hearing loss🦻🏽

Question 1

two types of hearing loss

Answer 1

1. conductive
2. sensorineural

Question 2

outer ear ddx (conductive)

Answer 2

1. cerumen
2. foreign body
3. otitis externa
4. otomycosis
5. tumour

Question 3

ddx of abnormal tympanic membrane on otoscope

Answer 3

1. OM
2. OM with effusion
3. chronic suppurative OM
4. cholesteatoma- middle ear growth (benign), can destroy bones, become infected. mx: surgical removal
5. ruptured tympanic membrane

Question 4

unilateral sensorineural hearing loss ddx

Answer 4

1. sudden: brainstem stroke, idiopathic
2. chronic: acoustic neuroma, meniere

do MRI brain!!!

Question 5

bilateral sensorineural hearing loss ddx

Answer 5

1. presbycusis- age related hearing loss, irreversible, degeneration of cochlea/ nerve/ structures. mx: hearring aid/ surgical implant
2. noise: occupation/ recreational exposure
3. drugs: Aminoglycosides, high-dose furosemide, chemotherapy (cisplatin, 5-FU), erythromycin or tetracycline antibiotics.

Question 6

history

Answer 6

1. any problem with speech?
2. onset
3. functional impairment

Question 7

How to classify types of hearing loss?

Answer 7

• Conductive: Any defect limiting sound conduction from the auricle and external ear canal, through the middle ear, into the inner ear.
• Sensorineural: A lesion in the inner ear, auditory nerve or brainstem.
• Mixed: Both conductive and sensorineural.

Question 8

tuning fork:
a. name the test
b. function of each test
c. interpretation of each test
d. which tuning fork to use

Answer 8

a. test: rinne & weber
b. fx of rinne: air conduction vs bone conduction
b. fx of weber: unilateral conductive or sensorineural hearing loss
c. rinne: conductive: bc>ac (conductive), ac>bc(normal/sensorineural)
c. weber: midline (n), bad ear (conductive), good ear ( sensorineural)
d. 512 Hz

“rinne positive” means air conduction is better than bone conduction!!!

Question 9

investigations/ PE

Answer 9

1. rinne & weber
2. otoscopy
3. formal audiometry
4. ct temporal bone
5. tympanometry
6. contrasted MRI internal acoustic meatus: acoustic neuroma

Question 10

fx of audiometry

Answer 10

1. Pure tone testing (audiometry) quantifies air and bone conduction across a range of sound frequencies.
   
   • Determines severity of hearing loss
   • Identifies any air/bone gap
   • Clues on possible aetiologies (some aetiologies affect certain frequencies more than others)

Question 11

what is tuning fork 128 Hz used for?

Answer 11

vibration sense

Question 12

should we do rinne or weber first?

Answer 12

rinne is for ac or bc
weber is for u/l conductive or sensosrineural

weber

Question 13

symptoms to ask

Answer 13

hearing loss
otalgia
discharge
pruritus
fever
redness
any insertion of foreign body
swimming
feeling of fullness in ear
head trauma
progressive or sudden
which ear
fmh/ age
tinnitus
vertigo
n/v

Question 14

meniere dss

Answer 14

• Episodic aural fullness, hearing loss or tinnitus, and vertigo with nausea or vomiting.
• Each episode lasts 20 min-24 hr
• Low-frequency, only during attacks
• May progress to permanent or bilateral

Question 15

acoustic neuroma

Answer 15

• Benign tumour at cerebellopontine angle from CN8
• slowly progressive unilateral SNHL + vertigo
• If large → lower motor neuron CN 5,6,7 palsies