Cranial Nerves

Question 1

I

Answer 1

Ask patient if they have noticed any change in smell

Question 2

II

Answer 2

Inspection: size and symmetry, screening q.
Acuity: distant vision, near vision, colour vision
Fields: inattention, fields, blind spot
Reflexes: accommodation, direct and consensual pupillary reflexes, swinging light test
Optic disc: ophthalmoscopy

Question 3

III, IV, VI

Answer 3

Inspect: strabismus, ptosis
H-test
Saccades

CN6 lesion: eye cannot move laterally
CN4 lesion: eye cannot move inferiorly when facing medially
CN3 lesion: most eye movements impaired, eye rests in ‘down and out’

Question 4

V

Answer 4

Inspect: temporalis / masseter muscle wasting
Sensory: ophthalmic, mandibular and maxillary distributions
Motor: clench jaw and feel temporalis and masseter, open jaw against resistance
Corneal reflex, jaw jerk

Question 5

VII

Answer 5

Inspect: facial asymmetry
Motor: raise eyebrows, scrunch up eyes, purse lips together, show teeth, puff out cheeks

Question 6

VIII

Answer 6

Crude hearing test
Weber’s (512 Hz): patient’s forehead. One side louder: conductive deficit or contralateral side has sensorineural deficit
Rinne’s (512 Hz): mastoid process. Sound stops? Place near ear. Air conduction should be louder than bone. If they cannot hear it again, conductive loss in that ear.
Others: vertigo tests e.g. Dix-Hallpike

Question 7

IX and X

Answer 7

Inspect: ‘ahhh’ and use pen torch to inspect palate symmetry and uvula deviation
Motor: assess speech, cough and swallow
Others: gag reflex

Question 8

XI

Answer 8

Inspect: sternocleidomastoid/ trapezius wasting
Motor: turn head to side against resistance and shrug shoulders against resistance

Question 9

XII

Answer 9

Inspect: tongue whilst in mouth for muscle wasting and fasciculations

Motor: stick out tongue, move from side to side and test power