Disease: Amyotrophic lateral sclerosis
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.
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.
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 â a surgically created hole at the front of the neck leading to the windpipe (trachea) â 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.
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.
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.
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