Middle ear Flashcards
What epithelium on external ear
Stratified squamous keratinised
What epithelium in middle ear
Ciliated columnar epithelium with goblet cell
Can produce mucous which can cause glue ear
What are the three layers of the tympanic membrane
Outer = continuous with EAM
Middle fibrous
Inner layer of respiratory = same as middle ear
What structures of the tympanic membrane
Paratensa - tense Paraflaccid - flaccid Cone of light - anterior inferior Umbo in the middle Annulus surrounds Look at photo
If small perforation of TM
Small hearing loss
If large = large loss
What does middle ear do
Transforms acoustic energy from air to fluid
Acts as sound amplifier
What are the bones in the middle ear
Malleus
Incus
Stapes which is attached to foot plate in oval window
How does middle ear do its job
TM bigger than footplate so gives more energy
What can disrupt the middle ear
Trauma Bony sclerosis Chronic infection can erode incus Fibrous tissue between ossicles so don't conduct Oteosclerosis
What is otosclerosis
AD bony deposition in annular ligament that surrounds oval window where staple plate is so sound doesn’t conduct into cochlea
CONDUCTIVE DEAFNESS
MAY HAVE TINNITUS AND TRANSINT VERTIGO
RX = HEARING AID OR SURGERY - STAPEDECTOMY
What is the role of the Eustachian tube
Connects middle ear to nasopharynx
Acts to equalise pressure in ear to that of EAM as middle ear needs to be at atmospheric pressure to work
What can cause dysfunction
Inflammation
Infection
Genetics
Blockage
What happens if dysfunction
-ve pressure develops inside ear
Causes transudate to be pulled out of mucosa
Increased pathogens
What is otitis media
Inflammation / infection of the middle ear
Occurs when Eustachian tube stops working and fluid builds up underneath the ear drum
OME - can be sequels of otitis media but is regarded as a difference non-infective condition
If adult what should you suspect
Is there a tumour blocking the ear drum causing Eustachian tube dysfunction
Do flexible nasal-endoscopy
How do you Rx
Grommet to equalise pressure if recurrent
Children do not require unless persistent and hearing loss is affecting development
Why are young children particularly prone / RF
Eustachian tube smaller
Adenoids much larger
Cleft palate
Down syndrome
Other RF
- URTI / scarlet fever
- Bottle fed / use of dummy
- Passive smoking
- Adenoids
- Asthma
- Malformations e.g. cleft palate
- Reflux
- GORD / obesity in adults
What causes acute otitis media
Usually URTI (viral) induced effusion 2 to Eustachian dysfunction - RSV - Rhinovirus Can be bacteria H.influenza S.pneumonia = most common M.catarrhalis
What is the history
Short history
Prodromal URTI
Increasing pain
Bulging red ear drum causing pain which is relieved if perforates
Perforation = discharge
Hearing loss
May have fever but don’t act sick
Ear drum can perforate and discharge released
Can be very non-specific in young children - fever, vomit, irritable, poor feed so always examine if unwell
How do you Dx
Otoscopy showing red infected ear or perforated membrane
Always examine ears and throat of unwell children
Consider MC+S swab if discharge
CT / MRI if complications
How do you Rx
Analgesia + anti-pyretic
When do you give Ax
Symptoms 4+ days Systemically unwell Immunocompromsied <2 + bilateral Perforation or discharge Admit if child <3 months
What Ax
Amoxicillin
Erythromycin 2nd line
5-10 days
Co-amox if no improvement
What do you do if recurrent or complicated
Grommet insertion
What are extra-cranial complications of AOM
Perforation Acute mastoiditis / mastoid abscess Facial nerve palsy Labrynthitis Ossicular / cochlear nerve damage = Hearing loss Tympanosclerosis due to scarring Chronic perforation
What are intracranial complications
Febrile convulsion Brain abscess Meningitis Cavernous sinus thrombosis Sub or extradural empyema
What causes chronic otitis media
Cholesteatoma
Perforated TM with persistent or repeated infection
- Psuedomona
- S.aureus
What are the symptoms and how do you Rx
Intermittent non-offensive discharge Hearing loss May have pain May develop 2 otitis externa due to discharge Complications = same as otitis media
Rx
- Ax and steroid ear drop if infection present
- Myringoplasty to repair drum and prevent infections
What is cholesteatoma
Abnormal collection of skin (keratinising squamous cells) in middle ear causing local destruction
Usually present in childhood due to eustachian dysfunction but can be congenital
What are the symptoms
Hx repeated smelly watery discharge despite Ax
Doesn’t resolve
Gradual unilateral hearing loss
Headache
Pain
May get vertigo / facial nerve palsy if extends which suggests inmepnding CNS complications
Other complications same as otitis media
How do you Dx
Otoscopy shows crust in upper part of ear drum
May not see if wax so debridement needed before
May see discharge if 2 infection
If complications
PTA
CT temporal bone
How do you treat
Refer ENT for mastoidectomy to take away dead skin
What can cholestatoma lead too
