Biology 202
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Amyotrophic Lateral Sclerosis

Evelyn Rodrigo

Have you ever had an experience of morning paralysis where you see yourself lying down, and you think you're awake so you try to get up, but suddenly you realize that you can't move? I have, several times. They have been the most frustrating and scariest times of my life. As I try harder to move, concentrating all my energy into moving one arm, the deeper I seem to be sinking in this indescribable feeling of entrapment. I hear the people outside my room and try to get their attention by screaming. Instead, I hear a soft slurred sound coming from my throat. Then I start to panic. I can't breathe! My energy is depleted and my body is exhausted. Eventually, I start to relax. The first time this happened to me, a mosquito landed on my big toe while I was thinking of what to do. Without being consciously aware of it, I move my big toe. My body jerks and suddenly I can move! Thank God for the mosquito, otherwise I wouldn't have known that all I had to do was move my big toe towards me. Ever since, whenever I would have another one of these experiences, I would relax and gently move my big toe towards me. If you've had one of these experiences, then you've probably had a glimpse of how it feels to have a fully developed amyotrophic lateral sclerosis.

Amyotrophic Lateral Sclerosis (ALS), more commonly known as Lou Gehrig's disease, is a neurological disorder that involves the degeneration of motor neurons. A-myo-trophic is derived from the Greek language. A connotes something negative or none. Myo means it has something to do with the muscles. Trophic translates to "nourishment". (1) The term Lateral is attributed to the parts of the spinal cord that ALS usually affects. (2) The scarring that results from the degeneration of these neurons and nerves in the spinal cord is known as sclerosis. (2)

In 1941, Lou Gehrig, a famous baseball player, died of ALS. His name has been associated with this progressive fatal neuromuscular disease ever since. (3) Another person whose name is associated with this disease is the French neurologist, Dr. Jean-Martin Charcot. He was the first to identify that motor neurons from the spinal cord are the main part of the nervous system affected by this disease, in 1869. For that, amyotrophic lateral sclerosis is also known as maladie de Charcot. (2)

ALS is progressive and because there is no known cure or way of reversing it's effects, it is also fatal. Death usually ensues between 2 to 5 years after diagnosis. However, advances in research and the increase of support groups make it possible for some to survive longer. Twenty percent of ALS patients live longer than five years and almost ten percent live as long as ten years after diagnosis. Although cases of ALS have been observed among twenty- and thirty-year olds, it generally develops later in life (between the age of 40 and 70). Men and women, as well as different racial groups are equally susceptible in developing ALS although there seems to be a high incidence of this disease in Guam and the Trust Territories of the Pacific. ALS is becoming more and more prevalent in United States. Five thousand new patients are diagnosed with this disease every year as reported by the United States National Institutes of Health. (1)

The loss of voluntary muscle control occurs over a period of time. It usually starts with some form of weakness of a limb, accompanied by twitching and cramping of muscles of the hands and feet. A person with ALS usually has trouble walking straight and is likely to drop things that are placed in his hands. Difficulty in speaking is also expected along with difficulties in chewing, and swallowing. In addition, some drooling may occur. In its more advanced stages, breathing problems result and often lead to respiratory failure and death. Because the motor neurons of the brain and spinal cord degenerate, the brain is unable to send signals to the muscles of the limbs. This lack of muscle stimulation from the nervous system causes the muscles of the limbs to "waste away" and eventually the person becomes paralyzed. (1), (3)

The causes for this progressive neuromuscular degeneration are not known and this makes it difficult to come up with preventive measures against this disease. However, some five to ten percent of ALS cases are linked to genetic causes. In these cases which are classified as familial, the child with a history of ALS in his family has a fifty percent chance of developing the disease later in life. The genetic defect is associated with a gene in chromosome 21. This defective gene, known as SOD1 gene, was found to be causing the majority of the familial cases of ALS. SOD (superoxide dismutase) enzyme defends the motor neurons from free radicals that might invade them. When this becomes defective, it loses its ability to perform its function. The other ninety percent of ALS cases are classified as sporadic. This is more common than the familial form of ALS in the U.S. For these cases, the cause is a big mystery even though there are lots of speculations. Viral infections, toxic agents, and severe physical trauma are some possible causes that are being explored. (1), (3)

Diagnosis of ALS is difficult because it mimics a lot of other neurological disorders such as progressive bulbar palsy, progressive muscular atrophy, and progressive pseudo bulbar palsy. There is no single test to diagnose ALS, rather, a series of tests are done to eliminate the possibility of these related diseases being wrongly diagnosed (2). This series of tests usually begins with electrodiagnostic tests done by electromyography (EMG) or nerve conduction velocity (NCV). High-resolution serum protein electrophoresis is a technique used to study blood and urine samples. Hormone levels of the thyroid and the parathyroid are measured, a spinal tap is performed and x-rays are taken using techniques like magnetic resonance imaging (MRI). There are numerous other tests done and physicians decide which of these tests, if not all, are appropriate for the patient. (1)

Unfortunately, a cure for ALS has not yet been discovered. The treatments available are only meant to alleviate the symptoms of ALS. Among the many drugs being studied, including Allopurinol (Zyloprim), Antioxidants (such as Vitamins E, C, Beta-Carotene), Gabapentin (Neurontin), Insulin-like Growth Factor 1 (Myotrophin), and Riluzole (Rilutek), etc., Riluzole is the first to be approved by the FDA. Gabapentin is another drug available in the market and, like Riluzole, it claims to prolong the life of a person with ALS for at least a few months (1), (4). Allopurinol is a xanthine oxidase inhibitor and hopes to prevent the process of motor neuron wasting. Vitamin E was found to slow down the degeneration process of ALS in mice but did not prolong the life of the animals. Antioxidants are suggested to be able to protect nerve cells from the damaging effects of toxic free radicals. (4) Another drug called Myotrophin, although not in the market yet, is attracting much attention. Two clinical trials indicated that this drug is safe and one clinical trial indicated that it has an ability to delay the deterioration of muscle tissue in ALS patients by twenty-six percent. The FDA's Peripheral and Central Nervous System (PCNS) Advisory Committee had a consensus about the drug being safe. However, they advised FDA not to approve the drug without having the manufacturer of Myotrophin conduct more clinical tests to establish its efficacy. Many ALS patients are petitioning the FDA to ignore the advise of the committee because they argue that another set of clinical tests would take years to finish and they may not be alive by that time. The FDA has not made their final decision on this matter. (5)

ALS affects only the motor system. A person with ALS can think, see, hear, taste, feel, and smell as well as he could before developing the disease. He is aware of his surroundings but is not able to do anything to interact with it. Lucky for me, moving a big toe can take me away from this feeling of entrapment. A person with ALS has nothing. He has to deal with not being able to move for the rest of his life. Myotrophin, because it delays total paralysis of the muscles, offers some hope of being able to live a productive life just a little bit longer. However, it has not been approved by the FDA and is not available to all ALS patients. Instead, medications like Riluzole, which prolong the life of an ALS patient without delaying any of its symptoms, is available. If many ALS patients prefer to die rather than live without mobility (6), why would they want to take something like Riluzole? Several medications have been approved, with only one clinical trial, for cancer and AIDS because there are no better options available. Why are they making an exception to this rule with Myotrophin? As one ALS patient writes, "To the FDA: Why are you protecting us to death? (5)"

WWW Sources

1)ALS Association

2)Health Answers

3)On Health

4)Department of Neurology at Baylor College of Medicine

5)Department of Neurology at Baylor College of Medicine

6)Euthanasia World Directory




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