Brainscape's Knowledge GenomeTM

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


See full index

Diagnostic Audiology > Causes of hearing disorders > Flashcards

Causes of hearing disorders Flashcards

Disorders causing hearing impairment: Tympanic membrane perforation, glue ear, otitis media, otosclerosis, ossicular dislocation, trauma, tumours, vascular, metabolic, neurological, immunological, presbycusis, noise-induced hearing loss, ototoxicity, unilateral hearing loss, sudden sensorineural hearing loss, vestibular schwannoma, stroke-related hearing impairment, central presbycusis

1
Q

What are the three types of hearing loss?

A

Sensorineural, conductive and mixed

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

What is sensorineural hearing loss?

A

-Affects the inner ear/ central auditory system (outer hair cells and/ or nerve pathways)
-Most common type of hearing loss
-Permanent

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

What are some of the causes of sensorineural hearing loss?

A

Aging, noise exposure, infectious diseases, medications, diabetes, Meniere’s disorder, genetic, tumours

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

What is the recommended treatment for sensorineural hearing loss?

A

Hearing aids or cochlear implant

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

What is conductive hearing loss?

A

-Affects the outer and middle ear
-Can be temporary more often

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

What are some of the causes of conductive hearing loss?

A

Choleastoma (collection of skin cells in the ear), foreign bodies, ear wax, otitis media (fluid in the middle ear), microtia (malformation of pinna and outer ear), perforated tympanic membrane, otosclerosis (fusion of the bones in the ear)

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

What is mixed hearing loss?

A

-Combination of sensorineural and conductive hearing loss
-Most of the time there is more than one cause (one causing sensorineural hearing loss, one causing conductive hearing loss) acting in conjunction

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

What is microtia?

A

-Congenital abnormality of the outer ear
-Pinna is small or missing
-Ear canal may be narrowed or missing
-Cochlea is present and usually normal

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

What is otitis externa?

A

-Inflammation of the skin in the ear canal
-Caused by water, objects in the ear and infections
-The pinna becomes red and damp and the inside of the ear is irritated and red
-Prevent by not inserting small objects into ears and making sure ears are dry following exposure to water

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

What is the treatment for otitis externa?

A

Antibiotics or microsuction

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

What is exostosis (also known as “surfer’s ear”)?

A

-Bony benign growths that are usually multiple and have a wide base
-Formed of laminar bone
-Occurs due to repeated exposure to cold water/ alcohol ear drops

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

What is osteoma?

A

-A benign cartilage/ bony growth
-Has a short thin base and is easily removed
-Harmless except if it touches the TM or blocks the canal

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

In what cases can ear wax (cerumen) cause hearing loss?

A

-If it is blocking the ear canal
-However it is very common and part of the normal function of the ear

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

What is a tympanic membrane perforation?

A

-A hole in the tympanic membrane
-It is very common in children with ear infections
-Usually heals without treatment in a few days or weeks
-May become chronic in which case a surgeon will need to help manage it
-If the edges are rounded it is likely that the perforation has been there for a while

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

What are the possible causes of a tympanic membrane perforation?

A

-Ear infection which causes a buildup of fluid behind the tympanic membrane which bursts the TM and leaks out
-Injury to the TM such as a blow to the ear or pushing an object deep into the ear
-Changes in pressure such as while flying or scuba diving
-Sudden loud noise such as an explosion (change in pressure again)

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

What does “middle ear” refer to?

A

The tympanic membrane, middle ear cavity and the ossicles

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

What are the names of the two conditions causing inflammation of the middle ear?

A

Acute otitis media and chronic otitis media

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

What is Eustachian tube dysfunction?

A

-The function of the Eustachian tube is to help you balance pressure in your middle ear and drain fluid from the middle ear
-When there is a dysfunction of the Eustachian tube this does not happen properly
-It is the first stage in any type of otitis media

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

What is Eustachian tube dysfunction caused by?

A

Can be caused by an upper respiratory tract infection (URTI- also known as a cold), adenoids, smoking, bottle feeding and congenital anomalies such as a cleft palate

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

What is acute otitis media caused by?

A

Bacteria which have travelled to the middle ear from a fluid build up in the Eustachian tube

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

What are some of the common symptoms of acute otitis media?

A

Otalgia (ear pain), fever, vomiting, diarrhoea

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

When is acute otitis media most common in an individual?

A

-In childhood
-85% of children have at least one episode of acute otitis media by the age of 3
-Most likely to get it at 6-12 months

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

What does acute otitis media look like on otoscopy?

A

Red and bulging tympanic membrane

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

What is a possible complication of acute otitis media?

A

Mastoiditis: bacterial infection affecting the mastoid bone
-If untreated the mastoid bone may need to be removed or it can lead to serious conditions such as blood clots, meningitis or a brain abscess

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

What are the treatment options for acute otitis media?

A

-Watch and wait for the infection to clear up by itself
-Antibiotics
-Grommets- small ventilation tube placed into the tympanic membrane to allow aeration of the middle ear space

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

What is otitis media with effusion (otherwise known as glue ear)?

