Hearing loss Flashcards
What are the two main categories of hearing loss?
- Conductive
- Sensorineural
What is meant by conductive hearing loss?
Problem with sound travelling from the environment to the inner ear
What is meant by sensorineural hearing loss?
Problem with sensory system/vestibulocochlear nerve in the inner ear
Give some examples of causes of sensorineural hearing loss
- Presbycusis (age-related)
- Sudden sensorineural hearing loss (SSNHL)
- Meniere’s disease
- Labyrinthitis
- Acoustic neuroma
- Neurological conditions, e.g. stroke, MS
- CNS infections, e.g. meningitis
- Medications, e.g. loop diuretics, gentamicin
Give some examples of causes of conductive hearing loss
- Ear wax (or something else blocking the canal)
- Infection (e.g., otitis media or otitis externa)
- Fluid in the middle ear (effusion)
- Eustachian tube dysfunction
- Perforated tympanic membrane
- Otosclerosis
- Cholesteatoma
Presbycusis is defined as…
Age-related hearing loss
Describe the presentation of prescbycusis
- Gradual and symmetrical hearing loss
- Loss of high pitched sounds first
Patients with presbycusis are at increased risk of developing…
Dementia
Describe the investigation of presbycusis
Audiometry
Describe the management of presbycusis
- Hearing aid
- Cochlear implant (in patients where hearing aids are not sufficient)
Sudden sensorineural hearing loss is defined as…
Hearing loss over less than 72 hours, and no conductive cause can be found
In SSNHL is the presentation commonly unilateral or bilateral?
Unilateral
What is the most common cause of SSNHL
90% of cases are idiopathic
Describe the investigation of SSNHL
Audiometry
What are the diagnostic requirements on audiometry to make a diagnosis of SSNHL?
Loss of at least 30 decibels in three consecutive frequencies
Describe the management of SSNHL
- Otological emergency, therefore immediate referral to ENT is required
- If underlying cause is found then this is treated, e.g. CNS infection
- Idiopathic SSNHL is treated with steroids (oral or intra-tympanic)
What are the main functions of the Eustachian tube?
To equalise pressure and drain fluid form the middle ear
Describe the presentation of ETD
- Reduced/altered hearing
- Sensation of fullness/discomfort in the ear
- Tinnitus
Describe the investigation of ETD
- Tympanometry
- Audiometry
- Nasopharyngoscopy (using an endoscopic camera to visualise the ET)
ETD may be related to…
- Viral URTI
- Allergies (e.g. hayfever)
- Smoking
Describe the management of ETD
Conservative:
- No treatment (wait for it to resolve spontaneously, e.g. recovering from a viral URTI)
- Valsalva manoeuvre
Pharmacological:
- Antihistamines
- Steroid nasal spray
- Decongestant nasal spray
Interventional:
- Grommets
- Balloon dilatation Eustachian tuboplasty
What is otosclerosis?
A condition where there is abnormal remodelling of the small bones in the middle ear (mainly affecting the stapes) leading to conductive hearing loss
Otosclerosis usually occurs at what age?
Before the age of 40 years
What causes otosclerosis?
Combination of environmental and genetic factors
Otosclerosis can be inherited in what kind of pattern?
Autosomal dominant
Does otosclerosis tend to affect the hearing of lower-pitched or higher-pitched sounds?
Lower-pitched sounds are affected more
Describe the management of otosclerosis
Conservative:
- Hearing aids
Interventional:
- Surgery (stapedectomy or stapedotomy)
What is a cholesteatoma?
An abnormal collection of squamous epithelial cells in the middle ear which invade local tissues/nerves and erode the ossicles, leading to conductive hearing loss
Cholesteatoma can predispose the patient to…
Significant infections
Describe the clinical features of a cholesteatoma
- Unilateral conductive hearing loss
- Foul smelling discharge from the ear
Which investigation is used to confirm the diagnosis of cholesteatoma?
CT head
Describe the management of a cholesteatoma
Surgical removal
