Otology

Question 1

-basic anatomy of ear - see image

• -semicircular canals make up vestibular system*
• -vestibulocochlear nn travels through internal auditory meatus then to brainstem*

Answer 1

Question 2

diseases of the external ear overview - image attached

Answer 2

Question 3

diseases of middle ear overview - image attached

Answer 3

Question 4

diseases of inner ear overview - image attached

Answer 4

Question 5

• hearing loss can be conductive. cause(1) or sensorineural. cause(1)
• audiometry of each

Answer 5

• conductive hearing loss = caused by any condition disease that impedes the conveyance of sound in its mechanical form through the middle ear cavity to the inner ear
• sensorineural loss = caused by either sensory or neural disease - of inner ear or auditory nerve
• audiometry conductive - air bone gap
• audtiometry of sensorineural - no air bone gap

Question 6

pure tone audiometry most commonly performed hearing test

• what does test determine(1)
• how is test carried out (4)
• what is normal (2)
• image shows symbols used in pure tone audiometry graphs*

Answer 6

pure tone audiometry most commonly performed hearing test

• test determines pts hearing threshold
• test carried out in each ear in turn while non-test ear is masked with white noise. first air conduction is tested. pt played sounds at a particular frequency at increasing amplitudes and asked when they can hear this. the quietest is recorded. repeated at four different frequencies. bone conduction is tested in similar manner but sounds transmitted via vibrator placed on mastoid bone.
• 95% of ‘normal’ population have air-conduction thresholds better than 25dB over four frequencies usual ones tested are 500, 1000, 2000, 4000 Hz
• image shows normal air conduction in left ear (x). and impaired air conduction in right ear(o)*

Question 7

• what does this measure (1)
• what does the peak on the graph represent. what does a normal ear graph look like(1). what does a negative middle-ear pressure graph look like(1). what does a fluid filled middle ear look like(1).
• -how is it done*

Answer 7

• test measures the middlea ear pressure and the stiffness/compliance of the ear drum these are related
• peak on the graph represents the middle ear pressure. normal ear graph has peak at zero. negative middle-ear pressure graph has peaked forces towards the left/negative. fluid filled middle ear graph shows a flat trace. see images
• -a probe with three channels is inserted into ear. one introduces sound, one allows pressure in ear canal to be varied, one carries microphone to measure how much sound energy is reflected from ear drum. maximal sound energy passes through the ear drum when the pressure in the ear canal is the same as that in the middle ear by varying the pressure in the ear canal and measuring the amount of sound reflected from the drum the middle ear pressure can be determined.*

Question 8

• presbycusis - a disorder of inner ear.
• what does it mean(1). course(1). pathophysiology(1).
• HPC - nature (2). onset(1). unilateral or bilateral(1). assx(2)
• SH (1)
• mx (1)
• inx (1)

Answer 8

• is means the hearing loss of old age. course is degerative. pathophysiology is loss of the outer hair cells of the cochlear.
• HPC - nature is hearing loss and ‘confusion in sound’ eg struggling to hear clearly in background noise. onset is gradual. bilateral. assx with tinnitus and vertigo sometimes.
• SH - can lead to social isolation, distress in social situations
• mx - no cure, hearing aids can help by amplifying sounds and masking tinnitus
• inx - shows a characteristic pure tone audiogram of loss of higher frequencies see image

Question 9

cholesteatoma -a disease of middle ear

• not a tumour as suffix may suggest. and nothing to do with cholesterol.
• -*pathophysiology of cholesteatoma. what is is (1) what does it contain. (1). most common location (1).
• pc (2). o/e poss otoscopy findings(3)
• pts may present solely with an assx/comp of chostioma. what are these (3)

Answer 9

cholesteatoma -

• not a tumour as suffix may suggest. and nothing to do with cholesterol.
• -*pathophysiology of cholesteatoma. it is a sac/cyst. contains kerininizing squamous epithelium (skin). most common location is in attic / epitypanic part of the middle ear
• pc - foul smelling discharge, conductive hear loss. o/e otoscopy - attic retration filled with squamous debris, discharge attic perforation, attic aural polyp
• assx/comp - facial palsy, vertigo, intracranial sepsis