A

-Collection of fluid in the middle ear space without signs of acute inflammation
-Most commonly affects children and 80% of children have at least one episode by the time they are 10
-Can cause hearing loss but is usually resolved within several weeks or months

27
Q

What is the treatment for otitis media with effusion?

A

-Watch and wait (child reviewed after 3 months to see if the problem has resolved itself)
-Autoinflation (pictured)- inflating balloon using nose increases pressure in the nasopharynx and opens the Eustachian tube which equalises the middle ear pressure
-Temporary hearing aids
-Grommets

28
Q

What is chronic suppurative otitis media?

A

-Chronic inflammation of the middle ear and mastoid cavity
-Recurrent ear discharge through a tympanic membrane perforation
-Results as a complication of acute otitis media

29
Q

What happens if chronic otitis media is left untreated?

A

The infection can spread to the meninges or the brain resulting in meningitis but this is rare in the UK

30
Q

What is atticoantral disease?

A

-Formation of a retraction pocket in the TM due to continuous negative pressure
-If the retraction pocket is deep the shredded keratin will not be able to migrate out of the ear canal
-Can lead to the development of choleastoma

31
Q

What is a cholesteatoma?

A

-Skin cyst in the middle ear
-Epidermal skin becomes trapped in the middle ear by a deformed tympanic membrane or migrates through a perforation
-It can grow out of control and cause significant damage to the structures of the middle ear and the mastoid

32
Q

What is otosclerosis?

A

-Abnormal bone growth
-Stapes fuses with surrounding bone and eventually becomes fixed
-Onset in adults in their 20s or 30s

33
Q

What are the treatment options for otosclerosis?

A

Hearing aids or surgery (the stapes can be removed and replaced with an artificial version in order to get better movement of the ossicular chain)

34
Q

What is the cause and treatment options for ossicular chain dislocation?

A

-Ossicular chain dislocation can occur following head injury/ trauma
-The stapes can come away from the incus
-Uncommon
-Can be managed with hearing aids or surgery

35
Q

What are the two types of tumours that can cause hearing loss?

A
  1. Malignant tumours- e.g. nasopharyngeal tumours which causes hearing loss in the affected ear and tinnitus
  2. Benign tumours- e.g. glomus tumour which is slow growing, causes hearing loss and tinnitus in the affected ear
36
Q

What is presbycusis?

A

The decrease of auditory function that occurs with aging- over 40% of people over 50 years old have hearing loss which increases to 70% for people over the age of 70

37
Q

What are the symptoms of presbycusis?

A

-Slowly progressive, bilateral hearing loss which is often accompanied by tinnitus
-Not accompanied by vertigo and imbalance

38
Q

What are the four types of human presbycusis?

A
  1. Sensory- affecting cochlear hair cells and supporting cells (most common)
  2. Neural- loss of afferent neurons in the cochlea
  3. Metabolic- atrophy of lateral wall and stria vascularis of the cochlea
  4. Mechanical- caused by stiffening of the basilar membrane which makes transmission of sound much less effective
39
Q

Where in the cochlea are the effects of aging seen first?

A

-In highly metabolic tissues such as the lateral wall of the cochlea were aerobic metabolism is very high
-This is evidence that age related hearing loss is not only due to a general loss of hair cells but also due to pathologies in the cochlear lateral wall

40
Q

What is ototoxicity?

A

-Effects of certain therapeutic agents and other chemical substances on the inner ear structures
-Causes cellular degradation of the tissue of the inner ear

41
Q

What are the five major categories of ototoxic drugs?

A
  1. Antibiotics (e.g. gentamicin)
  2. Analgesics (e.g. aspirin)
  3. Antimalarial (e.g. quinine)
  4. Antineoplastic (i.e. chemotherapy)
  5. Diuretics (i.e. drugs which increase amount of water and salt expelled from the body)
42
Q

What is the meaning of cochleotoxic and vestibulotoxic?

A

Cochleotoxic- affects the cochlea
Vestibulotoxic- affects the vestibular organs

43
Q

What are the four factors in ototoxicity?

A

-The drug and how much of an effect it has on the auditory system
-Synergy with drugs- taking two drugs with mild ototoxic effects together may have enhanced ototoxicity
-Exposure time- e.g. long term use may lead to ototoxicity
-Genetic predisposition

44
Q

How can having diabetes mellitus predispose someone to hearing loss?

A

-Elevations in blood glucose level causes damage to small blood vessels in the cochlea
-These vascular changes may affect small vessels in the cochlea as well as central pathways
-Can lead to sensory or neural hearing loss

45
Q

What is vestibular schwannoma/ acoustic neuroma?

A

-Slow growing benign tumour of the Schwan cells
-It is not cancerous but it occupies space so if it starts to grow it might press on a vital part of the brain such as the brainstem

46
Q

What are the 4 phases of vestibular schwannoma tumour growth?

