ALS affects the motor neurons which are the nerve cells that connect to muscles which cause the muscles to contract and move bones. The nervous system itself is a form of communication. Your senses (touch, taste, smell, etc.) pick up information from the environment, then sensory nerves send that info back to the brain and spinal cord, then your brain integrates the info and decides if it wants to move, and if so the brain sends signals via motor neurons. Any breakdown in this system will disrupt communication. It's very fascinating.
