Motor neuron disease (MND) is a debilitating neurological condition that affects the ability of the brain to communicate with muscles, leading to progressive muscle weakness and wasting. MND is also known as amyotrophic lateral sclerosis (ALS), Lou Gehrig's disease, or Charcot's disease. ALS is the most common synonym for MND as it refers to the specific type of motor neuron disease that progressively affects both upper and lower motor neurons. Lou Gehrig's disease is another name for ALS, named after the famous baseball player who died of the disease. Charcot's disease is named after the famous French neurologist who first described the disease in the late 1800s.