Cranial Nerve Examination

1. Clinical Skills
Cranial Nerves Examination
Warwick Medical School CSc2 Tutors
Prof Vinod Patel MD FRCP MRCGP DRCOG FHEA
2021

2. Aims
Introduce the skills required to:
• Take an effective clinical history
• Perform an examination of the cranial nerves
• Understand the common symptoms of neurological
disease
Objectives
By the end of the session you should be able to:
• Recognise common symptoms of neurological disease
• Conduct a comprehensive examination of the cranial
nerves
Learning outcomes
Use all Standard PPE,
Hand Hygiene, bare
below elbows

3. Where else will these topics be
covered?
Cranial Nerves Part 1 and 2
Anatomy

4. Cranial Nerves: Clinical Case
Case presentation:
• A 65-year-old woman was admitted with a one day Hx of left facial drooping.
No other symptoms.
• Chest CT revealed the ground-glass shadows in the right lower lung. RT-PCR
results for SARS-CoV-2 RNA were positive through throat swabs. Other
common viruses were not found: Influenza A or B, Parainfluenza, Adenovirus,
Coxsackie, RSV, Herpes Virus.
• Symptoms of left facial paralysis relieved after antiviral treatment. She patient
was discharged in the context of 3 consecutively negative RT-PCR test results
for SARS-CoV-2 RNA and complete absorption of the right lung lesions
Background: Coronavirus disease 2019 (COVID-19) is a highly infectious
disease, mainly causing respiratory symptoms. However, a few patients may also
have neurological symptoms.
Conclusion: This case suggests that COVID-19 may be presented with Bell’s
palsy and may be a potential cause of facial paralysis.
Coronavirus disease 2019 complicated with Bell’s palsy: a case report. Yue Wan, Shugang Cao, Qi
Fang, Mingfu Wang, Yi Huang. DOI: 10.21203/rs.3.rs-23216/v1. Research Square 2021

5. Cranial Nerves: Clinical Case
Case presentation:
• A 65-year-old woman was admitted with a one day Hx of left facial drooping.
No other symptoms.
• Physical examination showed left peripheral facial paralysis
• Brain MRI showed no abnormality. However, the chest CT revealed the
ground-glass shadows in the right lower lung.
• Symptoms of left facial paralysis relieved after antiviral treatment. She patient
was discharged in the context of 3 consecutively negative RT-PCR test results
for SARS-CoV-2 RNA and complete absorption of the right lung lesions (1
month later).
Coronavirus disease 2019 complicated with Bell’s palsy: a case report. Yue Wan, Shugang Cao, Qi

6. Cranial Nerves: History Taking

7. History taking
General points:
• Clarify symptoms precisely
• Consider contacting witness
Time relationships:
• Onset
– Vascular: sudden- seconds, minutes
– Infection: hours, days
– Inflammation: days, weeks
– Tumour: weeks, months, years
• Duration
• Pattern
Precipitating, exacerbating or relieving factors:
• What was patient doing at time of onset
• Consider time of day, menstrual cycle,
posture, medication
Associated symptoms:
• Nausea and vomiting
• Photo / phono phobia
• Neck stiffness
• Fever

8. Common symptoms
Visual loss Hearing loss
Disturbance of
smell or taste
Headache
Blackouts and
syncope
Dizziness and
vertigo
Muscle
weakness

9. History taking
PMHx
• Birth & development
• Previous symptoms
• Risk factors
DHx
• Prescribed
• OTC
• Recreational
SHx
• Impact on ADL
• Alcohol
• Diet
• Smoking
• Sexually Transmitted Disease or
blood-borne infection risk
• Travel history
FHx: eg
• Diabetes
• Familial Hypercholesterolaemia

10. Nervous system examination: Cranial Nerves

11. Use Latest Version
Clinical Skills
Course 2
Handbook:

12. “WIPE”
Wash hands
Introduction
Patient Consent
Explain procedure
Correct position & adequate exposure
• Patient should be sitting on a chair or bed
Professionalism:
• At the end of examination cover patient, thank patient and wash hands
During Examination

13. Cranial Nerves
Function
• Cranial nerves function to relay various types of information to and
from the body to the Cerebrum
• Motor (move muscles)
• Sensory nerves; they carry information from the body to the brain.
• Combination of motor and sensory nerves.
• Each pair of cranial nerves serves a specific purpose in your body,
and function as either a motor nerve, sensory nerve, or both.
• Clinical conditions can affect function of the nerves with specific
symptoms as a result of pathology
• They are what make us human social animals to a very great extent:
expression of emotion, speech, safe swallow, appearance, learning
technology, probe to the world!

