CN Exams Flashcards
Is CN I (olfactory) a peripheral nerve?
It’s actually a central nervous system tract terminating in olfactory bulb
How would you perform examination of cranial nerve I?
observe nose inside/outside, test each side with a different scent (patient eyes closed)
complete loss of smell is termed?
anosmia
What is the MC cause of anosmia?
common cold, trauma, loss with aging, blocked nasal passages
What is the term for decreased sense of smell?
hyposmia
Increased sense of smell is called?
hyperosmia
Perversion of smell is called?
parosmia
A patient that presents with a perversion of smell may indicate?
cortical lesion (parosmia)
When a patient is asked to identify something like peppermint but they respond that the scent is disagreeable, what would you term this issue?
cacosmia (abnormally disagreeable smell)
What substances are best used to test cranial nerve one?
peppermint, coffee, lemon, pine (not ammonia)
Is CN II a true nerve?
it’s a fiber tract of the brain
Name the area of the eye used for central vision?
macula
What test would you use for cranial nerve II? (optic nerve)
observe yes, test visual acuity (near and far vision), test confrontation (peripheral vision), pupillary light reflex, opthalmoscope exam
Which exam is option for cranial nerve II to test pupilloconstriction?
swinging flashlight test
The apparent pupillodilation with light introduction is known as?
Marcus-Gunn phenomenon
Any blockage of a red reflex (not an actual reflex) is an issue of?
cornea, lens, vitreous, or of retinal pigment
CN V spares what area of the face?
angle of the jaw
The angle of the jaw is innervated by?
CN root II
How would you test cranial nerve III (oculomotor)?
Accommodation, 6 cardinal field of gaze (watch for nystagmus), pupillary light reflex, observe the eyes (also checks IV and VI), corneal light reflex (verify any suspicion of ocular malalignment (also check IV and VI)
What CN does a fundoscopic evaluation test?
CN II and III optic and oculomotor
What would you diagnose your patient with if you looked in their eye and they presented with blurred nerve fibers and cup, tortuous, engorged veins and loss of venous pulsations at disc margin, and disc elevation and edema?
papilledema
What is the typical patient characteristics for pseudopapilledema?
blond caucasians
If the optic disc has a dead white color and associated visual loss the patient probably has?
primary optic atrophy
Optic atrophy secondary to another pathological process (glaucoma) would look like?
gray, ragged disc
If the fundus of the eye looks normal, but the patient has visual loss and inflammation visible behind portion of the optic disc, the patient probably has?
acute retrobulbar neuritis
What is the name of collections of degenerative deposits that often appear in the fundus of elderly people and are not considered to have any clinical significance?
drusen bodies
What muscles does cranial nerve V innervate?
muscles of mastication-temporalis, masseter, and medial pterygoid (function to CLOSE the jaw)
What test would you use for CN V?
trigeminal nerve
inspect muscles volume and strength (patient clench teeth and palpate temples, cheek, and jaw), corneal blink reflex, sensory exam of the face (light and sharp touch), jaw jerk reflex (patient closes eye, opens mouth and relaxes, place your fingers on chin and tap with reflex hammer)
During a CN V sensory exam, what would you want to do first?
objectify-check to see if the patient can feel general sensation (sharp from dull)
The corneal blink reflex may be absent in early cases of what pathology?
MS
Which nerve supplies motor innervation to all of the muscles of facial expression as well as taste on the anterior 2/3 of the tongue?
VII-facial nerve
The forehead is normally spared in unilateral lesions involving which pathway?
corticobulbar
What is the term for peripheral facial paralysis?
prosopoplegia
This lesion of CN VII is peripheral to the geniculate ganglion. There is a flaccid paralysis (LMN lesion) involving all ipsilateral facial muscles distal to the lesion site. CANNOT WRINKLE FOREHEAD and NO LOSS OF TASTE
Bells Palsy
This CN VII lesion is bilateral, the forehead is spared, the eyes are only partially involved, and the mouth and neck are fully involved.
Stroke
How can you test CN VII?
smile and look up (checks musculature), check taste on the ant 2/3 of the tongue
If there was a CN VII lesion, why would the eyelids still elevate as the patient looked up?
they are mainly innervated by CN III
What is the term for complete loss of taste?
aguesia
A decrease or loss of hearing is called?
hypoacusis
An increase in intensity of hearing is called?
hyperacusis
Conductive hearing loss common etiologies include?
auditory canal obstruction, tympani membrane (direct or indirect trauma), ossicles (trauma or advanced aging), and accumulation of fluid in the middle ear
nerve or perceptive hearing loss is usually attributed to disease of the end organ (Organ of Corti) or the auditory nerve defines which type of hearing loss?
sensorineural
What is ALWAYS accompanied by vertigo?
vestibular diseases
How is a nystagmus named?
The side toward which the fast movement occurs
How is a nystagmus named if there is no fast movement?
pendular
What tests are used for CN VIII?
observe external ears, webers, rinnes, otoscope exam, rotate head for dizziness, caloric irrigation, swivel chair test
What does the swivel chair test for?
cervicogenic vertigo
Is there ever speech disturbances with CN IX lesions?
never
Complete bilateral lesion of this nerve is not compatible with life because the patient would not be able to swallow/speak?
CN X
loss of voice
aphonia CN X
faulty articulation
dysarthria CN X
no articulation
anarthria CN X
faulty swallowing
aphagia CN X
increased air entering into nasal cavity
hypernasal CN X and IX
decreased air entering into nasal cavity
hyponasal CN IX and X
What tests are used for IX and X? (tested together)
have patient say AAAHHH and watch for soft palate to elevate, gag reflex (posterior 1/3 of tongue), check phonation (kuh, la, me), check taste on posterior 1/3 of the tongue
CN XI is primarily motor or sensory?
motor
Which portion of CN XI supplies the SCM and traps?
spinal portion
How do you test CN XI?
shoulder elevation against resistance, and SCM and trap strength (for both, tilt head to the same side you are testing, turn chin opposite and for SCM flex head when contracted bilaterally. for traps elevate shoulder when contracted bilaterally)
CN XII tests include?
stick out tongue and tongue in cheek test
If the tongue sticks out to the right during a CN XII exam, what side is the lesion on?
right
