Hearing Loss Notes
This is a sample of our (approximately) 3 page long Hearing Loss notes, which we sell as part of the ENT Notes collection, a MBChB (hons) (1st) package written at University Of Leicester in 2014 that contains (approximately) 36 pages of notes across 16 different documents.
The original file is a 'Word (Docx)' whilst this sample is a 'PDF' representation of said file. This means that the formatting here may have errors. The original document you'll receive on purchase should have more polished formatting.
Hearing Loss Revision
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Hearing Loss Classification
- Deafness = subjective decline in hearing acuity affecting one or both ears
- Conductive hearing loss ("Obstructive") o Pathology external or middle ear amenable to surgery
- Sensory-neural hearing loss ("failure of transmission") o Pathology affecting cochlear, auditory nerve or auditory centers in the brain o Often involves loss of hair cells from the Organ of Corti, therefore is usually permanent
Conductive hearing loss
External ear occlusion e.g wax, foreign body, congenital agenesis of the ear Infection (otitis media/externa) Glue ear Trauma (direct blow, acoustic trauma) Osteosclerosis - fixation of stapes on oval window (runs in families, associated with tinnitus and mild vertigo) Iatrogenic (surgery)
Sensorineural hearing loss
Idiopathic Presbycusis o Age-related hearing loss, usually loss of high-frequency sounds initially, because hair cells responding to high-frequency sounds are most easily damaged) Viral infections (measles, mumps, meningitis) Tumours affecting the cochlear nerve Trauma - temporal bone fractures Drugs - aminoglycosides e.g gentamycin Central - brainstem CVA
Investigations Tuning Fork Test
o 512 Hz, middle C - so heard not felt) Rinnes o Place tuning fork on mastoid bone and acoustic meatus and ask which is loudest (normally air conduction > bone conduction =
positive Rinne's test) o Negative test = pathology where bone conduction > air conduction = conductive hearing pattern o In sensorineural loss both AC and BC are decreased therefore AC should still be > BC Webers o Place tuning fork in middle of forehead o Normal sound is equally loud in both ears o In unilateral conductive hearing loss the sound will lateralise to the affected side
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