What reflex helps assess the integrity of the acoustic nerve (CN VIII) in newborns?

The Moro reflex, also known as the startle reflex, is a helpful indicator in assessing the integrity of the acoustic nerve (CN VIII) in newborns. This reflex is elicited when a newborn feels a sudden loss of support, producing an involuntary response characterized by spreading out the arms (abduction), pulling the arms back in (adduction), and often crying. The perception of loud sounds or sudden movements can trigger this reflex, which demonstrates the functioning of the auditory pathways related to the acoustic nerve.

Although the other reflexes listed are important for developmental assessment, they do not specifically relate to the acoustic nerve function. The rooting reflex helps with feeding, the stepping reflex is related to walking patterns, and the grasp reflex is important for hand movements. None of these are designed to assess auditory processing or the response to sound stimuli in the same way that the Moro reflex does. Understanding how the Moro reflex integrates sensory input, including auditory cues, assists in evaluating neurological health in neonates.