What're the symptoms of amyotrophic lateral sclerosis?
The first sign of amyotrophic lateral sclerosis is usually slight weakness in one leg, one hand, the face, or the tongue. Other problems may include increasing clumsiness and difficulty performing tasks that require precise movements of the fingers and hands. Muscle twitching may also occur. The weakness slowly spreads to the arms and legs over a period of months or years. As the nerves continue to waste away and decrease in number, the muscle cells that would normally be stimulated by those nerves also start to waste away, and the muscles weaken. Less often, the earliest sign of amyotrophic lateral
sclerosis is weakness in the bulbar muscles, those muscles in the mouth and throat that control chewing, swallowing, and speaking. A person with bulbar weakness may become hoarse or tired after speaking at length, or speech may become slurred. In addition to weakness, the other cardinal signs of amyotrophic lateral sclerosis are muscle wasting and persistent twitching (fasciculation). These are usually seen after weakness becomes obvious. Fasciculation is quite common in people without the disease, and is virtually never the first sign of amyotrophic lateral sclerosis.
While initial weakness may be limited to one region, amyotrophic lateral sclerosis almost always progresses rapidly to involve virtually all the voluntary muscle groups in the body. Later symptoms include loss of the ability to walk, to use the arms and hands, to speak clearly or at all, to swallow, and to hold the head up. Weakness of the respiratory muscles makes breathing and coughing difficult, and poor swallowing control increases the likelihood of inhalation of food or saliva (aspiration). Aspiration increases the likelihood of lung infection, which is often the cause of death. With a ventilator and scrupulous bronchial hygiene, a person with amyotrophic lateral sclerosis may live much longer than the average, although weakness and wasting will continue to erode any remaining functional abilities. Most people with amyotrophic lateral sclerosis continue to retain function of the extraocular muscles that move the eyes, allowing some communication to take place with simple blinks or through use of a computer-assisted device.
Amyotrophic lateral sclerosis is a progressive, disabling disease. Walking, speaking, eating, swallowing, breathing, and other basic functions become more difficult with time. These problems can lead to injury, illness, and other complications.
Respiratory problems are the most common serious complication of amyotrophic lateral sclerosis. As the muscles in the throat and chest area become weak, swallowing and coughing become more difficult, which may sometimes cause food and saliva to be inhaled into the windpipe (aspiration). This may lead to pneumonia. Breathing problems tend to get worse as the disease progresses, increasing the risk of infection and respiratory failure.
People with amyotrophic lateral sclerosis die most often from pneumonia, pulmonary embolism, lung failure, or heart failure (probably due to lack of adequate breathing as the chest muscles weaken), usually within 3 to 6 years after symptoms begin. A few may live for many years after symptoms begin.
As the disease progresses, the person with amyotrophic lateral sclerosis loses the ability to carry out everyday activities such as dressing, eating, and working. Eventually getting out of bed at all becomes impossible without assistance. The person becomes restricted to a wheelchair or bed. (Bedsores can be a problem.) As the respiratory muscles weaken, breathing becomes more and more difficult. The risk of pneumonia increases.