CRANIAL NERVES and function

I. Olfactory (sensory or motor)

Sensory

II. Optic (sensory or motor)

Sensory

III. Oculomotor (sensory or motor)

Motor

IV. Trochlear (sensory or motor)

Motor

V. Trigeminal (sensory or motor)

Both

VI. Abducens (sensory or motor)

Motor

VII. Facial (sensory or motor)

Both

VIII. Vestibulocochlear (sensory or motor)

Sensory

IX. Glossopharyngeal (sensory or motor)

Both

X. Vagus(sensory or motor)

Both

XI. Accessory (sensory or motor)

Motor

XII. Hypoglossal (sensory or motor)

Motor

Olfactory nerve (number)

I.

Optic nerve (number)

II.

Oculomotor nerve (number)

III.

Trochlear nerve (number)

IV.

Trigeminal nerve (number)

V.

Abducens nerve (number)

VI.

Facial nerve (number)

VII.

Vestibulocochlear nerve (number)

VIII.

Glossopharyngeal nerve (number)

IX.

Vagus nerve (number)

X.

Accessory nerve (number)

XI.

Hypoglossal nerve (number)

XII.

Olfactory function

special sensory; olfaction (smell)

Optic function

special sensory; vision

oculomotor function

sensory: vision

motor: all extrinsic eye muscles, ciliary muscles, constrictor pupillae muscles

trochlear functions

superior oblique muscles

trigeminal function

sensory: face, anterior scalp, conjunctiva, eye bulb, nasal cavity; paranasal sinuses, mucosa, oral cavity; cheeks, teeth, gums, palate

motor: muscles of mastication and other oral / throat muscles

abducens function

lateral rectus muscles

facial function

sensory: taste - anterior 2/3 of tongue; soft palate

motor: muscles of facial expression, glands; parotid, lacrimal, submandibular, sublingual, oral, nasal; pharyngeal mucosal glands

vestibulocochlear function

auditory; special sensory; balance and hearing

glossopharyngeal function

sensory: posterior 1/3 tongue; pharynx

motor: blood vessels in carotid body and sinus

vagus function

sensory: posterior 1/3 tongue

motor: smooth muscles and glands of pharynx, larynx, esophagus, palatoglossal muscles; internal organs: digestion, respiration, heart rate, respiratory rate; reflexes: sneeze, cough, swallow, vomiting; aortic arch: cardiac muscle

Accessory functions

spinal; sternomastoid and trapezius (upper)

hypoglossal function

intrinsic / extrinsic tongue muscles (except palatoglossus)

olfactory physical assessment

1. ask client to close eyes

2. occlude one nostril at a time

3. identify 2 different odors per nostril

4. assess for CSF fluid rhinorrhea (if head trauma)

optic physical assessment

1. Snellen test on each eye to check for CNs II, III, IV, VI function

2. rest visual fields

3. observe client in good lighting for pupil size, shape, position, equality

4. drooping eyelid

5. direct pupillary light reflex

6. consensual pupillary light reflex

7. accommodation convergence reflex

8. corneal light reflex

9. extraoccular movements in 6 positions

oculomotor physical assessment

-same as II, III, IV, VI

-EOM (Extraocular movement CNs III, IV, VI)

trochlear physical assessment

same as II, III, IV, VI

Trigeminal physical assessment

Sensory:

1. test 3 divisions on each side separately

2. compares each division on both sides for equality

3. test light touch w/ wisp of cotton

4. test sharp and dull

5. test temp. if indicated

Motor:

6. test strength of temporalis and masseter muscle movements

abducens physical assessment

same as II, III, IV and VI

Facial physical assessment

1. observe face at rest for expression and symmetry

2. ask client to raise eyebrows

3. ask client to close eyes tightly and attempt to open without resistance

4. ask client to smile and/or show teeth

vestibulocochlear physical assessment

1. whisper test (both ears)

2. Webber test - tuning fork, conductive hearing loss

3. Rinne Test - bone conduction

glossopharyngeal physical assessment

1. open wide, say "AAaahh"

2. pen light to observe for symmetrical rise of soft palate

3. gag reflex at back of throat using tongue blade

4. listen for hoarseness

vagus physical assessment

same as IX

Accessory physical assessment

1. place hands on client's shoulders / ask to shrug shoulders against resistance

2. place your hand firmly on client's cheek and ask to turn head from side to side with resistance

hypoglossal physical assessment

1. inspect tongue for symmetry, atrophy, deviation, twitching

2. ask client to protrude tongue in midline

3. ask client to push each cheek out w/ tongue against resistance