Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease with an occurrence rate in France similar to multiple sclerosis (two to three new cases per year for every 100,000 residents). It has a specific affect on neurons responsible for motor control, in particular motor neurones and central motor neurones. The former, located in the spinal cord, are directly linked to muscles and are used for muscle contraction and stretching. The latter, located in the brain, receive movement orders. As the disease develops, the neurons degenerate and the muscles are no longer stimulated and stop working. Movements, walking and speech become increasingly difficult and patients tend to pass away an average of two to five years after diagnosis, generally due to respiratory failure.