14. General inspection
Neuro-Ophthalmology
Baloh, Robert W., Goldman-Cecil Medicine, 396, 2535-2541.e2
Horner syndrome. Note the
characteristic ptosis of the left eye
associated with constriction of the pupil
(miosis). This patient had syringomyelia,
but Horner syndrome has many possible
causes. (From Forbes CD, Jackson WF.
Color Atlas and Text of ...
Copyright © 2020 Copyright © 2020 by Elsevier, Inc. All rights
reserved.
Kumar & Clark's Cases in Clinical Medicine, 15, 461-508
Bell's palsy.
Copyright © 2013 Copyright © 2013 Elsevier Ltd. All rights
reserved.
Parkinson's disease and other akinetic rigid
syndromes I
Fuller, Geraint, MA MD FRCP, Neurology, 88-89
Posture in Parkinson's disease.
Note the slight stoop and the
position of the right arm.
Copyright © 2010 © 2010, Elsevier Limited. All
rights reserved.

15. General inspection
Strabismus
Kanski, Jack J., MD, MS, FRCS, FRCOphth, Synopsis of Clinical Ophthalmology,
Chapter 18, 321-333
Copyright © 2013 Copyright © 2013 Elsevier Ltd. All rights reserved
Myotonic dystrophy: Neurological diagnostic facies.
Mir MA. Atlas of clinical diagnosis , 2nd edn.
Edinburgh: Saunders, 2003.

16. CN I: Olfactory nerve
Function
• Responsible for transmitting everything we smell to the brain
• This nerve travels from the cerebrum to the olfactory bulb, where
smells are analyzed
• Disruptions to this nerve can cause hypo-osmia or anosmia, an
inability to detect normally
• This also dramatically impacts our sense of taste and appetite

17. CN I: Olfactory nerve
Examination of the olfactory
cranial nerve. Occlude one
nostril, hold the vial with
aromatic substance under the
nose, and ask the patient to
deeply inspire. If the patient's
eyes are open, make sure there
are no visual cues to odors.
Neurologic System
Ball, Jane W., DrPH, RN, CPNP, Seidel's Guide to
Physical Examination, Chapter 23, 567-606
Copyright © 2019 Copyright © 2019 by Elsevier,
Inc. All rights reserved.
Nervous system
Walker, Rodney W.H., Hutchison's Clinical
Methods, 16, 309-354
Parkinson's disease: showing
the typical rigid, flexed posture
involving the trunk and limbs.
The face is impassive.
Copyright © 2018 © 2018 Elsevier Ltd. All rights
reserved.
Cranial Nerve I : Olfactory
Vytopil, M. Netter's Neurology, 4, 50-
53
Subfrontal
Meningioma.MR,
Magnetic resonance.
Copyright © 2020 Copyright © 2020
by Elsevier, Inc. All rights reserved.
CN I: Olfactory Nerve
 Ask “has there has
been any difficulty or
change in your sense
of smell?” Rarely
need to formally
examine with easily
available “smells” such
as coffee or orange.
 Check nose not
blocked.

18. • Loss of sense of smell occurs when there are problems in the nasal cavity, nasal structure,
olfactory nerve located at the roof of nasal cavity.
• Some people with COVID-19 lose their sense of smell because the virus damages the
olfactory receptor nerve endings or supporting olfactory cells within their nose.
• Those who suffer from smell disorders experience taste disturbances as well
• Usually regenerate every 6 weeks in the nose to replace receptors that have been damaged by
pollution and toxic fumes. Following a viral attack such as flu or COVID-19 this capacity to
regenerate is sometimes lost.
• The scientists have found that the sense of smell is the most sensitive and accurate at the age
of 30 to 60 years
• Women of all ages have more sensitive sense of smell than men
Life in the Time of COVID-19
…Key Symptoms- loss or change to your sense of smell or taste

19. CN II: Optic nerve
Function
• The optic nerve transmits electrical
signals from the retina to the brain
• Occipital lobe transforms these
signals into an image of what we
see in the world around us
• Disorders of the optic nerve and the
other structures in the eye, can lead
to visual disturbances, double
vision, and blindness.
CN II: Optic Nerve
 Check visual acuity with Snellen chart:
consider pinhole to eliminate refraction
problems (record as: Right VA 6/x, Left
VA 6/y)
 Pupillary light and accommodation
reflexes: check pupil size (state in mm,
right and left), check axis, distant object
then near, light reflex with pen torch.
 Assess visual fields: by direct
confrontation.
 Direct ophthalmoscopy: light reflex for
cataract, optic disc, macular area,
general retina and peripheries.
 Colour Vision: Consider checking with
Ishihara plates.

