Which of the following is a key characteristic of a lower motor neuron lesion?

A key characteristic of a lower motor neuron lesion is decreased muscle tone. Lower motor neuron lesions disrupt the signals that connect the brain and spinal cord to the muscles, leading to muscle weakness or paralysis. This results in flaccidity, which is characterized by a reduction in muscle tone.

Decreased muscle tone occurs because lower motor neurons are responsible for conveying the neural impulses necessary for muscle contractions. When these neurons are damaged, the ability to activate muscle fibers is compromised, leading to a lack of tension in the muscles. This contrasts with conditions associated with upper motor neuron lesions, where increased tone, spasticity, and hyperactive reflexes are typically present due to the disinhibition of the reflex pathways. In lower motor neuron lesions, however, the loss of excitatory input and reduction in muscle tone are defining features.