Hearing loss Flashcards
What are the 3 types of hearing loss?
- Conductive
- Sensorineural
- Mixed
What is meant by conductive hearing loss?
Hearing loss arising due to a pathology of sound conduction through the tympanic membrane or ossicles
What is meant by sensorineural hearing loss?
Hearing loss arising due to a pathology of sound detection in the nerves or middle ear components
What are some causes of conductive hearing loss?
- Otitis externa
- Acute otitis media
- Chronic otitis media
- Otitis media with effusion (Glue ear)
- Cholesteatoma
- Perforation
- Otosclerosis
What is shown?
Tympanic membrane perforation
What are some causes of tympanic membrane perforation?
- Acute otitis media (Younger)
- Trauma (E.g. Barotrauma, insertion of objects into the ear)
How will tympanic membrane perforation present?
Sudden severe pain sometimes followed by bleeding from the ear, hearing loss, and tinnitus
What investigations are required in tympanic membrane perforation?
Otoscopy
Audiometry
How is tympanic membrane perforation managed?
Usually heals spontaneously
When is surgical repair of tympanic membrane perforation indicated?
If the patient is symptomatic with recurrent discharge
What is otosclerosis?
Hereditary disorder in which new bony deposits occur within the stapes footplate and the cochlear, resulting in gradual onset hearing loss
Who is most at risk of otosclerosis?
- Family history
- Women (Linked to high oestrogen)
- Pregnant women (High oestrogen)
- 2nd - 3rd decade
How will otosclerosis present?
Gradual onset hearing loss
How will otosclerosis present on audiometry?
Conductive or mixed hearing loss
A classic feature is Carhart’s notch at 2KHz
How is otosclerosis managed?
- Hearing aids
- Stapedectomy
What are some causes of sensorineural hearing loss?
- Presbycusis
- Noise-induced hearing loss
- Drug-induced hearing loss
- Vestibular schwannoma
- Meniere’s disease
- Skull fracture
What is presbycusis?
Degenerative disorder of the cochear resulting in hearing loss
What causes presbycusis?
- Loss of outer hair cells - environmental noise toxicity over time is a major factor
- Loss of ganglion cells
- Strial atrophy
How does presbycusis present?
Gradual onset hearing loss
What will audiometry show in presbycusis?
- Higher frequencies affected most
- Usually sensorineural hearing loss
What condition is shown?
Presbycusis
How is presbycusis managed?
- High-frequency-specific hearing aid
- Usualy high frequency
- Highly variable onset
How does noise-induced hearing loss occur?
Cochlear damage can occur, for example, from shooting without ear protectors or from industrial noise
Describe the legal implication of noise-induced hearing loss in the workplace?
Employers have legal responsibility regarding protection at work