Question 10

cholesteatoma

• aetiology (2)
• pathophysiology pathway

Answer 10

-aetiology

>congential - rare thought to arise from squamous cells in middle ear

>acquired - common the exact aetiology is unknown

-pathophysiology theory

>negative pressure in middle ear affects most the pars flacida of tympanic membrane inc the epitympanic membrane / attic

>this causes it to balloon back forming pocket

>the mirgratory epithelium of outer layer of tympanic membrane can fall into this pocket and cannot escape

>this ball of squamous debris slowly enlarges and is infected with pseudomonas hence foul smelling ottorhea

>the cyst/sac tends to grow upwards into attic and backwards into mastoid

Question 11

cholestesatoma

• cholesteatoma may damage important structures in/near middlea ear and mastoid and cause complications - eg (4)
• mx

Answer 11

-ossicles - leading to conductive deafness

-facial nn - leading to facial palsy

-labrynth - leading to vertigo

-erosion of tegmen (roof of middle ear) - leading to intracranial sepsis

-mx - surgical removal. operation required depends on size and extent of disease. small cholesteotoma limited to attack may require only atticotomy. if involves mastoid may require modified radical mastoidectomy

Question 12

otitis media with effusion / glue ear. otitis media = inflammation of middle ear

• -*pathophysiology pathway (2)
• poss aetiologies (3)

Answer 12

-pathophysiolgy

>poor ventilation of middle ear

>leads to a sterile/non-purulent effusion often thick and sticky

-possible aetiologies

>sequela of acute otisis media

>infection or allergy of middle ear mucosa

>eustacian tube dysfunction resulting from poor/delayed development, obstruction due to large adenoid, nasal conditions/abnormalities, cleft palate

Question 13

otitis media with effusion

• affects 70-80% of children at some point. in most it resolves spontaneously however some can last months-years. indication for mx (2)
• main pc(1). comps (2)
• mx (2)

Answer 13

• indication for mx - lasts more than 3 months and is symptomatic
• main hpc is hearing loss. usually mild loss of reduction of 20-30dB of threshold.

-comps - chronic hear loss can lead to altered behaviour and learning in children . chronic effusion can predispose to repeated attacks of acute otitis media infection spreads to fluid filled middle ear via eustachian tube

-mx

>grommets. small plastic tube inserted into tymp membrane and remain there for 1-2 years before being extruded out to external ear. provide alternate route for middle ear ventilation. effusion resolves. most children grow out of glue ear so it is hoped that by time of extrusion effusion will have been resolved. some may require reinsertion

>another option is hearing aids

Question 14

otosclerosis

• otosclerosis is a disease of what part of the ear (1).
• pathophysiology (1)
• how can this lead to conductive and sensorineural hearing loss

Answer 14

• otosclerosis is a disease of the otic capsule= dense osseous labyrinth of the inner ear that surrounds the cochlea, the vestibule and the semicircular canals
• pathophysiology

>hard compact bone of labyrinth replaced by patches of spongy bone

-conductive hearing loss - the abnormal boney overgrowth can affect the footplate of the stapes which results in its fixation . predominate cause of hearing loss

-sensorineural hearing loss-the abnormal bone is also thought to produce toxins that can affect cochlea causing

Question 15

otosclerosis

• pc(1). usual age(1). bilateral or unilateral. onset (1). exac(1). assx(3)
• nature of ear drum o/e (1). method of diagnosis(1) dd(1)
• mx. mild-mod hearing loss (2). severe conductive loss (1)

Answer 15

• pc - hearing loss . usually around 30. bilateral. progressive. womens’ sx may get worse during pregnancy. assx can be tinnitus, positional vertigo, paracusis willisii = usual sx meaning pt hears better in noisy environmeny
• ear drum o/e is normal. diagnosised by surgical exploration of middle ear and exmaination of footplate of stapes. dd ossicular adhesions/fixation.
• mx mild-mod hearing loss observation or hearing aid. severe conductive loss surgical stapedectomy. a prosthetic stapes is inserted.

