Cranial Nerves

Question 1

what is the order of the cranial nerves

Answer 1

1. olfactory
2. optic
3. oculomotor
4. trochlear
5. trigeminal
6. abducens
7. facial
8. acoustic
9. glossopharyngeal
10. vagus
11. accessory
12. hypoglossal

Question 2

Anosmia

Answer 2

 Olfactory neuropathy caused by upper respiratory tract infection
 Trauma, causing the brain and olfactory bulb to move may tear the olfactory nerves
 Fractures of the cribriform plate may cause CSF rhinorrhoea (blood stained CSF leaking from the nose)

Question 3

The skin over the angle of the mandible is not supplied by V, but

Answer 3

cervical plexus

Question 4

Injury to the trochlear nerve results in

Answer 4

the patient not being able to look medially and inferiorly
Superior Oblique
 Patient experience diplopia while walking downstairs or reading a book

Question 5

Injury to right abducent nerve

Answer 5

would cause diplopia when looking right – the right eye would not abduct fully

Question 6

facial nerve injury at the cerebellopontine angle

Answer 6

 Balance and hearing problems
 Ipsilateral facial muscle paralysis  Hyperacusis (pain on loud sounds)  Taste disturbances
 Reduced lacrimal secretion

Question 7

Facial nerve injury within the petrous temporal bone, depending on exact location

Answer 7

 Reduced lacrimal secretion
 Hyperacusis (pain on loud sounds)
 Taste disturbances
 Ipsilateral facial muscle paralysis

Question 8

fascial injury distal to the stylomastoid foramen

Answer 8

 Ipsilateral facial muscle paralysis

 Dry eye, drooling

Question 9

CENTRAL fascial palsy

Answer 9

• upper motor neuron lesion

- can raise eyebrows, cannot blow cheeks

Question 10

PERIPHERAL fascial palsy

Answer 10

• lower motor neurone lesion

- cannot raise eyebrows or blow cheeks

Question 11

injury to hypoglossal nerve

Answer 11

If injured, ipsilateral tongue weakness, therefore the tongue deviates to the side of the lesion

Question 12

HORNER’S SYNDROME

Answer 12

 Ptosis (drooping) of the upper eyelid
 Pupillary constriction (miosis)
 Anhydrosis (lack of sweating)
 Flushing of the face

Question 13

oculomotor nerve injury - No parasympathetic input for pupil constriction

Answer 13

Dilated pupil

Question 14

oculomotor nerve injury - Loss of motor innervation to

levator palpebrae superioris

Answer 14

 Ptosis

Question 15

oculomotor nerve injury - Loss of motor innervation to extraocular muscles except superior oblique (trochlear nerve) and lateral rectus (abducent nerve)

Answer 15

The eye turns downwards and outwards