20. CN II: Optic nerve
Ear, nose and throat and eye disease
Vaz, Francis, Kumar and Clark's Clinical
Medicine, 30, 1311-1336
Snellen chart.
Copyright © 2017 © 2017 Elsevier Ltd.
All rights reserved.
The visual system
Borooah, Shyamanga, Macleod's Clinical Examination, 8, 151-169
Confrontation visual field testing: Sit facing the patient, 1
metre away. To compare your visual field (assumed
normal) with the patient's, present a white target or still
then wiggling finger at a point equidistant between
yourself and the patient. Map out the visual field in
comparison to yours.
Copyright © 2018 © 2018 Elsevier Ltd. All rights reserved.
The Eye : II. Receptor and Neural Function of the
Retina
Hall, John E., PhD, Guyton and Hall Textbook of
Medical Physiology, Chapter 51, 647-660
Ishihara charts: Upper: In this
chart, a person with normal vision
reads “74,” but a red-green color-
blind person reads “21.” Lower: In
this chart, a red-blind person
(protanope) reads “2,” but a green-
blind person (deuteranope) reads
“4.” A p...
Copyright © 2016 Copyright © 2016 by Elsevier, Inc.
All rights reserved.

21. Confrontation visual field testing: Sit facing
the patient, 1 metre away. To compare your
visual field (assumed normal) with the
patient's, present a white target or still then
wiggling finger at a point equidistant between
yourself and the patient. Map out the visual
field in comparison to yours.

22. CN II: Optic nerve
The neurological examination : General signs and the cranial nerves
Talley & O'Connor's Clinical Examination, Chapter 32, 500-539
Cranial nerves II and III. (a) The pupils: inspect
for size and symmetry; (b) testing the pupillary
reflex
Copyright © 2018 ©2018 Elsevier Australia. 1st edition ©1988, 2nd
edition ©1992, 3rd edition ©1996, 4th edition ©2001, 5th edition
©2006, 6th edition ©2010, 7th edition ©2014 Elsevier Australia

23. CN II: Optic nerve
The Neurologic Examination
Corbett, J.J., Fundamental Neuroscience for Basic and Clinical Applications, Chapter 33, 480-493.e1
Ophthalmoscopic examination. The examiner locates the red reflex
( A ) and then focuses on the details of the optic nerve ( B ) through
the pupil.
Copyright © 2018 Copyright © 2018 by Elsevier, Inc. All rights reserved.

24. CN III, IV & VI: Oculomotor (III)
Function
• Oculomotor nerve has three main functions
• (1) transmission of signals that allow the eyes to move in every
direction not controlled by other cranial nerves
• (2) Parasympathetic fibres to the iris to constrict and dilate when
adjusting to light and accommodation
• Supplies upper eyelid muscle (levator palpebrae superioris)
• A lesion in the oculomotor nerve can cause not only double vision
(diplopia) but failure of constriction of the pupil
• Due to its location, the oculomotor nerve is susceptible to damage by
elevated Intra-cranial Pressure
• A fixed dilated, painless pupil dilatation a sign of serious neurological
trouble
• Pupils not reacting to light- a sign of major cerebral dysfunction and a
sign used to verify death

25. CN III, IV & VI: Trochlear (IV) & Abducens
(VI) nerves
Function
• Trochlear Nerve controls a muscle that moves the eyeball down and
out (Superior Oblique).
• A lesion of this nerve can cause diplopia, which can be improved by
tilting the head away from the affected eye
• Abducens Nerve controls the muscle that moves the eye away from
the nose (Lateral Rectus). A lesion of the abducens nerve causes
double vision, in which one image is directly next to the other.
Sometimes the abducens nerve can be impacted on both sides in
cases of increased intracranial pressure, such as brain tumour

