Perrine Davy et Maureen Sorbet
If Lou Gehrig does not speak to you necessarily, maybe Stephen Hawking be a little more familiar to you. Perhaps this great character appears to you to be familiar, especially because of his contribution to the formation of the universe. Perhaps if we had mentioned Charcot’s name, it would have spoken to you more. Indeed, our subject is about amyotrophic lateral sclerosis, a disease that had touched Hawking (physicist), Gehrig (baseball player) and Charcot, who described and gave his name to this disease.
Amyotrophic lateral sclerosis, also defined as a motor neuron disease or Lou Gehrig’s disease, is a neurological disease which slowly and progressively destroys motor neurons. Motor neurons allow to transmit the movement orders (sent by the brain) to the muscles that will perform the movement. These neurons are located in the brain, in the spinal cord as well as in the medulla oblongata (ensures the junction between the brain and the spinal cord). Thus, ALS can take two forms: “spinal” (which begins with the involvement of a limb), and “bulbar” (which starts with the attack of the muscles of the mouth). The spinal form represents two-thirds of the cases, and affects the men around the age of 55. This form is the consequence of the degeneration of motor neurons situated in the spinal cord. The bulbar form concerns rather women and appears around 60-65 years old, and corresponds to the degeneration of motor neurons in the brain that controls the movements of the tongue and the palate. These two forms can succeed or develop simultaneously, the disease progresses almost always to a complete form (spinal and bulbar). Finally, it leads to death within a few years of onset. The real cause is unknown, some studies suggest that both genetics and environment play a role in the development of ALS. Indeed, five to ten percent of cases are hereditary and have gene mutations involved in the ALS development. Furthermore, theories exist, that of glutamate (neurotransmitter of nerve messages) that would be released too large and could exhaust neurons; that of a deregulation of a growth factor that could lead to the degeneration of motoneurons; an inflammatory reaction at the level of the motor neurons or an apoptosis which is done too early. The prevalence of people living with ALS varies among geographic regions worldwide. Overall, in a population of 100,000 people, there are two new ALS cases each year. The average age of people in the world who are diagnosed with ALS is around sixty years old and there are slightly more men than women with ALS disease (1,5M/1W).
There are different symptoms which characterize ALS, gradually these symptoms expand into more obvious weakness until the incapacity. The majority of cases beginning with limb damages. The early symptoms are paralysis in the arm, leg, shoulder or tongue; the occurrence of muscle cramps and muscle weakness, the loss of muscle spasticity, slurred and nasal speech, and the occurrence of difficulties with chewing or swallowing.
To this day, there is no treatment for this disease. However, medications can be prescribed to relieve some symptoms of the disease or even slow down (but still without much success). Sessions with movement re-educators (physiotherapists, occupational therapists) are being considered to reduce pain and maintain muscle elasticity. With the advancement of the disease, fans can be set up for breathing.
Keywords : Amyotrophic lateral sclerosis; neurodegenerative; muscle wasting (fonte musculaire); spinal cord (moelle épinière); medulla oblongata (bulbe rachidien); apoptosis (apoptose); weakness (faiblesse).
REFERENCES
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