Post on 18-Dec-2014
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To CLINICAL ANATOMY OF CRANIAL NERVES
Byy
Dr . Giridhar M KanthiProf & Head
Dept of Basic principlesS D M College of Ayurveda. Udupi
8/23/2011 1Dr G M Kanthi Prof S D M C A Udupi
“ h & ”“ You have I nose & II eyes ”
I ‐ Olfactory n & II ‐ Optic nI ‐ Olfactory n. & II ‐ Optic n.
8/23/2011 Dr G M Kanthi Prof S D M C A Udupi 2
8/23/2011 Dr G M Kanthi Prof S D M C A Udupi 3
The cranial nerves all exit from the bottom surface of the brain and brainstem
and exit the skull through various holes (foramina) to reach their targets
Cranial Nerve 1 Smell
and exit the skull through various holes (foramina) to reach their targets.
Cranial Nerve 2
Cranial Nerve 3
Cranial Nerve 4
Vision
Eye movement
Eye movementCranial Nerve 4
Cranial Nerve 5
Cranial Nerve 6
Eye movement
Facial sensation
Eye movement
Cranial Nerve 7
Cranial Nerve 8
C i l N 9
Facial movement
Hearing and balance
O d T tCranial Nerve 9
Cranial Nerve 10
Cranial Nerve 11
Organs and Taste
Organs and Taste
Shoulder shrug & head turn
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Cranial Nerve 12
g
Tongue movement
Cranial Nerves attachments
8/23/2011 5Dr G M Kanthi Prof S D M C A Udupi
C N IOlfactory Nerve
CN II
C N IVC N III
C N V
C N VII
C N IV
C N VIC N VII
C N IXC N XI
C N VIII
C N XC N XII
I ‐ Olfactory1. One
2 OfI On
II ‐ Optic
III – IV – VI ‐ Extraoculars
2. Of
3. Our
4 T i d
II Old
III Olympus
V Trigeminal
VII ‐ Facial
III – Oculomotor
IV – Trochlear
VII Abducent
4. Trained
5. Teacher
6 Asked
IV Towering
V Tops
VI A VII Facial
VIII ‐ Vestibulocochlear
VII ‐ Abducent6. Asked
7. For
8 A
VI A
VII Finn
VIII AndIX ‐ Glossopharyngeal,
X ‐ Vagus
8. A
9. Good
10. Vehicle
VIII And
IX German
X Viewed
XI: Accessory
XII H l l
10. Vehicle
11. And
12. Horse
X Viewed
XI Astounding
XII HopsXII: Hypoglossal
8/23/2011 7Dr G M Kanthi Prof S D M C A Udupi
Extraocular muscles
“ LR 6 SO 4 R 3 "“ LR 6 ‐ SO 4 ‐ Rest 3 "
LR 6 Lateral Rectus ‐‐> VI abducens
SO4 Superior Oblique ‐‐> IV Trochlear
Remaining 4 eyeball movers ‐‐> III oculomotor
8/23/2011 Dr G M Kanthi Prof S D M C A Udupi 8
8/23/2011 Dr G M Kanthi Prof S D M C A Udupi 9
I ‐ Olfactory
II O tiFore brain
II ‐ Optic
III – Oculomotor
Mid b iIV – Trochlear
Mid brain
V TrigeminalV Trigeminal
VII ‐ Abducent
VII ‐ FacialPons
VIII ‐ Vestibulocochlear
IX ‐ GlossopharyngealIX Glossopharyngeal,
X ‐ Vagus
XI: AccessoryMedulla
y
XII: Hypoglossal8/23/2011 10Dr G M Kanthi Prof S D M C A Udupi
I Some (Sensory)Some
SaysII Say (Sensory)
III Marry (primarily Motor)
Says
Marry
Money IV Money, (primarily Motor)
V But (Both)
Money
But
VI My (primarily Motor)
VII Brother (Both)
VIII Says (Sensory)
My
Brother
VIII Says (Sensory)
IX Big (Both)
X Bras (Both)
Says
Bad X Bras (Both)
XI Matter (primarily Motor)
XII More (primarily Motor)
Business
Marry
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(p y )Money
Summary of the Cranial Nerves
I ‐ Smell
II ‐ Vision ‐ Visual acuity, visual fields and ocular function
II, III ‐ Pupillary reactions
III IV VI E t l t i l di iIII, IV, VI ‐ Extra‐ocular movements, including opening
of the eyes & eye movementof the eyes & eye movement
ptosis (III nerve) and pupil reaction to light (II & III nerve)p ( ) p p g ( )
8/23/2011 12Dr G M Kanthi Prof S D M C A Udupi
Paralysis of ( III ) oculomotor nerve
Results
Partial ptosis
Dilation of pupil
Loss of accommodation
Diplopia
Lateral squint
