Ear Disease and Hearing Loss Flashcards
The tymphatic membrane/middle ear gives you a ____dB increase in sound pressure
30dB
Why, due to their eustachian tubes, are kids more likely to get OMEs and middle ear infections?
Smaller, more horizontal, doesn’t work as well
What does E COLI stand for?
Ear
Cochlear nerve
Olivary complexes
Laternal lemnisces
Inferior colliculus
What types of Hearing Loss are there?
- Conductive; pinna, outer/middle ear
- Sensorineural; start from nerve component (cochlea)
- Mixed
- Central Disorders; usually with age
What do we use to stage severity of a hearing loss?
An audiogram
Horizontal axis: different frequecies. The normal range of hearing 20Hz - 20kHz,
Vertical Axis: Measures the sound pressure. a 10dB increase = 100x the sound level. Therefore your sound pressure doubles every ~3dB. Normal is 0-20dB
- *Mild** 20-40dB
- *Moderate** 40-70dB
- *Severe** 70-90dB
- *Profound** >90dB
0 is a reference point, what 95% of healthy kid could hear.
What are the levels of hearing loss in NZ?
>10.3% degree of hearing loss
>6.6% report disability by hearing loss
>0.7% report diability due to deafness
What are the social consequences of hearing loss?
- speech and language deficits
- Learning difficulties
- auditory processing difficulties
- Academic achievement
- Low self-esteem and confidence
- social isolation
- reduced employment oppurtunities
- Safety: alarms etc
What are medical consequences of Hearing Loss?
- Middle ear disease and it’s complications
Cholesteatoma: skin inthe middle ear
WHat do you take during a history?
Age
Duration (>10 years loss of CNS stimulation. Also if born with you need to work quickly to not lose language)
Severity (life and audiometer)
Onset: rapid/gradual, constant/fluctuating
Precipitating Factors; noise (temporary or perm), trauma, drugs
Past medical and family history
Ass. Symptoms: tinnitus, vertigo, aural fullness, headaches
What is tinnitus?
Buzzing, whoosing, ringing sound of the ears, that isn’t organised and isn’t assoctiated with other psychosis issues.
What do we use to exam the ears?
- Otoscopy: to see the inner anatomy
- Clinical test of hearing: whisper test
- Tuning for testing: Webber and Rinne tests
Neurological Examination: cranial nerves, cerebellar function
General exam
What investigations do we do of the ear?
- Audiogram: usually a pure tone (frq test). Anything below 20dB is normal
- Otoacoustic emissions: ability of OHC to make their own sound
- ABR (auditory brainstem response): measures E COLI
- CT(conductive HL), MRI (Central HL)
- ENG: eye movements
- Blood tests: physillis
- Genetic testing
- Cardiac, renal and opthamology consult
Whats a few types of conductive hearing loss that you can get?
Exostoses: “surfers ear” Bony growths in the ear due to cold water exposure
What are the common findings of otitis media with effusion?
- Common in 1-4 year olds; only an issue of for >some weeks
- Eustachian tube dysfunction
- Infection/inflammation
- Negative pressure: like a thick silicone glue
- Effusion
What is mastoiditis?
Complication of otitis media, infects mastoid ear cells → abcyss
- Medial emergency: as abcyss is mm away from the brain, can break into the brain
- Hearing loss secondary
- Red lump behind the ear, ears pushed forward from the pressure.
Tympanic membrane perforation.
- Consequence of otitis media, trauma or surgery
What type of hearing loss does someone with Microtia/atresia have?
Maximal conductive hearing loss due to a misshappen ear, normal cochlea (as they have different embryological function)
How would you get a negative Rinne test?
If your bone conduction is better then your ear conduction
What area few types of sensoneural hearing loss, and are these easier or harder to treat then conductive?
Much harder to treat, and usually treated bysome kind of amplification.
Ask them if they’ve been in ICU!
What is happening in this case?
Balance indicates vesibular system is involved
Audiogram shows a low frequency sensorneural hearing loss.
MRI scan shows a lesion → vesitibulaar schwannoma
What is vestibular schwannoma
Benign lesion, 1:100,000
Most common cerebellopontine angle lesion
Most present w asymmetrical SNHL
Treatment: observation, surgery, stereotactic radiotherapy (GAMMA)
Explain this case
Idiopathic, due to a virus
Treatment: cochlear implant
Whats a cochlear implant
- For bilateral severe-profound hearing loss
- Quality of sound not as good, for speech not music!! Can’t handle the multi-tonal aspect of music
- Prelingually deaf children <3yr
- Postlingually deaf kids and adults
How exactly is a cochlear implant put in?
Via mastoidectomy approach
- Sound enters external mic
- Sound waves go to sound processor and is converted to an electrical signal/digital info
- Sends info to surgically implanted reciever under the skin
- Sends signal down wire through the cochlear along the spiral where it can stimulate spiral ganglion. Bypasses the inner ear
What are some other interventions for HL?
Ear Disease: middle ear/mastoid surgery;
Sensorineural HL: auditory brainstem implant, skip cochlea and go straight to brain.
Hearing Loss: Hearing aids, FM systems, interpreters
What are the Weber and Rinne tests?
Discover if hearing loss is conductive or sensorineural
Rinne test
The doctor strikes a tuning fork and places it on the mastoid bone behind one ear. When you can no longer hear the sound, you signal to the doctor.
Then, the doctor moves the tuning fork next to your ear canal.
When you can no longer hear that sound, you once again signal the doctor.
The doctor records the length of time you hear each sound.
Weber test
The doctor strikes a tuning fork and places it on the middle of your head.
You note where the sound is best heard: the left ear, the right ear, or both equally.
