Lower motor neuron symptoms typically include which of the following?

Lower motor neuron symptoms are primarily characterized by muscle weakness and specific changes in muscle tone and control. The correct answer, which includes muscle atrophy and fasciculations, reflects these key aspects.

Muscle atrophy refers to the wasting away or decrease in the size of muscle fibers, which is a direct result of lower motor neuron damage or dysfunction. Lower motor neurons are responsible for sending signals from the spinal cord directly to the muscles. When they are injured or degenerate, the muscles they innervate lose their stimulation, leading to atrophy.

Fasciculations are involuntary contractions or twitching of small groups of muscle fibers in response to lower motor neuron irritation or damage. These can often be observed in patients with conditions affecting lower motor neurons, such as amyotrophic lateral sclerosis (ALS) or polio.

In contrast, other options highlight symptoms typically associated with upper motor neuron lesions rather than lower motor neurons. For instance, spasticity is characterized by increased muscle tone and exaggerated reflexes, not atrophy. The Babinski reflex is an abnormal response present in upper motor neuron lesions, and increased reflexes also indicate upper motor neuron involvement. Thus, they do not align with the symptoms associated with lower motor neuron damage.