A patient with a basilar skull fracture may have drooping gaze due to damage to which cranial nerve?

The correct answer is CN III, which is also known as the oculomotor nerve. A basilar skull fracture can potentially result in damage to this nerve, leading to drooping of the eye gaze (ptosis) and issues with eye movement. The oculomotor nerve is responsible for controlling most of the eye's movements, the eyelid's elevation, and pupil constriction. When it is compromised due to a fracture in the base of the skull, the patient may present with a drooping eyelid and an eye that may be positioned downwards and outwards, reflecting the loss of function of the muscles innervated by the oculomotor nerve.

Addressing the other options, the trochlear nerve (CN IV) controls the superior oblique muscle, which allows for certain eye movements but does not typically result in ptosis when damaged. The optic nerve (CN II) is responsible for vision and would not produce drooping gaze symptoms directly. The trigeminal nerve (CN V) primarily handles sensation in the face and motor functions such as biting and chewing, and while it plays a critical role in facial functions, it is not responsible for controlling eye movement or eyelid position. Therefore, understanding the roles of these