Audiograms and Tympanograms

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72-year-old gentleman with nasopharyngeal cancer complaining of deafness in his left ear.

 

  • Audiogram A – left sided conductive hearing loss
  • Tympanogram type B
  • Left otitis media with effusion

 

35-year-old right handed man who is a keen air rifle shooter presents with left sided hearing loss.

 

  • Audiogram with left unilateral noise induced hearing loss
  • Tympanogram Type A
  • Left noise induced hearing loss

50-year-old lady complaining of hearing loss associated with episodes of vertigo and aural fullness

  • Audiogram with low frequency sensorineural hearing loss 
  • Type A
  • Meniere’s disease

80-year-old gentleman whose wife has noticed that he is having to put the volume up on the TV. He otherwise has not complained of any symptoms.

  • Audiogram E – bilateral symmetrical presbycusis
  • Presbycusis 
  • Type A

35-year-old female who recently gave birth has noticed a deterioration in her hearing. Her mother had experienced similar symptoms in her 30s.

  • Audiogram B – Conductive hearing loss with Cahart’s notch
  • Type As or A
  • Otosclerosis

Supporting Information

Information

Meniere’s disease – right earlow frequency loss- sensorineural- one of the criteria for menieres. 

Can be high loss in acute attacks. 

Meniere’s- unknown aetiology, maybe expansion of endolymphatic fluid volume -> pressure of the basilar membrane rupture of Reisner’s membrane. 

Symptoms: 

  • Fullness
  • Episodic tinnitus
  • Episodic nausea and vertigo
  • Deafness– low frequency although high in acute attacks. 
  • Attacks can last a few hours
  • Prodrome sometimes
  • Patients are normal between attacks.  The vertigo improves but the hearing can permanently decline. 
  • Tests- electrocochleography and calorics
  • Meniere’s syndrome (triad)- episodic deafness, tinnitus, vertigo. 

Management- controversial

  • Reduce salt and regulate fluid intake, avoid monosodium glutamate and caffeine
  • Reduce smoking and stress
  • Vestibular rehabilitation
  • Betahistine and vestibular sedatives (stemetil)
  • Surgery– endolymphatic sac decompression, vestibular nerve section, gentamicin destruction of labyrinth. Surgical labyrinthectomy in severe cases. myringotomy and tube insertion.  
  • SHAM study- endolymphatic sac decompression Vs cortical mastoid- both groups improved but no difference
  • Profound hearing loss- try BAHA, then cochlear implants

Examples

 Normal

Conductive hearing loss- can be caused by wax, granuloma, otitis media etc. See here carhart notch- ossicular pathology i.e. otosclerosis- reduction in bone conduction at 2000h

Presbycusis- age related hearing loss- gradual high frequency sensorineural hearing loss due to age related changes in hearing mechanism:

  • Reduction of number of inner and outer hair cells
  • Cell death due to arterial disease
  • Degeneration of central pathways

It is sensorineural loss which affects high frequencies and causes problems with clarity and background noise. 20% of people over 70 have at least moderate hearing impairment. 

Management- hearing aids, induction coils and lip-reading training. 

Noise induced hearing loss- specific sensorineural loss at 4000hz– due to the frequency the cochlear is most sensitive. 

Sensorineural hearing loss in the left- acoustic neuroma or other CP lesion. Profound most likely to benefit from cochlear implant

Acoustic neuroma- CP angle lesion-

  • Differential diagnosis– meningioma, epidermoid cyst and cholesteatoma
  • If bilateral –> NF II (AD on chromosome 22)–> associated with ependymomas and meningiomas
  • Inheritance pathognomonic sign–>juvenile subcapsular cataract. 
  • Use T1 weighted MRI with contrast- gadolinium.
  • Presentation– tinnitus and hearing loss- normally unilateral. If late then ICP raise and cerebellar dysfunction
  • Schwannomas may be cystic
  • Management
    • Serial MRI watchful waiting if asymptomatic
    • Stereotactic radiosurgery with gamma knife
    • Surgical excision- translabyrinthine, middle fossa and retrosigmoid.  In this surgery hearing can be sacrificed and an ABI (auditory brainstem implant) is attached to the brainstem via the lateral opening of the 4th ventricle (foramen of Luschka). 
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