CN I-VI Flashcards
what are the three exams for CN I?
observation of external nose
observation of internal nose
sense of smell in both nostrils
unilateral or bilateral anosmia is commonly caused by..
blocked nasal passage, cold, loss with aging, trauma
bilateral anosmia may also be caused by…
blocked nasal passage, cold, loss with aging, trauma
rare causes for unilateral anosmia include…
minor head trauma
nutritional cuases for anosmia include
zinc deficiency
function of rods
See in low light
functions for cones
See colors
function of optic chiasm
nasal half decusate, temporal half uncrossed
retinal area for centrla visionis…?
macula
the remainder of the retina is concerned with___and___.
paracentral and peripheral vision
retrobulbar neuritis involves…?
optic N or tract, MC cause is MS
optic neuritis involves…?
various forms of reninitis
papilledema involves…?
increased intracranial pressure
optic atrpohy involves…?
decreased visual acuity and change in color/optic disc
secondary optic atrophy involves…?
glaucoma
foster kennedy syndrome
tumors at base of frontal lobe, ipsilateral blindness and anosmia
tay sachs disease
cerebromacular degeneration with severe mental deficiency
holmes-Adie syndrome
tonic pupillary reaction and absence of one or more tendon reflexes
extropia
outward/lateral movement
esotropia
inward/medial movement
hypertropia
up
hypotropia
down
inability to laterally gaze may be affected by…
disease of CN VI, MS
frontal lobe controls
saccadic (rapid/darting) eye movement
occipital lobe controls
smooth or following eye movement
the fast component of nystagmus respresents
saccadic movement from the frontal lobe
the mooth component is what follows in nystagmus is controlled by…
occipital lobe
ptosis can be caused by…
paralysis/superior tarsal muscle
lesions affecting CN IV make ti difficult for the patient to…
roll their eyes
what test is performed to isolater CN VI?
6 cardinal fields of gaze
lesions affecting CN VI make it difficult for the patient to…
look left and right
lesions affecting CNII will diminish..
pupilloconstriction with bilateral assymmetry
lesions affecting CN III will affect the primary motor portion of the eye refle and it will diminish…
ability to carry out pupilloconstriction in ipsilateral eye
loss of diencephalon or midbrain function results in….
unopposed sympathetic (pupillodilator) domonance
pupils that are fixed and dilated represent…
brain dead patients
holmes-adie syndrome has the following clinical findings
reaction to light slow, consricted longer, dilate slow
argyll robertson pupill has the following clinical findings
no direct or indirect reaction to light, only accomodation
identify potential causes for argyll robertson syndrome
diabetes, neurosyphilis
horner’s syndrome is caused by…
lesions of neck proximal to carotid artery
signs and symptoms of horner’s syndrome
ptosis, pupiloconstriction
facial anhydrosis
ipsilateral facial vasodilation
summary of CN III, IV, VI examination
what do the eyes look like from the outside?
how do the eyes function?
what do the eyes look like on the inside?
eyelid ptosis may be caused by lesions involving..
hypothalamus brainstem spinal cord peripheral CN 3 peripheral sympathetics myoneural pathways possible muscular and local causes
describe the proess to evaluate the patietnt’s ocular alignment
look straight forward, lateral (bilateral) check for sceral tissue, elicit ciliospinal refle
visual acuity is assessed by utilizing?
snellen chart
assessment of peripheral vision
confrontation
what cranial nerves are being evaulated when testing for peripheral vision
III, IV
what are the degrees that we should see in peripheral vision on each side?
60 degrees superior
60 degrees nasal
75 degrees inferior
100 degrees temporally
6 cardinal fields of gaze assesses
etraocular movement
accomodation is assessing
convergence, puilloconstriction, lens thickening
3 components of accomodation
convergence
lens thickening
pupilloconstriction
causes for nystagmus..
conflicting proprioceptive input from CN VIII and cervical and cerebellar sources
the side toward which the quick component of nystagmus travels is the side that
bears the name
coneal light reflex evaluate for..
relative position of the 2 points of reflection of light
describe how the corneal light reflex test is performed
patient’s eyes forward, light source shined into both eyes
pupillary light reflex evaluate the patient for
constriction of both pupils equally, assuming intract pathways
describe how the pupillary light reflex test is performed
introduce light into one eye, note pupilloconstriction in both eyes, switch to toher eye and do the same
swinging flashlight light relfex evaluates the patient for
equal pupilloconstriction
describe how the swinging light reflex test is performed
shine light in eye, watch other eye, if it doesn’t constrict as much, then there may be a retinal or CN II lesion
marcus gunn phenomenon
apparent pupillodilation with light
identify 4 basic components to the funduscopic exam while trying to identify pathological changes
optic disc
vessels
macula
general background
the margins between the optic disc in the fundus should be..
sharp temporally and less so medially
if the physiological cup is greater than half the size of the disc this indicates
increased intraocular pressure (glaucoma)
papilledema has the following funduscopic characteristics…
the disc appears blurred with jagged edges
tortuous, engorded veins
loss of venous pulsations at disc margin
obliteration of physiologic cup and optic disc and edema
pseudo-papilledema typically is seen in what percent of the population?
up to 5%
identify pictures of eyes
normal fundus optic atrophy optic neuritis papilledema glaucoma detached retina diabetic retinopathy hypertensive retinopathy drusen bodies
CN V functions as a mixed crainial nerve. what are the 3 divisions?
opthalmic
maxillary
mandibular
true or false: CN V includes the angle of the jaw
false
describe a sensory exam of CN V
introduce sharp and light touch stimulus with the aptient’s eyes open
random sharp pinprick with one control and have the patient point to the area that they feel was touched with the sharp pinprick and cotton wisp (eyes closed)
compare side to side light touch (eyes closed)
compare side to side with pinprick (eyes closed
if findings are an area of hyperesthesia or hypoesthesia then the area of question should be compared to an area that we already know has intact sensory function
where else do we perform the sensory exam?
upper extremities
cervical afferents to the facial nerve nuclei provides a neurological innervation to…
the face, but sparing the angle of the jaw
the mandibular branch of CN V has what kind of branch?
recurrent/meningeal branch
the recurrent/meningeal branch innervates what?
dura
what are the muscles of mastication?
temporalis, masseter and medial pterygoid
what is the primary function of the right lateral pterygoid is to move the jaw tip..
to the left
what is the primary function of the left lateral pterygoid is to move the jaw tip…
to the right
peripheral nerve or brainstem disease affecting CN V is usually responsible for…
sensory impairment
peripheral nerve or brainstem disease causing and impairment often has atrophy of the…
temporalis and masseter
corneal ulceration and/or inflammation may be present when a lesion fracture the opthalmic division and this is termed…
neuroparalytic keratitis
referred pain tot he face may have what kind of causes?
TMJ syndrome
oral problems
dental problems
another name for trigeminal neuralgia?
tic douloureux/fathergill’s neuralgia
what is trigeminal neuralgia?
pain in a clear distribution pattern involving CN V
examination of CN V
observe motor function, muscle volume, observation of jaw deviation on forced opening, opposition of jaw on closure and lateral jaw movements
palaption of masseter and temporalis muscle while clenching
LMN lesion affecting CN V may occur anywhere in the nerve cell body from the pontine nucleus to the peripheral CN and will result in paralysis and denervation atrophy of the mastication muscles
corneal reflex is assessing the sensory reflex CN V and motor reflex CN VII (may be diminished in early MS)
