Examination of all cranial nerves for medical and applied medical students reference purpose

1. Examination of Cranial Nerves Examination
I to XII
Dr Shamshad
Majmaah University
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Dr Shamshad

2. Objectives
1. Identify the correct steps of cranial nerves examination I-VII.
2. Perform clinical examination of these cranial nerves.
Identify common clinical abnormalities
3. Report the examination findings.
4. Identify the correct steps of examination of cranial nerves
IX to XII Perform clinical examination of these cranial nerves
Identify common clinical abnormalities.
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3. Initial Etiquettes
I. Greet and Introduce yourself
II. Assure confidentiality ; respect patient privacy
III. Explain procedure to patient and ask for consent
IV. Be polite: say “please” & “thank you”
V. Clean and warm your hands.
VI. Position examiner: Right side of patient.
Ask if he/she is currently experiencing any pain.
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4. 1.Position of patient :
Lying flat on bed or sitting or standing position seeing
the comfort of patient
2. Expose part to be examined:
(don't over or underexpose the part).
 Begin by general inspection of the head and neck.
 Look for craniotomy scars, which suggests previous surgery.
 The cranial nerves are then examined sequentially.
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5. I: Olfactory nerve Examination
[Brief Smell Identification Test ]
Requirements: Solutions form in test tubes
Eucalyptus ,Clove oil , peppermint oil,cinnoman ,coffee…
 Used the known solution .Ask if the person is allergic to any
substances.
 Ask if he/she has noticed a change in his sense of smell or taste
 History of trauma, head injury, sinusitis, epistaxis..
 Conduct the examination as efficiently as possible with eyes
closed.
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6. Compare both right and left side nostrils.
Avoid pungent or irritant solution
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7. Applied aspect:
 Anosmia- loss of sense of smell
 Hyposmia- decrease ability to detect smell
 Hyperosmia- increased sensitivity to the sense of smell
 Dysosmia- distorted sense of smell or presence of unpleasant
smell in the absence of any actual odor (olfactory
hallucinations)
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8. II: Optic nerve Examination
[Asses each eye separately ]
Requirements:
 Pen torch
 Snellen chart
 Ishihara plates
 Ophthalmoscope
 Mydriatic eye drops
(if necessary)
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10. Ask sudden loss of vision, headache , use glasses for near or far
distance or Pain ,photophobia..
1: Assess size ,shape color symmetry of pupils :
Normal round, equal and dark colour Abnormal (Peaked),
unequal, dilated or constricted.
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11. 2: Visual acuity (distance)
 Using Snellen chart
Test each eye : Record the lowest line the patient is able
to read (e.g. 6/6 (metric).
which is equivalent to 20/20 (imperial).
Patients with poor vision:
1: Assess if they can count the number of fingers you’re
holding up (recorded as “Counting Fingers” )
2: Hand movements (recorded as “Hand Movements” ).
3: Pen torch shone into each eye (“Perception of Light”/”PL” or
“No Perception of Light”/”NPL”).
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12. 3: Pupillary reflexes
I: Direct pupillary reflex
II: Consensual pupillary reflex
III: Swinging light test
I: Direct pupillary reflex:
A normal direct pupillary reflex involves constriction of
the pupil that the light is being shone.
II: Consensual pupillary reflex:
A normal consensual pupillary reflex involves the
contralateral pupil constricting as a response to light entering the
eye being tested.
III: Swinging light test:
Move the pen torch rapidly between the two pupils to
check for a relative afferent pupillary defect
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13. I: Direct pupillary reflex
II: Consensual pupillary reflex
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14. 4: Accommodation reflex:
Ask the patient to focus on a distant object .Place your
finger approximately 20-30cm in front of their eyes .Ask the
patient to switch from looking at the distant object to the nearby
finger/thumb.
Observe the pupils: for
1: constriction and
2: convergence bilaterally.
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15. 5: Colour vision assessment:
Assess using Ishihara plates
*If the patient normally wears glasses for reading, ensure these
are worn for the assessment.
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16. 6: Visual field assessment: Confrontation test:
 Sit directly opposite the patient, at a distance of around 1 meter.
 Ask the patient to cover one eye with their hand. If the patient
covers their right eye, you should cover your left eye (mirroring
the patient).Ask the patient to focus on part of your face (e.g.
nose) and not move their head or eyes during the assessment.
 You should do the same and focus your gaze on the patient’s
face.
