Amyotrophic lateral sclerosis, also called ALS or Lou Gehrig's disease, is a progressive neurodegenerative disorder that leads to the death of motor neurons. Motor neurons link the muscles to the central nervous system and allow the brain to control muscle movement throughout the body. In ALS, the degeneration of motor neurons leads to muscle weakness and lack of muscle control. In the final stages of the disease, patients experience a number of devastating symptoms.
Malnutrition
Motor neurons control a number of muscle reflexes throughout the body--muscle movements that occur without conscious signals from the brain. Among these is the pharyngeal reflex, also called the gag reflex, that gets activated by touching the soft palate and works to prevent in choking. During ALS, motor neurodegeneration leads to a dysregulation of nerve reflexes. As a result, patients with ALS may experience extreme difficulty eating, as their gag reflex may trigger out of control. Over time, this can lead to malnutrition, according to the American Academy of Neurology.
Difficulty Breathing
Inspiration and expiration is controlled by movements of a muscle that runs horizontally along the bottom of the ribcage called the diaphragm. The diaphragm moves up and down during breathing, changing the air pressure in the lungs and helping to draw air in and out of the lungs. In ALS, the neurons that control movement of the diaphragm degenerate. This begins as a muscle weakness in the diaphragm that increases the difficulty of breathing that increases in severity as ALS progresses. In the late stages of the disease, the nerves responsible for the movement of the diaphragm degenerate completely, making it impossible to breathe without medical support.
Paralysis
In the end stages of ALS, motor nerve degeneration reaches the point where the nerve cells cannot communicate with muscles, leading to paralysis. Paralysis begins with the weakening of the muscles early in the disease and progresses to complete paralysis once the nerve cells controlling the muscles degenerate completely. According to the ALS Association, ALS-associated paralysis usually begins in the hands and feet, works its way up the limbs, and then affects the trunk of the body. Once the muscles within the torso and chest become paralyzed, the patient will require 24-hour medical support to live.