Question 16

noise induced hearing loss / acoustic trauma

• -many people have experienced mild self limiting hearing loss +/- tinnitus after listening to loud music. however long term exposure to loud music can cause acoustic trauma that has to permanent sx*
• pathophysiolgy(2)
• audiogram appearance

Answer 16

-pathophysiology

>cochlear damage - sensorineural hearing loss

>also may occur sometimes is tympanic membrane rupture or middle ear damage - conductive hearing loss

Question 17

noise induced hearing loss / acoustic trauma

• pc - hearing loss - assx (1)
• sh (1)
• mx (2)

Answer 17

• pc - hearing loss - assx - tinnitus
• sh - worked in noisy environment
• mx - hearing aid. tinnitus counselling. prevention is paramount!

Question 18

obscure auditory dysfunction

????

Question 19

tinnitus

• can be an assx with hearing loss of any cause and an also occur with normal hearing. many people experience but its is transient and mild
• for some it may be life long and troublesome. comp (1)
• two types of tinnitus (2)

Answer 19

• depression can be a complication
• two types of tinnitus are intrinsic = the noise is usually heard by only pt. and extrinsic = noise may be heard by observer.

Question 20

tinnitus

causes of extrinsic tinnitus (3)

causes of intrinsic tinnitus (8)

central intrinsic causes (3)

Answer 20

causes of extrinsic tinnitus

>insect in external ear, vascular causes (eg arteriovenous malformations, glomus jugulare tumour i assume this is the one to watch out for), palatal myclonus

causes of intrinsic tinnitus

>drugs, labrynthitis, trauma, vascular (i assume same as above), presbycusis, menieres disease/endolymphatic hydrops, noise, otosclerosis

central intrinsic causes

>idiopathic, VIII nn tumours, temporal lobe epilepsy

Question 21

menieres disease

-PC (3) HPC - unilateral or bilateral. episodes occur when(1) last for how long(1) what may precede episode (2). what happens after an episode(1). course (1). nature of vertigo(1). nature of hearing loss (1). assx(3) reliever/behaviour (1) comps (1) sh(1)

Answer 21

• PC is triad of - hearing loss, tinnutis and vertigo
• HPC
• usually unilateral initially, can become bilateral
• episodes occur can occur at any time, sporadic and unpredictable. last for 30 mins-4 hrs. tinnitis and a feeling of fullness/pressure may precede an episode. after an episode pt may feel a little off balance for a few days. chronic course.
• vertigo is acute, spinning, disabling. hearing affects the lower frequencies in the early stages of disease, and returns to normal after episode.
• may be assx of nausea, vomiting and nystagmus.
• pt has to stay in bed until episode is over
• may be complicated by anx as unpredictable and debilitating nature of episodes.
• sh - may affect pts daily activities

Question 22

menieres disease

-pathophysiology (3)

Answer 22

• pathophysiology thought to be
• >there is distention of labrynth or endolymphatic hydrops*
• >and episodes occur due to ruptures in reissners membrane leading to mixing of the endolymph and perilymph*
• >or as a result of sudden release to an obstruction in endolymph circulation thus causing vertigo which settles as the inner ear fluids stablize once mo*re

Question 23

menieres disease

• diagnosis based on (1)
• important dds to exclude as causes of vertigo (6)
• mx - acute phase (1) non-acute phase (5) if severe and debilitating (1)

Answer 23

• diagnosis based on hx
• important dds to exclude as causes of vertigo - epilepsy, MS, tumours, vascular disease, labrynthitis, benign paroxysmal positional vertigo
• mx

>acute phase - vestibular sedatives

>non-acute - betahistine a vasodilator, diuretics, low caffeine, low salt, reassurance

>if severe and debilitating may need ablation surgery. i assume this affects hearing. nb must hope condition does not affect other ear in future

Question 24

acoustic neuromas

• what are acoustic neuromas (2) pathophysiological pathway to sx(1)
• pc(2) unilateral or bilateral. comp(1)

Answer 24

• acoustic neuromas are schwannomas of the vestibular division of cnviii. slow expansion of tumour leads to compression of cnviii and otological sx
• pc - hearing loss, +/- tinnitus. unilateral. a pt presenting this with no known cause must be investigated. a common complication is for tumours to undergo cystic change, a bleed in the cyst can lead to rapid enlargement + sudden onset new sx.