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17. …Confrontation test:
 Position the hatpin (or another visual target such as your finger)
at an equal distance between you and the patient (this is
essential for the assessment to work).
 Assess the patient’s peripheral visual field by comparing to
your own and using the target. Start from the periphery and
slowly move the target towards the center, asking the patient to
report when they first see it.
 If you are able to see the target but the patient cannot, this
would suggest the patient has a reduced visual field.
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18. Confrontation test
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19. Inspection: 1: Ptosis, diplopia, strabismus or nystagmus.
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20. 2: Eye movements:
 Hold your finger (or a pin) approximately 30cm in front of the
patient’s eyes and ask them to focus on it. Look at the eyes in the
primary position for any deviation or abnormal movements.
 Ask the patient to keep their head still whilst following your
finger with their eyes.
 Ask them to let you know if they experience any double vision or
pain.
 Move your finger through the various axes of eye movement in a
‘H’ pattern. Observe for any restriction of eye movement or any
nystagmus.
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21. 3: Corneal light reflex test or Hirschberg test:
For strabismus that evaluates eye alignment based on the
location of reflections of light shined at the eyes
 Ask the patient to focus on a target approximately half a meter
away whilst you shine a pen torch towards both eyes.
 Inspect the corneal reflex on each eye:
 If the ocular alignment is normal, the light reflex will be
positioned centrally and symmetrically in each pupil.
 Deflection of the corneal light reflex in one eye suggests a
misalignment.
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22. Vth C N: Trigeminal Nerve
Requirements : Cotton swab, pin , knee hammer, Tuning fork
(128Hz), two test tubes with 5 ml warm water and cold water .
Explain the procedure .Instruct patient to close their eyes & say
‘yes’ each time they feel you touch their face.
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23. I: Sensory Assess:
Light touch, temperature and pain sensation
symmetrically on face.
1. Ophthalmic (V1): Sensory information from the scalp &
forehead, nose, upper eyelid conjunctiva & cornea.
2. Maxillary (V2): Sensory information
from the lower eyelid, cheek, nares, upper lip,
upper teeth &gums.
3. Mandibular (V3):
3A: Sensory information from the chin, jaw,
lower lip, mouth, lower teeth and gums.
3B: Motor information to the muscles of mastication.
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24. II: Motor Assess:
Inspection:
Wasting of muscles: temporalis and masseter muscles.
Palpation:
Power of muscles:
1:the masseter muscle, asking the patient to clench the teeth to allow
you to assess and compare muscle bulk.
2: Ask the patient to open their mouth whilst you apply resistance
underneath the jaw to assess the lateral pterygoid muscles.
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25. III: Superficial reflex :
Corneal reflex:
 Clearly explain the procedure.
 Gently touch the edge of the cornea using a wisp of cotton wool.
Response: In healthy individuals, both direct and consensual
blinking is observed.
IV: Jaw Reflexes/Jaw Jerk:
 Explain the procedure and instruct to apply reinforcement test
Response: Healthy individuals,
this should trigger a slight closure of the mouth.
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26. VIIth CN: Facial Nerve
Equipments:
Solutions :Salt, Sugar, Lemon, Aspirin/paracetamol tablet,
Stopwatch
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27. I: Sensory Examination:
 Ask the patient if they have noticed any recent changes in
their sense of taste.
 Instruct the patient to close eyes and respond by telling what
is the taste of the solution .
 Using the different known solutions of sugar, salt lemon and
aspirin or paracetamol tablet test the taste sensation applying
on tip, lateral border, and anterior 2/3 part of tongue.
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28. II: Motor Examination: Inspection: Look for muscles of facial
expression : Facial asymmetry Look for Forehead wrinkles,
nasolabial folds and the angle of the mouth and Facial movement
1: Frontalis  raised eyebrows
2 Orbicular oculi Closed eyes
3: Orbicularis oris Blown out cheeks
4: levator anguli oris and zygomaticus major Smiling
5: Orbicularis oris and buccinator Pursed lips
6: Stapedius muscle: Hearing changes : Ask the patient if he notice
any changes to the hearing hyperacusis
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29. III: Secreto-motor examination: Ask for dryness of eyes, or mouth.
Bell's palsy
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30. VIIIth CN: Auditory/Vestibulocochlear Nerve
Requirements :
Tuning fork (256 or 512hz), Stop watch, Otoscope,
2 ml syringe with cold and warm water(30 and 44oC)
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31. VIIIth CN: Auditory/Vestibulocochlear Nerve
I: Brief history:
Change in their hearing recently
II: Inspection:
For wax or dishcage or mass in the ear
1: Explain the procedure
 Ask the patient to close the eyes and one ear mask
 Repeat the words or number whispered through each ear
from behind.
