Visual, Auditory, and Vestibular Systems Flashcards
smallest row of #s/letters a pt can accurately read
visual acuity
visual acuity is a function of
central vision of macula
macular functions
central vision (visual acuity) and color vision
visual acuity is recorded as
fractional # which compares pt’s vision w/ nl population
impaired near vision
presbyopia
if acuity improves when looking thru a pinhole, it suggests the problem is
ocular
impaired acuity that doesn’t improve when looking thru pinhole or using corrective lenses
lesion of optic nerve or macula
quantitative method of visual field testing using flashing dots on computer
perimetry
physiological blind spot
in temporal visual field of each eye since optic disk in nasal retina doesn’t have rods or cones
enlarged blind spot seen with
papilledema b/c optic nerve swells
pathological abnormal blind spots elsewhere in visual field of one eye
scotomas
cause of scotoma
lesion in retina or optic nerve
cause of narrowed or small visual fields
glaucoma or retinal degenerative disease
visual field shape in relation to distance from patient
cone shaped, enlarge with distance
same narrow breadth of visual fields even with distance from patient
tunnel vision, is a psych issue
homonymous hemianopsia via lesions where
contra optic tract, optic radiations, or occipital lobe
congruent visual field defects seen more when lesion is
posterior (occipital lobe or radiations)
heteronymous hemianopsia via lesions where
optic chiasm
optic nerve lesions give
scotomas or monocular blindness
sudden blindness in part of/whole eye, which is achy/tender with movement
optic neuritis
optic neuritis fundoscopic exam
optic disc is swollen w/ indistinct blurry margins
retrobulbar neuritis
optic neuritis where inflamm is deeper so optic disc looks normal
optic disc looks white/pale with sharply defined edges
optic atrophy - there’s been loss of ganglion cell axons
tumor arising from sella turcica that affects optic chiasm
pituitary tumor
meyer’s loop
inferior optic radiations
severe visual loss from bilateral occipital lobe lesions
cortical blindness (pupillary light reflex is intact and fundoscopy is nl)
cause of cortical blindness
stroke from thrombosis of distal basilar a. or emboli down it’s PCA branches
conductive deafness via
water or wax plugging up ear canal or fusion/disruption of bony ossicles
problem “before” the hair cell receptors
conductive deafness
sensorineural deafness is
damage/impairement of hair cell receptors or auditory nerve
sensorineural deafness via
drug toxicitiy or persistent exposure to loud noise
low tone hearing loss seen with
conductive deafness
high tone hearing loss seen with
sensorineural deafness
unilateral nerve deafness due to
CN8
weber test to nl ear with
sensorineural deafness
weber test to deaf ear with
conductive deafness
rinne test with bone > air
conductive deafness
records eye movements and nystagmus
ENG (electronystagmogram)
position for dix-hallpike maneuver selectively tests
posterior semicircuclar canal within tilted/lowered ear
viral infection/inflamm causing severe vertigo w/ N/V, unilateral dec hearing, and unsteady gait
acute labyrinthitis
recurrent vertigo, deafness, and tinnitus
Meniere’s dz
cause of Meniere’s dz
K+ rich endolymph leaks into perilymph and disrupts ionic gradient
Tx for Meniere’s
dietary salt restriction, diuretics
tx for acute labyrinthitis and meniere’s
benzos, antiemetics, antihistamine
degeneration of otoliths and displaced Ca crystals that lodge around cilia or hair cells
benign positional vertigo
if diplopia improves when you cover either eye (binocular diplopia), think
cranial nerves or extraocular muscles
if diplopia improves when you cover one specific eye (monocular diplopia), think
retina or lens issue
MLF lesion gives nystamus in what direction
opposite
pupils constrict to accommodation but not light
Argyll Robertson pupil of neurosyphilis or dorsal midbrain/Parinaud’s syndrome (pineal tumor)
