It is more common among men than women. The life expectancy of ALS patients is, on average, about 3 to 5 years after diagnosis. Sometimes ALS stops progressing, and in a very small percentage of cases it even reverses. Nerves are bundles of nerve fibers, or cells, that connect the brain and spinal cord to all of the various parts of the body and carry information back and forth between the central nervous system and the rest of the body. There are many different kinds of nerves.
Some nerves are responsible for our ability to sense things like sounds, sights, and smells.
Other nerves lead to the involuntary muscles, such as those in the heart and digestive tract, which are the muscles we cannot control consciously. ALS doesn't affect either of these types of nerves - those that sense things or those that lead to the involuntary muscles. Rather it affects the motor neurons, the nerves that lead to the skeletal, or voluntary, muscles. The anterior horn cells are the nerves that send the messages from the spinal cord to the muscles. The damage that ASL does can affect both the anterior horn cells and the corticospinal tract.