26. CN III, IV & VI:
CN III, IV & VI: Oculomotor (III), Trochlear (IV) and Abducens (VI) Nerves
 Inspect for ptosis, squint and check for diplopia. ? divergent or convergent squint
 Use classic sequence: ↔ lateral to lateral and ask about double vision and assess
range of movement, ↕ assess up and down movements eyes in midline, lateral and
then medial
 When checking for diplopia, observe for nystagmus at same time: jerky, pendular,
rotational- First Check that patient can see clearly with both eyes individually
 Oculomotor (III) all extraocular muscles except those supplied by Trochlear (IV)
and Abducens (VI) Nerves
 Trochlear (IV) Nerve supplies superior oblique
 Abducens (VI) Nerve supplies lateral rectus
 LR6 SO4 Mnemonic: All extraocular muscles are III, except LR (lateral rectus) is VI
and SO (superior oblique) is IV

27. CN III, IV & VI: Oculomotor (III), Trochlear
(IV) & Abducens (VI) nerves
The visual system
Borooah, Shyamanga, Macleod's Clinical Examination, 8, 151-169
Control of eye movements. The direction of displacement of the
pupil by normal contraction of a particular muscle can be used to
work out which eye muscle is paretic (weak). For example, a patient
whose diplopia is maximal on looking down and to the right =
Oculomotor lesion- down and out.
Copyright © 2018 © 2018 Elsevier Ltd. All rights reserved.
Ptosis
Repke, Carolyn S.,
Ophthalmology Secrets in
Color, Chapter 37, 292-297
Copyright © 2016 Copyright
© 2016 by Elsevier, Inc. All
rights reserved.
Eyes
Ball, Jane W., DrPH, RN, CPNP, Seidel's Guide
to Physical Examination, Chapter 12, 225-252
Strabismus.(Courtesy Freda Lemmi,
2009.)
Copyright © 2019 Copyright © 2019 by
Elsevier, Inc. All rights reserved.

28. CN V: Trigeminal nerve
Function
• Trigeminal Nerve is a sensory nerve and
motor nerve
• Sensory function: sensation from the face to
the brain
• Motor function: controls some facial muscles
important for mastication eg Masseters,
Pterygoids
• Severe complications of the trigeminal nerve
is trigeminal neuralgia, an extreme form of
facial pain.
• This may be caused by a virus, by
mechanical irritation due to rubbing by a
bundle of blood vessels near the nerve,
inflammation, tumour.
CN V: Trigeminal Nerve
 Facial Sensation: ophthalmic,
maxillary, mandibular
 Muscles of mastication: masseters
and temporalis, pterygoids (chewing)
 Corneal reflex: light wisp of cotton
wool applied over the cornea on the
lateral part of iris (motor efferent
component is facial). This test rarely
done (useful for pituitary
examination)
 Jaw Jerk: positive in bilateral UMN
lesions above the pons

29. CN V: Trigeminal nerve
Sensory and motor pathways
Johns, P. Clinical Neuroscience, Chapter 4,
49-59
The three branches of the
trigeminal nerve provide
sensation to most of the
head and neck. The
trigeminal nerve also
innervates the oral and nasal
cavities, paranasal air
sinuses, teeth, intracranial
dura and cerebral arteries.
Copyright © 2014 Copyright © 2014
Elsevier Ltd. All rights reserved
The Neurologic Examination
Corbett, J.J., Fundamental Neuroscience for Basic and Clinical
Applications, Chapter 33, 480-493.e1
Testing of sensory portions of the
trigeminal nerve. Examples show a
probe touching the ophthalmic ( A ) and
mandibular ( B ) territories of the
trigeminal nerve; the maxillary division
is tested by touching the cheek below
the eye. A wisp of tissue can be used.
Copyright © 2018 Copyright © 2018 by Elsevier, Inc. All
rights reserved.
The neurological examination : General signs
and the cranial nerves. Talley & O'Connor's
Clinical Examination, Chapter 32, 500-539
Cranial nerve V (motor):
‘Clench your jaw’—feel the
masseter muscles
Copyright © 2018 ©2018 Elsevier Australia.
The neurological examination : General
signs and the cranial nerves
Talley & O'Connor's Clinical Examination,
Chapter 32, 500-539
Cranial nerve V: the jaw
jerk
Copyright © 2018 ©2018 Elsevier

30. CN V: Trigeminal nerve
Brain and Spinal Cord
Paulsen, F., Sobotta Atlas of Human Anatomy, Vol. 3, 12, 211-342
Herpes zoster ophthalmicus. Patient with (herpes) zoster
ophthalmicus (skin in the innervation area of the first
trigeminal branch is affected by the infection with varicella
zoster virus, facial herpes zoster
Copyright © 2013 © Elsevier GmbH, Munich Urban & Fischer Verlag is an imprint of Elsevier
GmbH.
The nervous system
Epstein, Owen. Pocket Guide to Clinical Examination, Chapter 11, 221-278
Left trigeminal nerve lesion. Jaw deviation to the left.
Copyright © 2009 © 2009, Elsevier Limited. All rights reserved.

