adaptations

Even with ALS, people can stay active and independent for as long as possible. Small changes can make daily life easier^[16]:

Mobility: Physical therapy, mobility aids and simple home changes can reduce fall risks and help people stay active. The use of adaptive products like wheelchairs is a move in the direction of self-sufficiency, not away from it^[17].
Communication: Speech therapy, voice banking and communication devices or apps can help people stay connected^[16].
Personal care and safety: Home changes like grab bars or shower chairs, assistive equipment and caregiver support make bathing, dressing and daily routines easier^[16].
Technology support: Computers, along with other assistive systems, supply entertainment and social interaction and make it possible for the person with ALS to help with tasks like paying bills, tracking down information, hiring services, and shopping^[17].

Adaptive tools are available for assorted daily tasks, such as eating, opening jars and doors, buttoning or zipping up clothing, writing, and taking a shower^[17].

Emotional and Mental Health Support

ALS affects not just the body but also the heart and mind. People may experience feelings of sadness, frustration or anxiety. Loved ones may feel the same as they adjust alongside the person with ALS^[16].

Ways to cope include^[16]:

Talking with a counselor or therapist to process feelings and build coping strategies
Joining a support group to connect with people who understand ALS
Trying stress-relief practices such as meditation, deep breathing, journaling or gentle exercise
Sharing feelings with loved ones to feel less alone

Planning Ahead

ALS may mean planning ahead for care. It can be difficult to think ahead, but planning early can help people feel more in control^[16]:

Advance care planning: Creating advance directives and living wills to ensure wishes are honored
Financial and legal planning: Meeting with a financial advisor or an elder law attorney to prepare for medical costs, insurance and legal documents
Long-term care options: Exploring home care, hospice or assisted living before needed can provide peace of mind

Support for Caregivers

Caring for someone with ALS is an act of love, but it can also be hard. Caregivers may be helping with meals, medications, hygiene and emotional support. Over time, the role may grow as the person’s needs change^[16].

Caregiver tips include^[16]:

Learning safe ways to lift, feed or bathe the person with ALS
Taking regular breaks to rest and recharge
Learning about the disease to anticipate needs and provide better support
Accepting help from family, friends or home health aides
Joining a caregiver support group

Those with ALS are competent thinkers, even if they are typically unable to communicate clearly. It’s important to talk through choices openly while making joint decisions about the person’s ALS care, and to ask if the person wants assistance before helping. Never take over tasks that still can be performed if the person is provided with adaptive tools and time^[17].

Patience is a must. While it may often seem quicker and more efficient to take over certain tasks, caregivers should demonstrate patience and allow the person with ALS to accomplish all of the tasks they can^[17]. For individuals with ALS, self-reliance and excellent care are imperative^[17].