Ear infection Hearing loss Mastoiditis Labrynthitiis Vertigo Tinnitius Damage to facial nerve Meningitis Brain abscess / paralysis Venous sinus thrombosis
What is otitis media with effusion ‘glue ear’
Collection of fluid in middle ear
Non-infective
Occurs when an effusion is present after regression of symptoms of acute OM
What is most common cause of hearing loss in children
Otitis media with effusion
How do you Dx
Otoscope shows fluid level of bubbles behind the ear drum
PTA = conductive loss
Tympanometry = flat trace
What causes it
Eustachian tube dysfunction
- More common in Cleft / Syndrome
Adenoidal hypertrophy
Resolving AOM
Who is more at risk
Day care Older siblings Parenteral smoking URTI Oversized adenoid Cleft palate Down syndrome
What are symptoms
Hearing loss Speech delay Behaviour problems Poor balance Can go on to develop otitis media
How do you Rx conservatively
Most improve by themselves so 3 months of active observation
Autoinflation if >4 - blow balloon using nose to create pressure and open up tube
Valsalva manoeuvre
What advise
Stop smoking
Likely seasonal variation
Breast feeding reduces risk
What are more invasive Rx
What are risk of Grommet
Grommet insertion if bilateral >3 months and affecting hearing / Down’s or cleft palate
Adenoidectomy as last resort
Hearing aids / bone implant if other options not effective
Risk
- Infection
- Tympanosclerosis
- TM perforation
What do you ask in history / examination of discharging ear
When did it start
Associated Sx
Otoscope
What further investigation
Refer for pure tone audiometry / appropriate hearing test for age
Possible CT if continually discharge
Must exclude a post nasal space tumour as cause of fluid in an adult
What causes perforated tympanic membrane
Infection = most common (Acute otitis media)
Previous surgery e.g. grommet which doesn’t close
Baro trauma
Blow to the ear
What may it cause
Ear pain when perforation occurs + discharge
Hearing loss
Recurrent discharge
Increased risk of otitis media
How do you Rx
None in most usually heals 6-8 weeks Avoid getting water in Prescribe Ax if due to an episode of AOM - Avoid ototoxic - Ciprofloxacin = 1st line Myringoplasty if fails to heal by itself
What is tympanosclerois
Hyalinzation and calcification of connective tissue in middle ear or TM
What can it cause
White plaque on ear drum as calcified
Conductive hearing loss if affects the ossicles
What are RF
Recurrent middle ear infection
Perforated TM
How do you Rx
Hearing aid
Reconstruction of ear drum
What are mastoid air cell
Form love middle ear
Air filled spaces in mastoid process of temporal bone
Air released from mastoid Antrum into tympanic cavity when pressure is too low
What is mastoiditis
Inflammation of mastoid air cells
What causes
Persistent otitis media
Choleastoma
What are symptoms
Red ear Swelling around ear Tenderness External ear may protrude forward Discharge if perforates Fever Headache Hearing loss VERY UNWELL
How do you Dx
Refer ENT
CT
Complications of mastoiditis
Menignitis
OM
Hearing loss
CN palsy
How do you Rx
IV Ax
Myringotomy
+- definitive mastoidectomy
Most common cause of otitis media / rhino sinusitis
Strep pneumonia
Most common cause of tonsillitis
Strep A
What is recommended to Rx motion sickness
Hyoscine (transdermal patch)
Non-sedating antihistamine
What are common bacterial pathogens in discharging ear
Psuedomona S>aureus S.pneumonia H.influenza M.catarrhalis
What do you want to know in HX
Duration Any ear pain Fever / systemic Sx suggesting infective Any hearing loss Any dizzy Any FB Any facial nerve palsy Any trauma Rx tried
What does trauma suggest discharge could be
CSF from basal skull fracture
What are other Dx
Cholesteatoma FB Malignant otitis externa Otitis externa Ottis media with effusion Perforated TM
What can middle ear infections cause
Facial nerve palsy
What is most common cause of this
Bell’s but Dx of exclusion so need to actively exclude other causes
What are other causes
Trauma
- Iatrogenic
- Temporla fracture
- Cholestatoma
Infectious
- Ramsay hunt - VZV reactivation
- 2 to acute / chronic otitis media / malignant
Neoplastic
- Parotid or temporal bone tumour
- Acoustic neuroma
Congenital
- CHARGE
Inflammatory
- Sarcoid
- GBS
- MS
Other
- CVA
How do you investigate
Examine - Ear - Throat - Parotid - Mass? Bloods Audiogram PTA MRI if suspect central cause
How do you manage
Eye care - tears / tape shut
Refer ophthalmology
Oral steroid for Bells -1 mg/kg
Oral anti-viral for Ramsay
What is Ramsay Hunt
HAZ reactivation in ganglion of facial nerve
Intense pain, palsy and vesicles
What does facial nerve innervate in the eye
Orbicularis oculi
So if palsy not able to close the eye
If only mild some people will still be able to close
What nerve innervates eye opening
Oculomotor
So if damaged = ptosis as can’t open ear
What grades facial nerve
House Brackmann
If forehead still moves what does this suggest
UMN
Scan brain to look for stroke
What path does facial nerve take
Through ear and parotid
If other branches are affected what can you get
Taste disturbance
HYperacusis
Lacrimation