31. NCBI-NIHR 2019

32. Pituitary mass lesions:
Can affect CN- 2,, 3, 4, 5, 6

33. Richard Kiel - Actor
Pituitary Foundation Accessed 2021
NCBI-NIHR 2019
Pituitary mass lesions: GH Secreting Tumour-
Acromegaly and Gigantism
Can affect CN- 2,, 3, 4, 5, 6

34. Pituitary mass lesions: ACTH Secreting
Tumour- Cushing’s Syndrome
Can affect CN- 2,, 3, 4, 5, 6

35. CN VII: Facial nerve
Function
Facial: Both motor and sensory
• Motor: most muscles of the face. It also
helps modulate hearing through control of
the stapedius muscle
• Sensory: transmits taste signals from the
front of the tongue and a small area around
the ear
• Parasympathetic: make the eyes tear and
mouth salivate
• This is why inflammation of the facial nerve-
especially Bell’s Palsy- can lead to more
problems than just facial weakness, though
such weakness is usually the most obvious
symptom.
CN VII: Facial Nerve
 Facial movement muscles: frontalis,
orbicularis oculi, buccinator,
orbicularis oris, naso-labial,
 (Greater superficial petrosal N supplies
lachrymal and salivary glands)
 (Stapedius nerves: dampens loud
noises)
 (Chorda tympani : taste to anterior 2/3
of tongue)
• NB: In Stroke there is Frontalis
Sparing (ie not affected) due to
bilateral innervation of the frontalis

36. CN VII: Facial nerve
The nervous system
Davenport, Richard, Macleod's Clinical Examination, 7, 119-150
Component fibres of the facial nerve and their
peripheral distribution.
Copyright © 2018 © 2018 Elsevier Ltd. All rights reserved.
The Nervous System
Swartz M. Textbook of Physical Diagnosis, Chapter 18, 583-636.e2
Testing the facial nerve. A and B, Tests for
the lower division. C, Test for the upper
division.
Copyright © 2014 Copyright © 2014, 2010, 2006, 2002, 1998,
1994, 1989 by Saunders, an imprint of Elsevier Inc.
The neurological examination : General signs and the cranial nerves
Talley & O'Connor's Clinical Examination, Chapter 32, 500-539
Cranial nerve VII: ‘Shut your eyes tight and stop
me opening them’ (normal)
Copyright © 2018 ©2018 Elsevier Australia. 1st edition ©1988, 2nd edition
©1992, 3rd edition ©1996, 4th edition ©2001, 5th edition ©2006, 6th edition
©2010, 7th edition ©2014 Elsevier Australia

37. CN VII: Facial nerve: Bell’s Palsy
Brain and Spinal Cord
Paulsen, F., Sobotta Atlas of Human Anatomy, Vol. 3, 12, 211-342
Peripheral paralysis of the facial nerve [VII], right side. Skin folds on the right side of the face have disappeared. a
When the patient is asked to raise the eyebrows, only the left side of the forehead displays...
Copyright © 2013 © Elsevier GmbH, Munich Urban & Fischer Verlag is an imprint of Elsevier GmbH.
Bell's phenomenon (also known as the palpebral oculogyric reflex) is an
upward and outward movement of the eye - when an attempt is made to close
the eyes. The upward movement of the eye is present in the majority of the
population, and is a defensive mechanism. Difficult to see except with Facial
Palsy.

