Which sign is most characteristic of lower motor neuron lesions?

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Multiple Choice

Which sign is most characteristic of lower motor neuron lesions?

Explanation:
Lower motor neuron lesions disrupt the final common pathway, so nerves that directly activate muscle become hyperexcitable after injury, leading to visible twitches of the muscle fibers known as fasciculations. These twitches are a classic sign of denervation and LMN damage. While muscle atrophy can occur as the muscle is no longer innervated, and tremor or hyperreflexia point away from LMN injury (tremor is not specific to LMN, and hyperreflexia is a sign of upper motor neuron involvement), fasciculations are the most distinctive, characteristic manifestation of LMN lesions and help differentiate it from UMN disorders.

Lower motor neuron lesions disrupt the final common pathway, so nerves that directly activate muscle become hyperexcitable after injury, leading to visible twitches of the muscle fibers known as fasciculations. These twitches are a classic sign of denervation and LMN damage. While muscle atrophy can occur as the muscle is no longer innervated, and tremor or hyperreflexia point away from LMN injury (tremor is not specific to LMN, and hyperreflexia is a sign of upper motor neuron involvement), fasciculations are the most distinctive, characteristic manifestation of LMN lesions and help differentiate it from UMN disorders.

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