Hearing Loss Flashcards
Causes of conductive hearing loss (5)
obstruction
perforation
problems with ossicular chain: otosclerosis
impaired eustachian tube ventilation e.g. effusion from nasopharyngeal ca.
petrous temporal bone fracture
Pathology of sensorineural hearing loss (3)
defects to:
- oval window of cochlea (sensory)
- cochlear nerve (neural)
- central pathways
Causes of sensorineural hearing loss (6)
ototoxic drugs:
- gent, vanco, streptomycin
- chloroquine/hydroxychloroquine
- furoesmide, cisplatin
post-infection:
- meningitis, measles, mumps, flu
- herpes, syphilis
meniere’s
acoustic neuroma
presbyacusis
cochlear vascular disease
Auditory neuropathy spectrum disorder
disorder in transmission of sound from inner hair cells to brainstem resulting in impaired discrimination of speech beyond what is expected.
Auditory processing disorder
disorder of central auditory pathways resulting in impaired COMPREHENSION; hearing is technically intact
Neonatal deafness screening
ALL children screened either via otoacoustic emissions or via audiological brainstem responses.
Congenital causes of central hearing loss (3)
hyperbilirubinaemia/kernicterus
hypoxia
ventricular haemorrhage
Congenital causes of conductive hearing loss (4)
physical anomalies
congenital cholesteatoma
Treacher-Collins:
- downward slanting eyes
- drooping lower eyelid
- micrognathia
- malformed ears
Pierre-Robin>congenital facial abnormalities
Congenital causes of sensorineural hearing loss (5)
AD:
- Waardenburg: heterochromia, widely spaced eyes, white tuft of hair and white patch on forehead
- Klippel-Feil
AR:
- Pendred:goitre
- Usher’s: retinitis pigmentosa
- Jevell-Lange-Nielson: QTc
X-linked:
- Alports: GN
- Turner’s
congenital infection: rubella, syphillis, toxoplasmosis GBS, CMV
ototoxic drugs
Peri/post-natal causes of hearing loss (8)
anoxia birth trauma cerebral palsy kernicterus ototoxic drugs lead skull fracture meningitis
Mx of childhood deafness (2)
Cochlear implant:
- under GA
- directly stimulates acoustic nerve
- better if language already established
- requires post-op rehab as noises perceived differently
- need pneumococcal vaccine beforehand to prevent meningitis
Bone-anchored hearing aid:
- augments bone conduction
- better for conductive or unilateral hearing loss or for those who don’t like in-ear hearing aids
causes of conductive hearing loss in children (3)
wax:
- olive oil 1st line
- suctioning 2nd line
otitis media
otitis media w. effusion (glue ear):
- Hx of recurrent otitis media
- otoscopy can be normal
- tympanometry shows flattened curve due to non-compliant membrane
Mx of deafness in adults (3)
exclude dangerous cause:
- acoustic neuroma
- cholesteatoma
- effusion from nasopharyngeal ca.
palliatve: hearing aid
definitive: NB cochlear implants can be fitted up to 70yrs
Causes of sudden sensorineural hearing loss in adults (8)
noise exposure gentamicin toxicity acoustic neuroma vasculopathy mumps MS TB rarer: stroke, sarcoid, takayusu's, Chlamydia, pneumonia, immune complexes/Abs
Mx of sudden sensorineural hearing loss in adults (5)
get ENT help
find cause:cultures, Abs, TSH, glucose, cholesterol, ESR, FBC, LFT, viral titres, audiology, evoked response audiometry
MRI/CT
audiometry and brainstem evoked response
Steroids may help if given immediately
