Amyotrophic lateral sclerosis (ALS)
Medically reviewed on Jul 17, 2018
Amyotrophic lateral sclerosis (a-my-o-TROE-fik LAT-ur-ul skluh-ROE-sis), or ALS, is a progressive nervous system (neurological) disease that destroys nerve cells and causes disability.
ALS is often called Lou Gehrig's disease, after the famous baseball player who was diagnosed with it. ALS is a type of motor neuron disease in which nerve cells gradually break down and die.
Doctors usually don't know why ALS occurs. Some cases are inherited.
ALS often begins with muscle twitching and weakness in a limb, or slurred speech. Eventually, ALS affects control of the muscles needed to move, speak, eat and breathe. There is no cure for ALS, and eventually the disease is fatal.
Early signs and symptoms of ALS include:
- Difficulty walking or doing your normal daily activities
- Tripping and falling
- Weakness in your leg, feet or ankles
- Hand weakness or clumsiness
- Slurred speech or trouble swallowing
- Muscle cramps and twitching in your arms, shoulders and tongue
- Difficulty holding your head up or keeping good posture
ALS often starts in the hands, feet or limbs, and then spreads to other parts of your body. As the disease advances and nerve cells are destroyed, your muscles progressively weaken. This eventually affects chewing, swallowing, speaking and breathing.
ALS doesn't usually affect your bowel or bladder control, your senses or your thinking ability. It's possible to remain actively involved with your family and friends.
ALS is inherited in 5 to 10 percent of cases, while the rest have no known cause.
Researchers are studying several possible causes of ALS, including:
- Gene mutation. Various genetic mutations can lead to inherited ALS, which causes nearly the same symptoms as the noninherited form.
- Chemical imbalance. People with ALS generally have higher than normal levels of glutamate, a chemical messenger in the brain, around the nerve cells in their spinal fluid. Too much glutamate is known to be toxic to some nerve cells.
- Disorganized immune response. Sometimes a person's immune system begins attacking some of his or her body's own normal cells, which may lead to the death of nerve cells.
- Protein mishandling. Mishandled proteins within the nerve cells may lead to a gradual accumulation of abnormal forms of these proteins in the cells, destroying the nerve cells.
Established risk factors for ALS include:
- Heredity. Five to 10 percent of the people with ALS inherited it (familial ALS). In most people with familial ALS, their children have a 50-50 chance of developing the disease.
- Age. ALS risk increases with age, and is most common between the ages of 40 and 60.
- Sex. Before the age of 65, slightly more men than women develop ALS. This sex difference disappears after age 70.
- Genetics. Some studies examining the entire human genome (genomewide association studies) found many similarities in the genetic variations of people with familial ALS and some people with noninherited ALS. These genetic variations might make people more susceptible to ALS.
Environmental factors may trigger ALS. Some that may affect ALS risk include:
- Smoking. Smoking is the only likely environmental risk factor for ALS. The risk seems to be greatest for women, particularly after menopause.
- Environmental toxin exposure. Some evidence suggests that exposure to lead or other substances in the workplace or at home may be linked to ALS. Much study has been done, but no single agent or chemical has been consistently associated with ALS.
- Military service. Recent studies indicate that people who have served in the military are at higher risk of ALS. It's unclear exactly what about military service may trigger the development of ALS. It may include exposure to certain metals or chemicals, traumatic injuries, viral infections, and intense exertion.
As the disease progresses, people with ALS experience complications, which may include:
Over time, ALS paralyzes the muscles you use to breathe. You may need a device to help you breathe at night, similar to what someone with sleep apnea might wear. For example, you may be given continuous positive airway pressure (CPAP) or bi-level positive airway pressure (BiPAP) to assist with your breathing at night.
Some people with advanced ALS choose to have a tracheostomy — a surgically created hole at the front of the neck leading to the windpipe (trachea) — for full-time use of a respirator that inflates and deflates their lungs.
The most common cause of death for people with ALS is respiratory failure. On average, death occurs within three to five years after symptoms begin.
