Overview of the lateral skull base. The supraclinoidal internal carotid artery (ICA) is located above the distal dural ring. The ophthalmic artery runs below the optic nerve. The oculomotor, trochlear, and V1 run in the wall of the cavernous sinus (CS). The abducens nerve runs medial to V1 inside the C. V2 and V3 can be seen running through the foramen rotundum and foramen ovale, respectively. The petrolingual ligament attaches to the petrous apex and runs to the lingual process of sphenoid bone. The facial nerve travels inside the petrous bone, and the geniculate ganglion can be identified. The  greater superficial petrosal nerve (GSPN) travels anteriorly toward the foramen lacerum. The petrous apex has been partially removed, providing access to the ventrolateral aspect of the brainstem in a transcranial route. (Image courtesy of JC Fernandez-Miranda)