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V ‐ Facial sensation, movements of the
jaw, and corneal reflexes
VII ‐ Facial movements and gustation
VIII ‐ Hearing and balance
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IX, X ‐ Swallowing, elevation of the palate, gag reflex and gustation
V, VII, X, XII ‐ Voice and speech
XI ‐ Shrugging the shoulders and turning the head
XII M t d t i f tXII ‐Movement and protrusion of tongue
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Olfactory Nerve – Cranial Nerve 1
The olfactory nerve is essentially responsible for the sense of smell.
It courses along the base of the frontal lobes and perforates throughIt courses along the base of the frontal lobes and perforates through
the base of the skull and rests inside the roof of the nose.
Recently, these nerves have received additional interest because of their
potential for involvement in the harvest of naturally existing stem cells.
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Olf NOlfactory Nerve
Olfactory Bulb
Olfactory Tract
Test each nostril with essence bottles
of coffee, vanilla, peppermint.
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Evaluate the potency of the nasal passages bilaterally
Cranial Nerve IInform to close the eyes
place a small bar of soap near the patent nostril
ask the patient to smell the object
This part of the exam is often omitted
ask the patient to smell the object
unless their is a reported history suggesting head
t t i i h l titrauma or toxic inhalation.
Very little localizing information can be obtained
8/23/2011 18Dr G M Kanthi Prof S D M C A Udupi
The olfactory nerve is essentially responsible for the sense of smell.
Gather some items with distinctive smells
(for example, cloves, lemon, chocolate or coffee).
Test each nostril with essence bottles of coffee, vanilla, peppermint.
C. N I. video
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Cranial Nerve II
Using an ophthalmoscope,
Retinal vessels and fovea
Observe the optic disc
e a esse s a d o ea
Note the pulsations of the optic vessels
Check for a blurring of the optic disc margin
Change in the optic disc's color form its
normal yellowish orangey g
8/23/2011 21Dr G M Kanthi Prof S D M C A Udupi
The initial change in the ophthalmoscopic examination
in a patient with increased intracranial pressure
is the loss of pulsations of the retinal vessels.
Thi i f ll d b bl i f th ti di iThis is followed by blurring of the optic disc margin
and possibly retinal hemorrhages. p y g
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Cranial Nerve II
Visual acuity by using aVisual acuity by using a
pocket visual acuity chart
Visual acuity
Evaluate the visual fields,
color vision, and optic disc appearance
8/23/2011 23Dr G M Kanthi Prof S D M C A Udupi
visual fields
Cranial Nerves II and IIIObserve the diameter of the pupils in a dimly
light room.
Shine the penlight light into one eye at a timeShine the penlight light into one eye at a time
and check both the direct and consensual light
i h ilresponses in each pupil.
Note the symmetry between the pupils.
Test for pupillary constriction
Note their size and possible asymmetryNote their size and possible asymmetry.
8/23/2011 24Dr G M Kanthi Prof S D M C A Udupi
The two circles below represent the vision seen by both eyes. Initially,
both the right and the left optic nerve record and take back to the brain
2 colors – black and yellow2 colors – black and yellow.
