Question

Which of the following disorders is described as damage to motor nerves innervating skeletal muscles; skeletal muscles weaken; death usually results 5 years after diagnosis?

A) ALS (Amyotrophic lateral sclerosis)
B) Parkinson's disease
C) Huntington's disease
D) Multiple sclerosis

Answer 1

Amyotrophic lateral sclerosis (ALS) is the disorder characterized by damage to motor nerves that causes muscle weakening and usually results in death about 5 years after diagnosis, with patients maintaining cognitive function.

Step-by-step explanation:

The disorder described as damage to motor nerves innervating skeletal muscles, where skeletal muscles weaken and death usually results around 5 years after diagnosis, is Amyotrophic lateral sclerosis (ALS). This neurodegenerative disorder leads to muscle atrophy followed by paralysis and death, often within 3 to 5 years after symptoms present. The cause of ALS involves the degeneration of motor neurons in the spinal cord and brain stem as well as the motor cortex, impacting the ability to move, speak, and swallow, and eventually affecting respiratory function. Although patients suffer these debilitating physical deficits, individuals with ALS typically retain their cognitive abilities.

The roots of the term ALS give insight into its effects: 'Amyotrophic' means 'no muscle nourishment', 'lateral' refers to the affected area of the spine that communicates with muscles, and 'sclerosis' indicates hardening. This progressive disease attacks the neurons controlling voluntary muscles and advances rapidly, resulting in a severe decline in motor function over time.