ALS facts for kids
Quick facts for kids Amyotrophic lateral sclerosis |
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Parts of the nervous system affected by ALS, causing progressive symptoms in skeletal muscles throughout the body
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| Specialty | Neurology |
| Patient UK | Amyotrophic lateral sclerosis |
Amyotrophic lateral sclerosis (ALS) is a serious condition that affects the nervous system. It is also known as motor neuron disease (MND) or Lou Gehrig's disease. ALS causes special cells called motor neurons to stop working. These neurons are like messengers that tell your muscles what to do. When they stop working, muscles become weak and stiff. This makes it hard to move, speak, swallow, and even breathe over time. Doctors diagnose ALS by looking at a person's symptoms and doing tests to make sure it's not another condition. Sometimes, ALS starts with weakness in the arms or legs (called limb-onset). Other times, it starts with trouble speaking or swallowing (called bulbar-onset).
Understanding ALS Types
ALS is part of a group of conditions called motor neuron diseases. These conditions specifically affect the motor neurons that control your body's voluntary muscles. Doctors classify ALS in different ways. They look at which parts of the motor neurons are affected, which body parts show symptoms first, if it's passed down in families, and how old a person is when it starts.
How ALS Affects Motor Neurons
Your body has two main types of motor neurons: upper motor neurons (in your brain and spinal cord) and lower motor neurons (which connect your spinal cord to your muscles). To move a muscle, a signal travels from your brain, down an upper motor neuron, then to a lower motor neuron, and finally to the muscle. When ALS damages these neurons, it causes different problems.
- Damage to upper motor neurons can cause muscles to become stiff and reflexes to be extra strong.
- Damage to lower motor neurons can lead to muscle weakness, shrinking muscles, and tiny muscle twitches you can see under the skin.
Most people with ALS have damage to both types of motor neurons. This is called classical ALS.
Where ALS Symptoms Start
ALS symptoms often start in one part of the body before spreading. The two main ways it can start are:
- Limb-onset ALS: This begins with weakness in the hands, arms, feet, or legs. It makes up about two-thirds of classical ALS cases.
- Bulbar-onset ALS: This starts with weakness in the muscles used for speaking, chewing, and swallowing. It accounts for about a quarter of classical ALS cases.
A very small number of people first experience difficulty breathing. This is called respiratory-onset ALS.
When ALS Starts
ALS can begin at any age. However, it most often starts when people are between 40 and 70 years old. About 10% of cases start before age 45, and about 1% start before age 25. When ALS starts at a younger age, it often progresses more slowly. If ALS starts later in life (after age 65), it can sometimes progress more quickly.
What ALS Looks Like: Signs and Symptoms
ALS causes muscles all over the body to become weak, shrink, and have spasms. This happens because the motor neurons that control them are damaged. Interestingly, most people with ALS can still hear, see, touch, smell, and taste normally. Their senses are usually not affected.
First Signs of ALS
The first signs of ALS can be very mild and easy to miss. Often, the earliest symptoms are muscle weakness or muscles getting smaller, usually on one side of the body. Other early signs can include:
- Trouble swallowing or breathing.
- Muscle cramps or stiffness.
- Weakness in an arm or a leg.
- Speech that sounds slurred or nasal.
Where symptoms first appear depends on which motor neurons are damaged first.
- If it's limb-onset ALS, people might trip or stumble when walking. They might also find it hard to do things with their hands, like buttoning a shirt.
- If it's bulbar-onset ALS, speaking clearly or swallowing food can become difficult. Their voice might sound quieter or nasal.
A few people first notice problems with their breathing.
How Symptoms Progress
As ALS progresses, it becomes harder to move, swallow, and speak. Muscles can become very stiff and tight. Reflexes might become stronger than usual. Many people with ALS also feel pain, not directly from the disease, but from not being able to move much. Muscles continue to weaken, shrink, and twitch.
Managing Later Stages of ALS
In later stages, chewing and swallowing become very difficult. This can lead to problems with eating and a risk of food going into the lungs. Keeping a healthy weight can be a big challenge. Sometimes, a feeding tube is needed to help with nutrition. Breathing muscles also weaken, making it hard to breathe without help. Even with these challenges, many people with advanced ALS report feeling good and having a good quality of life with proper support.