Most people with ALS will develop trouble speaking over time. This usually starts as occasional, mild slurring of words, but progresses to become more severe. Speech eventually becomes more difficult for others to understand, and people with ALS often rely on other communication technologies to communicate.
People with ALS can develop malnutrition and dehydration from damage to the muscles that control swallowing. They are also at higher risk of getting food, liquids or saliva into the lungs, which can cause pneumonia. A feeding tube can reduce these risks and ensure proper hydration and nutrition.
Some people with ALS experience problems with memory and making decisions, and some are eventually diagnosed with a form of dementia called frontotemporal dementia.
Amyotrophic lateral sclerosis (ALS) is difficult to diagnose early because it may mimic several other neurological diseases. Tests to rule out other conditions may include:
Electromyogram (EMG). During an EMG, your doctor inserts a needle electrode through your skin into various muscles. The test evaluates the electrical activity of your muscles when they contract and when they're at rest.
Abnormalities in muscles seen in an electromyogram can help doctors diagnose ALS, or determine if you have a different muscle or nerve condition that may be causing your symptoms. It can also help guide your exercise therapy.
- Nerve conduction study. This study measures your nerves' ability to send impulses to muscles in different areas of your body. This test can determine if you have nerve damage or certain muscle diseases.
- Magnetic resonance imaging (MRI). Using radio waves and a powerful magnetic field, an MRI produces detailed images of your brain and spinal cord. An MRI can spot spinal cord tumors, herniated disks in your neck or other conditions that may be causing your symptoms.
- Blood and urine tests. Analyzing samples of your blood and urine in the laboratory may help your doctor eliminate other possible causes of your signs and symptoms.
- Spinal tap (lumbar puncture). Sometimes a specialist may remove a sample of your spinal fluid for analysis. A specialist inserts a small needle between two vertebrae in your lower back and removes a small amount of cerebrospinal fluid for testing in the laboratory.
- Muscle biopsy. If your doctor believes you may have a muscle disease rather than ALS, you may undergo a muscle biopsy. While you're under local anesthesia, a small portion of your muscle is removed and sent to a lab for analysis.
Treatments can't reverse the damage of amyotrophic lateral sclerosis, but they can slow the progression of symptoms, prevent complications and make you more comfortable and independent.
You may need an integrated team of doctors trained in many areas and other health care professionals to provide your care. This may prolong your survival and improve your quality of life.
Your team will help you select the right treatments for you. You always have the right to choose or refuse any of the treatments suggested.
Two medications are currently approved by the Food and Drug Administration for the treatment of ALS.
- Riluzole (Rilutek) — This drug appears to slow the disease's progression in some people, perhaps by reducing levels of a chemical messenger in the brain (glutamate) that's often present in higher levels in people with ALS. Riluzole is taken as a pill and may cause side effects such as dizziness, gastrointestinal conditions and liver function changes.
Edaravone (Radicava) — The FDA approved edaravone in 2017 based on six-month clinical trial that showed it reduced the decline in daily functioning associated with ALS. The drug is given via intravenous infusion (typically 10-14 days in a row, once a month), and side effects may include bruising, gait disturbance, hives, swelling and shortness of breath.
Edaravone contains sodium bisulfite, which may cause serious allergic reactions in people with sulfite sensitivity.
Your doctor may also prescribe medications to provide relief from other symptoms, including:
- Muscle cramps and spasms
- Excessive salivation
- Excessive phlegm
- Sleep problems
- Uncontrolled outbursts of laughing or crying
Breathing care. You'll eventually have more difficulty breathing as your muscles become weaker. Doctors may test your breathing regularly and provide you with devices to assist your breathing at night.
You may choose mechanical ventilation to help you breathe. Doctors insert a tube in a surgically created hole at the front of your neck leading to your windpipe (tracheostomy), and the tube is connected to a respirator.
Physical therapy. A physical therapist can address pain, walking, mobility, bracing and equipment needs that help you stay independent. Practicing low-impact exercises may help maintain your cardiovascular fitness, muscle strength and range of motion for as long as possible.
