The Cranial Nerve Examination - PowerPoint Presentation

Slide1

The Cranial Nerve Examination

Daniel Foran

Slide2

Examination of 12 cranial nerves

Today we will cover...

Understand the sensory and motor functions of the cranial nerves

Recall the components of the cranial nerve examination

Demonstrate good examination technique

Interpret the clinical findings of the

cranial nerve

examination

Slide3

There are TWELVE Cranial Nerves

I. Olfactory

II. Optic

III. Oculomotor

IV. Trochlear

V. Trigeminal

VI. Abducens

VII. FacialVIII. VestibulocochlearIX. GlossopharyngealX. VagusXI. AccessoryXII. Hypoglossal

Your exam checklist:

Slide4

Two Mnemonics

I. Olfactory

II. Optic

III. Oculomotor

IV. Trochlear

V. Trigeminal

VI. Abducens

VII. FacialVIII. VestibulocochlearIX. GlossopharyngealX. VagusXI. AccessoryXII. Hypoglossal

Names and order

Ooh

Ooh

Ooh

To

TouchAndFeelVeryGoodVelvetAhHeaven

Function

S

ome

SayMoneyMattersButMyBrotherSaysBigBrainsMatterMore

S: Sensory

M: Motor

B: Both

Slide5

Why is this important?

The Cranial nerve exam is all about

structure

Slide6

Introduction: WIPER

4

E

xpose

5

R

eposition

2

I

ntroduce yourself and examination

1

W

ash Hands

3

P

ermission and Pain

Slide7

General Inspection: SWIFT

Tremor

Fasciculations

Involuntary Movements

Scars

Wasting

pupil size/ shape/ symmetry

Squint

Ptosis

Facial Droop

Abnormal eye position

Slide8

The Olfactory Nerve

Cranial Nerve I

I. Olfactory

Sensory

Slide9

Components of the Olfactory nerve examination

“I would ideally like to assess smell more formally using for example the Pennsylvania smell identification test”

“Have you noticed any changes in your sense of smell?”

I. Olfactory

Sensory

Slide10

The Optic Nerve

Cranial Nerve II

II. Optic

Sensory

Slide11

First, TWO questions…

II. Optic

Sensory

“Do you wear glasses or contact lenses?”

1

“Have you noticed any changes in your vision recently?”

2

Slide12

Components of the Optic nerve examination: AFROS

S

pecial Tests

II. Optic

Sensory

O

phthalmoscopy

R

eflexes (pupillary)

F

ields

A

cuity

Slide13

Components of the Optic nerve examination: Acuity

II. Optic

Sensory

Ideally:

Use a

Snellen

chart

Make sure the patient wears their glasses if they normally wear glasses for reading

Position patient 6m away from the chart

1

Ask the patient to cover one eye

2

Ask the patient to read the lowest line they can

3

Repeat with the other eye

4

In the exam:

Cover one of the patient’s eyes at a time

Get them to read the text on your ID card

Slide14

Components of the Optic nerve examination: Fields

II. Optic

Sensory

Visual Inattention

Visual Fields

Tell patient: “look at my nose”

Put your arms out to the sides with fingers pointed upwards

Tell patient: “keep looking at my nose and point to the finger that moves”.

Wiggle Left

Wiggle Right

Wiggle both at once

https://visionhelp.wordpress.com/2016/04/03/is-strabismic-suppression-a-form-of-attentional-neglect/

http://neurosurgeryblog.tumblr.com/post/97967863155/testing-visual-fields-to-confrontation-medlife

“Look at my nose and cover your left eye with your left hand”

“With your right eye look into my left eye”

Close/cover your right eye

“Keep looking at my eye and tell me when you see my fingers out of the corner of your eye”.

Move your fingers towards the centre from all 4 corners of the visual field.

Slide15

Demonstration: Testing Visual Fields

II. Optic

Sensory

Slide16

Demonstration: Testing Visual Fields

II. Optic

Sensory

Slide17

Components of the Optic nerve examination: Reflexes

II. Optic

Sensory

Firstly…

Get the patient to focus on a spot on the wall behind you

Ask them to place one hand vertically between their eyes

“I am briefly going to shine a torch into your eyes”

Remember to dim the lights!

