EAR Flashcards
Bones of the ear in order from closest to tympanic membrane
Malleus, incus, stapes
Three main types of hearing loss
Conductive
Sensorineural
Mixed
What type of hearing loss is associated with the outer and middle ear?
Conductive hearing loss
What type of hearing loss is associated with the inner ear?
Sensorineural hearing loss
What is the most common type of hearing loss?
Sensorineural hearing loss - 90%
What is mixed hearing loss?
Both conductive and sensorineural hearing loss
What is a Rinne’s positive result?
Air conduction > bone conduction
If a person is Rinne’s positive but hearing has reduced equally for both bone and air conduction, what type of hearing loss do they have?
Sensorineural hearing loss
If a person is Rinne’s negative, what kind of hearing loss do they have? HINT: 2 potential types
Conductive hearing loss or severe sensorineural hearing loss
What conduction is heard better in a Rinne’s negative test?
Bone > air conduction
What is a normal Weber’s test result?
Sound heard equally in both ears
In Weber’s test, if the sound is heard louder on the side of intact ear, what is the likely hearing loss?
Sensorineural
In Weber’s test, if the sound is heard louder on the side of the affected ear, what is the likely hearing loss?
Conductive
What is pure tone audiometry?
Measures quietest sounds a person can hear at different frequencies (pitch) in each ear. Results plotted in pure tone audiogram
Four degrees of hearing loss severity
Mild, moderate, severe , profound
Describe tympanometry
Test of middle ear functioning. Looks at compliance of eardrum to changing air pressures, indicating how effectively sound is transmitted into middle ear
Number of people in UK severe or profoundly deaf
> 900,000
What is a common cause of temporary hearing loss?
Wax
List 4 problems with the outer ear that can cause hearing loss
Congenital malformations of the ear
Wax
Infection
Exostosis
What is exostosis (surfer’s ear)?
Abnormal bone growth within the ear canal
What causes exostosis?
Irritation from cold wind and water exposure causes bone surrounding ear canal to develop lumps of new bony growth which constrict ear canal. Where canal is blocked, water and wax become trapped and cause infection
Three causes of hearing loss caused by the middle ear
Perforated ear drum
Otitis media with effusion
Otosclerosis
What is otosclerosis?
Abnormal growth of bone of middle ear. Prevents structures from working properly, causes hearing loss. For some, this may become severe
Describe chronic suppurative otitis media (CSOM)
Inflammation of middle ear and mastoid cavity
Characterised by discharge from middle ear through a perforated tympanic membrane
At least 6 weeks
After which condition can chronic suppurarive otitis media occur?
Following an URTI that has led to acute otitis media
Five problems with the inner ear that can cause hearing loss
Presbyacusis Noise exposure Genetic Ototoxicity Vestibular schwannoma
What is the most common type of sensorineural hearing loss, caused by aging of auditory system? It occurs gradually and initially affects the ability to hear higher pitched sounds
Presbycusis
Pronounced prezbikusis
Hallmark of presbycusis
Progressive, symmetrical loss of high-frequency hearing over many years
What factors influence the onset and severity of presbycusis?
Genetic predisposition, socioeconomic status, noise exposure, smoking, hypertension, diabetes, vascular disease
Approximatly how many decibels is a whisper?
30
Approximatly how many decibels is a jackhammer?
130
Give an example of a drug that causes tinnitus
NSAIDs
Give 2 examples of drugs that cause temporary hearing loss
Loop diuretics
Macrolides
Give an example of a drug that causes permenant hearing loss and/or vestibular damage
Aminoglycosides
Benign, usually slow growing tumour from an overproduction of Schwann cells
Vestibular schwannoma (acoustic neuroma)
Typical vestibular schwannoma presentation
Asymmetrical hearing loss, tinnitus, dizziness. CN VII symptoms if large
How is vestibular schwannoma diagnosed?
MRI of internal acoustic meatus
Managment of vestibular schwannoma
Dependent on size & symptoms
Monitoring
Radiotherapy
Surgery
Two central causes of hearing loss
Dementia, depression
Mechanism of hearing
Sound waves travel via external canal to tympanic membrane, causing it and attached chain of ossicles to vibrate. Motion of stapes against oval window sets up waves in fluids of cochlea, causing basilar membrane to vibrate. This stimulates organ of Corti to send nerve impulses to brain
What proportion of people with tinnitus also experience hearing loss?
2/3
Two examinations that should be done for tinnitus
Otoscopy
Blood pressure
Causes of tinnitus - 12 listed
Hearing loss Loud noise Stress + anxiety Ear infections Wax Ménière's disease Glue ear Otosclerosis Perforated eardrum Hypertension Neuroma Diabetes
Managment options for tinnitus
Hearing aid Relaxation CBT Using sound Addressing sleep problems
