CRANIAL NERVE ASSESSMENT

Dr. PAWAN SHARMA (PT)

M.P.T. (NEURO)

ASSISTANT PROFESSOR,

SHRI U.S.B. COLLEGE OF PHYSIOTHERAPY

ABU-ROAD, RAJASTAHAN

Email- pawan.physio2011@gmail.com

Contact- 07727989353

IV Trochlear

III Oculomotor

VII Facial

VI Abducens

V Trigeminal

CEREBRAL

HEMISPHERE

MIDBRAIN

PONS

MEDULLA

CRANIAL NERVES II Optic

I Olfactory

VIII Vestibulo-

cochlear

XII Hypoglossal

XI Accessory

X Vagus

IX Glossopharyngeal

CRANIAL NERVES 2

CRANIAL NERVES

The 12 pairs of cranial nerves are part of the

peripheral nervous system.

The Roman numeral is based on descending

order of the cranial nerve's attachment to the

CNS.

As a rule, cranial nerves do not cross in the

brain.

Cranial nerves may be sensory, motor both

somatic or parasympathetic, or have mixed

function.

General Characteristics:

CRANIAL NERVES 3

REMEMBER ME… SOME

SAYS

MONEY

MATTERS

BUT

MY

BROTHER

SAYS

BIG

BRAIN

MATTERS

MOST

S-SENSORY

M- MOTOR

B- BOTH

All in

sequence

CRANIAL NERVES 4

CN I - OLFACTORY

• ORIGIN: Cerebral hemisphere

• INNERVATION: Nasal mucous

membranes.

• FUNCTION: Sense of smell

• DYSFUNCTION: Anosmia

CLINICAL EVALUATION • Use non-noxious aromatic

substances, i.e. coffee, lemon,

garlic, etc.

• Test each nostril separately.

• Mark if any abnormality noted

CRANIAL NERVES 5

CN II – OPTIC NERVE

• VISUAL ACUITY: Snellen

chart for distant vision,

Jaegers chart, newspaper or

fingers for near vision.

• VISUAL FIELDS:

Confrontation.

• FUNDI AND OPTIC DISCS:

Visualization of the termination

of the optic nerve by looking

through pupil with

ophthalmoscope.

CRANIAL NERVES 6

CN II – OPTIC NERVE(cont..)

Tested by-

1. Visual acuity

2. Color vision

3. Visual field

CRANIAL NERVES 7

Near field

Far field

Color

matching

Confrontation

test

CN II – OPTIC NERVE(cont..) Visual acuity-

Snellen chart(Far vision)

◦ Chart is placed at 20 feet or 6 meter and patient is asked to read it

◦ The formula is d/D

Where d is 6 meter and D is the distance from which he can read it clearly

Normal is 6/6 or 20/20

Jaegers chart(Near vision)

◦ Paragraphs are printed in successive coarser type with 0 is finest and 7 is biggest

◦ Patient is asked to read through the hole

CRANIAL NERVES 8

CN II – OPTIC NERVE(cont..)

Color vision-

◦ Checked by asking to

match different colors

• Day or night blindness

can be assessed

• Visual field-

Confrontation test

Peripheral visual fields-

Goldmann Perimeter

CRANIAL NERVES 9

SPECIFIC DYSFUNCTIONS • Blurred vision or complete blindness.

• Ipsilateral vision loss - Optic atrophy, retinal/optic nerve lesions, trauma.

• Visual loss (one or both eyes) - Optic chiasm or occipital lobe lesions.

• Hemianopia - (loss of half of visual field in one or both eyes) - Lesions of optic chiasm, tracts, or radiations.

• Cortical blindness - Lesion of occipital cortex bilaterally, pupil reflexes intact.

• Papilledema - Optic nerve tumor, venous obstruction, chronic increased ICP.

• Optic atrophy - MS, optic neuritis, increased ICP. • Scotomas- (Abnormal blind spots on visual fields)

- optic neuritis or atrophy.

CRANIAL NERVES 10

CN III – OCULOMOTOR NERVE ORIGIN: Midbrain

INNERVATION: EOM's;

eyelid; ciliary; and sphincter of

iris.

FUNCTION: Eye movement

inward (medially), upward,

downward, and outward; pupil

Constriction, shape and

equality; elevates upper eyelid;

accommodation reflex.

DYSFUNCTION: Unable to

look up, down, or medial

(dysconjugate gaze); ptosis,

pupil dilatation - bilateral or

ipsilateral, and loss of

accommodation reflex.

CRANIAL NERVES 11

CN III – OCULOMOTOR

NERVE(cont..) • Observe for eye opening and

symmetry.