3 Features:

Direct response

When the light enters a pupil, it dilates

Consensual response

When the light enters one pupil, the contralateral pupil also dilates

Relative response (aka: swinging torch test)

Repeatedly swing the torch between the two eyes

If one pupil inappropriately dilates, it suggests there may be a sensory deficit from the other pupil

Slide18

Demonstration: Testing Pupillary Reflexes

II. Optic

Sensory

Slide19

Components of the Optic nerve examination: Ophthalmoscopy and Special Tests

II. Optic

Sensory

Ophthalmoscopy

“Ideally I would like to examine the fundus using ophthalmoscopy”

Special Tests

Colour vision

“Ideally I’d test colour vision using Ishihara plates”

Blind Spot

“Ideally I’d test the patient’s blind spot using a red Q-tip”

Slide20

The Oculomotor,

Trochlear, and Abducens Nerves

Cranial Nerves III, IV, and VI

Motor

VI. Abducens

IV. Trochlear

III. Oculomotor

Slide21

Components of the Oculomotor, Trochlear, and Abducens nerve examination

Motor

VI. Abducens

IV. Trochlear

III. Oculomotor

Accommodation

Nystagmus

The ‘H’ Test

Inspect the eyes for any nerve palsies

Nerve Palsy

Muscle(s) affected

Appearance

Causes

CN III

CN IV

CN VI

SR, IR, MR, IO

Superior Oblique

Lateral Rectus

Down and out

Head tilting

Convergent Squint

Diabetes

Orbit Trauma

Raised ICP

Slide22

H Testing, Nystagmus and Accommodation

Motor

VI. Abducens

IV. Trochlear

III. Oculomotor

Cranial Nerves, 3

rd

Ed. 2010, Wilson-Pauwels, Stewart,

Akesson

, Spacey, PMHP-USA

“Keep your head still and follow my finger with your eyes – tell me if at any point you

see double

or if moving your eyes is

painful

”

Finger ~50cm from face

Move

slowly

in a ‘H’ shape

Look for obvious Ophthalmoplegia and nystagmus

Nystagmus

Move finger

quickly

from side to side to elicit

Accommodation Reflex

“keep looking at my finger”

Move your finger slowly in towards the patient’s nose

Pupils should

constrict

during convergence

Slide23

Demonstration: H test and accommodation

Motor

VI. Abducens

IV. Trochlear

III. Oculomotor

Slide24

Knowledge Recap: Nerves I, II, III, IV, and VI

“Have you noticed any changes in your sense of smell?”

I. Olfactory Nerve

II. Optic Nerve

Acuity: ideally using Snellen chart at 6m

Fields: including inattention

Reflexes: direct and consensual responses and swinging torch test

Ophthalmoscopy

Special Tests: colour vision and blind spot testing

III, IV, and IV. Oculomotor Trochlear and Abducens Nerves

‘H’ Test

Nystagmus

Accommodation

Slide25

The Trigeminal Nerve

Cranial Nerve V

V. Trigeminal

Both

Slide26

Components of the Trigeminal nerve examination

V. Trigeminal

Both

Ophthalmic Branch

Maxillary Branch

Mandibular Branch

https://www.mayoclinic.org/diseases-conditions/trigeminal-neuralgia/symptoms-causes/syc-20353344

Reflexes

Jaw Jerk

Corneal

Motor

Jaw Clench

Opening Jaw against resistance

Light Touch: Face

Sensory

Slide27

1. Ask patient to close their eyes

2. Test the cotton wool on their sternum

3.

