Cranial Nerves

Olfactory (CN I) function

smell

Optic (CN II) function

vision

Oculomotor (CN III) function

eye movement, pupil constriction

Trochlear (CN IV) function

superior oblique muscle of the eye (eye down and inward)

Trigeminal (CN V) function

facial sensation, mastication

Abducens (CN VI) function

lateral rectus muscle (eye abduction)

Facial (CN VII) function

facial expression, taste (2/3 of tongue)

Vestibulocochlear (CN VIII) function

hearing and balance

Glossopharyngeal (CN IX) function

taste posterior tongue, swallowing

Vagus (CN X) function

parasympathetic control, voice, swallowing

Accessory (CN XI) function

SCM and trapezius

Hypoglossal (CN XII) function

tongue movement

olfactory pathology & signs

- head trauma, neurodegenerative disease

- loss of smell

optic pathology & signs

- optic neuritis, MS, tumors

- vision loss, visual field defects

oculomotor pathology & signs

- aneurysm, diabetes neuropathy

- ptosism dilated pupil, down and out eye

trochlear signs

vertical diplopia, difficulty looking down

trigeminal pathology & signs

- trigeminal neuralgia

- facial pain or numbness

trigeminal branches

V1, V2, V3

abducen signs

medial eye deviation, diplopia

facial pathology & signs

- bell's palsy

- facial droop, inability to close eye

vestibulocochlear pathology & signs

- acoustic neuroma

- vertigo, hearing loss

glossopharyngeal signs

dysphagia, loss of gag reflex

vagus signs

hoarseness, dysphagia

accessory signs

shoulder weakness, difficulty turning head

hypoglossal signs

tongue deviation, speech difficulty

special sensory

- olfactory

- optic

- vestibulocochlear

motor

- oculomotor

- trochlear

- abdicens

- accessory

- hyperglossal

both motor and sensory

- trigeminal

- facial

- glossopharyngeal

- vagus