“…Aneurysms of the ophthalmic artery, posterior communicating artery, internal carotid artery, basilar artery, superior cerebellar artery (SCA) and the posterior cerebral artery (PCA) have been documented to cause trochlear nerve palsy 1,3,4,7,14) . All of these reports noted the location of aneurysm may itself have placed pressure on the trochlear nerve.…”