“Say yes when you feel the cotton wool touching your face”

4. Test all branches

5. Move from side to side and ask if it feels the same on both sides.

6. “Ideally I’d offer to test pain sensation with a

neurotip

Components of the Trigeminal nerve examination

V. Trigeminal

Both

Sensory: light touch to the face

Motor: Jaw clenching and opening against resistance

https://geekymedics.com/cranial-nerve-exam/

1. Palpate for masseter contraction over angle of the jaw

2. Palpate for temporalis contraction over the temples

1. Push upwards on the patient’s chin

2. “Open your jaw against my hand”

Slide28

“Ideally I’d offer to test the…”

V. Trigeminal

Both

Jaw Jerk Reflex

Corneal Reflex

Slide29

Demonstration: the Trigeminal nerve

V. Trigeminal

Both

Slide30

The Facial Nerve

Cranial Nerve VII

VII. Facial

Both

Slide31

Components of the Facial nerve examination

VII. Facial

Both

Sensory: change in taste and loud noise sensitivity

Motor: raise eyebrows, screw up eyes, puff out cheeks, smile, purse lips

Inspection of facial tone

Reduced wrinkling of the forehead

Drooping of the corner of the mouth

Flattening of the nasolabial folds

https://www.aafp.org/afp/2007/1001/p997.html

Slide32

Components of the Facial nerve examination: sensory

VII. Facial

Both

“Have you noticed any change in your taste recently?”

1

“Do you feel you’re particularly sensitive to loud noises at the moment?”

2

Slide33

Bell’s sign: up-gaze on attempted eye closure

Components of the Facial nerve examination: motor

VII. Facial

Both

Smile

Purse Lips

Raise Eyebrows

Screw up Eyes

Puff out Cheeks

Slide34

Demonstration: the Facial nerve

VII. Facial

Both

Slide35

The Vestibulocochlear Nerve

Cranial Nerve VIII

VIII. Vestibulocochlear

Sensory

Slide36

Rinne’s Test

Weber’s Test

Components of the Vestibulocochlear nerve examination

VIII. Vestibulocochlear

Sensory

https://geekymedics.com/cranial-nerve-exam/

Crude test of hearing

Stroke

tragus

/ occlude external auditory meatus of one ear

Whisper

numbers in the patient’s other ear

Ask them to

repeat

the whispered numbers

Slide37

Components of the Vestibulocochlear nerve examination

VIII. Vestibulocochlear

Sensory

Rinne’s Test

Weber’s Test

Tells you whether the defect is

conductive

or

sensorineural

Helps identify the

side(s)

of the defect

https://biology-forums.com/index.php?action=gallery;sa=view;id=9356

Firstly always explain (concisely) to the patient what you are about to do (especially if using instruments).

https://www.medistudents.com/en/learning/osce-skills/neurology/cranial-nerve-examination/

Heel

Stem

Prongs

Vibrate the tuning fork

Place tuning fork heel on mastoid process behind ear: “this is sound 1”

Plac

e tuning fork prongs just outside the external auditory meatus: “this is sound 2”

“Which sound was louder?”

Vibrate the tuning fork

Place tuning fork heel on the centre of the patient’s forehead

“Do you hear the sound more on the left or right, or just in the middle of your head?”

Slide38

Demonstration: Rinne’s and Weber’s tests

VIII. Vestibulocochlear

Sensory

Slide39

Interpreting Weber’s and Rinne’s Tests

VIII. Vestibulocochlear

Sensory

Weber’s Test

Rinne’s Test

Diagnosis

Central

Normal

Air>Bone (both ears)

Bone>Air (Left ear)

Lateralises to Left ear

Conductive hearing loss in Left ear

Air>Bone (both ears)

Bone>Air (Right ear)

Sensorineural hearing loss in left ear

Complete sensorineural deafness in right ear

Lateralises to Left ear

Lateralises to Right ear

Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition.

Slide40

Knowledge Recap: Nerves V, VII, and VIII

VII. Facial Nerve

Sensory: change in taste and loud noise sensitivity

Motor: raise eyebrows, screw up eyes, puff out cheeks, smile, purse lips

VIII. Vestibulocochlear Nerve

Hearing test: get patient to repeat whispered numbers

Rinne’s Test

Weber’s Test

V. Trigeminal Nerve

Sensory: light touch to the face

Motor: Jaw clenching and opening against resistance

Reflexes: Corneal and Jaw Jerk

Slide41

The Glossopharyngeal and Vagus

NervesCranial Nerve IX

Both

X.

Vagus

IX. Glossopharyngeal

Slide42

3

Cough Assessment

4

Swallow Assessment

Components of the Glossopharyngeal and

vagus

nerve examination

Motor

X.