Understanding the Journey of ALS
The journey of ALS is different for everyone. Most people live for about two to four years after diagnosis. However, about 10% of those affected live longer than ten years. The most common reason people with ALS pass away is from breathing problems, sometimes made worse by lung infections. Support like non-invasive ventilation can help with breathing and extend how long someone lives. Doctors and families often discuss care options early on to ensure comfort and support. There are ways to track how ALS progresses, similar to how doctors track other conditions. These systems help doctors understand the disease better for research. It's hard to predict exactly how ALS will affect each person. For example, the famous scientist Stephen Hawking lived for 55 years after his diagnosis, which was very unusual.
Thinking, Feelings, and Behavior with ALS
About 30–50% of people with ALS experience changes in their thinking or behavior. These changes can become more noticeable as the disease progresses. People might have trouble with language, planning, or remembering things. Sometimes, people with ALS might laugh or cry without meaning to, or at times that don't match how they feel. This is called pseudobulbar affect. It can be confusing for others, but it's a symptom of the disease. About 10–15% of people with ALS also show signs of frontotemporal dementia. This can cause changes like repeating phrases, not caring about things, or acting without thinking. ALS and frontotemporal dementia are now seen as connected conditions.
What Causes ALS?
For most cases of ALS (about 90–95%), the exact cause is unknown. This is called sporadic ALS. Scientists believe that a mix of genetic factors (things passed down in families) and environmental factors (things in our surroundings) play a role. No single environmental factor has been proven to cause ALS. ALS can happen at any age, but it becomes more likely as people get older. Most people are diagnosed between 40 and 70 years old. ALS is slightly more common in men than women, especially before age 70.
Genetics and ALS
About 5–10% of ALS cases are familial ALS, meaning they run in families. This happens when there's a known genetic cause. Scientists have found more than 40 genes linked to ALS. Four of these genes are responsible for about half of all familial cases. Even in cases where there's no clear family history, genetic changes can sometimes be the cause. Genetic testing can help identify these changes.
Environmental Factors and ALS
Scientists think that ALS might be caused by a combination of a person's genetic risks and things they are exposed to throughout their life. Some things that have been linked to a slightly higher risk of developing ALS include:
- Heavy metals like lead and mercury.
- Chemicals like pesticides.
- Electric shock.
- Physical injuries, including head injury.
- Smoking (more so in men).
These factors usually have a small effect on their own. Some jobs, like farming, might involve exposure to several of these risks. Other factors being studied include playing professional sports and military service.
How Doctors Diagnose ALS
There isn't one single test that can definitively say someone has ALS. Instead, doctors make a diagnosis by carefully looking at a person's symptoms and ruling out other conditions. They will ask about your medical history and do regular check-ups to see if symptoms like muscle weakness, shrinking muscles, or stiffness are getting worse.
In the U.S., it can take about 11 to 15 months from the first symptom to get a confirmed ALS diagnosis. To help speed this up, doctors have developed tools like "thinkALS" to help recognize common ALS signs earlier.
Ruling Out Other Conditions
Because ALS symptoms can be similar to many other conditions, doctors do tests to make sure it's not something else.
- Electromyography (EMG) checks the electrical activity in muscles.
- Nerve conduction velocity (NCV) measures how fast electrical signals travel through nerves.
- Magnetic resonance imaging (MRI) scans of the brain and spinal cord can show other problems, like a tumor or multiple sclerosis, that might be causing symptoms.
Doctors may also test blood and urine samples. In some cases, a muscle biopsy (taking a small sample of muscle) might be done. Some infections, like Lyme disease, or other nerve conditions can sometimes cause symptoms similar to ALS. Doctors carefully check for these to make the correct diagnosis.
Managing ALS
There is no known cure for ALS, but treatments focus on managing symptoms and providing support to improve quality of life. This care works best when a team of healthcare professionals works together.
Breathing Support
Non-invasive ventilation (NIV) is a main treatment for breathing problems in ALS. It uses a mask over the nose or face connected to a machine that helps you breathe. NIV can help people live longer and feel better. It's often used at night first, as breathing problems can start during sleep. As ALS progresses, breathing can become harder during the day too. Doctors regularly check breathing function. Starting NIV early, when breathing symptoms begin, is linked to living longer. For very advanced ALS, if NIV isn't enough, doctors might suggest invasive ventilation. This involves a tube placed directly into the windpipe. While it helps with breathing, it doesn't stop the disease from progressing.
