Amyotrophic lateral sclerosis involve-
**Core Concept**
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder characterized by the loss of motor neurons in the spinal cord, brainstem, and motor cortex. This neuronal degeneration leads to muscle weakness, atrophy, and paralysis.
**Why the Correct Answer is Right**
ALS involves the selective degeneration of motor neurons, which are responsible for transmitting signals from the central nervous system to muscles. This degeneration is thought to be due to a combination of genetic and environmental factors, leading to the activation of various cellular pathways that ultimately result in motor neuron death. The degeneration of motor neurons in ALS is characterized by the loss of alpha motor neurons in the spinal cord and upper motor neurons in the motor cortex.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because ALS is not primarily associated with the degeneration of sensory neurons.
**Option B:** This option is incorrect because ALS is not primarily associated with the degeneration of autonomic neurons.
**Option C:** This option is incorrect because ALS is not primarily associated with the degeneration of cognitive neurons.
**Clinical Pearl / High-Yield Fact**
ALS is often referred to as Lou Gehrig's disease, named after the famous baseball player who was diagnosed with the condition in 1939. The disease has a variable course, with some patients experiencing a rapid decline in motor function, while others may remain relatively stable for several years.
**Correct Answer: D. Degeneration of motor neurons.