38. • Usually temporary unilateral facial paralysis or weakness. Dysarthria.
• Symptoms appear suddenly over a 48 - 72-hour period, then improves over
weeks, can be permanent
• Note dryness of the eye, and excessive tearing in one eye. Individuals may also
have facial pain or abnormal sensation, altered taste, and intolerance to loud
noise. Most often these symptoms lead to significant facial distortion
• Viral infection: Cold sores and genital herpes (herpes simplex), Chickenpox
and shingles (herpes zoster), Infectious mononucleosis (Epstein-Barr),
Cytomegalovirus infections, Respiratory illnesses (adenovirus), German
measles (rubella), Mumps (mumps virus)
• Impaired immunity from stress, sleep deprivation, physical trauma, minor illness
or autoimmune syndromes are suggested as the most likely triggers. Facial
nerve swells, becomes inflamed, pressure within the Fallopian canal of the skull.
• Differential Diagnosis: brain tumor, stroke, Myasthenia gravis, Lyme disease,
Sarcoidosis, Trauma
• Treatment: Steroids: steroids and aciclovir (antiviral), physiotherapy, eye
lubricants
Bell’s Palsy

39. Frontalis Muscle: Stroke versus Bell’s Palsy
Bell's Palsy is a peripheral nerve
effect whereas a ischemic stroke is a
central process.
As shown in the diagram, the forehead
receives motor innervation from both
hemispheres of the cerebral cortex. A
stroke that compromised motor
innervation of the face would therefore
only result in paralysis of the lower half
of the face - the forehead still receiving
innervation from the unaffected
hemisphere.
A peripheral lesion, such as Bell's
Palsy, interrupts the innervation after
the motor commands from both
hemispheres have joined, so that the
forehead (frontalis) is paralyzed.

40. COVID 19: Cranial Nerve Disorders:
Yavarpour-Bali H, Ghasemi-Kasman M. Update on neurological
manifestations of COVID-19. Life Sci. 2020;257:118063.
doi:10.1016/j.lfs.2020.118063

41. CN VIII: Vestibulo-cochlear nerve
Function
• This nerve has two main components
• (1) Cochlear component relays
acoustic information to the brain so that
we can hear
• (2) Vestibular portion sends signals
regarding balance and movement.
• Problems with the vestibulocochlear nerve
can cause either hearing loss or vertigo, and
often cause both
• A common problem involving cranial nerve
VIII is an acoustic neuroma. This benign
tumour can press against the nerve, leading
to hearing loss or dizziness.
CN VIII: Vestibulo-cochlear Nerve
 Assess hearing
 Weber’s: lateralizing test, use 512
or 256 Hz tuning fork, place on
middle of forehead and ask patient
to lateralize the sound. ? equal or
lateralized
 Rinné’s test: in healthy patients, air
conduction better than bone
conduction. Use mastoid process

42. CN VIII:
Vestibulo-cochlear
nerve
Cranial Nerve VIII : Auditory and Vestibular
Toh, Elizabeth, Netter's Neurology, 9, 102-112
Hearing Tests: Weber and Rinne.
Copyright © 2020 Copyright © 2020 by Elsevier, Inc.
All rights reserved.

43. CN IX & X: Glossopharyngeal (IX) & Vagus (X) nerves
Function
Glossopharyngeal nerve has many functions.
• Sensory:
• Taste from the back of the tongue
(facial is front)
• Sensation from a small portion of the
ear and parts of the tongue and throat
• Motor:
• Innervation of one muscle important for
swallowing- stylopharyngeus
• Parasympathetic: salivation by the parotid
gland.
• BP Control: It also receives important
information on BP from chemoreceptors and
baroreceptors in the carotid body. Irritation of
the glossopharyngeal nerve can lead to
glossopharyngeal neuralgia, a condition in
which it is very painful to swallow (cause of
dysphagia- rare)
CN IX & X:
Glossopharyngeal (IX) and Vagus (X) Nerves
 Assess movement of the soft palate. Look
at position of uvula. Check phonation.
 Assess sensation of the soft palate with a
gag reflex (rarely done, mention only)
 Glossopharyngeal is taste to the posterior
third of the tongue and afferent limb of
the gag reflex
 Vagus is efferent in the gag reflex and
motor supply to pharynx, soft palate and
larynx

44. CN IX & X: Glossopharyngeal (IX) & Vagus (X) nerves
Function
Vagus Nerve
• Motor: Controls the pharynx (for swallowing) and larynx (for speaking)
• Sensory: Sensation from the pharynx, part of the meninges and a small
portion of the ear. Detects taste (from the throat) – “bile”
• Cardio-respiratory Functions: Detects special signals from chemo and
baroreceptors near the heart (in the aortic arch). Furthermore, the vagus
nerve relays parasympathetic fibers to the heart, the signals from which can
slow the heart's beating. Because of its relationship to the heart, disorders of
the vagus nerve can result in arrythmias.
• Stimulation of the vagus nerve has been shown to be potentially useful in a
wide array of disorders, including epilepsy

