Amyotrophic Lateral Sclerosis
A Crippling Disease
Amyotrophic Lateral Sclerosis (ALS), otherwise known as " Lou Gehrig's Disease ", is a devastating disease that effects the nerve cells in the brain and spinal cord. French neurologist, Jean-Martin Charcot, first discovered the disease in 1869. Attention was not brought to the disease until 1939, when New York Yankees first basemen Lou Gehrig retired because of his diagnosis (4). Specifically referred to as a "neurodegenerative disease", ALS is the lack of nourishment to muscles (5). If you break "Amyotrophic" down into its latin meanings "A" means no, "Myo" is muscle, and "Trophic" means nourishment (6). It slowly eats way at the ability to eat, speak, walk, and breath, and will eventually lead to the victims death. ALS is the most common of five motor neuron diseases: botulism, tetanus, poliomyelitis, and spinal muscular atrophy. Motor Neurons run from the brain to the brain stem, connect to the spinal cord, and from the spinal cord they reach out to the corresponding muscles (5).
A Motor Neuron is a nerve cell directly and indirectly responsible for the relaxation and contraction of muscles. ALS is the decay of motor neurons, not sensory neurons. Motor neurons can be branched into three different groups. Somatic motor neurons, which are linked with the contraction of skeletal muscles, like biceps or quadriceps (5). General visceral motor neurons, these ones are involved in the contraction of arteries, the heart, and other involuntary muscles (5). The last branch is the special visceral motor neurons, these are involved with the movement in facial muscles and neck (5). These three neurons are sub-classifications of lower motor neurons; they connect from the spinal cord to their respective muscles. The other classification motor neurons would be upper motor neurons. These neurons are located in the motor area of the cerebral cortex, these neurons send the signal to the lower neurons through the spinal column. (5)
￼(diagram of upper motor neurons dying on the right side of the brain, connecting to the lower motor neurons, and cutting off muscle growth) (5)
The causes of why these motor neurons die is not yet understood. Many theories have been experimented. and they have narrowed them down to 30 or 40. The four main theories are "Glutimate Excitotixicity", "Increased Calcium in Cells", "Oxidative Stress", and "Mtochondrial Damage"(5). Scientist have discovered many of these theories are linked ultimately in the death of motor neurons.
"Glutamate Excitotoxicity" (2 (page 9)) is a theory referred to nerve
cells and their neurotransmitter. Nerve cells will
communicate with neurotransmitters to get a signal or message
across a synapse. For nerve cells to simulate upper and lower
motor neurons, they need glutamate as a neurotransmitter (5).
Despite needing glutamate, too much of it will lead cell death.
"Glutamate Excitotoxicity" (5) is the idea that there is a surplus of
glutamate, and glia cells are no longer able to take it in. Glia cells can be broken into four different categories. Astrocytes, oligodendrocytes, microglia, ependymal cells. Each one of these cells protects and provides different qualities to the CNS. (7 p.454)
Another theory is "Increased Calcium in Cells" (5) refers to the action of what happens when there is too much calcium in the body and cells. Calcium is not only important for bones but are also crucial for aiding to regulate muscle contraction and transmit impulses along nerves. If there is an abundant amount of calcium in your bones, just as in your nerves, it will do damage.
"Oxidative stress" (5) is the idea that oxygen radicals, which
are unbalanced, pull other molecules apart to complete their
own. Scientist consider it highly possible that this could lead to
damaged nerves and the death of cells
"Mitochondrial damage"(5) is the idea...
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