Ear Flashcards
3 divisions of the ear
outer
middle
inner
What 3 components make up the outer ear?
Pinna
External auditory meatus
lateral tympanic membrane
What structures are in the middle ear?
Ossicles - malleus, incus , stapes
Facial nerve
eustacian tube
What part of the ear does the eustacian tube link up with?
Middle ear
What is the part of the middle ear located being the pars flaccida known as?
Attic
What is the inner ear comprised of?
Cochlea Semicircular canals (vestibule and labyrinth)
What does the cochela do?
creates electrical impulses to the cochlea nerve
What do the vestibule and labyrinth do?
balance
The Eustachian tube connects the middle ear with what?
nasopharynx
What is the mastiod process and how does this relate to middle ear infection?
Bony lump behind pinna
mastiod air cell system opens directly to middle ear so infection can spread causing mastioditis
What is conductive hearing loss and what part(s) of the ear does it involve?
Interruption to the hearing system in the external or middle ear
What is sensorineural hearing loss and what structures are involved?
hearing process is interrupted at the cochlea or auditory nerve
What test can help distinguish between conductive and sensorineural hearing loss?
tuning fork test
What type of hearing test is this?:
Place someone in a sound proof room. Present with series of sounds and measure bone and air conduction in each ear.
Pure tone audiometry
What type of hearing test is this?:
Presenting stimulus to ear and measuring the resultant changes of electrical activity in the nervous system
evoked/electrical response audiometry
What type of hearing test is subjective and requires cooperation?
Pure tone audiometry
Which type of hearing test is subjective and can therefore be used to assess hearing in children?
Electrical response audiometry
What are otoacoustic emissions and what are they used to assess?
Electrical signal generated by the inner ear in response to sound.
Used to assess hearing in babies
What is tympanometry?
Blowing a small current of air into ear to measure distensibility of ear drum and middle ear.
4 gestational infections that can lead to congenital sensorineural hearing loss?
Toxoplasmosis
Rubella
cytomegalovirus
herpes
What is the acquired sensorineural hearing loss associated with aging known as?
Presbyacusis
What are 3 infective causes of acquired sensorineural hearing loss?
Meningitis
Mumps
Measles
4 causes of acquired conductive hearing loss?
Wax
Glue Ear
Otitis externa
Chronic suppurative otitis media
Why is it important to treat blunt trauma to the ear quickly?
If there is bleeding between the skin and the cartilage
the cartilage can necrose due to insufficient blood supply and then your left with a cauliflower ear
What is haematoma auris?
Bleeding between skin and cartilage in pinna
What is the best management for haematoma auris?
drain the blood
pressure dressing
Wehn should syringing of earwax be avoided?
If the eardrum is perforated
What is otitis externa an infection of?
Skin of the external ear canal
What is otitis externa also known as?
Swimmer’s ear
What organisms commonly cause otitis externa?
Pseudomonas
Staphylococcus
Symptoms of otitis externa?
Pain
Itching
Sometimes a fetid discharge
What is the treatment of otitis externa?
Clean the ear
Keep it dry
Short course of antibiotic drops
What can excessive and prolonged use of antibiotic drops lead to?
Change of normal flora
Fungal infection - otomycosis
What are Exostoses and what is the condition also known as?
Broad based bony swellings in the external ear and are thought to be an inflammatory response to cold water exposure.
Surfer’s ear
What are osteomas and how do they differ from exotoses?
Benign bony tumour of the external ear canal. More common in men unilateral not a result of cold water exposure narrower pedunculated
What is necrotising otitis externa?
progressive osteomyelitis of the of the temporal bone resulting from otitis externa
Which patients are most at risk of necrotising otitis externa?
Patients with compromised immunity
(poorly controlled diabetes
Symptom of necrotising otitis externa?
Severe, unremitting, deep seated pain that does not respond to analgesics
What type of organism usually causes acute otitis media?
Virus - ascending via the Eustachian tube.
In what age group is acute otitis media usually seen?
Children - they have shorter, wider and more horizontal Eustachian tubes and an immature immune system,
4 key features of acute otitis media
otalgia
fever
deafness
otorrhea (if fetid this suggests anaerobic organism)
How does a bacterial infection compare with a viral one in acute otitis media.
Viral are short lived
Bacterial may last for a week or more
What makes acute otitis media so painful?
Build up of pus and therefore pressure behind tympanic membrane.
How is the intense pain often relived in acute otitis media?
