Some Causes of Acquired Hearing Loss
Cause* | Suggestive Findings | Diagnostic Approach† |
|---|---|---|
External ear (conductive loss) | ||
Obstruction (eg, caused by cerumen, a foreign body, otitis externa, or, rarely, tumor) | Visible during examination | Otoscopy |
Middle ear (conductive loss) | ||
Hearing loss that may fluctuate Sometimes also dizziness, pain, or fullness in the ear Usually abnormal-looking TM Often a history of acute otitis media or other causative event | Otoscopy Tympanogram | |
Chronic ear discharge Usually visible perforation Granulation tissue or polyp in the canal Sometimes cholesteatoma | Otoscopy For cholesteatoma, CT or MRI | |
Apparent by history Often visible perforation of the TM, blood in the canal or behind the TM (if intact) | Otoscopy | |
Family history Age at onset in 20s to 30s Slowly progressive | Tympanogram | |
Tumors (benign and malignant) | Unilateral loss Often lesion visible during otoscopy | CT or MRI |
Inner ear (sensory loss) | ||
Genetic disorders (eg, connexin 26 mutation, Waardenburg syndrome, Usher syndrome, Pendred syndrome) | Sometimes a positive family history (but usually negative) Consanguinity Connexin 26 mutations account for the vast majority of non-syndromic hearing loss cases and should be screened for initially Sometimes a white forelock of hair or different colored eyes suggests Waardenburg syndrome Loss of both vision and hearing can suggest Usher syndrome | Genetic testing CT and/or MRI |
Usually apparent by history | Clinical evaluation | |
> 55 years in men, > 65 years in women Progressive, bilateral loss Normal neurologic examination | Clinical evaluation | |
History of use Bilateral loss Variable vestibular symptoms Renal failure | Clinical evaluation Blood tests to measure drug levels | |
Infections (eg, meningitis, purulent labyrinthitis) | Obvious history of infection Symptoms that begin during or shortly after an infection | Clinical evaluation |
Autoimmune disorders (eg, rheumatoid arthritis, systemic lupus erythematosus) | Joint inflammation, rash Sometimes a sudden change in vision or eye irritation Often known history of the disorder | Serologic testing |
Episodes of unilateral, fluctuating hearing loss accompanied by aural fullness, tinnitus, and vertigo | Gadolinium-enhanced MRI to rule out tumor | |
Barotrauma (with perilymphatic fistula)‡ | History of abrupt pressure change (eg, scuba diving, rapid descent in airplane) or a blow to the ear canal Sometimes severe ear pain or vertigo | Tympanometry and balance function tests CT of temporal bone Surgical exploration if vertigo persists |
Head trauma (with basilar skull fracture or cochlear concussion)‡ | History of significant injury Possibly vestibular symptoms, facial weakness Sometimes blood behind the TM, CSF leak, ecchymosis over the mastoid | CT or MRI |
Auditory neuropathy‡ | Good sound detection, but poor word understanding | Auditory testing (auditory brain stem response [ABR], otoacoustic emissions) MRI |
Central nervous system (neural loss) | ||
Tumors of the cerebellopontine angle (eg, acoustic neuroma, meningioma) | Unilateral hearing loss, often with tinnitus Vestibular abnormalities Sometimes facial or trigeminal nerve deficits | Gadolinium-enhanced MRI |
Demyelinating disease (eg, multiple sclerosis) | Unilateral loss Multifocal neurologic deficits Waxing and waning symptoms | MRI of the brain Sometimes lumbar puncture |
* Each group is listed in approximate order of frequency. | ||
† All patients should have otoscopy and audiologic testing. | ||
‡ Mixed conductive and sensorineural loss may also be present. | ||
TM = tympanic membrane. | ||