After the fibers cross in the optic chiasm, only the yellow picture from
Each eye is returned to the left occipital lobe
and only the black picture is returned to the right occipital lobe.
Right EyeLeft Eye
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Right EyeLeft Eye
Ptosis is the lagging of an eyelid.
The ptosis from a III nerve palsy is of greaterThe ptosis from a III nerve palsy is of greater
severity than the ptosis due to a lesion of the
sympathetic pathway,
Anisocoria is a neurological term indicating
that one pupil is larger than another.
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Visuall Tesst
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ViSual acuiityeest
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Cranial Nerves III, IV and VI – Oculomotor, Trochlear, Abducent
Eyes movement in all direction without moving the head.
The movement of both eyes in one direction is called a conjugate movementsThe movement of both eyes in one direction is called a conjugate movements
The oculomotor nerve is the most diverse.
It is responsible for moving each eye towards the nose, up, down, and
external rotationexternal rotation.
Additionally, it is responsible for shrinking the size of the pupil and allow
less light to enter the eye.
8/23/2011 30Dr G M Kanthi Prof S D M C A Udupi
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A problem with the oculomotor nerve might result in
double vision when looking at near object and cause
trouble when reading.trouble when reading.
The trochlear nerve is responsible for internal rotation of the eye.
A problem with this nerve often is noticed by the patient as they
have trouble walking down stairs.
abducens nerve is responsible for moving each eye temporally – or
f th A bl ith th i th lt i d blaway from the nose. A problem with the sixth nerve results in double
vision on looking at distant objects.
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2 4 66 nerrve test
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Trigeminal Nerve ‐ Cranial Nerve 5
The trigeminal nerve is one of the largest cranial nerves.
It also has many functions.
The entire sensation from the face, the forehead, the cheeks,
and the jaw are returned to the brain from the three different
divisions of this nerve.
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Trigeminal Nerve ‐ Cranial Nerve 5
Three different divisions of this nerve.
1. Opthalmic br. ‐ Sensory to Fore head, air sinus, Eyeball (ciliary, eyelids)
side & tip of nose, and lacrimal gland
2. Maxillary br. ‐Middle cranial fossa, pterygopalatine fossa,
Imfraorbital canal, and Face
3 M dib l b t id li l l h id d di t i
8/23/2011 37Dr G M Kanthi Prof S D M C A Udupi
3. Mandibular br. ‐ pterygoid, lingual, mylohyoid, and diagastricz
Cranial Nerve – V Trigeminal Test for ‐ Jaw power
Sensation of face
Corneal and jaw reflexes
1. Palpate the masseter muscles
Corneal and jaw reflexes
2. Note masseter wasting on observation
3. Ask the patient to open their mouth against
resistance applied by the instructor at the base
of the patient's chin.
8/23/2011 38Dr G M Kanthi Prof S D M C A Udupi
4. Test gross sensation –
Tell the patient to close their eyes and say "sharp" or
"d ll" h th f l bj t t h th i f
5. Ask the patient to also compare the strength
"dull" when they feel an object touch their face
p p g
of the sensation of both sides
6. Touch the patient above each temple, next
h d h id f h hito the nose and on each side of the chin
7. Test the corneal reflex ‐ look for the eye to blink
8/23/2011 39Dr G M Kanthi Prof S D M C A Udupi
Trigeminal Nerve ‐ Cranial Nerve 5
• Corneal reflex: patient looks up and away.
• Touch cotton wool to other side.
• Look for blink in both eyes, ask if can sense it.
• Repeat other side [tests V sensory, VII motor].
F i l ti t il h it f h d h k j• Facial sensation: sterile sharp item on forehead, cheek, jaw.
• Repeat with dull object. Ask to report sharp or dull.
• If abnormal, then temperature [heated/ water‐cooled tuning fork],
light touch [cotton].
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light touch [cotton].
Trigeminal Nerve ‐ Cranial Nerve 5
• Motor: pt opens mouth, clenches teeth (pterygoids).
• Palpate temporal, masseter muscles as they clench.