Eardrum bursts, relieving pressure
several weeks after a bout of AOM the parents notice that their kid is still a little deaf. Whayt could cause this and is this normal?
There can still be some residual fluid in the middle ear for several weeks, causing some deafness and yes this is normal.
How dos the mastoid relate to AOM and what is a known complication?
Mastoid abcess
What is the key to management of AOM?
Analgesia
Antibiotics - not always required
If an ear drum perforates but fails to heal and causes recurrent bouts of discharge, what is this condition?
chronic suppurative otitis media
What would a patient with chronic suppurative media complain of?
Discharge from ear
Increasing deafness
3 treatment options for a perforated eardrum?
- reassurance and advice on water caution
- antibiotics and water caution
- myringoplasty
What type of antibiotics are toxic to the inner ear?
aminoglycosides
What is a cholesteatoma?
Following a perforated eardrum, squamous epithelium migrates from the outer ear to the middle ear and collects in a mass.
How do complications arise from a cholesteatoma?
the mass can become erosive and gradually eat away at the bone and soft tissue
What 3 locations can infection resulting from cholesteatoma spread to
Brain
facial nerve
inner ear
What 5 things would make you suspect cholesteatoma in a patient with a perforated eardrum?
persistent smelly discharge no improvement with drops severe hearing loss dizziness unexplained neurological signs symptoms
7 complications of cholesteatoma?
Meningitis facial palsy acute mastoiditis labyrinthitis intercranial abscess venous sinus thrombosis
What is persistent fluid in the middle ear for 3 months or more known as?
Otitis media with effusion/Glue Ear
What is the most common cause of hearing loss in children?
OME
Between what ages is OME most prevalent?
2-7 years
At what time of year is OME more prevalent?
Winter months
What are two possible causes of OME?
Infection
Eustachian tube dysfunction
What other tissue is associated with OME?
Adenoids
Children with what 2 conditions are most susceptible to OME?
Down’s syndrome
cleft palate
Aside from hearing loss what else might parents of children with OME also notice?
Dizziness
Clumsiness
Is pain usually associated with OME?
No
What is OME likely to impact if left unchecked?
Schooling
Behaviour
How will the ear drum appear in a case of OME?
fluid level or a translucent ear drum
What are the management steps for OME?
Wait 3 months
Mod-severe deafness? - grommets or hearing aid
Recurrent glue ear - adenectomy
What is it important to reassure parents about regarding OME?
It’s a common condition that shouldn’t affect the child’s hearing in the long term.
Define tinnitus
Noise in the ear or head in the absence of stimulus
Is most tinnitus subjective or objective?
Subjective - heard only by pt
Is tinnitus usually bilateral or unilateral
bilateral
If tinnitus is pulsatile what does this suggest?
Due to adjacent blood vessel in head or neck
What is age related hearing loss known as?
Presbycusis
Why does unilateral tinnitus warrant a more urgent referral than bilateral tinnitus?
Very rarely can be a symptom of an intercranial tumour.
Why is it important to take a drug history when a pt complains of tinnitus?
Many drugs, such as aspirin have a side effect of tinnitus
What medical conditions are associated with tinnitus?
HTN
anaemia
How long does it take most traumatic tympanic perforations to heal?
around 6 weeks
What should pts be advised to do in the event of a tympanic perforation?
Keep ears dry to avoid infection
What can arise from blunt trauma to the middle ear?
Haemotympanum
What will a haemotympanum result in and what is the management of this?
Conductive deafness
Will usually resolve itself
If hearing loss persists after a haemotympanum has resolved, what may have occurred and what do you do?
Ossicular injury
May require reconstructive surgery
What type of hearing loss can occur with a temporal bone fracture?
Conductive
Sensorineural
Mixed
What may happen to the tympanic membrane following a temporal bone fracture?
Perforation
Haemotympanum
What are the possible symptoms of a temporal fracture?
Deafness Otalgia Otorrhoea - blood/csf Rhinorrhoea - blood/csf vertigo
What is the Battle sign, when do you check for it and what does it indicate?
Ecchymosis of the post auricular skin
Following head injury
Fracture of the temporal bone
What is the racoon sign, when do you check for it and what does it indicate?
Ecchymosis of the periorbital skin
Following head injury
Fracture of the temporal bone
What type of investigation is necessary following a suspected temporal bone fracture?
CT head
Following head trauma what examination is required of the ear?
Tuning fork and pure tone audiometry
