Simple Tests For Cranial Nerves
The Twelve Cranial Nerves
I Olfactory
-Smell (Sensory)
To test: Have subject close eyes. Place orange in front of nose
& ask subject to identify the smell. *Do NOT use ammonia.
Frontal lobe damage may cause an inability to smell or anosmia.
II Optic
-Vision (Sensory)
To test: Have subject read letters on a board. Also check
peripheral vision by having subject look at your nose while you,
the tester, takes a small object and moves it through subject's
peripheral vision along side of head. Have subject identify when
the object disappears in their peripheral vision. Repeat on other
side.
III Oculomotor
-Messages to innervated muscles (Sensory)
Raises upper eyelid, turns eye up, down, & towards the nose,
constricts pupil, accommodates eyes (Motor)
To test: Have subject follow your finger with his eyes as you
move your finger in an "H" pattern so that subject must
watch your finger move up, down, & sideways in & out.
IV Trochlear
-Messages to innervated muscles (Sensory)
-Eyeball movement turning eye downward & laterally to the
side (Motor)
To test: Have subject follow your finger in an "L"
pattern down in front of the bridge of subject's nose & then
outward towards lower cheek.
V Trigeminal
Three Divisions
1. Opthalmic
-Sensation of cornea, skin of forehead, scalp, eyelids, nose,
& mucous membranes of the paranasal sinuses & nasal
cavity (Sensory)
2.Maxillary
-Sensation of skin over maxilla, upper teeth & jaw, mucous
membrane of nose, maxillary sinus, & palate (Sensory)
3.Mandibular
-Muscles of mastication (Motor)
-Sensation of skin over cheek, lower teeth & jaw, TMJ, and
anterior tongue (Sensory)
To test: Place stimulus close to eye to test blink response. Have
subject clench teeth and palpate masseter muscle size.
VI Abducens
-Lateral eye movement (Motor)
To test: Have subject follow object with his eyes as it moves
from side to side
VII Facial
-Taste from anterior 2/3 of tongue, lacrimal gland (Sensory)
-Muscles of facial expression; stapedius (Motor)
To test: Have subject smile. Have subject identify taste on
anterior 2/3 of tongue.
VIII Vestibulocochlear (Auditory)
-Position & movement of head, balance & equilibrium,
hearing (cochlear)(Sensory)
To test: Test subject's ability to hear a whisper behind ear.
Test balance standing with eyes open & closed with feet
together.
IX Glossopharyngeal
-Taste of posterior 1/3 of tongue (Sensory)
-Swallowing (Motor)
To test: Test GAG reflex
X Vagus
-Sensation from larynx, pharynx, esophagus, trachea, heart, &
other thoracic abdominal organs, & smooth muscle of the
heart; carotid & aortic bodies (Sensory)
-Movement of several organs (Motor)
To test: Have subject speak. Is the sound of their voice clear?
XI Spinal Accessory
-Messages of innervated neck & shoulder muscles; pharynx
& larynx with CN X (Sensory)
-Shoulder & head movement; SCM & trapezius (Motor)
To test: Have subject rotate head right & left. Have subject
elevate both shoulders.
XII Hypoglossal
-Messages of tongue innervation (Sensory)
-Tongue movements (Motor)
To test: Have subject stick out tongue & look for any
deviations. Tongue always deviates towards the side of injury.
Cranial nerve facts
Cranial nerves I, III, & VIII are sensory only
The nuclei of CN III - XII are located in the brainstem
CN V is the largest cranial nerve & its cell bodies are
located in the midbrain
*Tip to remember the CN's & in order:
On Old Olympus
Towering Tops
A Finn And German
Vaulted and Hopped