A physical therapist can also help you adjust to a brace, walker or wheelchair and may suggest devices such as ramps that make it easier for you to get around.
Regular exercise can also help improve your sense of well-being. Appropriate stretching can help prevent pain and help your muscles function at their best.
Occupational therapy. An occupational therapist can help you find ways to remain independent despite hand and arm weakness. Adaptive equipment can help you perform daily activities such as dressing, grooming, eating and bathing.
An occupational therapist can also help you modify your home to allow accessibility if you have trouble walking safely.
Occupational therapists also have a good understanding of how assistive technology and computers can be used, even if your hands are weak.
Speech therapy. Because ALS affects the muscles you use to speak, communication is an issue in advanced ALS. A speech therapist can teach you adaptive techniques to make your speech more clearly understood. Speech therapists can also help you explore other methods of communication, such as an alphabet board or simple pen and paper.
Ask your therapist about the possibility of borrowing or renting devices such as tablet computers with text-to-speech applications or computer-based equipment with synthesized speech that may help you communicate.
- Nutritional support. Your team will work with you and your family members to ensure you're eating foods that are easier to swallow and meet your nutritional needs. You may eventually need a feeding tube.
- Psychological and social support. Your team may include a social worker to help with financial issues, insurance, and getting equipment and paying for devices you may need. Psychologists, social workers and others may provide emotional support for you and your family.
Potential future treatments
Clinical studies on promising medications and treatments are occurring in ALS all the time.
Whether you are eligible for a clinical study depends on many factors related to your ALS and also whether there are ongoing studies enrolling patients. While many of these studies are promising, they are still only studies, and it isn't yet clear if these treatments will help people with ALS. Talk to your doctor about what might be available for you.
Coping and support
Learning you have ALS can be devastating. The following tips may help you and your family cope:
- Take time to grieve. The news that you have a fatal condition that will reduce your mobility and independence can be difficult. You and your family will likely experience a period of mourning and grief after diagnosis.
- Be hopeful. Your team will help you focus on your ability and healthy living. Some people with amyotrophic lateral sclerosis live much longer than the three to five years usually associated with this condition. Some live 10 years or more. Maintaining an optimistic outlook can help improve quality of life for people with ALS.
- Think beyond the physical changes. Many people with amyotrophic lateral sclerosis lead rich, rewarding lives despite physical limitations. Try to think of ALS as only one part of your life, not your entire identity.
- Join a support group. You may find comfort in a support group with others who have ALS. Your family members and friends helping with your care also may benefit from a support group of other ALS caregivers. Find support groups in your area by talking to your doctor or by contacting the ALS Association.
Make decisions now about your future medical care. Planning for the future allows you to be in control of decisions about your life and your care.
With the help of your doctor, hospice nurse or social worker, you can decide whether you want certain life-extending procedures.
You can also decide where you want to spend your final days. You may consider hospice care options. Planning for the future can help you and your loved ones put to rest some common anxieties.
Preparing for an appointment
You might first consult your family doctor about signs and symptoms of ALS. Your family doctor will talk to you about your symptoms and do an initial physical examination. Then your doctor will probably refer you to a doctor trained in nervous system conditions (neurologist) for further evaluation.
What you can do
You may need many tests to diagnose your condition, and this process can be stressful and frustrating. These strategies may give you a greater sense of control.
- Keep a symptom diary. Before you see a neurologist, start using a calendar or notebook to jot down when and how you notice problems with walking, hand coordination, speech, swallowing or involuntary muscle movements. Your notes may show a pattern that's helpful for your diagnosis.
Find a neurologist and care team. An integrated care team led by your neurologist usually is most appropriate for your ALS care. Your team should communicate and be familiar with your individual needs.
An integrated team may prolong survival and improve your quality of care.
What to expect from your doctor
Your family doctor will carefully review your family's medical history and your signs and symptoms. Your neurologist and your family doctor may conduct a physical and neurological examination, which may include testing:
- Muscle strength
- Muscle tone
- Senses of touch and sight