CNS/HN - Hearing Loss

Question 1

Differential Diagnosis for Deafness and Hearing Loss

Answer 1

• SNHL
• Otosclerosis
• Meniere’ s

Deafness and hearing loss

Probability diagnosis 
Impacted cerumen
Serous otitis media (glue ear)
Otitis externa
Otitis media
Congenital (children)
Presbyacusis

Serious disorders not to be missed  
Neoplasia:
•acoustic neuroma
•temporal lobe tumours (bilateral)
•otic tumours

Infection:
•generalised infections (e.g. mumps, measles)
•meningitis
•syphilis

Other:
•perforated tympanic membrane
•cholesteatoma
•perilymphatic fistula (post-stapedectomy)
•Meniere syndrome

Pitfalls (often missed) 
Foreign body
Temporal bone fracture
Otosclerosis
Head injury
Barotrauma
Noise-induced deafness

Rarities:
•Paget disease of bone
•multiple sclerosis
•osteogenesis imperfecta

Masquerades checklist Diabetes
Drugs (see list)
Thyroid disorder (hypothyroidism)

Is the patient trying to tell me something?
Unlikely.

Question 2

Key History - Deafness and Hearing Loss

Answer 2

Key history

• Onset and progression of any deafness
• noise exposure
• drug history
• swimming or diving
• air travel
• head injury
• family history
• A recent or past episode of a generalised infection would be relevant and the
• presence of associated aural symptoms such as ear pain, discharge, tinnitus and vertigo.
• Enquire about the effect of noise

Question 3

Key PE - Deafness and Hearing Loss

Answer 3

Key examination

• Inspect the facial structures, skull and ears and the ear with an otoscope.
• Ensure that the external auditory canal is clean
• Perform simple office hearing tests including tuning fork tests

Question 4

Key Investigation - Deafness and Hearing Loss

Answer 4

Key investigations •Audiometry and tympanometry

•Swab of any ear discharge for M&C

Question 5

Key Diagnostic Tips - Deafness and Hearing Loss

Answer 5

Diagnostic tips
•People with conductive deafness tend to speak softly, hear better in a noisy environment and hear well on the telephone. The opposite applies for sensorineural deafness.
•Ototoxic drugs: alcohol, aminoglycosides e.g. streptomycin, neomycin, gentamicin, tobramycin, chemotherapeutic agents, quinine, salicylates/aspirin excess, diuretics e.g. ethacrynic acid, frusemide

Question 6

History - SNHL

Answer 6

• HOPI
• which ear
• sudden or gradual
• on and off or continuous
• getting worse
• 1st time
• effect of noise> Can you hear better on noisy environment?
  Associated symptoms
• Pain
• Discharge
• nausea and vomiting
• vertigo/dizziness
• tinnitus
• cough and colds
• fever
  Ddx/Risk Factors
• previous history of ear infection
• Trauma
  (head injury, swimming, diving, air travel)
• exposure to loud noise
• occupation
• previous surgery
• medications
• Family history

General
PMH
SADMA

Question 7

Physical Examination - SNHL

Answer 7

Physical examination:

• Inspect facial structures, skull and ears
• ENT: EAC, otoscope examination (redness, foreign body, wax, tympanic membrane, effusions); whisper test, rinne and weber tests (more sensitive; 256 or 512Hz); do tests on other side; Hum test
• Look into nose and throat: redness, enlarged tonsils
• Chest/CVS/Abdomen/CNS

Question 8

Management - SNHL

Answer 8

Investigations and Management

• If CHL due blockage from URTI: decongestants and antihistamines
• ALL SNHL is an emergency;
• Acoustic neuroma can cause sudden hearing loss in 10%
• No need to refer for audiometry
• DO an MRI and refer to ENT specialist to rule out acoustic neuroma

Question 9

History - Otosclerosis

Answer 9

• HOPI
• which ear
• sudden or gradual
• on and off or continuous
• getting worse
• 1st time
• effect of noise> Can you hear better on noisy environment?
  Associated symptoms
• Pain
• Discharge
• nausea and vomiting
• vertigo/dizziness
• tinnitus
• cough and colds
• fever
  Ddx/Risk Factors
• previous history of ear infection
• Antibiotic during pregnancy
• Trauma
  (head injury, swimming, diving, air travel)
• exposure to loud noise
• occupation
• previous surgery
• medications
• Family history

General
PMH
SADMA
Support

Question 10

Physical Examination - Otosclerosis

Answer 10

Physical Examination
- General appearance 
- General Apperance 
- Vital signs 
- EENT 
- Ask for Consent 
- Hearing tests: 
	o Palpate tragus and mastoid for tenderness
	o Otoscopy: occlusion by ear wax, cholesteatoma, skin, signs of middle ear infection,  tympanic membrane, discharge and swelling 
	o Masking/Whisper Test 
	o Rinne
	o Weber

Hearing test results:
- On examination, the weber is centralized and on Rinne test BC > AC which is suggestive of a bilateral conductive hearing loss

Question 11

What are the causes of CHL?

Answer 11

• Otitis media
• impacted cerumen
• cholesteatoma
• otosclerosis
• paget disease

Question 12

Causes of SNHL?

Answer 12

• Ototoxicity
• acoustic neuroma
• cochlear degeneration
• trauma

Question 13

Management - Otosclerosis

Answer 13

Condition -
Conductive hearing loss due to Otosclerosis - , and your family history is suggestive of this condition. Do you know what it is? In our middle ear, there are 3 bones which conduct sound. Sometimes, the spongy bone “stapes” becomes hard and sclerotic which makes it difficult to move in response to sound waves.

Common
Most common cause of CHL
F>M

Cause / RIsk factor
precipitated by pregnancy
CHL - you hearing more in noisy environment

Clinical feature/ symptoms
Progressive hearing loss

Complication
Not life threatening

Question 14

Management - Otosclerosis

Answer 14

Referral to an ENT consultant - formal audiometry or hearing test
Stapedectomy (approximately 90% effective)
Hearing aid (less effective alternative
Review
Reading Materials