• Test jaw jerk:Test jaw jerk:
Dr's finger on tip of jaw.
Grip patellar hammer halfway up shaft and tap Dr's finger lightly.
Usually nothing happens, or just a slight closure.
If increased closure, think UMNL, esp pseudobulbar palsy.
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Facial Nerve ‐ Cranial Nerve 7
The facial nerve is responsible for moving most of the muscles of the face.
It helps us to smile, raise an eyebrow, wrinkle the forehead, puff our cheeks,
straighten our neck muscles in order to shave, and sometimes even to wiggle
Our ears. Interestingly, enough, the taste from the front 2/3 of the tongue is
transmitted to the brain from the facial nerve and parts of the facial nerve aids
In allowing the salivary glands to secrete their fluid to assist in chewing and
digestion.
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Cranial Nerve VII – Facial 1. inspect the face during conversation and
rest, noting any facial asymmetry
2 D i i hi f l2. Drooping, sagging or smoothing of normal
facial creases.
3. Ask the patient to raise their eyebrows,
smile showing their teeth,
Branches of the facial nerve
"Ten Zombies Bought My Car“
Temporal Zygomatic Buccal Masseteric Cervical
8/23/2011 43Dr G M Kanthi Prof S D M C A Udupi
Temporal, Zygomatic, Buccal, Masseteric, Cervical
Faciaal nerve Teest
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Auditory Nerve ‐ Cranial Nerve 8
Another name for the auditory nerve is the vestibulo‐cochlear nerve.
It is so called this because it serves 2 purposes.
The hearing or sound information is transmitted back to the
b i h h h hlbrain through the cochlear nerve.
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The balance information is transmitted through the vestibular g
portion of the nerve.
There is a fairly well known tumor although misnamed
ll d h h f hcalled an Acoustic Neuroma which arises from this nerve.
It is misnamed because this commonly benign tumor actually arises fromIt is misnamed because this commonly benign tumor actually arises from
the vestibular nerve and is not a nerve tumor as the name implies.
Vestibular test
8/23/2011 46Dr G M Kanthi Prof S D M C A Udupi
Vestibular test
Cranial Nerve VIII ‐ Auditory Rinne's test
The Rinne’s test compares air conduction to
bone conductionbone conduction.
Perform an otoscopic examination of both
Occlusion of the external auditory meatus
Eardrums to rule out a severe otitis media
Occlusion of the external auditory meatus
Perforation of the tympanic membrane
8/23/2011 47Dr G M Kanthi Prof S D M C A Udupi
Cranial Nerve VIII ‐ Auditory
A h iAssess hearing
1. By instructing the patient to close their eyes,
Vigorously rub your fingers together very near
to the ear.to the ear.
2. The sound was the same in both ears, or
louder in a specific ears
3. If there is lateralization or hearing
abnormalities perform the Rinne and Weber Tests
Th W b t t i t t f l t li ti
Weber’s test
The Weber test is a test for lateralization
8/23/2011 48Dr G M Kanthi Prof S D M C A Udupi
Heearring
TTesst
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RInne’es& weber’ssTe
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st
VeestIbulaarTes
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t
•Dr's hands arms length by each ear of pt.
• Rub one hand's fingers with noise on one side, other hand noiselessly.
• Ask pt which ear they hear you rubbing Ask pt. which ear they hear you rubbing.
• Repeat with louder intensity, watching for abnormality.
• Weber's test: Lateralization
• 512/ 1024 Hz [256 if deaf] vibrating fork on top of patients head/ forehead.
• "Where do you hear sound coming from?"
• Normal reply is midline.
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• Rinne's test: Air vs. Bone Conduction
• 512/ 1024 Hz [256 if deaf] vibrating fork on mastoid behind ear.
Ask when stop hearing it.
• When stop hearing it, move to the patients ear so can hear it.
• Normal: air conduction [ear] better than bone conduction [mastoid].
• If indicated, look at external auditory canals, eardrums.
