CEN COMPREHENSIVE REVIEW GUIDE – NEWEST 2025/2026 Q&A

◉ Cranial nerve IV. Answer: Trochlear - It enables movement in the eye's superior oblique muscle. This makes it possible to look down. The nerve also enables you to move your eyes toward your nose or away from it. Damage to the trochlear nerve (IV) can also cause double vision with the eye adducted and elevated. The result will be an eye which can not move downwards properly (especially downwards when in an inward position). ◉ Cranial nerve V. Answer: Trigeminal - three main branches the ophthalmic (V1), maxillary (V2), and mandibular (V3) provide sensation to the skin of the face and also controls the muscles of chewing.[16] Damage to the trigeminal nerve leads to loss of sensation in an affected area. Other conditions affecting the trigeminal nerve (V) include trigeminal neuralgia, herpes zoster, sinusitis pain, presence of a dental abscess, and cluster headaches. ◉ Cranial nerve VI. Answer: Abducens - responsible for the movement of the lateral rectus muscle, which allows your eye to rotate away from the center of your body and look to the left or right. Damage to the abducens nerve (VI) can also result in double vision. ◉ Cranial Nerve VII. Answer: Facial - controls most facial expressions & secretion of tears & saliva & taste. The facial nerve is also the most commonly affected cranial nerve in blunt trauma. ◉ Cranial nerve VIII. Answer: Vestibulocochlear - supplies information relating to balance and hearing via its two branches, the vestibular and cochlear nerves. The vestibular part is responsible for supplying sensation from the vestibules and semicircular canal of the inner ear, including information about balance, and is an important component of the vestibulocochlear reflex, which keeps the head stable and allows the eyes to track moving objects. The cochlear nerve transmits information from the cochlea, allowing sound to be heard. When damaged, the vestibular nerve may give rise to the sensation of spinning and dizziness (vertigo). Function of the vestibular nerve may be tested by putting cold and warm water in the ears and watching eye movements caloric stimulation. Damage to the vestibulocochlear nerve can also present as repetitive and involuntary eye movements (nystagmus), particularly when the eye is moving horizontally. Damage to the cochlear nerve will cause partial or complete deafness in the affected ear. ◉ subdural hematoma. Answer: When blood enters the subdural space which is anatomically the arachnoid space. Commonly subdural hemorrhage occurs after a vessel traversing between the brain and skull is stretched, broken, or torn and begins to bleed into the subdural space. These most commonly occur after a blunt head injury but may also occur after penetrating head injuries or spontaneously ◉ subarachnoid hemorrhage. Answer: Bleeding into the subarachnoid space, where the cerebrospinal fluid circulates. Non-traumatic subarachnoid hemorrhage is most commonly due to the rupture of a cerebral aneurysm. When aneurysm ruptures, blood can flow into the subarachnoid space. Other causes of subarachnoid hemorrhage include arteriovenous malformations (AVM), use of blood thinners, trauma, or idiopathic causes. ◉ Intraparenchymal hemorrhage. Answer: Intraparenchymal hemorrhage is bleeding into the brain parenchyma proper. There is a wide variety of reasons due to which hemorrhage can occur including, but not limited to, hypertension, arteriovenous malformation, amyloid angiopathy, aneurysm rupture, tumor, coagulopathy, infection, vasculitis, and trauma. ◉ epidural hematoma. Answer: a collection of blood in the space between the skull and dura mater. Approximately 85% to 95% of epidural hematomas have an overlying skull fracture. ◉ Digoxin. Answer: Slows heart rate and increases filling of the ventricles. Therapeutic range for digoxin is 0.8-2.0. S/S of digoxin toxicity are confusion, arrythymia, loss of appetite, n/v/d, visual changes