What is Amyotrophic Lateral Sclerosis?

Amyotrophic lateral sclerosis (ALS), sometimes called Lou Gehrig's disease, is a rapidly progressive, invariably fatal neurological disease that attacks the nerve cells (neurons) responsible for controlling voluntary muscles. In ALS, both the upper motor neurons and the lower motor neurons degenerate or die, ceasing to send messages to muscles. Unable to function, the muscles gradually weaken, waste away, and twitch. Eventually the ability of the brain to start and control voluntary movement is lost. Individuals with ALS 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 ventilatory support. In most cases the disease does not impair a person's mind, personality, intelligence, or memory, nor does it affect a person's ability to see, smell, taste, hear, or recognize touch. A small percentage of patients may experience problems with memory or decision-making, and there is growing evidence that some may even develop a form of dementia. The cause of ALS is not known, and scientists do not yet know why ALS strikes some people and not others.

Is there any treatment?

No cure has yet been found for ALS. However, the FDA has approved the first drug treatment for the disease-riluzole. Riluzole is believed to reduce damage to motor neurons and prolongs survival by several months, mainly in those with difficulty swallowing. Other treatments are designed to relieve symptoms and improve the quality of life for people with ALS. Drugs also are available to help individuals with pain, depression, sleep disturbances, and constipation. Individuals with ALS may eventually consider forms of mechanical ventilation (respirators).

What is the prognosis?

Regardless of the part of the body first affected by the disease, muscle weakness and atrophy spread to other parts of the body as the disease progresses. Individuals have increasing problems with moving, swallowing, and speaking or forming words. Eventually people with ALS will not be able to stand or walk, get in or out of bed on their own, or use their hands and arms. In later stages of the disease, individuals have difficulty breathing as the muscles of the respiratory system weaken. Although ventilation support can ease problems with breathing and prolong survival, it does not affect the progression of ALS. Most people with ALS die from respiratory failure, usually within 3 to 5 years from the onset of symptoms. However, about 10 percent of those individuals with ALS survive for 10 or more years.

A-myo-trophic comes from the Greek language. "A" means no or negative. "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 the region.

As motor neurons degenerate, they can no longer send impulses to the muscle fibers that normally result in muscle movement. Early symptoms of ALS often include increasing muscle weakness, especially involving the arms and legs, speech, swallowing or breathing. When muscles no longer receive the messages from the motor neurons that they require to function, the muscles begin to atrophy (become smaller). Limbs begin to look "thinner" as muscle tissue atrophies.



What Types of Nerves Make Your Body Work Properly?

The body has many kinds of nerves. There are those involved in the process of thinking, memory, and of detecting sensations (such as hot/cold, sharp/dull), and others for vision, hearing, and other bodily functions. The nerves that are affected when you have ALS are the motor neurons that provide voluntary movements and muscle power. Examples of voluntary movements are your making the effort to reach for the phone or step off a curb; these actions are controlled by the muscles in the arms and legs. The heart and the digestive system are also made of muscle but a different kind, and their movements are not under voluntary control. When your heart beats or a meal is digested, it all happens automatically. Therefore, the heart and digestive system are not involved in ALS. Breathing also may seem to be involuntary. Remember, though, while you cannot stop your heart, you can hold your breath - so be aware that ALS may eventually have an impact on breathing.