Hearing Loss and Audiologic Issues Flashcards
what are the three types of hearing loss?
- sensorineural
- conductive
- mixed
- pathology arises from the cochlea or the nerves leading to or from the cochlea
- most often (not always) permanent
sensorineural
what are common causes of sensorineural hearing loss?
- presbycusis
- noise exposure
- ototoxicity
- sudden viral or vascular insults
- virus
- hearing losses arise from pathologies of the middle ear or external ear
- more amenable to medical or surgical intervention
- if no medical intervention, amplification is an option pending medical evaluation by ENT
- audiometric results will show air-bone gap of 15 dB or greater
conductive hearing loss
common causes of conductive hearing loss?
- cerumen impaction
- drainage in ear canal
- otitis externa
- otitis media
- ossicular pathology (congenital, truama, otosclerosis)
- cholesteatoma
- both conductive and sensorineural comoponents
- audiometric results will show air-bone gap of 15 dB or greater
mixed hearing loss
causes of mixed hearing loss?
- patients with presbycusis (age-related hearing loss)
- children with congenital sensorineural hearing loss and otitis media
- patients with otosclerosis and noise exposure
two types of infant audiologic testing?
Auditory brainstem response testing (ABR)
Otoacoustic Emission testing (OAE)
- click stimulus presented and evoked potential recorded
- waveform generated from low brainstem
- response compared to normative template in computer
- pass/refer
- if response present results r/o significant amount of hearing loss
ABR
- Sound stimuli introduced in ear
- response generated from cochlear outer hair cells
- emissions recorded in external auditory canal
- if response present results r/o significant amount of hearing loss
OAE
what are method of testing pediatric hearing?
- tympanometry
- visual reinforcement audiometry
- conditioned play audiometry
- not a test of hearing
- provided objective information about the integrity of the middle ear
- probe assembly is place in the ear canal an air tight seal is obtained
- pressure change is induced in the ear canal
Tympanometry
For Tympanometry- what does Type A represent?
Bell shaped curve= normal TM compliance
For Tympanometry- what does type B represent?
Flat tracing= no change with change in pressure
* middle ear fluid, effusion
* TM perforation or patent PE tube with large equivalent volume
For Typanometry- what does type C represent?
Negative pressure= retracted TM
when to refer to an audiologist?
- Hearing loss
- tinnitus
- dizziness
- plugged ear
- children: speech/language delay
sudden sensorineural hearing loss- evaluate middle ear pathology first
- Tests you can perform to assess type of hearing loss
- will not tell you the degree of hearing loss
Bedside tests
“Weber”
- Principle: sound will lateralize to the ear with the best cochlear function or the ear with the larges conductive component
- tuning fork is placed on forehead or top of head
- patient is asked to indicate the ear in which they perceive the sound
Weber
- hearing loss acquired as patient grows older
- the loss is sensorineural in nature
- hearing is typically symmetric between ears with high frequencies poorer than low frequencies
- if tinnitus is present- bilateral
- no surgical or medical treatment; hearing aid use is recommended if hearing loss is significant enough to interfere with communication
presbycusis
- hair cells in the cochlea are damaged due to exposure of excessive noise
- sensorineural loss that arises as a result from chronic exposure to loud noises, and acoustic trauma from one single episode
- no surgical or medical intervention available
- tinnitus is frequently an assoicated symptom
Noise induced hearing loss
- fixation of the stapes footplate
- hearing loss is conductive or mixed in nature
patients often present with:
* family hx of hearing loss
* hearing loss of gradual onset and progression (can be unilateral or bilateral)
* adult onset- more common in middle aged women
* can rapidly progress during pregnancy or after labor and delivery
otosclerosis
diagnosis and treatment of otosclerosis?
- ear exam is commonly within normal limits
- diagnosis is made based on audiometric findings, patient hx, physical exam and imaging
- sugical intervention= stapedectomy
- non-medical intervention= hearing aid use
- Benign tumor that arises from the vestibular nerve
- sx include: slowly progressing unilateral SNHL most common; progressive imbalance and or vague dizziness
- also referred to as a vestibular schwannoma
- tinnitus is common in the affected ear
- vertigo is a rare complaint
Bilateral AN’s are seen in neurofibromatosis type II in all ages
Acoustic Neuroma
diagnosis and treatment of acoustic neuroma?
- Audiometry and MRI are the best diagnostic tools
- treatment: surgical removal, radiatin, monitoring size via imaging, audiometric monitoring for progression of SNHL
- occurs with disruption of vascular supply to cochlea (stroke, surgery)
- multiple other possible etiologies: Viral, MS, autoimmune
- tinnitus is present with 70-85% of patients
- diagnosis is made based on audiometric finding and ENT exam
Sudden Sensorineural hearing loss
treatment of sudden sensorineural hearing loss?
- some hearing loss will improve spontaneously
- Rx with steroids and antiviral- initiated ASAP to increase the likelihood of recovery
- important to be able to differentiate between cerumen impaction, middle ear pathology, and SNHL
- Disease is a result of a malfunction in the endolymph volume regulation mechanism in the inner ear(pressure increases)
- cause is unknown
no known cure but medical therapy and surgical options are aimed at controlling the attack
* low-salt diet
* reduce caffeine, chocolate, alcohol, MSG
* medication
* endolymphatic sac depression
* labryinthectomy
Meniere’s disease
Meniere’s disease has distinct episodes of?
- Aural pressure or fullness in the affected ear
- unilateral tinnitus in the affected ear, often described as roaring sound
- prolonged rotational vertigo
- low frequency fluctuating sensorinerual heaing loss
- sensorineural hearing loss secondoary to drug use
- hearing loss is most often permanent
- sensorinerual hearing loss can continue to progress even after drug has been stopped
- hearing loss is usually bilateral and higher frequencies are poorer than low frequencies
- tinnitus is a frequent side affect and may be present prior to change in hearing
ototoxicity
which medications are ototoxic medications?
- Aspirin in very high doses (SNHL can be reversible)
- loop diuretics in very high doses (furosemide, lasix)
- aminoglycosides- especially in IV form (gentamicin, amikacin, tobramycinm kanamycin)
- chemotherapy drugs (carboplatin, cisplatin)
when doing the weber test if the sound lateralizes to their good ear- what type of hearing loss is it?
asymmetric sensorineural hearing loss
when doing the weber test if the sound lateralizes to their poorer ear- what type of hearing loss is it?
asymmetric conductive hearing loss
