Hearing loss Flashcards
What are the causes of conductive hearing loss?
External ear:
- Congenital atresia (microtia)
- Wax
- Foreign body
- Otitis externa
Tympanic membrane and middle ear:
- Otitis media
- Tympanic perforation
- Eustachian tube blocking (nasopharyngeal tumour, allergic rhinitis)
- Fixation of ossicles (fusion of ear bones)
- Otosclerosis
What are the causes of sensorineural hearing loss?
- Presbycusis (age related hearing loss)
- Menieres disease
- Traumatic or noise induced
- Cerebellopontine angle tumours - Vestibular schwannoma
- Autoimmune hearing loss (AIED)
- Congenital causes:
- Premature birth
- Neonatal jaundice
- Intrauterine infection
- Toxic - gentamicin, loop diuretics, aspirin, cytotoxics
- Sudden onset hearing loss - herpes simplex
What are the causes of insidious onset hearing loss?
- Presbycusis (age related hearing loss)
- Noise induced hearing loss
- Tumours
What are the causes of fluctuating hearing loss?
- Middle ear effusions
- Ménière’s disease
Is more copious ear discharge more associated with external ear infections or middle ear infections?
Middle ear infections
What conditions might ear discharge indicate?
- Otitis externa or media
- Perforated tympanic membrane
- Cholesteatoma
What factors of birth and pregnancy can lead to congenital deafness?
- Prematurity
- Low birth weight
- Neonatal jaundice
- Rubella infection
Management of sudden onset hearing loss
This is an emergency
- high dose prednisolone for 1 week
- audiogram next working day
- +/- intratypmanic steroid injection
What is the autosomal dominant inherited form of conductive hearing loss?
Otosclerosis
What are the medications that can cause hearing loss?
- Loop diuretics
- Gentamicin
- Aspirin
- Anti-neoplastic agents
- Quinines
What does Rinne’s test look for?
Conductive hearing loss
What are the two possible results from Rinne’s test?
Positive - normal - the tuning fork is still heard next to the ear when it is no longer heard when placed on the mastoid
Negative - abnormal - the tuning fork is heard best when placed on the mastoid process
What does Weber’s test look for?
Hearing loss - both conductive and sensorineural
It must be used in conjunction with Rinne’s test to work out which it is
On examination of a patient with hearing loss, they have a negative result in the left ear during Rinne’s test and when Weber’s test is performed the sound lateralizes to the left. What is the likely nature of the hearing loss?
Conductive loss in the left
On examination of a patient with hearing loss, they have a negative result in the left ear during Rinne’s test and when Weber’s test is performed the sound lateralizes to the right. What is the likely nature of the hearing loss?
Combined (conductive and sensorineural) loss in the left ear
On examination of a patient with hearing loss, they have a negative result in the right ear during Rinne’s test and when Weber’s test is performed the sound lateralizes to the left. What is the likely nature of the hearing loss?
Combined (conductive and sensorineural) loss in the right ear
On examination of a patient with hearing loss, they have a negative result in the right ear during Rinne’s test and when Weber’s test is performed the sound lateralizes to the right. What is the likely nature of the hearing loss?
Conductive loss in the right
On examination of a patient with hearing loss, they have a positive result in both ears during Rinne’s test but when Weber’s test is performed the sound lateralizes to the left. What is the likely nature of the hearing loss?
Sensorineural loss in the right
On examination of a patient with hearing loss, they have a positive result in both ears during Rinne’s test but when Weber’s test is performed the sound lateralizes to the right. What is the likely nature of the hearing loss?
Sensorineural loss in the left
On examination of a patient with hearing loss, they have a negative result in both ears during Rinne’s test but when Weber’s test is performed the sound lateralizes to the right. What is the likely nature of the hearing loss?
Combined loss in the left
Conductive loss in the right
On examination of a patient with hearing loss, they have a negative result in both ears during Rinne’s test but when Weber’s test is performed the sound lateralizes to the left. What is the likely nature of the hearing loss?
Combined loss in the right
Conductive loss in the left
On examination of a patient with hearing loss, they have a negative result in both ears during Rinne’s test but when Weber’s test is performed the sound does not lateralize. What is the likely nature of the hearing loss?
Conductive loss in both ears
When you examine the tympanic membrane, what features are you assessing?
- Perforations
- Bulging (middle ear fluid)
- Retracted/sucked in (Eustachian tube dysfunction)
- Colour
- Inflammation (red)
- Middle ear effusion (yellowish and serous, greyish in glue ear)
- Light reflex (over-rated as a sign)
What is the standardized hearing test that we use?
Pure tone audiogram
If a patient is unable to undertake the pure tone audiogram, what are the other options available?
Oto-acoustic emission testing (OAEs)
Brain stem evoked response audiometry (BERA)
What is the objective test used to assess middle ear function?
Tympanometry
When might a patient who presents with hearing loss need a CT of temporal bones?
- Cholesteatoma
- Malformations of external ear
As well as assessing hearing and examining the ear, what else must you examine in a patient with hearing loss?
Signs of facial nerve palsy
What is otosclerosis?
Inherited disease which produces a progressive, conductive or mixed hearing loss secondary to abnormal bone metabolism in the remnants of the otic capsule in the inner ear.
The most common site of attack in the ear is the fistula ante fenestra at the anterior part of the stapes footplate. The abnormal bone deposition anchors the stapes in the round window preventing normal conduction of sound.
How do patients affected by otosclerosis most often present?
In the third decade of life, with slowly progressive, bilateral conductive deafness, tinnitus and occasional mild vertigo.
(Otoscopy shows a normal ear drum in most cases, however 10% have a ‘flamingo tinge to the tympanic membrane. This is caused by hyperaemia.)
How do you manage someone with diagnosed otosclerosis?
Conservative - hearing aids
Surgical - stapedectomy and insertion of prosthesis
What is presbycusis?
How does it present?
Irreversible sensorineural hearing loss due to age related degeneration of the hair cells.
Patient will report bilateral hearing loss accompanied by tinnitus. Speech discrimination is affected first, especially when there is background noise.
How is presbycusis diagnosed?
Mainly through history and audiological evidence of bilateral sensorineural hearing loss that is more marked in the higher frequencies.
What sounds do those with presbycusis have particular difficulty hearing?
Speech, especially those sounds of speech which involve the higher frequencies. Sounds include ‘th’, ‘f’, ‘s’ and ‘k’
How are those with presbycusis managed?
- Provision of an appropriate hearing aid
- Provision of environmental aids as well
- Cochlear implantation
