Amyotrophic lateral sclerosis (ALS) is a progressive disease that causes severe weakness due to progressive degeneration of a specific set of motor nerves in the spinal cord. People with ALS will gradually lose the ability to use their muscles.
Many experts refer to ALS as a single disease, though it is an umbrella term for a group of diseases.
Collectively, ALS is the most common type of motor neuron disease. It is sometimes called Lou Gehrig’s disease, after a famous baseball player who had the condition.
The reason why some people develop ALS is unclear, but environment and genetics are factors. While there is no cure, treatments can help alleviate the symptoms and improve the quality of life.
ALS
As ALS progresses, these cells degenerate and die. They stop sending messages to muscles, and a person can no longer control voluntary movement. Over time, the muscles weaken and degenerate.
Progressive muscle weakness occurs in all cases of ALS, but this may not be the first indication of the condition.
In the early stages, signs and symptoms may be barely noticeable. They become more evident over time, but the progression varies from person to person.
Common early symptoms
- tiny repeated muscle twitches that generally affect the tongue or fingers
- generalized fatigue
- mild clumsiness
- cramping
Later symptoms include:
- difficulty with daily activities, including walking
- weakness in the feet, hands, legs, and ankles
- cramping and twitching in the arms, shoulders, or tongue
- difficulty maintaining good posture and holding the head up
- uncontrolled outbursts of laughing or crying, known as pseudobulbar affect
- changes in thinking or memory
- slurred speech and difficulty with voice projection
- pain
- fatigue
- trouble swallowing saliva, or choking on saliva
- difficulty breathing and swallowing in the later stages
Some people with very late-stage ALS have problems with decision making and memory, eventually leading to a form of dementia called frontotemporal dementia, which includes symptoms such as fluctuations in mood and emotional responses. This may only affect less than a third of people with ALS.
The Centers for Disease Control and Prevention (CDC) estimates that less than
Risk factors for ALS include:
- Gender: ALS is
slightly more common in men than women. - Age: ALS symptoms most commonly appear in a person between the ages of 40 and 70, but it can develop at other ages.
- Race: Caucasian and non-Hispanic people are
more likely to develop ALS. But anyone may develop the disease.
There are two types of ALS: sporadic and familial. Sporadic ALS develops randomly, accounting for 90% of cases. About 10% of ALS cases are familial. There is no clear risk factor or cause.
A person can inherit familial ALS. The child of a person with familial ALS has a 50% chance of developing the condition. Rarely does it affect a person in their teens.
ALS progression can vary for each person, but once it does progress, there is no cure. As the disease progresses, a person may gradually lose their ability to:
- walk
- talk
- swallow
- use their limbs
- breathe
In the mid stages, ALS causes muscle weakness and clumsiness. Muscle pain and cramping are very common in this stage. Later, complete muscle paralysis results in loss of motor functions. Eventually, the muscles shrink due to lack of use.
A small minority of people inherit ALS, but for the majority, the cause is unclear. Research has focused on genetics and environmental factors as possible causes of ALS.
Genetics
About
And 12–20% of familial cases result from mutations in the SOD1 gene, which is key to the functioning of motor neurons and other cells.
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People with ALS might consider genetic testing. Family members might also receive testing if the test identifies a disease-causing variant.
Other possible causes of ALS include:
- Disorganized immune response: The immune system may attack some of the body’s cells, possibly killing nerve cells.
- Chemical imbalance: People with ALS often have higher levels of glutamate, a chemical messenger in the brain, near the motor neurons. Glutamate in high quantities can be toxic to nerve cells.
- Mishandling of proteins: If nerve cells do not process proteins correctly, the resulting atypical proteins might accumulate and cause the nerve cells to die.
It is unclear which of these steps may affect the others, and whether some of the genes that have been identified in association with ALS may affect one or more of these processes.
Possible environmental factors
Research reports that military personnel deployed in the Gulf region during the 1991 war were more likely to develop ALS than those deployed elsewhere.
Also, research indicates some possible links between ALS and:
- mechanical or electrical trauma
- military service
- high levels of exercise
- exposure to high quantities of agricultural chemicals
- exposure to high levels of a variety of heavy metals
However, there is no conclusive evidence that any lifestyle changes reduce the risk of developing ALS.
No single test can diagnose ALS. Doctors consider the symptoms and the results of various tests to rule out other conditions with similar signs and symptoms.
Tests that may help diagnose ALS are:
- electromyography, which measures muscle response to electrical stimulation
- nerve conduction study, which tests how well the nerves send signals
Different stages of ALS cause different electromyography and nerve conduction study patterns. These can help rule out peripheral neuropathy and myopathy, a muscle disease.
An MRI scan can detect other problems that could be causing the symptoms, such as a spinal cord tumor or a herniated disk in the neck.
Blood and urine tests and a muscle biopsy can help rule out other conditions.
