Deafness Flashcards
congenital causes central
hyperbilirubinaemia/kernicterus; hypoxia
congenital causes conductive
abnormalities of pinna, external ear canal, drum ossicles; cholesteatoma
congenital causes sensorineural
genetic- Alports, Turners; infections- CMV, syphilis, HIV; ototoxic drugs
perinatal and postnatal causes
anoxia, birth trauma, cerebral palsy, kernicterus, meningitis, ototoxic drugs, lead, skull fracture
what is the hearing test for new borns
universal newborn hearing screening- otoacoustic emissions, ABR (audiological brainstem response)
management childhood deafness
hearing aids, cochlear implants
how can you prevent post implant meningitis after cochlear implant
pneumococcal vaccine 2 weeks before cochlear implant
what age can you use pure tone audiogram to test the childs hearing
5 years
what type of hearing air can be used to augment bone conduction
BAHA- bone anchored hearing aid
where is the anatomy for conductive hearing loss
pinna to oval window, foot of the stapes
where is the anatomy for sensorineural hearing loss
oval window to auditory cortex
causes of conductive loss in adults
external canal obstruction- wax, pus, debris, FB; drum perf- trauma, barotrauma, infection; ossicular chain- otosclerosis, infection, trauma
causes of sensorineural loss in adults
ototoxic drugs, post infective (meningitis, measles, mumps, flu, herpes); Menieres, trauma
management deafness in adults
hearing aid, cochlear implant, surgery
what drugs are ototoxic
vancomycin, gentamicin, streptomycin, chloroquine, hydroxychloroquine
rare causes deafness in adults
acoustic neuroma, B12 def, MS, carcinoma in brain
how is sensorineural sudden deafness defined
> 30db loss in 3 pure tone, over
how often is cause found in sensorineural sudden deafness
10% of the time
how often is a cause found in conductive sudden deafness
all the time- occlusion infection trauma fracture
what is otosclerosis
replacement normal bone with vascular spongy bone. autosomal dominant, FHx in 50% cases.
symptoms otosclerosis
conductive hearing loss. appears early adult life, worse in pregnancy, menstruation, menopause. can get tinnitus, vertigo
signs otosclerosis
10% have Schwartzs- pink tinge to the drum. Caharts notch on audiogram- dip at 2kHz
treatment otosclerosis
fluoride. hearing aid or surgery, cochlear implant
what is presbyacusis
age related hearing loss from accumulated environmental noise toxicity
what do you lose in presbyacusis
loss of high frequency sounds starts before 30years, deafness is gradual and often don’t notice for a while. hearing aids
what should you think of in sensrineural unilateral deafness
acoustic neuroma
what is an acoustic neuroma
benign tumour. behave as SOL
symptoms acoustic neuroma
ipsilateral tinnitus and sensorineural hearing loss. giddiness common, vertigo rare
cranial nerves at risk in acoustic neuroma
V, VI,VII
tests in acoustic neuroma
MRI- in all with unilateral deafness/tinnitus
DDX acoustic neuroma
meningioma
