cranial nerves examination

·         CN1 - olfactory - not tested routinely

o    Inspect for anything that may be blocking the nasal cavity

o    Smell

§  Breath in thru nose (while closing the other nostril)

§  Once patency established, ask patient to close eyes

§  Occlude one nostril. Place small bar of soap/ coffee and ask what it is

§  Switch nostrils

§  Ask patient to compare strength of the smell in each nostril

o    Nasopharyngeal carcinoma

·         CN2 - optic nerve

o    6 components - why this order? Going closer to patient as you go

§  Visual acuity

·         near

o    Use visual acuity chart (snellen’s char)

o    Test near vision using jaegger’s test type - 

use newspaper during ward rounds

·         Far

o    Snellen’s chart

o    Allow patient to use visual aid (contacts / glasses)

o    Position 6meter / 20 feet

o    Have patient cover one eye at time

o    Ask to read progressively smaller letters until they can go on further

o    Record the smallest line patient can read correctly

§  Colour vision

·         Test using ishihara chart

o    Pseudoisochromatic plates - each composed of a pattern of differently shaded dots.

o    To a colour blind person, the numbers cannot be seen properly

o    “what do you see?” (don’t give clues)

§  Field

·         Confrontation method

o    Face patienr one foot away

o    Patient to cover same side of eye

o    Fingers come out-to-in

§  Accommodation

o    Ask patient to focus on finger

o    Finger move closer

o    The eyes accommodate - pupils constrict

o    Near triad

§  Convergence

§  Pupil constriction

§  Increased convexity

§  Papillary reflex

·         Light reflex

o    Ask patienr to focus on an object in distance

o    Observe the OTHER eye as you shine torch into one eye.

o    Check if both eye light reflex  normal

§  Fundoscopy

o    Dim lights

o    Ask patient to look at one point

o    Report  - 3 things

§  Vessels,

·         Find out difference bet. Artery and vein

§  Optic disc

·         Cup size

·         Disc size

·         Cranial nerves III, IV and VI

§  Ptosis

·         Lagging of eyelid

o    Symph nerve going to eye  Muller’s muscle

o    3^rd cranial nerve palsy

o    Observe for ptosis

o    Do a H test (check for diplopia and nystagmus)

o    Observe muscle group pathology if any

§  LR, MR, SR, IR, SO, IO

§  Make sure you know if there is a lop-sided eye, which muscle affected and which nerve

·         Cranial nerve V

o    sensory

§  Test light touch and pain in V1, 2, 3

§  Tell patient to close eyes and say “sharp” when they feel it touch face

§  Corneal reflex

·         Sharpen cotton wool

·         Ask patient to look up and sideways - wide area of cornea

·         Touch cornea - BLINK

o    Motor    

§  Ask patient to clench teeth

§  Feel temporal and massetor

§  Jaw jerk

·         Ask patient to relax

§  Assess jaw muscle powers

·         Ask patient to deviate their jaw, push against it

·         Facial nerve VII

o    Motor component

§  Inspect

·         Symmetry

·         Sagging of mouth

·         Nasolabial fold

·         Drooping of eyelid

§  Ask patient to raise eyebrow

§  Smile to show teeth

§  Whistle

§  Puff out both cheeks

§  Power

·         Close eyes, force open

o    Sensory component

§  Taste

·         Not tested routinely

·         Use cotton, dip  into sat, viniger etc and touch on tongue

·         CN VIII Vestibulocochlear nerve

o    Rub fingers

o    Whisper test

§  A number

§  Ask patienr to repeat back the number or word

o    Rinne and weber test 256hz

§  Rinne

·         Find out if it is conductive or sensory pathology

·         Put fork onto bone

·         Ask patient to say stop when sound stop

·         Ask patient if they can hear the fork -they should.

§  Weber’s test

·         Put on forehead

·         Which ear louder? Equal?

o    Otos cope

§  Report

·         Discharge

·         Serumen

·         Timpanic membrane

o    Perforated

o    Bulging

o    Normal (intact)

·         Cone of light

·         Glossopharyngeal and Vagus

o    Ask patient to swallow

o    Note voice

§  Hoarseness suggest recurrent laryngeal nerve damage

o    Say ahh

§  Observe soft palate

§  Uvula deviated away from site of pathology

o    If say ahh something wrong, do GAG reflex

·         Cranial nerve 11

o    Trepezius

o    SCM

§  Comment on power

·         CN 12

o    Tongue inspection

o    Tongue protrusion

§  Pathology is the side of deviation

o    Tongue power

§  Ask patient to put tongue in cheek - push the cheek in

o    Yellow lorry