Therapies and Equipment
Physical therapy is very important. Therapists help people with ALS keep their strength, stay active, manage pain, and move as independently as possible. They might suggest gentle exercises like walking or swimming. Occupational therapy helps with daily tasks. Therapists can recommend special equipment like ramps, walkers, wheelchairs, or tools to help with dressing or eating. Speech therapy helps with speaking and swallowing difficulties. Therapists can teach ways to speak louder or more clearly. As speech becomes harder, they might suggest augmentative and alternative communication tools, like voice amplifiers or devices that track eye movements to help people communicate.
Nutrition and Eating
Keeping a healthy weight and getting enough nutrition is very important for people with ALS. Difficulty swallowing can make eating hard. Diet changes, like eating soft, moist foods, can help. If someone loses too much weight or can't swallow safely, a feeding tube might be needed. This tube is usually placed into the stomach. Feeding tubes help ensure people get the food and water they need.
Medications for ALS
Treatments to Slow the Disease
- Riluzole can help slow down the progression of ALS by about 2–3 months. It might work by reducing a chemical in the brain called glutamate.
- Edaravone has also been shown to slow the decline in function for some people with early-stage ALS. It may protect motor neurons from damage.
- Tofersen was approved in April 2023 for people with a specific type of ALS linked to the SOD1 gene. It helps reduce a harmful protein.
Scientists are also working on new gene-targeted therapies to treat ALS.
Treatments for Symptoms
Other medicines can help with specific symptoms:
- Fatigue, muscle cramps, and stiffness: Medications can help reduce these.
- Pain: Over-the-counter pain relievers or stronger medicines can be used.
- Depression and anxiety: Doctors can prescribe medicines to help with mood.
- Uncontrolled laughing or crying (pseudobulbar affect): A medicine called Nuedexta can help.
- Excess saliva: Medicines can help reduce saliva production.
Comfort and Support Care
Palliative care focuses on making people comfortable and improving their quality of life. It should start soon after an ALS diagnosis. This care helps people and their families discuss choices about future care. Hospice care provides comfort and support in the final stages of the disease. It helps manage symptoms and ensures a peaceful journey. Most people with ALS pass away at home.
ALS Around the World
ALS is the most common motor neuron disease in adults. It is the third most common serious brain condition after Alzheimer's disease and Parkinson's disease. Globally, about 1.9 people out of every 100,000 develop ALS each year. About 4.5 people out of every 100,000 have ALS at any given time.
- In Europe, about 2.6 new cases occur per 100,000 people each year.
- The chance of a European man developing ALS in his lifetime is about 1 in 350. For women, it's about 1 in 400.
ALS affects people of all backgrounds, but it is more common in white people than in African, Asian, or Hispanic people.
The number of ALS cases worldwide is expected to increase by about 69% between 2015 and 2040. This is mainly because the world's population is getting older.
A Look Back: History of ALS
The first descriptions of this disease date back to 1824 by Charles Bell. In 1869, a French neurologist named Jean-Martin Charcot first linked the symptoms to problems in the nervous system. He started using the name amyotrophic lateral sclerosis in 1874.
How ALS Got Its Name
The name Amyotrophic lateral sclerosis comes from Greek words:
- Amyotrophic means "no muscle nourishment" or muscles wasting away.
- Lateral refers to the side parts of the spinal cord where motor neurons are affected.
- Sclerosis means "scarring" or "hardening," referring to the damaged motor neurons.
ALS is sometimes called Charcot's disease after Jean-Martin Charcot. In some countries, especially the United States, it's known as Lou Gehrig's disease. This is named after the famous American baseball player Lou Gehrig, who was diagnosed with ALS in 1939.
ALS in Society and Culture
Many famous people have had ALS. Besides baseball player Lou Gehrig, the theoretical physicist Stephen Hawking lived with ALS for 55 years. His story was told in the movie The Theory of Everything. In August 2014, the "Ice Bucket Challenge" became very popular online. People filmed themselves pouring ice water over their heads and then challenged others to do the same. This challenge helped raise a lot of money for ALS research.
See also
In Spanish: Esclerosis lateral amiotrófica para niños