A
  1. Intracanalicular- tumour is confined to the internal auditory canal. Hearing loss and tinnitus are common, vertigo may also be present
  2. Cisternal- More severe hearing loss and disequilibrium
  3. Compressive- Occipital headaches and neuropathy of the fifth cranial nerve with hypoesthesia (reduced sensitivity) of the cornea and midface
  4. Hydrocephalic- Compression and obstruction of the fourth ventricle causing headaches, visual changes and altered mental status
47
Q

What are the symptoms of vestibular schwannoma?

A
  1. Unilateral sensorineural hearing loss- often gradual and slowly progressive
  2. Poor speech discrimination
  3. Tinnitus
  4. Imbalance (not true vertigo- more like slight imbalance/ light headedness)
48
Q

What kind of hearing loss is associated with vestibular schwannoma?

A

-Unilateral asymmetric sensorineural hearing loss at high frequencies
-Accompanied by decreased speech discrimination

49
Q

What tests are carried out if vestibular schwannoma is suspected?

A

-MRI (with contrast) is the most accurate diagnostic test
-ABR
-Speech discrimination

50
Q

When may someone be unable to get an MRI scan done?

A

If they have a cochlear implant

51
Q

What are the treatment options for vestibular schwannoma?

A

-Watchful waiting- surgery carries risks and if the tumour is not causing problems it may not be an appropriate way to go
-Stereotactic radiotherapy
-Surgery if the tumour is very large and compromising other structures

52
Q

What factors influence surgery as a treatment option for vestibular schwannoma?

A
  1. Tumour factors- size, site, rate of growth
  2. Patient factors- age, medical conditions, hearing
  3. Surgeon factors- experience, resources, approach
53
Q

What are the red flags in audiology that may indicate to us that someone has a vestibular schwannoma?

A

-Unilateral auditory symptoms
-Impaired facial sensation
-Unexplained imbalance

54
Q

What are the audiological indications of auditory neuropathy spectrum disorder?

A

-Present otoacoustic emissions
-Flat trace on ABR

55
Q

What is the site of lesion for auditory neuropathy spectrum disorder

A

Inner hair cells, auditory nerve

56
Q

What can cause auditory neuropathy spectrum disorder (ANSD)?

A
  1. Genetic- Nonsyndromic (otoferlin, autosomal recessive mutations in pejvakin) and syndromic (Charcot-Marie Tooth disease, Friedreich ataxia, Leber’s hereditary optic neuropathy, Refsum’s Disease, Mohr-Tranebjaerg Syndrome, Mitochondrial Disease)
  2. Autoimmune- Cogan’s syndrome, type 1 diabetes
  3. Infectious- Neurosyphilis, HIV, CMV in HIV positive patients, typhus
  4. Neonatal illness- Hyperbilirubinemia, hypoxia, prematurity
  5. Toxic/ metabolic- Facial-auditory nerve oxalosis, xylene exposure, and potentially alcohol, organic mercury and uremia
  6. Idiopathic
57
Q

How does ANSD present on a pure tone audiogram?

A

-Commonly reverse slope sensorineural hearing loss (poorer in low frequencies, better in higher frequencies
-Can be any degree/ shape (can even be within normal limits)

58
Q

Does ANSD affect speech perception?

A

-Not predicted by pure tone audiogram
-Sometimes it does, sometimes it doesn’t

59
Q

What are the treatment options for ANSD?

A

-Hearing aids
-Cochlear implants- especially with non-syndromic auditory neuropathies
-Radio aids- useful for hearing in background noise

60
Q

What is sudden sensorineural hearing loss defined as?

A

-Sensorineural hearing loss of 30 dB or greater over at least three audiometric frequencies occurring within a 72 hour period
-Relatively uncommon
-Usually unilateral

61
Q

What are the causes of sudden sensorineural hearing loss?

A
  1. Infectious- Lyme disease, syphilis
  2. Autoimmune disease
  3. Traumatic
  4. Vascular (stroke, TIA)
  5. Vestibular schwannoma- unlikely but possible
    -Only in 7-45% of patients can a defined cause be identified, most of the time it is idiopathic
62
Q

Is recovery from sudden sensorineural hearing loss possible?

A

-32-65% of patients recover without treatment
-Recovery usually within 2 weeks of onset
-Complete recovery in about 36% of people

63
Q

What is the treatment for sudden sensorineural hearing loss?

A

Corticosteroids (either intratympanic or oral)

64
Q

How can stroke cause hearing loss?

A

-Sudden sensorineural hearing loss highly prevalent in stroke survivors
-Can be caused by pathology in the inner ear, auditory nerve, cochlear nuclei
-Association between hearing loss and stroke can also be attributed to age-related changes of the inner ear/ auditory nerve as most stroke sufferers are over 60
-If the stroke involves the central auditory pathway patients may also suffer auditory processing deficits
-Mostly unilateral hearing loss

Diagnostic Audiology (12 decks)

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