Lecture 4 Flashcards
Causes of HL outer and middle ear origin
Atresia Cranio facial anomalies: treacher Collins, Down syndrome, cleft palate Otitis media: AOM vs OME Tympanic membrane perforation Otosclerosis
Atresia
Absence of opening in external canal often accompanied by microtia Can be uni or bilateral More common in males Cochlea is usually normal Hearing loss is conductive
Audiometric results: atresia
Maximum conductive loss at 60dB because bones will be vibrating enough for other ear to pick up the sound
Surgery is possible- mostly cosmetic, depends on age, more common with bilateral
Treacher Collins syndrome
Mandibulofacial dysostosis
Sometimes microtia/atresia
Ossicular defects
Cochlea is normal, no cognitive problems
Cleft palate
Eustachian tube dysfunction, the middle ear starts to fill with fluid because air doesn’t get to it
always have to get their hearing checked
Eustachian tube dysfunction
Poor middle ear aeration > cleft palate
Otitis media > inflammation of the middle ear
Fluctuating conductive hearing loss
Otitis media (middle ear inflammation)
OME: uncomfortable, fluid filled middle ear with no signs of active infection, muscular function, frequent colds, allergies
AOM: painful, inflamed, infected
Primarily a disease of children, most common cause of conductive hearing loss… 85-90% of all children will have at least one occurrence by age 6
TM perforation
Pars tensa- central, most common and safest… also marginal
Pars flaccida- attic, usually associated with cholesteatoma &/or destruction of the ossicles
Acute- traumatic cause, usually heals itself, typically smaller perforation
Chronic- usually larger perforations or those due to chronic infection, require surgical repair
Audiometric results: TM perforation
Flat or rising mild to moderate conductive hearing loss, so more hearing loss in lower frequencies
Otosclerosis
Most common cause of adult onset HL
Fixation of the stapes footplate in the oval window
Unilateral but other ear often becomes involved
50% hereditary
More common in females
Mild to moderate rising to flat conductive HL
Managed well by surgery or amplification
Causes of cochlear hearing loss
Genetic Infections Noise induced hearing loss Age related hearing loss Ototoxicity Menieres syndrome Head injury Sudden idiopathic hearing loss
Genetic cochlear HL
Syndromal: Down syndrome or ushers syndrome
Non-syndromal: connexin 26 (point mutation preventing a certain protein)
May be congenital vs progressive
Recessive or dominant
Varying degree of loss
Infections- cochlear
Congenital: maternal rubella
Perinatal: TORCH infections (during delivery)
Childhood or adulthood: meningitis (cochlear implant candidates), mumps (total unilateral hearing loss)
Noise induced hearing loss
Occupational or social Metabolic exhaustion of OHCs Morphological changes of cilia Loss of HCs Loss of supporting cells Hearing loss in high frequencies
Age related (presbycusis)
Aging changes to many cochlear and neural structures
Accumulation of lifelong damage
Poor speech discrimination
Gradual onset
May be confused with confusion, dementia, or depression
