Amyotrophic lateral sclerosis

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at February 11, 2016
StartDiseasesAmyotrophic lateral sclerosis

Amyotrophic lateral sclerosis, commonly called ALS, is a degenerative nerve disease that affects people between the ages of 40 and 70. An estimated 20,000 individuals suffer from ALS in the United States. ALS is also called Lou Gehrig’s disease after the Yankees baseball player of the 1930s who lost his life to the condition in 1941.

Contents

Definition & Facts

Amyotrophic lateral sclerosis causes progressive nerve and muscle failure. The “a” in the first word means “no,” the “myo” refers to “muscles,” and the “trophic” means nourishment. “Lateral” means “side,” and “sclerosis” means hardening.

In ALS the nerves in the spine that signal movement to the muscles stop working, causing muscles to harden into immobility. Eventually, individuals with this condition are unable to walk, talk, eat or breathe. However, the condition is progressive and treatment can help to slow the decline.

The most common form of ALS is called sporadic ALS, and it can affect anyone. The other form, called familial, has a genetic factor and runs in families. ALS leads to progressive loss of function that ultimately leads to death. Most people live from 2 to 5 years after initial diagnosis.

Symptoms & Complaints

The symptoms of ALS may start out barely noticeable, but grow gradually more debilitating. In the early stages, the symptoms may be so minor that they can be ignored, but the problems eventually travel to various parts of the body. Symptoms include:

Declining muscle function eventually makes the individual unable to walk, speak or eat. Because the disease affects muscle neurons, the person continues to have a sense of sight, hearing, taste, touch and smell. Involuntary muscles, such as those involved in heartbeat, gastrointestinal function, bowel function and bladder function and sexual function, are generally not affected directly by the disease. Some patients experience changes in cognitive function or behavior.

Causes

The genetic form of ALS occurs in 5 to 10 percent of cases. In the sporadic form, other factors come into play. Research found that patients with ALS have higher levels of glutamate, a neurotransmitter or brain chemical messenger, around nerve cells in the cerebrospinal fluid. Excessive levels of glutamate is known to be toxic to some types of nerve cells, which could explain the damage caused to nerves.

Immune responses may become disrupted and could also play a part in ALS development. It's possible that the immune system begins to attack the body’s own normal cells. Recent data also indicates that ALS is caused by nerve cells' inability to recycle toxins, which can accumulate around cells in the spine, causing damage to cellular structures. Finding ways to reverse this problem could help to extend the life and function of ALS patients.

For reasons that are not yet understood, people who have served in the military appear to be twice as likely to develop ALS than the general population. Speculation for this connection centers around increased exposure to environmental toxicants like lead and increased tobacco use and alcohol use.

Diagnosis & Tests

There is no one test that can determine if a patient has amyotrophic lateral sclerosis. Patients generally seek medical help when increasing muscle twitching and weakness begin to affect normal activities. The physician will do a full physical examination of the patients. Signs of motor neuron problems in a single limb will signal a more intensive evaluation of the individual over a period of time.

Electromyography measures electrical activity in muscles, which can tell the physician if there is a problem in the nerve signaling that produces movement. Nerve conduction tests are also used to determine nerve activity and muscle function.

MRIs can be taken to view images of the brain and spinal cord in order to detect problems and to eliminate the presence of tumors or other problems that could affect muscle activity. If no other cause for the nerve-muscle signal disruption can be determined, amyotrophic lateral sclerosis may be diagnosed.

Treatment & Therapy

Amyotrophic lateral sclerosis involves a number of physical, mental and social issues that require an experienced team of health professionals to provide the most effective management of the disease.

  • Riluzole® is currently the only FDA approved medication for ALS treatment. It works by reducing the amount of glutamate in the brain. Other medications can help to improve symptoms of muscle cramping, spasticity, pain, fatigue, constipation, drooling and uncontrolled laughing or uncontrolled crying.
  • Physical therapy is an important component of ALS treatment. Patients can learn to do exercises that help to increase muscle strength, range of motion and cardiovascular fitness thereby improving their overall health and function. Physical therapy can also help with pain management and effective use of assistive devices such as walkers or braces.
  • As the disease progresses, respiratory therapy is needed to help patients maintain effective breathing and to help with additional measures when needed.
  • Occupational therapy can help patients learn effective ways to live with ALS in their everyday life by learning to use devices to compensate for muscle weakness and to perform daily self-care tasks. In this way, patients can maintain their independence for a longer period of time.

Prevention & Prophylaxis

Currently, there is no proven method of preventing the development of amyotrophic lateral sclerosis. In cases of familial ALS, individuals with the genetic predisposition to develop the disease can turn to genetic testing to determine their chance of getting ALS and can receive early treatment to slow the progress.

Some research indicates that regular consumption of omega-3 polyunsaturated fatty acids reduces the risk for ALS. Both vegetable forms of alpha-linolenic acid and marine food omega-3 polyunsaturated fatty acids were associated with this reduced risk. These acids appear to be incorporated into cell membranes, reducing oxidative stress and inflammation. Eating brightly colored fruits and vegetables that are high in compounds called carotenoids may also have this beneficial effect on cells.