• Direct light response - brisk, sluggish, or non-reactive.

• Consensual response - present or absent.

• Pupil size and shape.

• Accommodation.

• Extra ocular movement (EOM's) (Abducens).

CRANIAL NERVES 12

CRANIAL NERVE FUNCTION & MUSCLE

INNERVATION

RELATIVE TO EYE MOVEMENT Superior rectus

CN III

Inferior oblique

CN III

Lateral rectus

CN VI Medial rectus

CN III

Superior oblique

CN IV Inferior rectus

CN III

CN IV – TROCHLEAR NERVE

ORIGIN: Midbrain

INNERVATION: Superior

oblique muscle.

FUNCTION: Down and

inward movement of the

eye.

DYSFUNCTION: Loss of

downward, inner

movement of eye,

dysconjugate gaze.

CRANIAL NERVES 14

SUPERIOR OBLIQUE MUSCLE

CN VI – ABDUCENS NERVE

ORIGIN: Pons

INNERVATION: Lateral

rectus muscle.

FUNCTION: Outward,

lateral movement of eye.

DYSFUNCTION: Loss of

lateral eye movement,

dysconjugate gaze.

CRANIAL NERVES 15

Clinical evaluation of CN III, IV, VI •Extraocular movements (EOM's)

•CN IV (Trochlear) and CN VI tested with CN III (Oculomotor)

LATERAL RECTUS

MUSCLE

CN V – TRIGEMINAL NERVE

ORIGIN: Pons. The sensory

nucleus extends from the

pons to the midbrain, and also

to the medulla and spinal

cord.

INNERVATION: Three

branches of CN V:

Ophthalmic, maxillary, &

mandibular.

Motor innervation to

masseter & temporal

muscles.

Sensory innervation to skin &

mucous membranes in head;

teeth, tongue, external

auditory canal, and cornea.

CRANIAL NERVES 16

CN V – TRIGEMINAL NERVE(cont..)

FUNCTION: Sensation of

pain, touch, hot, & cold; motor

movement of masseter &

temporal muscles.

DYSFUNCTION: Loss of

sensation - if affecting all

three branches, indicative of

peripheral injury.

Brainstem or upper cervical

cord injury may result in loss

of sensation to one or more

branches of the trigeminal

nerve.

Loss of corneal reflex.

CRANIAL NERVES 17

CN V – TRIGEMINAL NERVE(cont..)

Paresthesia and/or severe

pain indicative of nerve

compression or irritation

(Trigeminal neuralgia)

Deviation of jaw towards the

same side, loss of sensation.

Inability to bite down and

chew, inability to close jaw.

Chewing, speaking, washing

face, cold water, may

precipitate the

attack…TRIGGER POINT

CRANIAL NERVES 18

CN V – TRIGEMINAL

NERVE(cont..) Tic douloureux or

trigeminal neuralgia

Paroxysmal attacks of

severe, short, sharp, stabbing

pain affecting one or more

branch of the nerve.

Most excruciating pain

known (?)

Caused by inflammation of

nerve

In severe cases, nerve is cut;

relieves agony but results in

loss of sensation on that side

of the face

CRANIAL NERVES 19

TESTING TRIGEMINAL NERVE

o Sensation-

o Checked by extroceptive

modalities like superficial pain,

thermal, light touch over jaw,

cheeks, and forehead.

o Motor examination-

o Muscle power of masticatory

muscle namely the masseter

and temporalis.

o Inability to raise, depress,

protrude, retract and deviate

the mandible

o Jaw deflected toward same

side

CRANIAL NERVES

20

TESTING TRIGEMINAL NERVE Jaw jerk-

o Ask the patient to relax

jaw. Place finger on the

chin and tap it with

hammer.

o closing of mouth is the

response

o Brisk is normal

o Exaggerated is

pathological

◦ Corneal reflex-

o Cornea is touched with wisp

of wet cotton

o Response is closing of both

eyes

o Afferent- ophthalmic div of

VI nerve

o Efferent- Facial nerve CRANIAL NERVES 21

CN VII- FACIAL NERVE

ORIGIN: Pons & medulla.

INNERVATION: Anterior

two-thirds of tongue; facial

muscles, scalp, ear, and

neck.

FUNCTION:

Control of facial muscles

(expressions)

Motor limb of blink &

corneal reflex

Secretion of salivary &

lacrimal glands

Sensation of taste, anterior

two-thirds tongue.

