Lecture 13: Ear disease, hearing loss

Question 1

What are 3 reasons why middle ear infections are more common in children than adults

Answer 1

1. Tube is longer in adults and at a 30-40’ inclination
2. Children have weaker immune system, they are more likely to have upper respiratory tract infections
3. the muscles are not able to act on the eustachian tube appropriately at birth due to the wrong angle in children

Question 2

How do central hearing loss disorders present

Answer 2

Although audiogram is normal, the understanding of sound is worse- hard to treat.
More common in elderly.

Question 3

What are the consequences of hearing loss psychosocially and what are complications of chronic otitis media

Answer 3

Psychosocially:

1. Learning difficulties, Auditory processing difficulties, speech and language deficits
2. Low self esteem and confidence, social isolation, Safety risks
3. Reduced employment opportunities, academic achievement

Medically

1. Granulation tissue from chronic middle ear disease which can erode the mastoid bone
2. Cause abscess in the brain with oedema, midline shift

Question 4

What factors do you take into account for history for hearing loss

Answer 4

Depending on Age, severity, duration choose intervention

1. Onset: rapid/gradual/constant/fluctuation
2. Precipitating factors: noise, trauma, drugs (eg. gentamicin)
3. Past and family history; other operations
4. Associated symptoms: tinnitus, vertigo, fullness of hearing, headaches

Question 5

What are the main screenings of hearing loss

Answer 5

1. Audiogram: puretone one should be in the grey zone to be normal (10-20db)
2. For children visual reinforcement audiogram gets them to respond visually. Soundfield tests kids moving to the correct side.
3. Otoacoustic emissions records echos from the hair cells to give indication of normal inner ear function
4. Auditory Brainstem response is screening at neonates for interventions like cochlea implants
5. for adults: CT, MRI, ENG, electrocochleography
6. Bloods for viral infections
7. Genetic testing for kids.
8. Cardiac, renal, opthamological consult: Some electrolyte channels in inner ear are similar to these

Question 6

What are the main examinations of hearing loss

Answer 6

1. Tuning fork testing:
   a) Weber test: hold the hit tuning fork on frontal bone, ask which side is louder. to differentiate which side is the unilateral hearing loss:
   Sound will move to good ear in sensorineural, move to the bad ear in conductive loss

b) Rinne test: Hold hit tuning fork infront or behind one ear. If can hear better behind= negative= conductive hearing loss. If in front: positive- ok

2. Whisper test
3. Look in ears: Otoscopy
4. Neurological examination: esp for unilateral loss cranial nerves
5. Look for other syndromes in kids

Question 7

What is otosclerosis, arthritis and how does it cause conductive hearing loss (mostly in adults)

Answer 7

Metabolic disorders:

Otosclerosis: Abnormal bone remodelling in the ossicles to preventing conduction of sound

Arthritis: inflam arthritis at the joints in the ossicles

Question 8

What is a glomus

Answer 8

Rare, benign, vascular, tumour of the middle ear causes conductive hearing loss.

Can invade locally to cause facial nerve palsy, inferiorly into the carotid, jugular artery.

Question 9

What are 3 conditions which can lead to hearing loss associated with outer ear

Answer 9

Trauma which may lead to granulomas forming.
- Atresia (no ear canal)
- Microtia (losing the pinna)
Bone conduction devices are ok for these

• Stenosis, Exostoses which can be congenital or acquired (S: scarring from surgery or outer ear infection), (E: Surfers ear- bony growths into ear canal)

Question 10

What is the complication of Glue ear (Ottis media with effusion)

Common in children 1-4: Dull looking tympanic membrane

Answer 10

1.Mastoiditis : swelling with pus, posterior fold of the ear gone.

Medical emergency as can lead to haematogenous spread to the brain - brain abcess.

2. Tympanic membrane perforation: (also caused by surgery trauma). Needs myringoplasty at 8yrold to prevent infection, reinstate hearing.

Question 11

What causes acquired congenital sensorineural hearing loss

Answer 11

Prenatal infections, Medications, birth trauma.

Question 12

What is a vestibular schwannoma, how does it present, risks of non treatment and what is its possible treatment

Answer 12

• Rare benign tumour, but most common cerebellopontine angle lesion
• Person presents with asymmetrical SNHL

Risks:
- They can pull on the facial nerve, vestibular dysfunction on that side once its removed, meningitis, strokes etc

Treated using observation if less than 1.5 cm if no change in size in 10 years,
Surgery
Stereotactic radiotherapy if too unwell or too small, not always responsive though

Question 13

What is the treatment for bilateral severe-profound hearing loss and who gets it and the problems with it

Answer 13

Cochlear implant- when hearing aids don’t work anymore and cochlea is patent.
The electrode is placed via the mastoid into the cochlea
- prelingually deaf children ideally before 3
- Post lingually deaf children+ adults.

Because it only stimulates 10 places along the nerve instead of 100 sound quality is bad. But 6-12 mo+ hearing gets better with learning and memory

Question 14

What are other interventions for hearing loss (aside from severe complete hearing loss)

Answer 14

• Hearing aids
• FM systems: help to filter out noisy background for auditory processing disorders, presenting sounds straight to the ear.
• Sign Interpreters