PBL : Hearing loss

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PBL Hearing loss

• Cause of sensorioneural hearing loss
• (SNHL)

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sensorioneural hearing loss

• ??????????????????????????????????????????????????
  ??????? internal ear
• ????????????????
• ???????????
• ????????????????? ??????????????????????????????
• ????????????????????????? ???????????????????
• ????????????????????????????????????

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sensorioneural hearing loss

• Audiogram
• AC pure tone threshold gt 25 dB
• BC pure tone threshold gt 25 dB
• No air bone gap

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Cause of sensorineural hearing loss

• Congenital
• Presbycusis
• Infection
• Menieres disease
• Noise induced

• Trauma
• Tumor
• Endocrine systemic
• Ototoxicity
• Neurogenic
• Sudden sensorineural loss

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Congenital hearing loss

• Hereditary SNHL
• 90 ? Autosomal recessive
• Most common congenital malformation ? mondini
  malformation (AD) ? cochlear malformation
• Non-hereditary SNHL
• Infection ? rubella ,CMV, syphilis
• Drug ? teratogenic effect ? quinine

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Presbycusis

• 30 ? 65 years old
• Degenerative change
• Increase auditory threshold (high frequence)
• Equal SNHL
• Hearing aid

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Infection

• Most common
• Adult SNHL ? viral cochleitis
• Children SNHL ? meningitis ? H.influenza ?
  supperative labyrinthitis
• Viral .
• Mump ? unilateral SNHL
• Measal ? bilateral SNHL

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Menieres disease

• vertigo , hearing loss , tinnitus , aural
  fullness
• Unknown cause
• Idiopathic endolympatic hydrop , cochlear
  hypertension
• Fluctuate SNHL
• supportive treatment

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Noise exposure

• Acoustic trauma
• Gun , bomb
• exposure gt 140 dB
• Profound hearing loss
• Noise induced hearing loss
• Expose noise for long time
• Exposure gt 85 dB . 8 hours/day
• Occupational safety and health administration
• 90 dB ? 8 hours
• 95 dB ? 4 hours .
• Ear protection device

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Trauma

• Temporal bone fracture
• 20 ?Transverse fracture
• SNHL (labyrinth tear) , facial nerve pulsy
• Barotrauma
• Sudden pressure change scooba
• perilymph fistula

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Tumor

• Most common ? Acoustic neuroma
• Common site.
• Cerebellopontine angle (CPA)
• internal acoustic canal (IAC)
• CPA ? ventricle compression
• IAC ? acoustic vestibular n. compression
• Unilatral SNHL

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Endocrine and systemic

• Hypothyroid
• Effect developmemt of middle inner ear
• Stria vascularis atrophy , degenerate spiral gg.
• 25-50 ? SNHL
• Systemic disease ? ischemia vessel
• Autoimmune hearing loss ? SLE

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Ototoxicity

• Antibiotic ? aminoglycoside group
• Vestibulotoxic streptomycin, gentamicin
• Cochleotoxic tobramicin , amikacin
• Chemotherapy ? cisplatin gt 5-FU
• Diuretic ? furosemide
• Antimalaria drug ? quinine , chloroquine

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neurogenic

• Mutiple sclerosis ? 10-15 sudden SNHL

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Sudden sensorineural loss

• SNHL least 30 dB in 3 frequency in 3 day
• Known and unknown cause
• Idiopathic
• Viral theory
• Vascular theory
• Viral vascular combination theory
• Inner ear membrane rupture
• 40-70 recover

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Pseudohypacusis
- Pseudohypacusis is simply a factitious or
exaggerated hearing loss. - In situations
wherein there is secondary gain to patients -
Pattern of loss does not fit the clinical
picture.
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Question

• ????????????????????????? sensorineural hearing
  loss ?? 3 ?????
• ???????????
• ????????????????? ??????????????????????????????
• ????????????????????????????????????
• ?????????????????????????? SNHL ?????????????????
• Weber lateralize to Rt
• Rinne AC gt BC

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Question

• ?????????? ???? 35 ?? ??????????????????????? 2
  ??? ???????????????????? ????????
  ????????????????? ??????????????????????????????
  ??????????????????? ???????????????????
  ?????????????????????????????? ???????????????????
  
• Sudden sensory hearing loss
• ????????????????????? SNHL ?? 3 ????
• Streptomycin
• Cisplatin
• furosemide