Learn About ALS
What is ALS?
Amyotrophic lateral sclerosis (ALS), often referred to as "Lou Gehrig's Disease," is a terminally progressive neurodegenerative disease that affects nerve cells in the brain and the spinal cord.
ALS is a disease of "motor neurons", the cells that initiate and control the movement of muscles. Upper motor neurons originate in the brain and lower neurons originate in the spinal cord.
The progressive degeneration of the motor neurons with ALS eventually leads to their death. When the motor neurons die, the ability of the brain to initiate and control muscle movement is lost. ALS affects both upper and lower motor neurons. Upper motor neuron disease causes stiffness, which is called spasticity. Lower motor neuron disease causes weakness, atrophy and muscle twitching.