Question 25

acoustic neuroma

• inx (1)
• mx (3)

Answer 25

• inx - MRI
• mx - surgerical excision or highly focussed radiotheraphy or ‘watch and wait’ if tumour is slow growing
• in many cases a repeat scan will be ordered 4-6 months after referral to assess rate of growth. although potentially serious not treated with same urgency as other ent malignancies

Question 26

otitis externa

the overall cause of often a multifactorial combination of several of these factors

-most common general causes of otitis externa (3)

-most common local causes of otitis (3)

Answer 26

the overall cause of often a multifactorial combination of several of these factors-general causes of otitis externa

>skin conditions - eczema, psoriasis

>skin infections - impetigo

>neurodermatitis

-local causes of otitis externa

>trauma - eg cotton bud, dirty fingernail

>local inf - bact (pseudomonas, staphyloccocus) fung (candida, aspergillus), viral

>middle ear discharge

Question 27

otitis externa

• what is otitis externa (1). it may be acute or chronic
• PC (4) if severe/complicated (2)

Answer 27

• what is otitis externa is inflammation of the skin of the EAM
• PC -swollen, narrowed, itchy, acutely tender/aching EAM.
• may have hearing if loss skin partially or totally occules eam. may have mucinous ottorhea if comp by tympanic membrane perforation w. middle ear suppuration

Question 28

otitis exerna

-o/e(5). in fungal (1). in chronic (4)

Answer 28

o/e (otoscopy)

>swollen erythematous EAM - may not be able to see tympanic membrane

>skin may be cracked and crusted

>debris

>may have mucinous ottorhea if perf ear drum w. middle ear suppuration

>tenderness on movement, esp tragus

>in fungal - may see hyphae and spores in EAM

>in chronic - skin of EAM may be thickened, fissured and permantly moist, occasionally meatal stenosis

Question 29

otitis externa

-complications (3)

Answer 29

-complications

>inflammation may spread to auricle causing perichondritis

>may spread to surrounding tissues causing facial cellulitis

>if there is mucinous dischage pt must have a perforated ear drum nb there are no mucous glands in eam with underlying middle ear infection or cholesteatoma. nb this middle ear discharge may be the cause of the otitis externa

Question 30

otitis externa

• inx(1)
• mx - aim of therapy is to remove any irritant factors , treat infection , treat underlying skin disorders
• >*aural toilet. what is this (1)

>local medication - in drops or wick - (3)

>systemic antibiotics - indication is (1)

>prevention of recurrance (2)

-what must be done when the eam inflammtion settles

Answer 30

inx - ear swab taken for microbiological examination

• mx
• >*aural toilet - all poss debris removed with suction+microscope or dry mopping

>local medication - steroids, antibiotics, antifungals

>systemic antibiotics - indication is cellulits

>prevention of recurrance - prevent water entry can use petroleum jelly to help, do not put any object in ear eg bud or finger

-when eam inflammtion settles tympanic membrane must be inspected to exclude middle ear disease as underlying cause

Question 31

obscure auditory dysfunction (aka auditory processing disorder)

• this is an umbrella term for disorders that affect the way the brain processes auditory information
• pts usually have normal structure and function of the outer, middle and inner ear
• pts however cannot process the information normally, thought to arise from dysfunction in CNS
• pc (1)

Answer 31

• difficulty recognising and interpreting sounds esp speech

Question 32

-haematoma of pinna

>aetiology (1). pathophysiology (1). complication(2). mx(3)

-chrondrodermatitis nodularis helicis

>painful nodule of cartilage pf pinna, more often elderly pts, male, grows over a few month then stops, may regress

>aetiology - pressure and a compromised local blood supply eg sleeping on same side, cold weather

> ix - biopsy to rule out bcc and scc

>mx several options - conservative eg reduce pressure time, wear warm hat, local steroids, cryotherapy, surgical removal

Answer 32

-haematoma of pinna

>aetiology - trauma to ear eg blunt trauma

>pathophysiology - in auricle blood can track between perichondrium and cartilage resulting in haematoma

>comp - blood clot can organise causing dense scarring of ear. if infection occurs, abscess and necrosis of cartilage . results in cauliflower ear = gross deformity

>mx - drainage, pressure, antibiotic cover