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32. III: Rinne’s test: (Bone conduction)
 Place a vibrating 512 Hz tuning fork firmly on the mastoid
process (apply pressure to the opposite side of the head to make
sure the contact is firm).
 Confirm the patient can hear the sound of the tuning fork and
then ask them to tell you when they can no longer hear it.
When the patient can no longer hear the sound, move the
tuning fork in front of the external auditory meatus to test air
conduction.
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33. 1. Normal: air conduction > bone conduction
2. Sensorineural deafness: Air conduction > Bone conduction
3. Conductive deafness: Bone conduction > Air conduction
said as Rinne’s negative.
Ask the patient if they can now hear the sound again.
If they can hear the sound, it suggests air conduction is better
than bone conduction.
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34. Weber’s test :
 The tuning fork should be set in motion by striking it on your
heel of your palm
 Tap a 512Hz tuning fork and place in the midline of the forehead.
 Ask the patient “Where do you hear the sound?”
1. Normal: sound is heard equally in both ears.
2. Sensorineural deafness: Sound is heard louder in the side of
the unaffected ear.
3. Conductive deafness: sound is heard louder in the side of the
affected ear.
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36. Interpretation of Rinne and Weber Tests
Rinne Result Weber Result
I:Normal AC > BC in both ears Midline
I:Conductive
hearing loss
Affected ear: BC > AC
Unaffected ear: AC > BC
Lateralization: to
affected ear
2:Sensorineural
hearing loss
Both ears: AC > BC Lateralization to
unaffected ear, away
from affected ear
3:Mixed
hearing loss
Affected ear: BC >AC
Unaffected ear: AC > BC
Lateralization to
unaffected ear, away
from affected ear
AC=Air conduction, BC =Bone conduction
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37. IXth & Xth CNn:
Glossopharyngeal and Vagus Nerves
Brief history: If any difficulty in swallowing any changes in voice
or cough.
Inspection:
Ask the patient to open their mouth and inspect the soft palate and
uvula
Note: position of the uvula.
Ask the patient to say “ahh“: Inspect the palate and uvula which
should elevate symmetrically, with the uvula remaining in the
midline.
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38.  Swallow assessment:
 Ask the patient to take a small sip of water
and observe the patient swallow.
 The presence of a cough or a change to the
quality of their voice suggests an
ineffective swallow (due to
glossopharyngeal (afferent) and Vagus
(efferent) nerve pathology).
 Ask the patient to cough: Vagus nerve lesions can result
in the presence of a weak, non-explosive sounding bovine
cough caused by an inability to close the glottis.
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39. Gag reflex:
 This test is highly unpleasant for patients and therefore the
swallow test mentioned previously is preferred as an alternative.
 Stimulate the posterior aspect of the tongue and oropharynx .
 In healthy individuals triggers a gag reflex.
 The absence of a gag reflex due to glossopharyngeal and Vagus
nerve pathology.
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40. XIth CN: Accessory Nerve
Motor assessment:
Inspection: Sternocleidomastoid or trapezius muscle wasting
Palpation: Power of muscles:
 Trapezius muscle : Ask the patient to raise their shoulders
and resist you
 pushing them downwards.
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41.  Sternocleidomastoid muscle: Ask the patient to turn their
head left whilst you resist the movement and then repeat
with the patient turning their head to the right.
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42. XIIth CN – Hypoglossal nerve
Motor assessment :
Inspection: Tongue at rest
 Ask the patient to protrude tongue out: Look for Wasting and
fasciculations ( motor neuron disease)
 Deviation towards side of lesion( LMN)
Palpation: Power of muscles: Place your finger on the patient’s
cheek and ask them to push their tongue against it. Repeat this on
each cheek to assess and compare power (weakness would be
present on the side of the lesion).
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43. Paralyzed left side
Normal
Power of muscles
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45. References:
1. Mac Load’s clinical examination 13th edition Edition (2013), page 251-256
2. Hutchison’s Clinical Methods; An Integrated Approach to Clinical Practice, 22nd
Edition (2007), page 180-228.
3. Colour Atlas and Text of Clinical Medicine by Forbes and Jackson, 3rd Edition.
4. I acknowledge Dr. Ibrahim Adam for his excellent slides and figures in ppt on
cranial nerve examination.
5. The figures are taken from internet
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