Amyotrophic Lateral Sclerosis (ALS), sometimes referred to as “Lou Gehrig’s Disease,” is a progressive fatal neuromuscular disease that attacks nerve cells and pathways in the brain and spinal cord. Motor neurons, among the largest of all nerve cells, reach from the brain to the spinal cord and from the spinal cord to muscles throughout the body with connections to the brain. When they die, the ability of the brain to start and control muscle movement dies with them. With all voluntary muscle action affected, ALS patients in the later stages are totally paralyzed; through it all, however, their minds remain unaffected.
Amyotrophic 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 nourish the muscles are located. As this area degenerates it leads to scarring or hardening (“Sclerosis”) in the region. Over 5,000 Americans are diagnosed with ALS each year. There is great variation in the course of the disease.
Symptoms usually appear in individuals between the ages of 40-70, though the disease has been reported in both younger and older persons. Survival after the confirming diagnosis is, on average, two to five years. Progression of ALS varies with each individual; therefore, some will live longer–up to 10 years, and about five percent will exceed 12 years. In some cases, the disease seems to plateau. Many patients are able to live productive and satisfying lives especially with the use of assistive devices for daily living, and later in the disease, augmentative communication equipment.
Men and women are affected in almost equal numbers. Also, up to 10 percent of ALS cases are familial occurring more than once in a family lineage; but 90 percent of ALS cases show no hereditary pattern. Approximately one-third of patients become aware of the onset of the disease when their hands become clumsy, causing difficulty in the performance of fine tasks. Another one-third experience weakness in the legs and may trip because of mild foot drop. The remaining one-third notice slowing of speech or difficulty in swallowing.
ALS may be present for some time before any symptoms are noticed. This lack of noticeable symptoms occurs because the lost or damaged nerve cells are compensated for by nerve cells that remain functioning. One early symptom is generalized fatigue. As muscle cells deteriorate, patients may experience stiffness or occasional jerking of the arms or legs resulting from spasticity (muscle tenseness). Often symptoms begin in the hands and feet, then travel inward toward the center of the body. One side is usually more affected.
Paralysis eventually may be virtually complete, except for the muscles of the eyes. Anal and bladder muscles and function are not usually affected. There is no specific clinical test that can identify ALS. Diagnosis is made by a neurologist through a physical examination, a thorough patient medical history, and neurological testing. Diagnostic testing often includes the electromyogram (EMG) to test muscle activity, CT Scan, MRI (Magnetic Resonance Imaging), muscle and/or nerve biopsy, and extensive blood work.
While it is true that there is no cure for ALS, much can be done to help the patient live with the disease. Treatment aimed at relieving symptoms can be very effective. Generally, patients should continue usual daily activities, stopping before they become atigued. Patients should be encouraged to set their own limits of exertion, and to plan how they will use their energy and strength. The physician will probably suggest exercises, including breathing exercises, to strengthen unaffected or less-affected muscles.
These exercises are not vigorous or tiring, but are intended to help maintain mobility and prevent joint stiffness and muscle contracture. Various devices such as foot-drop braces, hand splints, limb supports or wheelchairs enable the patient to remain as independent as possible. Good skin care, massage and knowledge f proper body positioning can prevent sores for those who are confined to bed for lengthy periods of time. If bowel and bladder function are affected by immobility, increasing daily fluid intake should improve the situation or the doctor may prescribe stool softeners, bulk formers or laxatives.
A palate lift may help if there are speech problems, and soft foods are indicated if the patient has difficulty in swallowing. Because ALS selectively destroys the motor neurons in the nervous system, several hypotheses have been put forth as to the cause or causes of ALS. Researchers are exploring such areas as enetic factors, susceptibility genes, excitotoxicity, and premature cell death. In 1991, a team of ALSA-funded researchers linked familial ALS to chromosone 21. In 1993 the research team identified a defective SOD1 gene on Chromo-sone 21 as responsible for many cases of familial ALS.
Further study indicated structural defects in the SOD (super oxide dismutase) enzyme which reduces the enzyme’s ability to protect against free radical damage to motor neurons. In January 1996, a team of researchers reported that their studies suggest that the SOD1 gene mutations may enhance the ability of the SOD enzyme to act as a “peroxidase,” that is, xidizing and thereby damaging cell components. These studies open up possibilities for possible therapies or strategies to effectively mediate the effects of ALS.
But much more research on the SOD enzyme is needed. Clinical trials of selected neurotrophic and growth factors are continuing as biotechnology companies search for possible therapies for ALS. After 127 plus years, there is a first-ever treatment for ALS. It is Rilutekr, manufactured by Rhone-Poulenc Rorer. The drug, an antiglutamate, extends survival in ALS patients by an average three months. The drug was approved by the FDA in December 1995 nd became available by prescription in January 1996.
In addition, two other potential treatments could be approved for marketing by 1997, pending outcome of clinical data and FDA review. These are Myotrophin, a development from Cepalon, Inc. , and BDNF (brain derived neurotrophic factor) being tested by Amgen-Regeneron Partners. Both BDNF and Myotrophin appear to slow progression of the disease in distinct areas according to clinical trial data thus far. BDNF effects are shown in a slowing of the deterioration of breathing capacity; Myotrophin appears to slow the progression of muscle deterioration.
Therefore, both have demonstrated the capacity to extend quality of life in the ALS patient. Amyotrophic lateral sclerosis (ALS) is a fatal neurological disorder, characterized by progressive degeneration of motor cells in the spinal cord and brain. When the motor neuron cell can no longer send the impulses to the muscles there is increased muscle weakness, especially in the arms and legs, speech, swallowing, breathing. When muscles no longer receive the messages they require to function, they begin to atrophy (waste away).
ALS is very often referred to as “Lou Gehrig’s disease. ” Neither its cause or cure is known. Three known classifications of ALS have been described: Sporadic – the most common form of ALS in the United States Familial – suggest genetic dominant inheritance and accounts for a very small number of cases in the United States. Familial ALS requires further investigation before the significance of the hereditary factor can be firmly established. Guamanian – an extremely high incidence of ALS has been observed in Guam and the Trust Territories of the Pacific.
At the onset of ALS the symptoms may be so slight that they are frequently overlooked. With regard to the progression of the illness, and the appearance of ymptoms, the course of the disease may include the following: twitching and cramping of muscles, especially those in the hands and feet impairment of the use of the arms and legs “thick speech” and difficulty in projecting the voice in more advanced stages, shortness of breath, difficulty in breathing and swallowing ALS is individual in each person — in the area of the body affected as well as in the rate of progression.
It is important to stress that ALS does not affect the intellectual functioning. Nor does it interfere with the ability to taste, see, smell, hear or recognize touch.