ALS, or Lou Gehrig's disease as it is commonly known, is a progressive neurodegenerative disease of the nerve cells in the brain and spinal cord that control voluntary muscle movement. Patients with ALS experience a degeneration of motor neurons, the nerve cells in the central nervous system that initiate and control this voluntary movement of muscles. This progressive degeneration of motor neurons eventually culminates in the death of these nerve cells. When this happens, the brain loses its ability to initiate and control muscle movement. With voluntary muscle movement progressively affected as ALS progresses, patients in the later stages of the disease can often become totally paralyzed. "Bulbar" ALS, another form of ALS also called Progressive Bulbar Palsy, prominently affects the muscles involved in speech, swallowing, and tongue movements.
Watch the following segment from “Your Fantastic Mind,” which focuses on the possible causes of ALS aka Lou Gehrig’s disease, and clinical trials to find treatments: