Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

AUDE 5410 > Disorders of the inner ear > Flashcards

Disorders of the inner ear Flashcards

1
Q

homeostasis is defined as

A

The ability of an organism or a cell to maintain internal equilibrium by adjusting its physiological processes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

inner ear homeostasis is

A

“The process by which chemical equilibrium of inner ear fluids and tissues is maintained”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is necessary for proper inner ear function?

A

a tight control of ion movement across the cell membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

inner ear functions include?

A

-hair cell function
- regulation of extracellular endolumpatic and periplymph
-conduction of nerve impulse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are major ion s involved in the inner ear homeostasis ?

A

sodium and potassium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what other ions help in the inner ear

A

chloride
calcium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

ion homeostatis is controlled by

A

numerous ion channels and transporters in plasma membrane of cells, especially cells lining the scala media
-they regulate various genes
- and are an active transport of H2o across celll membrane is needed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what must happen before sound is perceived

A

-Before sound can be perceived it has to be converted to electrical impulses in the auditory nerve, a process mediated by the cilia of the inner ear hair cells
-The sound-induced excitatory deflection of the stereocilia causes a mechanoelectrical transduction (MET) current to depolarize the hair cells and initiate action potentials in the auditory nerve or vestibular nerve in response to acceleration/gravity changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what must endolymph and periplymp maintain?

A

-The endolymph and perilymph must maintain their specific ion concentration for maximum sensitivity of hair cells
-Significant hearing loss occurs when either of these support systems fail

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

inner ear potentials are :

A

-The hair cell has an intracellular potential of -80 mV relative to the surrounding perilymph
-The high K+ concentration in the endolymph creates a +80 mV endocohlear potential (EP) that couples with a -80 mV hair cell intracellular potential to create a differential potential of +160 mV
-80 mV – (-80mV) = 160 mV
-This arrangement of potentials between endolymph and perilymph is necessary for hair cell depolarization when stereocilia are deflected by the travelling wave

-The EP in the vestibular system is only ~+5 to +10 mV resulting in a much smaller total potential difference

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Stereocilia are laterally displaced either by

A

-Shearing movement of the tectorial membrane (outer hair cells) or
-Motion of the endolymphatic fluid (inner hair cells)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

how does potassium play a role in ion homeostasis ?

A

-The flow of K+ ions is down an electrical gradient that brings K+ into the cell from endolymph and then out the base of the cell into the perilymph
-If the entire hair cell was surrounded by endolymph the hair cell would not function
-The K+ ion concentration inside and outside the cell would not allow for a electrochemical gradient
-When these two fluids are same, transduction is compromised resulting in hearing loss/vestibular dysfunction
-This situation occurs during Meniere’s disease when membranous labyrinth rupture allows mixing of endolymph and perilymph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

look at slide 9

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what other 2 things are involved with ion homeostatis ?

A

Aquaporins and water transport

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are aquaporins?

A

-Aquaporins are proteins embedded in the cell membrane that regulate the flow of water between cells and play a central role in water homeostasis in both plants and animals
-They are part of the blood-brain barrier and probably the blood-labyrinth barrier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how does water play a part in ion homeostasis

A

-Water easily diffuses through cell membranes but that is not enough to maintain osmotic homeostasis in the inner ear
-Active water transport b/w cells occurs through aquaporin channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what kind of effects can happen if we have defects involving aquaporin?

A

-Defects involving aquaporin genes are associated with several human diseases
-Viral infections in the lungs can shut down aquaporin function causing inflammation and edema
-Bacterial and viral labyrinthitis may be caused by cochlear aquaporin dysfunction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is the most caused genetic hearing loss?

A

-Endolymphatic xerosis caused by various genetic anomalies is believed to be the cause of most genetic hearing loss in humans, for example
1)Connexin 26 genes
-abnormalities result in abnormal connexin gap junction proteins
-responsible by itself >50% of nonsyndromic hl
KCNE1 and KCNQ1
-Produce proteins that make up K+ channels on the apical stria
-Their absence leads to reduced endolymph and associated hearing loss seen in Jervell-Lange-Nielsen (JLNs) syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

hearing loss can result from what? (in terms of ion homeostasis?)

A

-Hearing loss can result from increased or decreased activity of the strial process
-Increased K+ transport in the endolymph or increased endolymph production
-endolymphatic hydrops
-too much endolymph
Decreased K+ transport in the endolymph or decreased endolymph production
-endolymphatic xerosis
-JLNS and connexin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

temporary disorders of ion homeostasis

A

-Several cochlear and vestibular disorders are transient and recover spontaneously, such as
-Sudden-onset hearing loss
-Diuretic otoxicity (e.g., Furesmide) recovery after stopping drugs
-Autoimmune labyrinthitis, which can have transient symptoms
-Meniere’s disease, which exhibits intermittent symptoms

IMPORTANT:
The fact that these disorders manifest temporary hearing loss and recovery indicates that the damage is not to the hair cells but to the ion homeostatic process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

how can HL look like in cochlear disorders?

A

Hearing loss – constant or fluctuating
-Any severity but always sensorineural, unless superimposed on a middle ear issue, which then results in a mixed hearing loss

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

how can their speech thresholds appear with cochlear disorders

A

Difficulty with speech perception – may not match h. loss levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is loudness recruitment associated with in cochlear disorders?

A

Loudness recruitment – abnormal loudness growth typically seen with presbycusis and high frequency hearing loss

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

how do patients ears feel in cochlear disorders?

A

Aural fullness – feeling plugged up or “water” in the ears

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

how does tinnitus look like in cochlear disorders?

A

-Described as a ringing in the ears, but it also can sound like roaring, clicking, hissing, buzzing, or “music”
-May be soft or loud, high pitched or low pitched
-Can be unilateral or bilateral
-Can be constant vs. intermittent
-Can change in pitch, loudness, and frequency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what are some symptoms in cochlear disorders?

A

-Sound tolerance conditions – abnormal/excessive response to sounds (Henry et al., 2022)
-Conditions that may be associated with psychological issues and not always a result of cochlear disorders
-Hyperacusis
-Misophonia
-Noise sensitivity
-Phonophobia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what is Hyperacusis

A

-physical discomfort/pain when a sound is loud but would be tolerable for most people
-a symptom of cochlear disorders

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what is misophonia ?

A

Intense emotional reactions to certain sounds (e.g., body sounds like chewing and sniffing) that are not perceived as loud
-a symptom of cochlear disorder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what is Noise sensitivity

A

increased reactivity to sounds including general discomfort and annoyance regardless of its loudness
-a symptom of cochlear disorders

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what is phonophobia

A

Anticipatory fear of sound. Can cause a comorbid condition (e.g., tinnitus) to get worse
-a symptoms of cochlear disorder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what are most common causes of SNHL ?

A

aging
exposure to toxic levels of noise (noise induced hearing loss)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what are other causes of disorders of the inner ear

A

-Genetic syndromic and non syndromic SNHL (discussed)
-Ototoxicity (discussed next session)
-Infections of the inner ear
-Autoimmune conditions that affect the inner ear (discussed later)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

what are most infections of the inner ear caused by ?

A

virus, but could be bacterial
bacteria can lead to meningitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

what are 2 kinds of virus known to cause inner ear infections

A

1)Ribonuceleic acid (RNA) virus (such as COVID-19, & ‘flu)
-Contain ribonucleic acid in their genome
-RNA viruses generally have very high mutation rates compared to DNA viruses because viral RNA polymerases lack the proofreading ability of DNA polymerases
-This is one reason why it was difficult to make effective long-lasting vaccines (such as the ‘flu vaccine and now the COVID-19 mRNA vaccine)
2)Deoxyribonucleic acid (DNA) virus
-Contain deoxyribonucleic acid in their genome
-More stable
-dna virus include small pox, herpes, and chicken pox

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

what is affected because of viral infections ?

A

-the destructive pattern and the auditory consequences of that destruction are essentially the same
-The organ of corti is affected primarily at the basal turn
-high freq SNHL is, therefore more common
-Individual hair cells are severely damaged or missing
Stria vascularis may become atrophied
-Tectorial membrane appears “shriveled” or rolls up
-Complete collapse of the Reissner’s membrane is often noted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

what are types of RNA virus infections

A

rubella virus
paramyxovirus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

what is rubella virus

A

-Responsible for German measles
-Rubella has a greater effect on the auditory system if contracted by the mother during the 1st or initial part of the 2nd trimester when the auditory system is developing
-It can lead to:
-congenital hearing loss
-congenital cataracts
-cardiovascular problems
-possible intellectual disabilities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

what is paramyxovirus

A

-Responsible for mumps

-Acquired permanent SNHL, typically unilateral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

what is Cytomegalovirus

A

-a dna virus
-Cytomegalovirus (CMV) is a common double-stranded DNA virus that belongs to the herpes virus family

40
Q

what is some background information about Cytomegalovirus (CMV)

A

-CMV infection can result in decreased life expectancy
-It can cause hepatomegaly & splenomegaly
-It can result in a rash – “blueberry muffin” (reddish blue to magenta) rash
-It can also result in decreased immunity, such as decreased immunity to the ‘flu vaccine because
-CMV has most genes compared to any known human virus (has a large human virus
-our immune system expends a lot of energy fighting this virus all life long

41
Q

who is more likely to get
Cytomegalovirus

A

newborns
-adults who get this as a child can manifest a delayed onset SNHL even as an adult

42
Q

how does Cytomegalovirus inherited ?

A

-It passes through the placenta and is teratogenic (it only affects the development of the fetus) to the fetus
-Infected mothers may only exhibit symptoms of a common cold/mild ‘flu

43
Q

what does cytomegalovirus cause?

A

-CMV causes a progressive profound permanent SNHL with the final stage generally being reached by ~ 3 to 5 years
-Many of these children are CI candidates
-Many newborns with CMV are not detected for congenital SNHL through newborn screening because of later-onset or progressive SNHL (Tvrdy, et al., 2011

44
Q

why might cytomegalovirus be difficult to catch ?

A

In infants, older children, and adults, CMV infection maybe “silent” or symptoms may mimic a common cold and cause no permanent damage
-infected newborns are generally considered contagious

45
Q

what else might Cytomegalovirus (CMV) cause?

A

-CMV may cause only a hearing loss, or it may cause significant neurological and other complications depending on when the infection occurred in vitro, such as
-Cardiovascular problems
-Neurological and motor deficits
-Blindness
-Intellectual disability

46
Q

how do you diagnosis Cytomegalovirus (CMV)

A

Diagnosis is through:
Urine polymerase chain reaction (PCR) is the gold standard
CT scan:
CMV can also show intracranial calcification

47
Q

What is some information of AIDS

A

-AIDS is caused by the microbe human immunodeficiency virus (HIV)
-HIV is a retrovirus
-Retroviruses rely on their enzyme reverse transcriptase to perform the reverse transcription of its genome from RNA into DNA (normal transcription is from DNA to RNA)
-This altered viral genome is integrated into the host’s genome
The virus then replicates as part of the infected cell’s DNA

48
Q

can a patient with HIV express signs/symptoms of aids?

A

not always

49
Q

what is HIV ?

A

HIV is neurotropic
-It attacks the nervous system

-HIV also is lymphotropic and immunotropic
-It attacks the lymph glands, both T and B cells, and the immune system

50
Q

what is something you shou;d consider for AID/HIV

A

For populations at risk for HIV, the condition must be considered in all cases of sudden bilateral or unilateral HL****

51
Q

what are some otological signs and symptoms of aids ?

A

-OME with or without CHL; SNHL (during later disease stages)
-Otalgia
-Vertigo
-Tinnitus
-Aural fullness
-Reduced OAEs (OHCs affected)
-Delayed ABR interwave latencies (central effects)

52
Q

auditory symptoms may be secondary to aids

A

-Ototoxic effects of the AIDS drugs
-Recurrent/chronic OME and other opportunistic infections that attack the ear due to the suppressed immune system

53
Q

how can pediatric aids be transmitted to the baby

A

-HIV also is transmitted through the placenta
-As the number of AIDS cases in women increase so does pediatric AIDS (PAIDS)

54
Q

what is often present in brain tissue with pediatric aids

A

-Often edema of the brain tissue is present

-There is no latent or dormant period for the virus with congenital or early-appearing encephalopathy/encephalitis that can damage the brain and CNS

55
Q

what is meningitis ?

A

Inflammation of the meninges (duramater, arachnoid mater, and pia mater) surrounding the brain and spinal cord

56
Q

what are primary meninges ?

A

the disease originates in the meningitis

57
Q

what are secondary meninges ?

A

-ome leading to mastoiditis/labyrinthitis
-cholesteatoma that spreads to the meningitis

58
Q

what are some symptoms of meningitis ?

A

-High fever
-Neck rigidity
-Malaise
-Nausea/vomiting
-In severe cases, coma and death

59
Q

if left untreated/severe infections can lead to in meningitis ?

A

-Blindness
-Paralysis due to damage of the motor centers of the brain
-Hearing loss/deafness
-One of the most significant causes of acquired sensorineural hearing loss
-Meningitis can cause permanent abnormal cochlear bone formation
-The vestibular system also may be affected resulting in
-Vertigo and balance problems

60
Q

what are treatments of meningitis

A

-Antibiotics
-Appropriate to the infecting organism or broad spectrum antibiotics
-Mastoidectomy
-If the infection is related to middle ear disease and is not resolved by antibiotics
-Amplification or cochlear implant if a severe/profound hearing loss has occurred
-For post-meningitis CI candidates, important to ensure there is enough space in the cochlea to place an implant because of the abnormal bone growth associated with this disease
-The bony growth in the cochlea can continue after the CI and may compromise the implant; decreases success rate of CIs

61
Q

what is perilymphatic fistula (PLF)

A

A PLF is an abnormal connection (a tear or defect) in either or both the oval and round window that separate the air filled ME and the fluid filled perilymphatic space of the inner ear

62
Q

what cause Perilymphatic Fistula (PLF)

A

-Idiopathic
-A history of straining or lifting; feeling the ear “pop”
-Can occur during the early or late period following stapedectomy
-Spontaneous PLF also discovered at the time of surgery for Meniere’s disease

63
Q

what are 4 recognized patterns of symptoms for Perilymphatic Fistula (PLF)

A

1)Episodic vertigo without hearing loss
2)Hearing loss without vertigo
3)Symptoms maybe virtually indistinguishable from Meniere’s disease, i.e., tinnitus, SNHL, vertigo, aural fullness
4)Miscellaneous symptoms with disequilibrium but not episodic vertigo

64
Q

what do we need to diagnosis perilymphatic fistula (PLF)

A

Presentation of a symptom complex
-High index of clinical suspicion
-Dix Hallpike positional testing can result in nystagmus and vertigo

65
Q

what are treatments for perilympatic fistula (PLF)

A

-Middle ear exploration (exploratory tympanotomy)
-Surgical repair for obvious traumatic perilymph leak and sealing of the round or oval window
-Patients cautioned against heavy lifting following repair surgery

66
Q

what are some outcomes of repairing the fistula in perilymphatic fistula (PLF)

A

1) improve/preserve hearing
2)resolve vertigo/disequilibrium
3)improve tinnitus systems

67
Q

what is the epidemiology of noise induced hl

A

Humans are particularly susceptible to noise in the audible sound spectrum - from 500 to 8000 Hz

68
Q

what does dBA mean in noise induced HL

A

the relative risk that measured sound could damage human hearing
-Damage to human hearing may occur when subjected to an > 8-hour daily exposure of continuous sound at 85 dBA over a period of many years

69
Q

noise induced HL is caused by ?

A

by dose and duration

by both dose (level of noise) as well as duration (amount of time) to exposure of sound

70
Q

what is noise defined as

A

“unwanted” sound

71
Q

what sound is more hazardous, high freq or low freq?

A

High frequency sounds (up to 5000 Hz) are more hazardous than low frequency sounds
-hearing protection devices also provide greater attenuate of high freq and less protection from low freq

72
Q

what pattern is seen for noise induced hearing loss

A

The classic pattern of NIHL is a “noise notch”
-Greatest threshold shifts are noticed at the basal end of cochlea between the 3000 and 6000 Hz region in response to BBN
-Peak loss is typically at 4000 and 6000 Hz, improving at 8000 Hz

73
Q

what does that noise notch in noise induced hearing loss represent ?

A

The noise notch may represent a vulnerability in the 3 to 6 kHz region because of
-Stronger mechanical forces due to cochlear geometry
-More tenuous blood supply of the cochlea

74
Q

what is threshold shift ?

A

It is a change in hearing sensitivity from baseline

75
Q

how many types of noise induced temporary thresholds shift are identified noise induced hearing loss

A

2 types
1) Noise-induced temporary threshold shift (TTS)
2)Noise-induced permanent threshold shift (PTS or NIPTS)

76
Q

what is Noise-induced temporary threshold shift (TTS)

A

-Reversible increase in auditory threshold following exposure to loud noise – swollen rootlets of stereocilia + hair cells
-Most TTS resolves after ~15 minutes but can persist for ~ 14 hours
-New evidence suggests that loud noise can result in hidden hearing loss – synaptopathy, with no permanent change in hearing thresholds (TTS)

77
Q

what is Noise-induced permanent threshold shift (PTS or NIPTS)

A

-A persistent change in hearing sensitivity persisting after ~14 hours
-Permanence is assumed if change still observed on a 30-day follow up hearing test – tip links break; fractured and detached stereocilia

78
Q

what do Noise-induced permanent threshold shift and Noise-induced temporary threshold shift vary in?

A

vary with frequency, intensity, and temporal properties of the noise

79
Q

what does initial noise exposure produce ?

A

Noise-induced temporary threshold shift
-Experienced as a dull or muffled sound quality
For example, at the end of a work shift or loud concert

80
Q

A daily dose of noise exposure that does not cause TTS will not cause PTS over a worker’s lifetime
(just remember)

A
81
Q

what are Noise-induced permanent threshold shift and Noise-induced temporary threshold accompanied by ?

A

tinnitus
-Temporary tinnitus after noise exposure may be a useful warning that PTS will occur if exposure continues without use of hearing protection devices (HPDs)

82
Q

how does noise affect the middle ear?

A

-Injury to the middle ear from noise is rare
-It occurs only with extremely high levels of noise
»tm perforations can occur at 165 db spl or above
»ossicular chain injury occurs at 290 db spl or above

83
Q

how might we see the middle ear in victims of bomb blasts?

A

In human victims of bomb blasts, including soldiers on the battlefield, TM perforations can be used a sign of possible concussion
-If the TM is perforated, more likely that the person has sustained a concussion from the blast

84
Q

how is the inner ear affected by noise?

A

-Exposure to loud noise levels can result in tinnitus
-Structures most vulnerable to noise in the cochlea are OHCs
>Initially, stereocilia lose their stiffness and, therefore, their ability to vibrate in response to sound
>The result is a reversible hearing loss or TTS
>After repeated hazardous levels of exposure, permanent damage occurs to stereocilia

-The more intense and prolonged the exposure, the greater the degree of hair cell loss

85
Q

how is the vestibular system affected by noise?

