What is the primary cause of amyotrophic lateral sclerosis (ALS)?

The primary cause of amyotrophic lateral sclerosis (ALS) is the degeneration of motor neurons. In ALS, the motor neurons located in the brain and the spinal cord progressively deteriorate and die. This degeneration leads to a gradual loss of muscle control and strength, as the neurons are responsible for sending signals from the brain to the muscles. When these neurons are damaged, the communication between the brain and muscles breaks down, resulting in the characteristic muscle weakness and atrophy seen in ALS patients.

Understanding that the degeneration of motor neurons is the hallmark is essential, as it highlights the clinical manifestations and the impact on neuromuscular function, which are central to identifying and treating the condition effectively. Other factors may contribute to the disease process, but the degeneration of motor neurons is the defining characteristic of ALS.