Lou Gehrig's Disease (ALS), or amyotrophic lateral sclerosis, is a progressive neurodegenerative disease that affects nerve cells in the brain and the spinal cord. A-myo-trophic comes from Greek. "A" means no. "Myo" refers to muscle, and "Trophic" means nourishment – No muscle nourishment. When a muscle has no nourishment, it "atrophies" or wastes away. "Lateral" identifies the areas in a person's spinal cord where portions of the nerve cells that signal and control the muscles are located. As this area degenerates, it leads to scarring or hardening ("sclerosis") in that particular region.
Causes
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 non-inherited 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 can be toxic to some nerve cells.
- Disorganized immune response. Sometimes a person's immune system begins to attack 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 can sometimes lead to a gradual accumulation of abnormal forms of these proteins in the cells, destroying the nerve cells.
Symptoms
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 the 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.
How is it diagnosed?
Lou Gehrig's disease doesn't always begin or become worse in the same way. The disease is different for every person who. In general, muscle weakness, especially in the arms and legs, is an early symptom for more than half of people with ALS. Other signs are tripping or falling a lot, dropping things, having some difficulty speaking, and cramping or twitching of the muscles. As the disease gets worse over time, eating, swallowing, and even breathing may become difficult.
It may take up to several months to know for sure that someone has Lou Gehrig's disease. The illness can cause symptoms similar to other diseases that affect nerves and muscles, including Parkinson's disease and stroke. A doctor will examine the patient and do special tests to see if it might be one of those other disorders.
Risk factors
Established risk factors for Lou Gehrig's Disease (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.
Researchers are learning more and more about ALS every day. What they discover will help them develop medications to treat symptoms and improve the lives of people who have this complicated disease.
