What is ALS?
Amyotrophic Lateral Sclerosis (ALS) is a motor neuron disease, first described in 1869 by the noted French neurologist Jean-Martin Charcot. ALS occurs rarely and spontaneously. To date, except in strongly genetic forms of the disease, the cause of ALS is not completely understood. The last decade has brought a wealth of new scientific understanding, but how it starts in the body is still unclear.
ALS, commonly known as Lou Gehrig’s disease, and outside of the United States as Motor Neuron Disease (MND) or Charcot’s Disease, is a progressive neurodegenerative disease that attacks motor neurons in the brain (upper motor neurons) and spinal cord (lower motor neurons) and affects muscle function. The motor neurons control the movement of various voluntary muscles, including the diaphragm. Associated with the loss of motor neurons to function in ALS, the various muscles cells waste away (atrophy), resulting in increased muscle weakness. A common first symptom is a painless weakness in a hand, arm, foot or leg, which occurs in more than half of all cases. Other early symptoms include difficulty with speech or swallowing. In conjunction with these symptoms, an individual will have twitching and cramping of muscles (called fasciculation), stiffness in muscles (spasticity), increasing loss of motor control in hands, arms and legs, weakness and fatigue, slurred or thick speech and difficulty breathing or swallowing.
The biological mechanisms that cause ALS are only partially understood. The only known cause of ALS is a mutation of a specific gene: the SOD1 gene. This mutation is believed to make a defective protein that is toxic to motor nerve cells. The SOD1 mutation, however, accounts for only 1 or 2 percent of ALS cases, or 20 percent of the familial (inherited) cases. Familial ALS represents between five to 10 percent of all cases. The rest arise spontaneously and mysteriously, making seemingly random attacks on previously healthy adults. ALS can strike anyone and at any time.
ALS is diagnosed using a variety of tests and examinations, including laboratory tests, muscle and nerve biopsy, spinal tap, X-rays, MRI’s and electrodiagnostic evaluation of axon function. However, the diagnosis of ALS is often a “rule-out” procedure. This means ALS is diagnosed after all other possibilities have been ruled out by specific tests. If your condition has been diagnosed as ALS outside of a major medical center or without extensive testing, it may be worth getting a second opinion.
Physicians have limited choices for treating ALS, and the options that do exist have come into use within the last 10 years. Studies suggest that patients’ length of survival and quality of life are enhanced by nighttime breathing assistance early in the course of the disease, and by aggressive application of alternate feeding options to assure good nutrition, once swallowing becomes difficult. At this time, Riluzole® (Rilutek) is the only drug that has been approved by the FDA for treatment of ALS. In clinical trials, Riluzole® has shown a slight benefit in modestly increasing survival time.
More significant advances of research into ALS have occurred in the last decade. Advances in technology and the genetic revolution are aiding researchers in unlocking the mystery surrounding ALS, eventually leading to a world without ALS.
What are the Symptoms?
Over a period of months or years, ALS causes increasing muscle weakness, inability to control movement, and problems with speaking, swallowing, and breathing. The first sign of ALS 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. Frequent muscle twitching may 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, t
he muscle cells that would normally be stimulated by those nerves also start to waste away, and the muscles weaken.
It is important to remember that having muscle weakness, fatigue, stiffness, and twitching doesn’t necessarily mean that you have ALS.
What Causes ALS?
The cause of ALS is unknown. About 5% to 10% of people with ALS have an inherited form of the disease. ALS is not contagious.