Pathology of Hearing Flashcards
Noise-induced and Age-related hearing loss
_____is the strongest predictor of hearing loss among adults aged 20-69
age
common complaints (5)
1) tinnitus
2) HL
3) otalgia
4) otorrhea
5) vertigo
sound that appears to be coming from one or both ears, internally generated
tinnitus
T/F Most american habituate to tinnitus and say they do not suffer from the condition
True
______ % of tinnitus patients hear the sound constantly, without intermission
83%
what is the primary cause of tinnitus?
- what other known causes are there?
primary: exposure to loud noise
secondary: stress, BP, meds, infections, head trauma
______ tinnitus is usually related to blood vessel or muscle spasm
- the sound can also be heard by an observer
pulsatile
tinnitus is more prevalent in adults but can be the first sign of _____ in children
HL
the source of tinnitus is difficult to determine but is likely associated with damage to __________
nerve endings at hair cells
what are some tinnitus treatments? (3)
masking devices, biofeedback, and relaxation exercises (wellness approach)
common complain: HL may arise due to ___________ (5)
noise exposure, meds, genetic predisposition, ototoxicity, or aging
two ototoxic exposure may interact to provide a _________ HL, which compounds risk of certain professions
syngergistic HL
common complaints: otalgia is what?
ear pain
T/F most otalgia is related to structures of the ear
false; most otalgia is not related to structures of the
ear, but more structures of larynx, pharynx, tonsils, muscles of mastication, TMJ, orthodonture
T/F Many of the most common and important otologic diseases are associated with any level of pain
False; they are NOT associated with pain
T/F Most otogenic pain is caused by infection or cerumen impaction
True
common complaints: what is otorrhea
fluid drainage from the ear
what is otorrhea most always due to?
infection, with the rare exception of a CSF leak
_________ drainage likely due to chronic otitis media or cholesteatoma
painless
__________ drainage likely due to acute otitis media and TM rupture
Painful
present with the principle component of “illusion of motion”
vertigo
vertigo is a condition of the _________ system, or peripheral or central
Vestibular
displaced otoconia from saccule entering and stimulating the lateral semicircular canal can cause ___________
BPPV (benign paroxysmal positional vertigo)
what is another cause of otoconial displacement
head trauma
how do ME disorder interfere with ME’s ability to act as impedance matching device
interfering with the mobility of ME structures
Otitis media
- common feature: eustachian tube malfunction
(allowing for bacteria secretion from nasopharynx to enter ME space) - kiddos more prone bc of shorter, wider, and more horizontal ETs
how can the blockage of the eustachian tube perpetuate otitis media
not allow effusions (fluid collections) to drain
OM blockage can be perpetuated at the nasal end by ___________
inflammation
- allergies, cigs, pool water chlorine
pus infection exhibiting swelling, increased blood flow, bleeding, and fever
acute otitis media
what is the idea of AOM
pus collects in the middle ear space until the TM ruptures, resulting in a sudden relief of symptoms
- can hear instantly
- effusion clears within month but can persist indefinitely & may be asymptomatic
- tubes are recommended for kiddos with 15dB loss / unresponsive to antibiotics
low grade or recurrent infections
- may be only intermittently response to antibiotics
chronic otitis media
collection of dead cells accumulates, incites growth on medial side of TM
cholesteatoma
what do the dead skin components provide at the center of the cholesteatoma
provide an excellent medium for bacterial growth and chronic infections are a consistent feature of cholesteatomas
T/F The growing mass induces bone erosion of any contacted bony structures
true
What some structures that can be affected by cholesteatoma (3)
ossicles, labyrinth, temporal bone
what can cholesteatoma present as
significant hL and vertigo
when encountered in _________, cholesteatomas are aggressive (fast growing)
kiddos
what is the intervention for cholesteatoma
surgical eradication
- will under many surgeries
antibiotic is ineffective
disease where normal head labyrinthine bone is replaced by vascular spongy bone
otosclerosis
what does otosclerosis most frequently affect?
