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

The Moro reflex is an important indicator of the neurological integrity of newborns, particularly regarding the function of cranial nerve VIII, which is the acoustic nerve. This reflex, also known as the startle reflex, involves a sudden extension and abduction of the arms followed by a return to a flexed position when the infant experiences a feeling of falling or hears a loud noise. The presence and symmetry of the Moro reflex suggest that the auditory sensory pathways are intact, as the response is triggered by auditory stimuli or sudden movements, reflecting the sensory and motor functions that involve the brainstem and cranial nerves.

It's crucial to note that while the other reflexes have their significance in assessing different aspects of neurological function, they do not specifically target or provide information regarding the integrity of the acoustic nerve. For instance, the rooting reflex is primarily associated with feeding responses, the grasp reflex assesses hand-finger coordination, and the stepping reflex relates to lower limb movement patterns and does not indicate auditory pathway function.