FFinalistSouthampton · 2027
Examinations

CPSA · Clinical examination · Neurological

Cranial nerve examination

Systematically test the 12 cranial nerves in order. The pattern of deficits localises the lesion — a single nerve, a brainstem level, or a supranuclear cause.

Practise it out loud

Position: Patient seated, facing you at eye level.

The routine

I — Olfactory
  1. 1Ask about any change in smell/taste (formal testing rarely required)
II — Optic
  1. 1Visual acuity (Snellen), fields to confrontation, inspection (pupils)
  2. 2Pupillary reflexes — direct, consensual, accommodation; swinging-light test for an RAPD
  3. 3Fundoscopy (papilloedema, optic atrophy)
III, IV, VI — Eye movements
  1. 1Test the H pattern of gaze; ask about diplopia at extremes
  2. 2III palsy: “down and out” eye, ptosis, fixed dilated pupil; IV: vertical diplopia on looking down; VI: failure of abduction
V — Trigeminal
  1. 1Sensation in all 3 divisions (ophthalmic/maxillary/mandibular)
  2. 2Motor: clench teeth (masseter/temporalis), jaw jerk
  3. 3Corneal reflex (offer)
VII — Facial
  1. 1Test all facial muscles: raise eyebrows, screw eyes shut, puff cheeks, show teeth
  2. 2Forehead spared = UMN (stroke); forehead involved = LMN (Bell’s palsy)
VIII — Vestibulocochlear
  1. 1Gross hearing + whisper test; Rinne & Weber (512 Hz)
IX, X — Glossopharyngeal & vagus
  1. 1Say “ahh” — uvula deviates away from the side of a X lesion; gag reflex (offer); swallow/cough
XI — Accessory
  1. 1Shrug shoulders (trapezius) and turn head against resistance (sternocleidomastoid)
XII — Hypoglossal
  1. 1Inspect the tongue for wasting/fasciculation; protrude — deviates towards the side of the lesion

Signs & what they mean

Forehead-sparing unilateral facial weaknessUMN VII lesion (e.g. stroke)
Whole-side facial weakness incl. foreheadLMN VII lesion (Bell’s palsy)
Ptosis + “down and out” eye + fixed dilated pupilThird nerve palsy (surgical — e.g. PComm aneurysm)
RAPD (swinging-light test)Optic nerve / retinal pathology
Tongue deviates towards the lesion; uvula deviates awayXII / X nerve lesion respectively

To complete, I would…

  • Perform a full peripheral neurological examination
  • Assess cerebellar function and gait
  • Check blood pressure and glucose

OSCE tips

  • The forehead is the key to VII: spared = UMN, involved = LMN.
  • Tongue towards, uvula away — memorise the directions.
  • Do the swinging-light test for an RAPD every time you test the pupils.
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