A

-It is doubtful that noise levels that cause NIHL can cause vestibular system injury
-Acoustic trauma, however, can cause vestibular system injury
>Most patients present with a history of noise trauma and balance symptoms

-It is important to remember that these patients may have other coincidental causes for their vestibular problems

86
Q

how do we diagnosis noise induced hearing loss

A

1)Clinical history and supportive audiometric data showing SNHL
2)Medical examination to rule out other causes of hearing loss
3)NIHL is usually symmetrical, but asymmetries of > 15 dB HL are not uncommon, for example
>Left sided hearing loss with right-handed shooting of weapons
>Other causes of asymmetric SNHL (e.g., vestibular schwannoma) should be ruled out
-In a pure NIHL
>Profound SNHL is rare
>Low frequency thresholds are rarely worse than 40 dB HL
>High frequency thresholds are rarely worse than 75 dB HL
4)Cessation of noise exposure can cause a slower progression of the hearing loss

87
Q

what is more hazardous, narrow band sounds or broad broad band noise?

A

very narrow band noise is more hazardous, but broad band noise over a longer duration can cause wide spread cochlear damage

88
Q

is noise induced hl a symmetrical or asymmetrical loss?

A

-Most NIHL is symmetric especially if caused by occupational or recreational noise exposure
-In some cases, it can be asymmetrical in the higher frequencies (3000 to 6000 Hz), especially with long-gun firearm use because of the head shadow, which protects one ear more than the other.

89
Q

how do we manage noise induced hl?

A

-There is no effective treatment for NIHL
-Prevention is the best management through
>Environmental controls to reduce noise in the work-place
Use of hearing protection devices to minimize the level of noise exposure
»For e.g., earmuffs and ear plugs
»Musician earplugs, which can attenuate environmental noise by 15 to 25 dB but allow speech/music to be heard
-Use of appropriate amplification when a permanent hearing loss occurs
-The use of anti-oxidants and other chemicals to protect against NIHL are currently being investigated

90
Q

how is acoustic trauma distinct from noise induced hearing loss?

A

It is a sudden permanent hearing loss from a single event or exposure without intervening TTS

91
Q

what are most acoustic trauma cause by ?

A

Most acoustic trauma is caused by impulse noise (sudden, short duration very loud sounds) such as
>Bombs/improvised explosive devices (IEDs)
>Firearms and other weapons
>Industrial blasts

92
Q

acoustic trauma involves what ?

A

-Acoustic trauma involves direct mechanical injury to the cochlea, with or without TM perforation
-Sound intensity b/w 165 to 190 dB SPL
>Can rupture or produce hemorrhage of the TM
>Disrupt or fracture the ossicular chain

93
Q

impact noise over 140 db SLP peak pressure can result in?

A

Noise-induced permanent threshold shift

94
Q

what are some signs and symptoms of acoustic trauma?

A

1)Visible TM perforation/hemorrhage on otoscopy
2)Audiometric results following acoustic trauma are similar to NIHL

3)Variety of other audiogram configurations possible, such as
>High frequency sloping configuration
>Flat configuration (more common)
4)Type Ad tympanogram with absent ARTs if ossicular disarticulation has occurred

5)Hearing loss from acoustic trauma may improve over a 4-to-6-month period
6)Surgery maybe required to repair TM and ossicles, if damaged

95
Q

blast injuries are part of acoustic trauma, how are blast injuries caused by?

A

-Blast injuries are caused by the indirect impact from a pressure wave generated by an explosion that causes an instant rise in pressure, creating a blast wave that starts at the site of the explosion and travels outward
»Blast waves occur when the compression of air in front of the pressure wave heats and accelerates air molecules, leading to a sudden increase in overpressure and temperature, which are transmitted into the surrounding environment as a propagating shock wave known as the blast wave

96
Q

what body part is the most susceptible organ to primary blast injury

A

the ear
>Blast injury can damage the entire auditory system resulting in TM perforation, ossicular disarticulation, tinnitus, otalgia, hearing loss, and/or vertigo

97
Q

in noise induced hearing loss, how can age affect that carhart notch?

A

aging can lead to flattening to noise notch

AUDE 5410 (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions