0521779407-09 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 21:12
664 Hearing Loss■Acute otitis media (AOM) and serous otitis media (SOM) most com-
mon cause in children
■Otosclerosis, associated with fixation of stapes, may present in preg-
nancy
■Trauma may lead to perforation of tympanic membrane or ossicular
discontinuity
Sensorineural hearing loss (SNHL)
■Usually due to problems within the cochlea or central auditory path-
way
■Aging is the most common cause of SNHL
■Exposure to ototoxic medication may lead to high frequency hearing
loss
■Trauma can result in temporal bone fracture and SNHL
■Vestibular schwannoma (or its more famous misnomer, acoustic
neuroma), the most common tumor of the cerebellopontine angle,
is associated with asymmetric hearing loss
■1 in 1000 infants are born with profound hearing loss
■This risk is 20×higher in the NICU
■10% of the elderly have significant SNHL
Signs & Symptoms
■Most common complaint is reduced hearing
■With SNHL, patients also complain of decreased clarity, specially in
background noise
■Tinnitus can be present in CHL and SNHL and can be greatly both-
ersome
■Pulsatile tinnitus is more common in CHL
■Neurological symptoms or signs are ominous and may reflect the
presence of cerebellopontine angle tumorstests
■Audiological Evaluation for CHL and SNHL: pure tone audiometry,
speech audiometry, immittance testing, acoustic reflexes
■Auditory Brainsterm Response (ABR) testing to exclude retro-
cochlear pathology when asymmetric SNHL is present
■Laboratory test including CBC, Platelets, ESR, ANA, RF, TSH, Choles-
terol, glucose, FTA, BUN, Creatinine, UA for evaluation of progressive
or premature SNHL
■CT scan of the temporal bone (1.0 min fine cuts, axial and direct
coronal images) to evaluate CHL (external ear canal and ossicular
chain) and SNHL (inner ear malformations)
■MRI of the internal auditory canal and brain with gadolinium con-
trast enhancement to evaluate asymmetric or progressive SNHL