Disease Paralysis of the<unk> , i.e.,<unk>  palsy, can arise due to: *direct trauma, *demyelinating diseases (e.g., multiple sclerosis), *increased intracranial pressure (leading to uncal herniation) *due to a space-occupying lesion (e.g., brain cancer) or a *spontaneous subarachnoid haemorrhage (e.g., berry aneurysm), and *microvascular disease, e.g., diabetes. In people with diabetes and older than 50 years of age, an<unk>  palsy, in the classical sense, occurs with sparing (or preservation) of the pupillary reflex. This is thought to arise due to the anatomical arrangement of the nerve fibers in the<unk> ; fibers controlling the pupillary function are superficial and spared from ischemic injuries typical of diabetes. On the converse, an aneurysm which leads to compression of the<unk>  affects the superficial fibers and manifests as a third nerve palsy with loss of the pupillary reflex (in fact, this third nerve finding is considered to represent an aneurysm—until proven otherwise—and should be investigated). Examination Eye muscles Cranial nerves III, IV, and VI are usually tested together as part of the cranial nerve examination. The examiner typically instructs the patient to hold his head still and follow only with the eyes a finger or penlight that circumscribes a large "H" in front of the patient. By observing the eye movement and eyelids, the examiner is able to obtain more information about the extraocular muscles, the levator palpebrae superioris muscle, and cranial nerves III, IV, and VI. Loss of function of any of the eye muscles results in ophthalmoparesis. Since the<unk>  controls most of the eye muscles, it may be easier to detect damage to it. Damage to this nerve, termed<unk>  palsy, is known by its down and out symptoms, because of the position of the affected eye (lateral, downward deviation of gaze). Pupillary reflex The<unk>  also controls the constriction of the pupils and thickening of the lens of the eye. This can be tested in two main ways. By moving a finger toward a person's face to induce accommodation, their pupils should constrict. Shining a light into one eye should result in equal constriction of the other eye. Fibers from the optic nerves cross over in the optic chiasm with some fibers passing to the contralateral optic nerve tract. This is the basis of the "swinging-flashlight test". Loss of accommodation and continued pupillary dilation can indicate the presence of a lesion on the<unk> .
Oculomotor nerve
Supratrochlear nerve
Olfactory nerve
Buccal branches of the facial nerve
Auriculotemporal nerve
Olfactory trigone
Nerve of pterygoid canal
Optician