cranial nerve exmination

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

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


Cranial Nerve 12

g

Tongue movement

Cranial Nerves attachments


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


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


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


(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 ( )


Paralysis of ( III ) oculomotor nerve

Results

Partial ptosis

Dilation of pupil

Loss of accommodation

Diplopia

Lateral squint


V ‐ Facial sensation, movements of the

jaw, and corneal reflexes

VII ‐ Facial movements and gustation

VIII ‐ Hearing and balance


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


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.


Olf NOlfactory Nerve

Olfactory Bulb

Olfactory Tract

Test each nostril with essence bottles

of coffee, vanilla, peppermint.


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


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


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


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


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


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.


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


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.


Visuall Tesst


ViSual acuiityeest


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.


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.


2 4 66 nerrve test


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.



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


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.


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



• 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].


light touch [cotton].


• 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.


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.


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


Temporal, Zygomatic, Buccal, Masseteric, Cervical

Faciaal nerve Teest


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.


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


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


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


Heearring

TTesst


RInne’es& weber’ssTe


st

VeestIbulaarTes


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.


• 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.


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.


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.


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


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


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


Glossopharrynggeal & Va


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


typically preserved in patients who injure their spinal cords

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


Accessorry nerve te


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.


Cranial Nerve XII – Hypoglossal yp g

The hypoglossal nerve controls the intrinsic

l t f th tmusculature of the tongue

Tongue function; wasting / fasciculation


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.


Hyppogllossal nerrve


Meemory

Teestt


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

[email protected]

giridhar@webduniya com


[email protected]

cranial nerve exmination

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