Actions of and Resulting Injuries of Damaged Cranial Nerves

Question 1

Your patient presents at your practice with loss of smell and a runny nose. Further tests reveal CSF rhinorrhea. Damage to what cranial nerve do you expect?

Answer 1

CN I (olfactory) #1

Question 2

Fracture to the cribriform plate would be a cause of concern because of damage to what cranial nerve?

Answer 2

CN I (olfactory) #1

Question 3

A patient presents to the ER with loss of pupillary constriction and tells you he was hit directly in the eye. An x-ray reveals there is trauma to the orbit. What cranial nerve do you suspect is the culprit for the loss of pupil control?

Answer 3

CN II (optic) #2

Question 4

Your patient tells you she has visual field defects. You examine her and find no issues with the eyeballs themselves. What cranial nerve do you think is affected her visual field?

Answer 4

CN II (optic) #2

Question 5

Pressure on the optic pathway or a clot in the temporal, parietal, or occipital lobes of the brain may lead to visual field defects. Which cranial nerve is in danger here?

Answer 5

CN II (optic) #2

Question 6

A patient presents to the ER with one dilated pupil, a droopy eye (ptosis) that turns down and out, and upon further examination you find that she does not have a pupillary reflex. You suspect damage to a cranial nerve. Which one is it?

Answer 6

CN III (oculomotor) #3

Question 7

Aneurysms, pressure from a hernia on the nerve, or a fracture involving the cavernous sinus of CN ___ causes ptosis, a dilated pupil, and loss of pupillary control.

Answer 7

III

Question 8

You are examining your patient’s eyes and you note that he cannot look down when his eye is adducted. Damage to what cranial nerve do you expect?

Answer 8

CN IV (trochlear) #4

Question 9

If this nerve was stretched around the brainstem or there was trauma and fracture to the orbit, the patient would be unable to look down when the eye is adducted. What cranial nerve is damaged?

Answer 9

CN IV (trochlear) #4

Question 10

Your patient came in for a routine SRP and you notice that she is unable to contract her masseters and temporalis muscles. She complains of facial parasthesia and her mandible deviates when she opens her mouth. Damage to which cranial nerve is likely?

Answer 10

CN V (trigeminal) #5

Question 11

Your patient’s mandible deviates when she opens. There is damage to her trigeminal nerve. Which branch of this cranial nerve is most likely?

Answer 11

V2 (maxillary branch of trigeminal)

Question 12

Your patient presents with eyes that cannot move laterally and she complains of double vision when she gazes to the side. Which cranial nerve is likely damaged?

Answer 12

CN VI (abducent) #6

Question 13

A patient presents to the ER having been kicked in the face. His cavernous sinus and orbit are fractured and he cannot gaze laterally without seeing double. Which cranial nerve is damaged?

Answer 13

CN IV (abducent) #6

Question 14

Your patient in the ER was sliced by a knife in his cheek. His face is drooping, his eye will not close, and his forehead cannot wrinkle. Which cranial nerve do you suspect is damaged?

Answer 14

CN VII (facial) #7

Question 15

A laceration or contusion in the region of the parotid would be a cause of concern for which cranial nerve?

Answer 15

CN VII (facial) #7

Question 16

A patient presents to the ER after falling down the stairs and hitting the side of her head. She’s lost taste on her tongue, has facial paralysis, has a dry eye, and is having hearing issues. Which cranial nerve do you think is damaged?

Answer 16

CN VII (facial) #7

Question 17

A patient has just had a stroke and his forehead is wrinkled. He also has paralysis of half of his facial muscles. Which cranial nerve do you think is damaged?

Answer 17

CN VII (facial) #7

Question 18

Your patient comes into your clinic complaining of new hearing loss in one ear and tinnitus (noises). This patient has no history of hearing problems. Which cranial nerve do you suspect is damaged from a tumor of the nerve?

Answer 18

CN VIII (vestibulocochlear) #8

Question 19

An acoustic neuroma of which nerve may cause tinnitus and progressive unilateral hearing loss?

Answer 19

CN VIII (vestibulocochlear) #8

Question 20

Loss of taste on the anterior 2/3 of tongue is indicative of damage to CN ___; loss of taste on the posterior 1/3 of the tongue is indicative of damage to CN ___.

Answer 20

VII (7); IX (9)

Question 21

A patient presents to the ER with a deep laceration to the back of the neck and complains of loss of some tastes, as well as no sensation on his soft palate. Which cranial nerve do you suspect is damaged?

Answer 21

CN IX (glossopharyngeal) #9

Question 22

Your elderly patient complains of a “weird uvula” and sudden hoarseness. You suspect a brainstem lesion in the area of which cranial nerve?

Answer 22

CN X (vagus) #10

Question 23

A patient presents to the ER with a very deep laceration to the neck and a drooping shoulder. His sternocleidomastoid is paralyzed. Damage to which cranial nerve do you expect?

Answer 23

CN XI (spinal accessory) #11

Question 24

A uvula that deviates to one side is indicative of damage to which cranial nerve?

Answer 24

CN X (vagus) #10

Question 25

Your patient comes into the clinic slurring his words and says his tongue is only going to one side and it is hanging out. He tells you his brother hit him in the head yesterday. X-rays show that he fractured the base of his cranium. You suspect damage to which cranial nerve?

Answer 25

CN XII (hypoglossal) #12