Week 208 - Glue Ear Flashcards
Week 208 - Glue Ear: How much does the Pinna and concha amplify sound by?
20dB
Week 208 - Glue Ear: What is the name of surfer’s ear?
Exostoses.
Week 208 - Glue Ear: What are the components of the middle ear cleft?
- Osicles
- Eustachian Tube
- Ear drum
- Mastoid
Week 208 - Glue Ear: What are the two components of the tympanic membrane?
- Pars Tensa
* Pars Flaccida (Attic)
Week 208 - Glue Ear: What are the causes of perforation?
- Trauma
- Infection
- Surgery
Week 208 - Glue Ear: How can perforation lead to hearing loss?
Without the tympanic membrane, sound is able to travel via two paths.
• The first is through the remnants of the ear drum and along the ossicles.
• The second is straight onto the round window.
These two pathways can interfere with each other or even cancel each other out.
Week 208 - Glue Ear: What effect on hearing can retractions cause?
Reduction in conductive hearing since they limit the vibration of the ossicles.
Week 208 - Glue Ear: What is the difference in sound energy between that which reaches the eardrum and that which reaches the round window?
The sound is amplified about 20x as it gets to the round window.
Week 208 - Glue Ear: What are the two mechanisms leading to the formation of a cholesteatoma?
- Retraction of the eardrum.
- The normal migration of epithelium from the umbo. (In a cholesteatoma this gets stuck leading to a build-up of skin tissue)
Week 208 - Glue Ear: What are the characteristics of cholesteatoma?
- Painless
- Conductive hearing loss
- Foul, scanty green discharge
Week 208 - Glue Ear: What are some of the complications of cholesteatoma?
- Mastoiditis
- Meningitis
- Facial nerve paralysis
- Brain abscess
Week 208 - Glue Ear: What is otosclerosis?
- Thickening of the bone near the footplate of the stapes that spreads across the stapes and fixes it in place.
- Autosomal dominant inherited disease.
Week 208 - Glue Ear: What are the symptoms of otosclerosis?
• Conductive hearing loss. (85% bilaterally)
Week 208 - Glue Ear: How is otosclerosis diagnosed?
- Family history
* Audiology (the hearing loss pattern has a very distinct pattern)
Week 208 - Glue Ear: From what does the spongy bone leading to otosclerosis first grow from?
fissula ante finestram
Week 208 - Glue Ear: What is the best treatment for otosclerosis?
Hearing-aids.
Week 208 - Glue Ear: What is presbyacusis?
Age-associated hearing loss, it is a near inevitability in western culture.
• Loss of hair cells and spiral ganglion cells.
• High-frequency hearing is lost first.
Week 208 - Glue Ear: What are some of the iatrogenic causes of inner ear damage?
- Surgery
* Aminoglycosides, loop diuretics, chemotherapeutics.
Week 208 - Glue Ear: What are the individual hearing organs inside the cochlear called?
• Organ of corti
Week 208 - Glue Ear: Aminoglycosides can damage the inner ear, give some examples.
Gentamicin, Streptomicin.