Basic Information on Amyotrophic Lateral Sclerosis
Individuals with amyotrophic lateral sclerosis lose their strength and the ability to move their arms, legs, and body. When muscles in the diaphragm and chest wall fail, individuals lose the ability to breathe without ventilator support.
In most cases, ALS does not impair a person's mind, memory, or senses. However, a small percentage of people may experience problems with memory or decision making, and there is growing evidence that some people may develop a form of dementia.
(Click ALS Symptoms for more information, including early symptoms.)
The cause of amyotrophic lateral sclerosis is not known, and scientists do not know why the disease strikes some people and not others.
ALS research scientists are investigating a number of possible causes, including:
- Autoimmune responses
(Click Causes of ALS for more information.)
Although there is no single test that can provide a definitive diagnosis, the presence of upper and lower motor neuron signs in a single limb is strongly suggestive. However, a diagnosis of amyotrophic lateral sclerosis is primarily based on the signs and symptoms and on a series of tests to rule out other diseases.
(Click ALS Diagnosis for more information.)