CRANIAL NERVES 22

CN VII- FACIAL NERVE(cont..) Motor-

◦ Facial asymmetry - Ipsilateral weakness/paralysis, right or left,

indicative of damage to motor nucleus or peripheral component

(lower motor neuron lesion) EX: Bell's palsy

◦ Contralateral weakness/paralysis of lower face indicative of

Contralateral motor cortex damage (upper motor neuron lesion)

or hemispheric lesion, i.e. massive CVA.

◦ Bilateral weakness or paralysis , E.g. myasthenia gravis or

Guillian Barre.

Parasympathetic-

◦ Loss or excessive tearing or salivation

• Sensory-

◦ Loss of taste from anterior 2/3

Combined problem-

◦ speech difficulty and drooling/difficulty handling food

CRANIAL NERVES

23

CN VII- FACIAL NERVE(cont..)

CLINICAL EVALUATION

o MOTOR FUNCTION:

o Observe for facial symmetry

o Flattening of nasolabial fold

o Ask patient to wrinkle

forehead, puff cheeks, smile,

show teeth, close eyes

against resistance, and

whistle.

o Wrinkle forehead- Frontalis

o Close eye- orbi oculi

o Purse lip- Buccinator

o Show teeth- Orbi oris

CRANIAL NERVES

24

CN VII- FACIAL NERVE(cont..) SENSORY FUNCTION:

• Test each side of tongue

separately.

• Test for sweet (tip of

tongue); sour (sides of

tongue); salty (over most of

tongue, but concentrated on

sides).

• Give sip of water between

tastes.

• Prevent flowing it to the

posterior aspect of tongue

• Reflex-

• Corneal reflex

• Glabellar reflex- Parkinson's

disease

CRANIAL NERVES

25

CN VII- FACIAL NERVE(cont..)

Guess your

observation

CRANIAL NERVES 26

BELLS PALSY

• Bell’s palsy: paralysis of

facial muscles on affected

side and loss of taste

sensation

• Caused by herpes simplex

I virus, trauma,

• Lower eyelid droops

• Corner of mouth sags

• Eye cannot be completely

closed (dry eye may occur)

• Lacrimation is seldom

affected

• Condition my disappear

spontaneously without

treatment

Bells phenomenon-

Upward and outward

movement of eye

CRANIAL NERVES 27

CN VIII – VESTIBULOCOCHLEAR

NERVE

ORIGIN: Pons and medulla

INNERVATION:

◦ Cochlear - ear

◦ Vestibular - ear

FUNCTION:

◦ Cochlear - Hearing

◦ Vestibular - Balance,

maintenance of body

position, and proprioception.

◦ Rule out for presence of

wax, pus, blood or foreign

body Before testing

CRANIAL NERVES 28

COCHLEAR NERVE Rinne’s test-

◦ For comparing bone and air

conduction

◦ Tuning fork placed at the

mastoid till the sound stop

being heard

◦ Then is placed in front of

ear to be tested

◦ +ve Rinne test i.e. air and

bone both are retained

◦ -ve Rinne test i.e. air is lost

but bone is

retained(conductive

deafness)

◦ If both are lost i.e.

sensorineural deafness

◦ BERA TEST CRANIAL NERVES

29

COCHLEAR NERVE(cont..) Weber's test-

◦ Evaluates lateralization

◦ Use vibrating tuning fork on

top of patient's head, ask

patient where he hears it

(one or both sides).

◦ Normally heard equally on

both the sides

◦ If one ear is occluded then

it acts like a resonating

chamber and hear more on

that side

◦ Conductive deafness-

involved side

◦ Sensorineural- Uninvolved

side

CRANIAL NERVES 30

VESTIBULAR NERVE

Look for Vertigo,

Nystagmus, loss of balance

NYLEN-BARANY

MANEUVER

◦ Patient lie down supine

with head off the bed

◦ 45 degree extended

◦ Lateral flexion to the

same side produces

Nystagmus

• Other tests are

• caloric test(cows)

• Galvanic test

• Rotation test

CRANIAL NERVES 31

CN VIII – VESTIBULOCOCHLEAR

NERVE DYSFUNCTION (Cochlear)

◦ Unilateral deafness

◦ Loss of sound appreciation

◦ Tinnitus

◦ (Rinne Test) AC >BC is

normal

◦ both diminished

indicative of nerve

damage

◦ BC> AC middle ear

disease.

◦ (Weber Test)

◦ Lateralization to good

ear is nerve damage,

◦ lateralization to bad

ear is, middle ear

disease CRANIAL NERVES 32

CN VIII – VESTIBULOCOCHLEAR

NERVE

DYSFUNCTION

(VESTIBULAR)

◦ Vertigo

◦ Balance disturbances

Vestibular branch normally

not tested unless patient

gives history of vertigo or

balance Disturbance

history is positive, caloric

testing is done by

physician.