Vagus

IX. Glossopharyngeal

2

“say ‘British constitution’”

1

Soft Palate Assessment

5

Gag Reflex

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Slide43

Soft Palate Pathology

Motor

X.

Vagus

IX. Glossopharyngeal

Normal Uvula

Deviated Uvula

Vagus

Nerve Lesion: Uvula deviates

AWAY

from the affected side

Slide44

The Accessory Nerve

Cranial Nerve XI

XI. Accessory

Motor

Slide45

Components of the Accessory nerve examination

XI. Accessory

Motor

Shrug shoulders against resistance

2

Turn head against resistance

3

Inspect muscle bulk for wasting

1

Supplies the trapezius and sternocleidomastoid muscles

Slide46

The Hypoglossal Nerve

Cranial Nerve XII

XII. Hypoglossal

Motor

Slide47

Components of the Hypoglossal nerve examination

XII. Hypoglossal

Motor

“Put your tongue in one cheek and push against my finger”

Press

one

finger against the tough and push

medially

Repeat

on the other side

Push tongue against resistance

“Move your tongu

e from side to side”

Tongue Movement

Stick tongue out for inspection

Wasting

Fasciculations

Flaccidity

Spasticity

Deviation

Slide48

Tongue Pathology

XII. Hypoglossal

Motor

Hypoglossal Nerve Lesion: Tongue deviates

TOWARDS

the affected side

Normal Tongue

Deviated Tongue

http://neuronalogy.com/hypoglossal-nerve-lesion-and-tongue-deviation-a-bicycle-analogy/

Slide49

Demonstration: the Glossopharyngeal, Vagus, Accessory and Hypoglossal nerves

Both

XI. Accessory

X.

Vagus

IX. Glossopharyngeal

XII. Hypoglossal

Slide50

Knowledge Recap: Nerves IX, X, XI, and XII

XI. Accessory Nerve

Motor: raise shoulders and turn head against resistance

XII. Hypoglossal Nerve

Stick tongue out for inspection

Motor: move tongue from side to side, push tongue against resistance

IX and X. Glossopharyngeal and

Vagus

Nerves

Soft palate assessment: “say

ahhh

”

Speech assessment: “say ‘British Constitution’”

Reflexes: Gag

Cough assessment

Swallow assessment

Slide51

Demonstration: The Whole Examination

Slide52

Presentation: to complete the examination I would…

Take a full neurological history

Perform a complete neurological examination of the upper and lower limbs

Perform a mini mental state examination

Assess gait and balance

Slide53

ADVICE

Practice as much as possible on patients/friends/familyEach time you practice try to think about your examination structure

Practice presenting to yourself in the mirror

Act confident when you perform the exam (even if you don’t feel it)

Slide54

Knowledge Recap: the whole exam (1/3)

“Have you noticed any changes in your sense of smell?”

I. Olfactory Nerve

II. Optic Nerve

Acuity: ideally using Snellen chart at 6m

Fields: including inattention

Reflexes: direct and consensual responses and swinging torch test

Ophthalmoscopy

Special Tests: colour vision and blind spot testing

III, IV, and IV. Oculomotor, Trochlear and Abducens Nerves

‘H’ Test

Nystagmus

Accommodation

Slide55

Knowledge Recap: the whole exam (2/3)

VII. Facial Nerve

Sensory: change in taste and loud noise sensitivity

Motor: raise eyebrows, screw up eyes, puff out cheeks, smile

VIII. Vestibulocochlear Nerve

Hearing test: get patient to repeat whispered numbers

Rinne’s Test

Weber’s Test

V. Trigeminal Nerve

Sensory: light touch to the face

Motor: Jaw clenching and opening against resistance

Reflexes: Corneal and Jaw Jerk

Slide56

Knowledge Recap: the whole exam (3/3)

XI. Accessory Nerve

Motor: raise shoulders and turn head against resistance

XII. Hypoglossal Nerve

Stick tongue out for inspection

Motor: move tongue from side to side, push tongue against resistance

IX and X. Glossopharyngeal and

Vagus

Nerves

Soft palate assessment: “say

ahhh

”

Speech assessment: “say ‘British Constitution’”

Reflexes: Gag

Cough assessment

Swallow assessment

Slide57

Any Questions?

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