What is Amyotrophic Lateral Sclerosis (ALS)?

Amyotrophic lateral sclerosis (ALS), sometimes called Lou Gehrig’s disease or classical motor neuron 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. Eventually the ability of the brain to start and control voluntary movement is lost.  Symptoms are usually first noticed in the arms and hands, legs, or swallowing muscles. Muscle weakness and atrophy occur on both sides of the body.  Individuals with ALS lose their strength and the ability to move their arms and legs, and to hold the body upright. When muscles in the diaphragm and chest wall fail to function properly, individuals lose the ability to breathe.  The disease does not affect a person’s ability to see, smell, taste, hear, or recognize touch.  Although the disease does not usually impair a person’s mind or personality, several recent studies suggest that some people with ALS may develop cognitive problems involving word fluency, decision-making, and memory.  The cause of ALS is not known, and scientists do not yet know why ALS strikes some people and not others.

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.