45. CN IX & X: Glossopharyngeal (IX) & Vagus (X)
nerves
The nervous system
Davenport, Richard, Macleod's Clinical
Examination, 7, 119-150
The lower cranial nerves:
glossopharyngeal (IX),
vagus (X) and accessory
(XI).
Copyright © 2018 © 2018 Elsevier Ltd.
All rights reserved.
The neurological examination : General signs and the
cranial nerves
Talley & O'Connor's Clinical Examination, Chapter 32, 500-
539
Cranial nerve X: ‘Say “Ah” '—look for
asymmetrical movement of the uvula
Copyright © 2018 ©2018 Elsevier Australia
The nervous system
Epstein, Owen, MB BCh FRCP, Pocket Guide to Clinical
Examination, Chapter 11, 221-278
Palsy of the left vagus. The palate
deviates to the right on phonation
(b).
Copyright © 2009 © 2009, Elsevier Limited. All rights
reserved.

46. CN XI: Accessory nerve
Function
Spinal accessory nerve is less
complicated!
• One main function: to cause the
contraction of the sternocleidomastoid
muscles and trapezius to move head
and shoulders
• Disorders of this nerve diminish the
ability to use these muscles
• Move shoulders not shrug as can
involve back muscles
CN XI: Accessory Nerve
 Assess trapezius and
sternocleidomastoid muscles

47. CN XI: Accessory nerve
The neurological examination : General signs and
the cranial nerves
Talley & O'Connor's Clinical Examination, Chapter
32, 500-539
(a) Cranial nerve XI: ‘Shrug your
shoulders—push up hard’. (b)
Wasting of the left trapezius
muscle
Copyright © 2018 ©2018 Elsevier Australia
Cranial nerve XI: ‘Turn your
head against my hand’
Shoulder girdle and arm
Standring S. Chapter 48, 797-836.e1
A left accessory palsy with Scapular
winging: No prominence of the lower fibres
of trapezius, in a case where there is some
early recovery into the upper fibers after
repair of the accessory nerve.
Copyright © 2016 © 2016, Elsevier Limited. All rights reserved.

48. CN XII: Hypoglossal nerve
Function
Hypoglossal nerve
• Motor nerve that controls all the
movements of the tongue. Difficulty
speaking (dysarthria) or moving food
in your mouth are potential
consequences of a damaged
hypoglossal nerve.
• Disorders of this nerve diminish the
ability to use these muscles
CN XII: Hypoglossal Nerve
 Assess the tongue and its
movements: wasted,
fasiculating, ? reduced power

49. CN XII: Hypoglossal nerve
Neurologic System
Ball J. Seidel's Guide to Physical Examination, Chapter 23, 567-606
Examination of the hypoglossal cranial
nerve. A, Inspect the protruded tongue for
size, shape, symmetry, and fasciculation. B,
Observe movement of the tongue from side
to side.
Copyright © 2019 Copyright © 2019 by Elsevier, Inc. All rights
reserved.
The neurological examination : General signs and the
cranial nerves
Talley & O'Connor's Clinical Examination, Chapter 32,
500-539
Right hypoglossal (XII) nerve
palsy—lower motor neurone
lesion: ‘Stick out your tongue’
Copyright © 2018 ©2018 Elsevier Australia
Left hypoglossal nerve lesion with
wasting.. From Epstein O, Perkin GD, de Bono DP,
et al. Clinical Examination. 2nd edn. London: Mosby;
1997.
Copyright © 2018 © 2018 Elsevier Ltd. All rights
reserved.

50. Clinical Skills Course 2 handbook
– P 38
Macleod’s Clinical Examination 14th edition
– Chapter 7, P.120-133
Clinical Key
– www.clinicalkey.com
References

52. Cranial Nerves: Anatomy and Function

53. Cranial Nerves: Additional slides
Key Points
• Cranial nerves are nerves that come from the brain and exit the skull through
the cranial foramina
• There are 12 paired cranial nerves that arise from the brainstem
• The trigeminal cranial nerve is the largest of the cranial nerves. It is involved in
corneal reflex and facial sensation along with chewing.

54. CN II: Optic nerve

55. CN II: Optic nerve

56. CN II: Optic nerve

57. CN II: Optic nerve