the oval window, extending to the footplate of the stapes by freezing (immobile chain of ossicles)
- can sometimes primarly affect cochlea
genetic condition that can develop in both ears
ossicular chain becomes poor conduction apparatus &. sign. conductive HL results
otoscleorisis
otosclerosis intervention includes the _________ to be surgically replaced in part or in whole by
graft tissues or manufactured substitutes such as small pistons which
reconnect remnant structures with the oval window
ossicular chain
bacterial biofilms are colonies/bacteria that exist in what two forms
sessile form (hibernating)
planktonic form (active)
where are biofilms commonly found
on living/non living areas (slime, ponds, etc.)
why are biofilms clinically relevant
- bacteria changes phenotype (making it easier to reject antibiotics)
- biofilm helps protect bacteria
what are some otolaryngologic diseases presumed to be mediated by biofilms
- chronic sinusitis
- chronic otitis media
- cholesteatoma
- tonsilitis
(chronicity is the common denominator)
biofilms can grow on implanted substrates (including CIs) and these are often the initial sites of _________
colonization
any drug/chemical that can damage OE, ME, IE
ototoxic
what are some common ototoxic drugs
cisplatin (cancer drugs)
antibiotics
aspirin
antidepressants
etc.
what are some ototoxic chemicals
1) organic solvents
2) heavy metals
3) in the home
how does an ototoxin like aspirin affect the neuron tuning curve (3)
1) elevated threshold
2) widened bandwidth
3) shifts CF toward lower frequency
diagram of the neuron tuning curve
any age related hearing loss
presbycusis
what is presbycusis characterized by (4)
1) reduced hearing sensitivity
2) reduced speech discrimination in noise
3) slowed central processing
4) impaired localization of sound sources
what should presbycusis be considered as
an accumulation of acquired auditory stresses, traumas, otologic diseases and drug/chemical exposures all superimposed on an intrinsic, genetically regulated ageing process
loss of hair cells, outer (mostly) or inner
- aging alone does not cause the loss of OHCs
sensory presbycusis
also called metabolic
degeneration of stria vascularis leading to disruption or reduction in EP
strial presbycusis
loss of SGN or changes in synaptic density further up the pathway prior to loss of hair cells
- may require huge losses before HL is noticed
- reduced OAEs may suggest weaknesses in MOC feedback before HL is noticed
neural presbycusis
changes in stiffness of BM
- may indicate damage to: spiral ligament, limbus, BM, or supporting cells
conductive presbycusis
any combination of other presbycusis’
mixed presbycusis
obvious due to the wide variety of potentiating exposures & genetic variances
intermediate presbycusis
NIHL can cause _____ or __________ hearing loss depending on the level of sound exposure
temporary (reversible) or permanent (irreversible)
results from moderately intense sounds such as a rock concert
TTs
results from 2 types of exposure
a) acoustic trauma (such as gun shot) that is sudden and usually painful [greater than 140 dB]
b) classical NIHL results from chronic exposure
[workday durations of greater than 85 dB]
PTS
how can a permanent SNHL be determined
detected clinically by finding that bone conduction is NOT better than air conduction.
what are some other symptoms/findings that could determine NIHL
- hx of long term exposure to dangerous noise levels
- HL involving high freq
- SRT consistent with audiometric loss
- HL stabilizes one noise exposure is terminated
- trauma noise that is usually short exposures greater than 140 dB
- stretch inner ear tissues / organ of corti may detach from BM / tectorial membrane becomes detached from sterociliary buncles
direct mechanical stress (trauma noise)
- metabolic exhaustion of activated (stimulated) cells
- activity induced vascular narrowing that leads to ischemia
- ionic poisioning, oxygen/nitrogen free radical, enzymes
induced metabolic activity (sub-traumatic noise)
what are the mechanisms of protection from NIHL
1) middle ear muscles
2) pillar cell buckling
- removing stereocilia from embedment which reduces likelihood of physical trauma to these hair cells
3) antioxidants
- Vitamincs A,C,E, etc.
