Hearing loss

Question 1

What are the 3 types of hearing loss?

Answer 1

• Conductive
• Sensorineural
• Mixed

Question 2

What is meant by conductive hearing loss?

Answer 2

Hearing loss arising due to a pathology of sound conduction through the tympanic membrane or ossicles

Question 3

What is meant by sensorineural hearing loss?

Answer 3

Hearing loss arising due to a pathology of sound detection in the nerves or middle ear components

Question 4

What are some causes of conductive hearing loss?

Answer 4

• Otitis externa
• Acute otitis media
• Chronic otitis media
  
  • Otitis media with effusion (Glue ear)
  • Cholesteatoma
  • Perforation
• Otosclerosis

Question 5

What is shown?

Answer 5

Tympanic membrane perforation

Question 6

What are some causes of tympanic membrane perforation?

Answer 6

• Acute otitis media (Younger)
• Trauma (E.g. Barotrauma, insertion of objects into the ear)

Question 7

How will tympanic membrane perforation present?

Answer 7

Sudden severe pain sometimes followed by bleeding from the ear, hearing loss, and tinnitus

Question 8

What investigations are required in tympanic membrane perforation?

Answer 8

Otoscopy
Audiometry

Question 9

How is tympanic membrane perforation managed?

Answer 9

Usually heals spontaneously

Question 10

When is surgical repair of tympanic membrane perforation indicated?

Answer 10

If the patient is symptomatic with recurrent discharge

Question 11

What is otosclerosis?

Answer 11

Hereditary disorder in which new bony deposits occur within the stapes footplate and the cochlear, resulting in gradual onset hearing loss

Question 12

Who is most at risk of otosclerosis?

Answer 12

• Family history
• Women (Linked to high oestrogen)
• Pregnant women (High oestrogen)
• 2nd - 3rd decade

Question 13

How will otosclerosis present?

Answer 13

Gradual onset hearing loss

Question 14

How will otosclerosis present on audiometry?

Answer 14

Conductive or mixed hearing loss
A classic feature is Carhart’s notch at 2KHz

Question 15

How is otosclerosis managed?

Answer 15

• Hearing aids
• Stapedectomy

Question 16

What are some causes of sensorineural hearing loss?

Answer 16

• Presbycusis
• Noise-induced hearing loss
• Drug-induced hearing loss
• Vestibular schwannoma
• Meniere’s disease
• Skull fracture

Question 17

What is presbycusis?

Answer 17

Degenerative disorder of the cochear resulting in hearing loss

Question 18

What causes presbycusis?

Answer 18

• Loss of outer hair cells - environmental noise toxicity over time is a major factor
• Loss of ganglion cells
• Strial atrophy

Question 19

How does presbycusis present?

Answer 19

Gradual onset hearing loss

Question 20

What will audiometry show in presbycusis?

Answer 20

• Higher frequencies affected most
• Usually sensorineural hearing loss

Question 21

What condition is shown?

Answer 21

Presbycusis

Question 22

How is presbycusis managed?

Answer 22

• High-frequency-specific hearing aid
• Usualy high frequency
• Highly variable onset

Question 23

How does noise-induced hearing loss occur?

Answer 23

Cochlear damage can occur, for example, from shooting without ear protectors or from industrial noise

Question 24

Describe the legal implication of noise-induced hearing loss in the workplace?

Answer 24

Employers have legal responsibility regarding protection at work

Question 25

How can noise-induced hearing loss be prevented?

Answer 25

Ear protection

Question 26

What will noise-induced hearing loss show on audiometry?

Answer 26

- Sensorineural hearing loss - Characteristically has a dip at 4 kHz - Classic dip at 4kHz in hearing - Preventable with protection

Question 27

What condition is shown?

Answer 27

Noise-induced hearing loss

Question 28

What are some drugs that can cause sensorineural hearing loss?

Answer 28

- Gentamicin (+Other aminoglycosides) - Chemotherapeutic drugs (E.g. cisplatin, vincristine) - Aspirin and NSAIDs (In overdose)

Question 29

What is a vestibular schwannoma (Acoustic neuroma)?

Answer 29

Rare, benign tumour of the CN VIII nerve sheath that arises in internal auditory meatus

Question 30

What are some possible associations with vestibular schwannoma?

Answer 30

Loud noise exposure Neurofibromatosis type 2

Question 31

Where do vestibular schwannomas occur?

Answer 31

Vestibular portion of CN VIII Within the temporal bone 95% unilateral

Question 32

Describe the gross appearance of vestibular schwannoma

Answer 32

Circumscribed tan/white/yellow mass

Question 33

Describe the histology of vestibular schwannoma?

Answer 33

Encapsulated, two growth patterns (Antoni A and Antoni B)

Question 34

How does a vestibular schwannoma present?

Answer 34

- Progressive sensorineural unilateral hearing loss and tinnitus - Imbalance in larger tumours - Facial numbness can occur due to compression of the trigeminal nerve as the tumour enlarges

Question 35

What investigation is required in vestibular schwannoma?

Answer 35

MRI

Question 36

How is vestibular schwannoma managed?

Answer 36

- Monitoring with MRI - Surgical excision

Question 37

What are some possible ENT symptoms of skull fracture?

Answer 37

- Hearing loss - Facial pasly - CSF leak