What Is ALS?
(Amyotrophic Lateral Sclerosis)
Amyotrophic lateral sclerosis (ALS), sometimes called Lou Gehrig's disease, is a rapidly progressive neurodegenerative disease that is 100% fatal. ALS attacks the nerve cells (neurons) responsible for controlling voluntary muscles (muscle action we are able to control, such as those in the arms, legs, and face). The disease belongs to a group of disorders known as motor neuron diseases, which are characterized by the gradual degeneration and death of motor neurons.
Motor neurons are nerve cells located in the brain, brain stem, and spinal cord that serve as controlling units and vital communication links between the nervous system and the voluntary muscles of the body. Messages from motor neurons in the brain (called upper motor neurons) are transmitted to motor neurons in the spinal cord (called lower motor neurons) and from them to particular muscles. In ALS, both the upper motor neurons and the lower motor neurons degenerate or die, and stop sending messages to muscles. Unable to function, the muscles gradually weaken, waste away (atrophy), and have very fine twitches (called fasciculations). Eventually, the ability of the brain to start and control voluntary movement is lost.
ALS causes weakness with a wide range of disabilities. Eventually, all muscles under voluntary control are affected, and individuals lose their strength and the ability to move their arms, legs, and body. When muscles in the diaphragm and chest wall fail, people lose the ability to breathe without ventilatory support. 50% of patients with ALS die from respiratory failure, usually within 3 to 5 years from the onset of symptoms.
Who Gets ALS?
ALS is a disorder that affects the function of nerves and muscles. Based on U.S. population studies, a little over 6,000 people in the U.S. are diagnosed with ALS each year. (That's 15 new cases a day.) It is estimated that as many as 20,000 Americans have the disease at any given time. According to the ALS CARE Database, 60% of the people with ALS in the Database are men and 93% of patients in the Database are Caucasian.
Most people who develop ALS are between the ages of 40 and 70, with an average age of 55 at the time of diagnosis. However, cases of the disease do occur in persons in their twenties and thirties. Generally though, ALS occurs in greater percentages as men and women grow older. ALS is 20% more common in men than in women. However with increasing age, the incidence of ALS is more equal between men and women.
There are several research studies – past and present – investigating possible risk factors that may be associated with ALS. More work is needed to conclusively determine what genetics and/or environment factors contribute to developing ALS. It is known, however, that military veterans, particularly those deployed during the Gulf War, are approximately twice as likely to develop ALS.
Half of all people affected with ALS live at least three or more years after diagnosis. Twenty percent live five years or more; up to ten percent will live more than ten years.
There is some evidence that people with ALS are living longer, at least partially due to clinical management interventions, riluzole and possibly other compounds and drugs under investigation.
Facts You Should Know
ALS is not contagious.
Although the life expectancy of a person with ALS averages about two to five years from the time of diagnosis, this disease is variable, and many people can live with the disease for five years and more. More than half of all people with ALS live more than three years after diagnosis.
Once ALS starts, it almost always progresses, eventually taking away the ability to walk, dress, write, speak, swallow, and breathe and shortening the life span. How fast and in what order this occurs is very different from person to person. While the average survival time is 3 years, about twenty percent of people with ALS live five years, 10 percent will survive ten years and five percent will live 20 years or more.
Progression is not always a straight line in an individual either. It is not uncommon to have periods lasting weeks to months where there is very little or no loss of function. There are even very rare examples in which there is significant improvement and recovery of lost function. These ALS "arrests" and "reversals" are unfortunately usually transient. Less than 1% of patients with ALS will have significant improvement in function lasting 12 months or more.
Approximately 6,000 people in the U.S. are diagnosed with ALS each year. The incidence of ALS is two per 100,000 people, and it is estimated that more than 20,000 Americans may be living with ALS at any given time.
ALS occurs throughout the world with no racial, ethnic or socioeconomic boundaries and can affect anyone.
Military veterans are approximately twice as likely to develop ALS.
The onset of ALS often involves muscle weakness or stiffness as early symptoms. Progression of weakness, wasting and paralysis of the muscles of the limbs and trunk as well as those that control vital functions such as speech, swallowing and later breathing generally follows.
There can be significant costs for medical care, equipment and home health caregiving later in the disease. It is important to be knowledgeable about your health plan coverage and other programs for which you may be eligible, including Social Security Disability, Medicare, Medicaid and Veteran Affairs benefits.
Riluzole, the only drug approved for ALS, was approved by the FDA in late 1995. This antiglutamate drug was shown scientifically to prolong the life of persons with ALS by at least a few months. More recent studies suggest Riluzole slows the progress of ALS, allowing the patient more time in the higher functioning states when their function is less affected by ALS.
The initial symptoms of ALS can be quite varied in different people. One person may have trouble grasping a pen or lifting a coffee cup, while another person may experience a change in vocal pitch when speaking. ALS is typically a disease that involves a gradual onset.
The rate at which ALS progresses can be quite variable from one person to another. Although the mean survival time with ALS is three to five years, many people live five, 10 or more years. Symptoms can begin in the muscles that control speech and swallowing or in the hands, arms, legs or feet. Not all people with ALS experience the same symptoms or the same sequences or patterns of progression. However, progressive muscle weakness and paralysis are universally experienced.
Gradual onset, painless, progressive muscle weakness is the most common initial symptom in ALS. Other early symptoms vary but can include tripping, dropping things, abnormal fatigue of the arms and/or legs, slurred speech, muscle cramps and twitches, and/or uncontrollable periods of laughing or crying.
When the breathing muscles become affected, ultimately, people with the disease will need permanent ventilatory support to assist with breathing.
Since ALS attacks only motor neurons, the sense of sight, touch, hearing, taste and smell are not affected. For many people, muscles of the eyes and bladder are generally not affected.
ALS is a difficult disease to diagnose. There is no one test or procedure to ultimately establish the diagnosis of ALS. It is through a clinical examination and series of diagnostic tests, often ruling out other diseases that mimic ALS, that a diagnosis can be established. A comprehensive diagnostic workup includes most, if not all, of the following procedures:
- Electrodiagnostic tests including electomyography (EMG) and nerve conduction velocity (NCV)
- Blood and urine studies including high resolution serum protein electrophoresis, thyroid and parathyroid hormone levels and 24-hour urine collection for heavy metals
- Spinal tap
- X-rays, including magnetic resonance imaging (MRI)
- Myelogram of cervical spine
- Muscle and/or nerve biopsy
- A thorough neurological examination
These tests are done at the discretion of the physician, usually based on the results of other diagnostic tests and the physical examination. There are several diseases that have some of the same symptoms as ALS, and most of these conditions are treatable.
GET INFORMED ABOUT ALS
Although there is no known cure for ALS, the drug Riluzole (Rilutek) has been approved for treatment and may slow progression of the disease. Riluzole is the only medication approved by the Food and Drug Administration for ALS. The 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 may cause side effects such as dizziness, gastrointestinal conditions and liver function changes. It is expensive, however, and appears modestly effective with an estimated three month extension in ALS patients life-span.
Medications prescribed include:
- Drugs such as baclofen or diazepam may help control spasticity.
- Gabapentin may be prescribed to help control pain.
- Trihexyphenidyl or amitriptyline may help patients swallow saliva.
Because choking is common as ALS progresses, patients may need a tube called a percutaneous endoscopic gastrostomy (PEG) tube or feeding tube to be placed into the stomach for feeding.
Physical therapy, rehabilitation, use of appliances such as braces or a wheelchair, and other treatments may help muscles work as well as possible and improve your general health. Those who develop difficulty speaking may benefit from speech therapy as well as speech synthesizers and computer-based communication systems.