Cranial Nerves

Question 1

Cranial Nerve I: Olfactory
Classification:
Major function:
Damage to nerve will cause:
Assessment:

Answer 1

Classification: Sensory
Major function: Smell
Damage to nerve will cause: Anosmia (inability to detect smells)
Assessment: Close eyes and identify 1-2 smells

Question 2

Cranial Nerve II: Optic
Classification:
Major function:
Damage to nerve will cause:
Assessment:

Answer 2

Classification: Sensory
Major function: Vision (acuity & field of vision) & Pupil reactivity
Damage to nerve will cause: Vision Loss n
Assessment: Read with one eye at a time, cover one eye and say numbers from four visual fields

Question 3

Cranial Nerve III: Oculomotor
Classification:
Major function:
Damage to nerve will cause:
Assessment:

Answer 3

Classification: Motor
Major function: Extraocular eye movements (expect LR and SO), pupil size & reactivity, convergence, eyelid elevation
Damage to nerve will cause: diplopia (double vision), strabismus (eyes do not align), ptosis (difficulty opening eye), pupil constriction
Assessment: pupil - shine light in eye and look for constriction in that eye and contralateral

Question 4

Cranial Nerve IV: Trochlear
Classification:
Major function:
Damage to nerve will cause:
Assessment:

Answer 4

Classification: Motor
Major function: Extraocular eye movements SO (down and inward)
Damage to nerve will cause: Difficulty looking down and inwards (can’t see feet)
Assessment: Pt. looks towards tip of their nose

Question 5

Cranial Nerve V: Trigeminal
Classification:
Major function:
Damage to nerve will cause:
Assessment:

Answer 5

Classification: Both
Major function: Chewing & sensation - touch, temperature to face, neck, sinuses and meninges
Damage to nerve will cause: Altered sensation, jaw dysfunction
Assessment: M - open mouth, hold jaw while medial force is applied, S - close eys, lightly touch face with tissue on forehead, cheek and base of jaw

Question 6

Cranial Nerve VI: Abducens
Classification:
Major function:
Damage to nerve will cause:
Assessment:

Answer 6

Classification: Motor
Major function: Extraocular eye movements of LR (turning eyes laterally)
Damage to nerve will cause: Eyes can not abduct and drift medially
Assessment: Have the pt. look side to side

Question 7

Cranial Nerve VII: Facial
Classification:
Major function:
Damage to nerve will cause:
Assessment:

Answer 7

Classification: Both
Major function: Facial expressions, taste (anterior 2/3), eyelid and lip closure
Damage to nerve will cause: Droopy mouth, difficulty speaking, inability to close eyes
Assessment: M - raise eye brows, strongly shut eyes, smile, grimace, puff cheeks, S - sugar and salt

Question 8

Cranial Nerve VIII: Vestibulocochlear
Classification:
Major function:
Damage to nerve will cause:
Assessment:

Answer 8

Classification: Sensory
Major function: Hearing, gaze stablity & equilibrium
Damage to nerve will cause: Deafness, balance problems, vertigo & nystagmus
Assessment: Close eyes and identify when pt. can hear subtle sounds (rubbing fingers together)

Question 9

Cranial Nerve IX: Glossopharyngeal
Classification:
Major function:
Damage to nerve will cause:
Assessment:

Answer 9

Classification: Both
Major function: Gag reflex, swallowing, phonation (voice quality), & taste (posterior 1/3)
Damage to nerve will cause: Loss of bitter and sour taste, impaired swallowing, speech impediments
Assessment: Touch back of throat with tongue depressor, have patient swallow

Question 10

Cranial Nerve X: Vagus
Classification:
Major function:
Damage to nerve will cause:
Assessment:

Answer 10

Classification: Both
Major function: Gag reflex, swallowing, speech, parasympathetic control of heart, lungs and digestive tract
Damage to nerve will cause: impaired swallowing, speech impediments and organ dysfunction
Assessment: assess gag reflex and swallowing, recite phrase

Question 11

Cranial Nerve XI: Accessory
Classification:
Major function:
Damage to nerve will cause:
Assessment:

Answer 11

Classification: Motor
Major function: Shoulder movements (shrug) and head rotation (SCM)
Damage to nerve will cause: Inability to shrug ipsilatreal shoulder and inability to turn head
Assessment: Shrug shoulders and then turn head

Question 12

Cranial Nerve XII: Hypoglossal
Classification:
Major function:
Damage to nerve will cause:
Assessment:

Answer 12

Classification: Motor
Major function: Muscles of tongue
Damage to nerve will cause: Dysarthria, deviation of tongue towards weak side
Assessment: Have patient repeat phrase, stick out tongue and move from side to side