7. Ear & pathology Flashcards
what is tinnitus
perception of hearing sound without an external source
what is vertigo?
hallucination of movement, rotational feeling (different to dizziness)
nerve supplying medial surface of tympanic membrane and middle ear cavity
glossopharyngeal
non otological causes of otalgia
-TMJ dysfunction (CN Vc)
-oropharynx disease (CNIX)
-larnyx/pahrynx disease (CNIX, CNX)
causes of perichondritis
insect bites
ear piercing
perichondritis
perichondrium infected overlying pinna, need ABx
what type of haematome develops in pinna haematoma?
subperichondrial
how to prevent re accumulation of blood in a drained pinna haematoma
apply tamponade, to keep perichondrium pushed up against cartilage
is cauliflower deformity reversible?
no
origin of external acoustic meatus
cleft between 1st and 2nd pharyngeal arches
lining of external acoustic meatus
keratinising, stratified squamous epithelium
effect of pulling cartilage of pinna back and up
straightens out external acoustic meatus
why does external acoustic meatus have a self cleansing function?
lack of square contact to remove debris. so needs lateral epithelial migration instead
common bacterial causes of otitis external
pseudomonas aeruginosa
staph
otitis externa
-symptoms
-rare complications
-itchy, pain, maybe discharge
-malignant otitis externa
malignant otitis externa
erosion through petrous bone, maybe life threatening, immunocompromised at risk
causes of otitis media
-commonly viral
-bacterial
appearance of TM in otitis media with effusion, why?
retracted due to increased negative pressure
air bubbles show fluid in middle ear cavity
explain how a cholesteatome forms
-blockage of Eustachian tube
-pars flaccida sucked in due to increased negative pressure
-stratified squamous epi and keratin get trapped in ‘pocket’
management of cholesteatoma
identify early
refer
function of ossicles
AMPLIFY and relay vibrations from TM to oval window of cochlea
common cause of acquired hearing loss in young adults
otosclerosis
cause of otosclerosis
unknown- viral/hereditary?
main issue in otosclerosis
sound vibrations can’t be transmitted effectively from TM to oval window of cochlea
type of hearing loss in otosclerosis
uni/bilateral conductive
why is pharyngotympanic membrane dysfunction a problem?
mucous not drained and pressure not equilibrated to atmospheric so ability of TM to vibrate appropriately decreases, ossicles affected
mamagement of otitis media with effusion
-watch and wait
-paracetmaol if pain
who usually gets otitis media with effusion?
children
sign of otalgia in children
tugging at ear
causes of acute otitis media
-viral common
-bacteria sometimes: strep pneumoniae, haemophilus influenzae
how could TM be perforated in acute otitis media?
lots of pus/pressure
how would you know someones TM has perforated
-acute otitis media
history of pain affecting hearing, then sudden tense pain, then sudden relief, maybe discharge
management of mastoiditis
-recognise, refer
-IV ABx
-maybe surgery
what is mastoiditis?
osteomyelitis of mastoid bone
signs of mastoiditis
red swollen distorted ear
how could signed sinus be affected by ear pathology
cholesteatoma/ ear infection could erode petrous bone and thrombus could form
what is the cochlea
spiral fluid filled tube with specialised hair cells that generate Ads when moved
where’s the primary auditory cortex?
temporal lobe
hats the vestibular apparatus?
fluid filled (endolymph) tubes with specialised hair cells that generate Abs when moved
classical history in Meniere’s disease
-30 mins-24 hours
-recover between epidoses
-hearing deteriorated over time
distinguish between acute labrynthitis and acute vestibular neuritis
AL:
-all inner ear structures involved so tinnitus, hearing loss, vertigo
AVN:
-only vertigo, vomining lasting days
cause of AL or AVN
preceding URTI
tuning fork hertz
512
if suspected hearing loss, what’s a social diagnostic test?
pure tone audiometry
where is the pathology in conductive hearing loss?
external or middle ear
where is the pathology in sensorineural hearing loss?
inner ear or CN VIII
examples of pathology causing conductive hearing loss
wax
acute otitis media
otitis media with effusion
otosclerosis
examples of pathology causing sensorineural hearing loss
prescubysis
meniere’s
ototoxic meds e.g. furosemide, vancomycin, gentamycin
acoustic neuromas
noise-related hearing loss
explain the result of Webers test in conductive hearing loss of R ear
sound materialises to side of the hearing loss (RHS) due to loss of normal masking influence of external ambient noise on RHS
positive rinne’s test
AC>BC when tuning fork on bone around ear vs perpendicular 1cm away from external acoustic meatus
what’s the result of webers test in sensorineural hearing loss of R ear?
sound lateralised to L ear
why is AC>BC normally?
air route includes amplification of vibrations from external and middle ear before reaching inner ear
bone route no amplification of vibrations
explain negative rinne’s test of R ear (conductive hearing loss)
BC>AC as air can’t get past blockage but bone bypasses it so problem must be external/middle ear of RHS
gold standard test for vestibular schwannoma / neoplasms of VIII or brainstem
gadolinium MRI
what meds could help with acute sensorineural hearing loss?
corticosteroids