Some health issues that can cause similar symptoms to ALS include HIV, Lyme disease, multiple sclerosis, polio, and West Nile virus.
A doctor may consider ALS as a possible cause if a person has symptoms and physical examination findings with features of both upper and lower motor neuron disease.
Upper motor neuron symptoms include stiffness, resistance to muscle movement, and brisk reflexes. Lower motor neuron symptoms include weakness, muscle atrophy, and twitching.
There is no cure for ALS, so treatment aims to alleviate symptoms, prevent complications, and slow the progression.
ALS can cause a range of physical, mental, and social changes. As a result, managing the symptoms, improving the quality of life, and prolonging life may involve a team of specialists.
The Food and Drug Administration (FDA) approved riluzole (Rilutek) for ALS treatment in 1995. It appears to slow the progression of the disease. It may work by reducing the body’s levels of glutamate, an excitotoxin linked to neuronal damage.
Other medications include:
- Radicava (edaravone)
- Relyvrio (sodium phenylbutyrate/taurursodiol)
- Qalsody (tofersen)
Several research projects are looking at ways to use new and existing drugs to treat individual aspects of ALS.
Doctors can also prescribe medications to treat the different symptoms.
Therapy
Physical therapy can help people with ALS manage pain and improve mobility.
A physical therapist may recommend:
- low impact exercises to enhance cardiovascular fitness and overall well-being
- mobility aids, such as walkers and wheelchairs
- devices to make life easier, such as ramps
Occupational therapy can help people maintain their independence for longer. An occupational therapist may:
- help choose adaptive equipment and assistive technologies that enable a person to keep up their daily routine
- provide training about how to compensate for hand and arm weaknesses
Speech therapy can be useful when speaking is difficult due to ALS. A speech therapist can teach a person adaptive techniques and other methods of communication, including writing and computer-based communication equipment.
Nutritional support is also essential, as difficulty with swallowing can make it hard to get enough nutrients. A registered dietitian can advise about creating meals that are easy to swallow.
Suction devices and feeding tubes can also help. A suction device is used to help remove saliva, which prevents choking. It is placed into the mouth and suctioned out. It is not a permanently placed device; it is usually used every time a person eats and also at regular intervals to remove accumulated saliva. A feeding tube can be placed in the nose and down to the stomach or surgically placed directly into the stomach.
As the respiratory muscles weaken, a person may benefit from breathing therapy, which might involve using a breathing device at night.
Some people need mechanical ventilation. This involves wearing a respirator connected to a tube. The other end of the tube goes into the windpipe through a surgically created hole in the neck, or tracheostomy.
ALS eventually affects all the voluntary muscles, which removes a person’s ability to control movements. In the later stages, ALS affects the nerves that control breathing, which can lead to respiratory failure.
The mean survival time after diagnosis for ALS is two to three years, though many may live for 10 years or longer. Increasing understanding of the disease, new therapies, and better care are allowing people who have ALS to survive for longer than in the past.
Steven Hawking, a leading physicist, received an ALS diagnosis at the age of 21 and died in 2018 at the age of 76.
Several strategies can help people with ALS and their loved ones adjust to a changing situation.
- Keep in touch: Social contact is important. Stay in touch with friends and participate in as many activities as possible.
- Reach out: In-person or online support groups can help answer questions and provide insight through shared experiences.
- Get equipped: Have a bag ready with tissues, hand wipes, and easy-to-hold cutlery for going out. Register to get a disability sign for the car. Make necessary adjustments at home, such as purchasing a device that raises the toilet seat.
- Plan ahead: It can be hard for a person to find that they can no longer do something. Foreseeing possible limitations and preparing can help make this easier when the time comes.
- Research financial help: As the disease progresses, treatment can become expensive. A person in the U.S. may be eligible for financial assistance through the Social Security Administration, Medicare, or Medicaid. There may also be specific benefits for veterans.
- Arrange time off for caregivers: Caregivers should take care of their own health and that of their loved ones. Arrange for a friend, relative, or another caregiver to stay for a weekend or take the person with ALS out for the day.
What you can do will depend to some extent on your finances. Support groups can help people cope with many of the challenges of ALS by providing advice, empathy, or practical help.
ALS can affect a person’s daily life in various ways, including having issues with walking, talking, breathing, eating, swallowing, and movement.
The cause of ALS is generally unknown. Few cases are familial, but scientists are still trying to research the definitive cause. Some potential causes include environmental factors and genetics.
There is currently no way to prevent ALS, but as scientists study the cause, prevention may become clearer. Some likely causes include environment and genetics.
Amyotrophic lateral sclerosis (ALS) affects certain motor nerve cells in the spinal cord. People with ALS gradually lose the ability to walk, talk, eat, swallow, and perform other motor functions.
Treatment for ALS involves managing symptoms, preventing complications, and slowing the progression of the disease.