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Cranial Nerves IX and X
The functions of the glossopharyngeal and the vagus nerve
are too many to list. In essence, these two nerves take to and
from the brain information regarding swallowing, taste, voice,
organ function, heart rate, abdominal function, etc.
In fact vagus means wandering in LatinIn fact, vagus means wandering in Latin.
8/23/2011 54Dr G M Kanthi Prof S D M C A Udupi
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Glossopharyngeal and Vagus Nerve ‐ Cranial Nerve 9,10
The vagus nerve actually starts from the brain and is continuous all
the way through and even reaches the intestines.
Since there are so many functions of this nerve,
the signal from the body also have to be returned to many
parts of the brain through the same nerve as well.
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Interestingly, it was discovered that this nerve
could serve as a conduit through which to treat epilepsy – or seizures.
A neurosurgeon can surgically wrap and electrode around this nerve and
t it t k d i hi h th b d t t t ilconnect it to a pacemaker device which can then be used to treat epilepsy
in some patientsin some patients
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Cranial Nerves IX and X - Glossopharyngeal & Vagus
Ask the patient to swallow and note any
difficulty doing so
Soft palate elevation,
Deviation & Gag reflex difficulty doing so.
Note the quality and sound of the patient's
voice. Is it hoarse or nasal ?
observe the soft palate uvula and pharynxobserve the soft palate, uvula and pharynx.
The soft palate should rise symmetrically,
the uvula should remain midline
8/23/2011 59Dr G M Kanthi Prof S D M C A Udupi
Pt "Ah" t i l ft l t t•Pt says "Ah": symmetrical soft palate movement.
Gag reflex [sensory IX motor X]:Gag reflex [sensory IX, motor X]:
• Stimulate back of throat each side. Stimulate back of throat each side.
• Normal to gag each time
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Glossopharrynggeal & Va
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gus
Accessory Nerve ‐ Cranial Nerve 11
The accessory nerve is responsible for turning the head,
nodding yes and no, and shrugging the shoulders. Specifically,
it controls the muscles called the sternocleidomastoid and the trapezius.
Since this nerve controls head turning and is a cranial nerve – as
opposed to a spinal nerve, the motion of turning the head is
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typically preserved in patients who injure their spinal cords
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Cranial Nerve XI - Accessory
Shoulder elevation & turning of neck
with head (trapezius and sternomastoid)
Evaluated by looking for wasting of the
i l b b itrapezius muscles by observing
Ask the patient to turn their head to
h d l h blthe side as strongly as they possibly
8/23/2011 64Dr G M Kanthi Prof S D M C A Udupi
Accessorry nerve te
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est
Hypoglossal Nerve ‐ Cranial Nerve 12Hypoglossal Nerve ‐ Cranial Nerve 12
The hypoglossal nerve is responsible for the complex movements of theThe hypoglossal nerve is responsible for the complex movements of the
tongue. There is some help from the vagus nerve but three of the four
main tongue muscles are controlled from the hypoglossal nerve.
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Cranial Nerve XII – Hypoglossal yp g
The hypoglossal nerve controls the intrinsic
l t f th tmusculature of the tongue
Tongue function; wasting / fasciculation
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Cranial Nerve XII – Hypoglossal
Note is their deviations of the tongue from midline,
Note complete lack of ability to protrude the tongue
Note is there the tongue will be protruded g p
from the mouth and remain midline.
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Hyppogllossal nerrve
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Meemory
Teestt
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Dr . Giridhar M Kanthi. B S A M; DHA; Ph.D
Prof & HeadProf & Head Dept of Basic principles
S D M College of Ayurveda. Udupi. 574 118S D M College of Ayurveda. Udupi. 574 118Karanataka
Residence – Hudco Colony L I G 39
Manipal – 576 104
Cell – 9448888378Land line - 08202570417
E mail – girisha_k @yahoo.com
girishakanthi@gmail.com
giridhar@webduniya com
8/23/2011 Dr G M Kanthi Prof S D M C A Udupi 71
giridhar@webduniya.com
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