CRANIAL NERVES 33

CN IX- GLOSSOPHARYNGEAL

NERVE

ORIGIN-

◦ Medulla

INNERVATION:

◦ Mucous membranes of tonsils, pharynx, posterior one-third of tongue, pharyngeal muscles, carotid sinus and carotid body

FUNCTION:

◦ Taste from posterior one-third of tongue - Afferent limb of gag, swallow, and cardiac reflexes.

• DYSFUNCTION:

◦ Loss of taste; Neuralgia

CRANIAL NERVES 34

CN X – VAGUS NERVE ORIGIN-

◦ Medulla

INNERVATION:

◦ Muscles of larynx, pharynx, and

soft palate.

◦ Parasympathetic innervation of

thoracic and abdominal viscera.

FUNCTION:

◦ Muscles of larynx, pharynx, and

soft palate

◦ Sensation conveyed from the

heart, lungs, digestive tract,

carotid sinus, & carotid body

◦ Efferent limb of gag and swallow

reflex

• DYSFUNCTION:

• Loss of gag & swallow reflex

• Loss of carotid sinus

• oculocardiac reflex; Dysphagia

CRANIAL NERVES 35

CN IX- GLOSSOPHARYNGEAL

and CN X - VAGUS

POSSITIVE FINDINGS-

Evaluate voice quality

(hoarseness or dysarthria)

Ask patient to open mouth,

say "ah", observe for

elevation of soft palate,

midline position of uvula.

Gag reflex, bilaterally

Swallowing

Taste (bitter) posterior one-

third tongue

CRANIAL NERVES 36

CN IX and X considered jointly, actions are seldom compared separately; they

are always tested together.

CN IX- GLOSSOPHARYNGEAL

and CN X - VAGUS

Negative Findings

Loss of voice quality,

(dysarthria or hoarseness)

Deviation of uvula toward

non-paralyzed side

Swallowing difficulty or

nasal regurgitation

Vagal irritation

(bradycardia)

CRANIAL NERVES 37

CN XI - SPINAL ACCESSORY

NERVE ORIGIN: Medulla

INNERVATION:

Sternocleidomastoid &

trapezius muscles

FUNCTION: Motor

function

Sternocleidomastoid &

trapezius

DYSFUNCTION: Muscle

weakness.

CRANIAL NERVES 38

CN XI - SPINAL ACCESSORY

NERVE • CLINICAL EVALUATION

• Palpate trapezius muscle as

patient shrugs shoulders

against resistance; evaluate

strength.

• Ask patient to turn head to

one side and push against

examiners hand or ask to flex

head against resistance,

palpate and evaluate strength

of sternocleidomastoid

muscle.

• Evaluate both right and left

side, compare for symmetry.

CRANIAL NERVES 39

CN XII –HYPOGLOSSAL

NERVE ORIGIN: Medulla

INNERVATION: Muscles of the tongue except palatoglossus

FUNCTION: Movement of the tongue

DYSFUNCTION:

◦ Unilateral lesions can cause paresis, atrophy, furrowing, fibrillation and fasciculation on the affected half

◦ On protrusion tongue deviates towards the affected side due to unopposed action of the Contralateral GENIOGLOSSUS

Flaccid paralysis

◦ Dysphagia

◦ Dysarthria

◦ Dyspnea

◦ Difficulty chewing food

CRANIAL NERVES

40

PUPILLARY REFLEX Afferent- Optic

Efferent-

Oculomotor

Yes(T)

Yes(O)

No(T)

No(O)

Yes(T)

No(O)

No(T)

Yes(O)

CRANIAL NERVES 41

Normal

Testing side- A and E = +nt

Opposite side- E +nt

Probable lesion in A of eye

being checked

Probable lesion in E of

Opposite eye

Lesion of E on same side and

E of opposite eye is normal

Afferent- Optic

Efferent-

Oculomotor

Yes(T)

Yes(O)

No(T)

No(O)

Yes(T)

No(O)

No(T)

Yes(O)

Normal

Testing side- A and E = +nt

Opposite side- E +nt

CORNEAL REFLEX

CRANIAL NERVES 42

Normal

Testing side- A and E = +nt

Opposite side- E +nt

Probable lesion in A of eye

being checked

Probable lesion in E of

Opposite eye

Lesion of E on same side and

E of opposite eye is normal

Afferent- Trigeminal

Efferent- Facial

Yes(T)

Yes(O)

No(T)

No(O)

Yes(T)

No(O)

No(T)

Yes(O)

Normal

Testing side- A and E = +nt

Opposite side- E +nt