Which condition is characterized by the progressive degeneration of motor neurons?

Amyotrophic lateral sclerosis (ALS) is characterized by the progressive degeneration of motor neurons, which are the nerve cells responsible for transmitting signals from the brain and spinal cord to the muscles, enabling voluntary movement. In ALS, both upper motor neurons (located in the brain) and lower motor neurons (located in the spinal cord) undergo degeneration. This leads to muscle weakness, atrophy, and eventual paralysis as muscle fibers lose their nerve supply. Patients with ALS typically experience symptoms that may include difficulty speaking, swallowing, and breathing as the disease progresses.

In contrast, multiple sclerosis (MS) primarily affects the myelin sheath surrounding nerve fibers and is classified as an autoimmune disorder. While it does affect the central nervous system and can cause motor function issues, the underlying pathology is different from ALS.

Parkinson's disease involves the degeneration of dopamine-producing neurons in a specific area of the brain, leading to motor control issues, but it does not primarily involve the motor neurons that ALS targets.

Cerebral palsy is a group of disorders affecting movement and muscle tone or posture, primarily caused by damage to the developing brain, usually before or during birth, rather than the degeneration of motor neurons.

Thus, the defining characteristic of ALS is the progressive degeneration of motor neurons