ENT Flashcards
what 3 main parts is the ear anatomy decided into?
the external ear
the middle ear
the inner ear
what makes up the external ear?
the Pinna (auricle) the external auditory canal
what is cauliflower ear?
The cartilage derives its nutritional support from the overlying
perichondrium. Separation of the two layers (with blood, infection or
inflammation often following trauma) may result in cartilage necrosis
resulting in a cauliflower ear
what is the function of the middle ear?
to amplify and transmit sound energy
what structures are in the middle ear?
ossicles (malleus, incus and stapes)
tensor tympanic and stapedius muscles - which are attached to the ossicles to regulate their movement
chords tympani - provides taste to the anterior two thirds of the tongue
facial nerve
what is the function of the inner ear?
Cochlea - Transduction of energy from sound to electrical
impulses, which are relayed and interpreted by the brain
3 Semicircular canals (superior, lateral and posterior) – Detect
angular head acceleration
Utricle and saccule – Detects linear acceleration
forwards/backwards and up/down respectively
what sound range can the average human ear detect?
between 20 and 20,000Hz
what is vertigo?
vertigo may be defined as the false sensation that the body or environment is moving
what are the most common causes of vertigo?
viral labyrinthitis vestibular neuritis benign paroxysmal positional vertigo Meniere's disease Vertebrobasilar ischaemia acoustic neuroma
other causes include:
- posterior circulation stroke
- trauma
- MS
- ototoxicity e.g. gentamicin
once you have established that a person has true vertigo what must you do?
it is imperative to ascertain the duration and frequency of attacks, asthis is the key to reaching the correct diagnosis and determining if
the disorder is most likely peripheral (pertaining to the ear) or central (brain).
what is the symptoms and signs benign paroxysmal positional vertigo?
Dix hall pike test will be positive
rotatory vertigo on moving head (triggered by change in head position)
gradual onset
each epsiode last around 10-20 second
what is meniere’s disease?
symptoms and signs
Meniere’s disease is a disorder of the inner ear of unknown cause. It is characterised by excessive pressure and progressive dilation of the endolymphatic system
- rotatory vertigo associated with fluctuating hearing loss often with low-frequency thresholds affects.
- tinnitus usually gets worsen during an attack
- patients classically get an aural fullness or pressure in one or both ears before the onset of vertigo
symptoms resolve in the majority of patients after 5-10 years but the majority of patients will be left with a degree of hearing loss and psychological distress is common
what is vestibular neuritis?what are the signs and symptoms of vestibular neuritis?
Vestibular neuronitis is a cause of vertigo that often develops following a viral infection.
recent viral infection
rotatory vertigo that is continuous for over 24 hours
often associated with nausea and vomiting
horizontal nystagmus is usually present
classically confined to bed and takes several days weeks to recover
there will be no hearing loss or tinnitus
what are the signs and symptoms of vestibular migraine?
rotatory vertigo can last minutes to hours to days
classically associated with headaches/photophobia/visual disturbance/phonophobia
what is labyrinthitis?
signs and symptoms viral labyrinthitis?
Inflammatory condition affecting the labyrinth in the cochlea and vestibular system of the inner ear. can be viral bacterial or associated with systemic disease - viral labyrinthitis is the most common form
- they will have had recent viral infection.
- it will be sudden onset vertigo usually not triggered by movement but exacerbated by movement
- nausea and vomiting
- hearing may be affected (sensorineural hearing loss)
- tinnitus
they may have nystagmus towards the unaffected side
they may have gait disturbances
there may be abnormality on inspection of the external ear canal and the tympanic membrane e.g. vesicles in herpes simplex infection
what investigations might you perform for vertigo?
-full neurological exam
- pure tone audiometry
- Dix-Hallpike test
- MRI of internal auditory meatus may be appropriate with asymmetrical sensorineural loss to exclude an acoustic
neuroma
- video head impulse testing
What are the investigations and management of benign paroxysmal positional vertigo?
INVESTIGATIONS: dix-hallpike manoeuvre, supine lateral head turns, audiogram, brain MRI
MANAGEMENT: BPPV has good prognosis and usually resolves spontaneously after weeks or months so patient education and reassurance is needed.
for symptomatic treatment you can do the Epley manoeuvre (particle reposition manoeuvre)
teaching the patient exercises that they can do themselves at home, termedvestibular rehabilitation e.g. Brandt-Daroff exercises
what are the investigations and management for Meniere’s disease?
INVESTIGATIONS: pure-tone air and bone conduction with masking, speech audiometry, tympanometry/immittance/stapedial reflex levels, oto-acoustic emissions
MANAGEMENT: low salt diet and diuretics
vestibular suppressants: meclozine, secondary options include prednisolone and betahistine
intratympanic injections (dexamethasone sodium phosphate)
vestibular and balance rehabilitation
if they have persistent hearing loss - hearing aids
what are the investigations and management of labyrinthitis?
INVESTIGATIONS
- audiogram
- Weber’s and RInne’s test will show sensorineural hearing loss
investigations to consider
- pure tone audiometry can be done to assess hearing loss
- full blood count and blood culture: if systemic infection suspected
- culture and sensitivity testing if any middle ear effusion
- temporal bone CT scan: indicated if suspecting mastoiditis or cholesteatoma
- MRI scan: helpful to rule out causes such as suppurative labyrinthitis or central causes of vertigo
- vestibular function testing: may be helpful in difficult cases and/or determining prognosis
MANAGEMENT vestibular suppressants (benzo e.g. diazepam), antiemetics and prednisolone can be added
Labyrinthitis vs vestibular neuritis?
Labyrinthitis should be distinguished from vestibular neuritis as there are important differences: vestibular neuritis is used to define cases in which only the vestibular nerve is involved, hence there is no hearing impairment; Labyrinthitis is used when both the vestibular nerve and the labyrinth are involved, usually resulting in both vertigo and hearing impairment.
how do you manage vestibular neuritis?
vestibular rehabilitation exercises are the preferred treatment for patients who experience chronic symptoms
buccal or intramuscular prochlorperazine is often used to provide rapid relief for severe cases
a short oral course of prochlorperazine, or an antihistamine (cinnarizine, cyclizine, or promethazine) may be used to alleviate less severe cases
vertigo vs dizziness?
Vertigo is the hallucination of movement and is often a
manifestation of inner ear dysfunction
Dizziness is a less specific complaint that may be a
manifestation of visual , CNS, Proprioceptive, Vascular,
Cardiac or ear abnormality.
what are the two main types of hearing defect?
CONDUCTIVE: When there is impediment to the passage of sound waves between the external ear and footplate of the stapes (decreased transmission of sound to the cochlea via air conduction)
SENSORINEURAL: if there us a fault in the cochlea (sensory) or the cochlear nerve (neural) - sound is transmitted normally to the inner ear but the problem is at the level of the cochlea and nerve
what are some causes of conductive deafness?
obstruction of the external ear canal: wax, inflammatory oedema, debris, atresia, foreign bodies
perforate of the tympanic membrane
discontinuity of the ossicular (infection or trauma)
fixation of the ossicular chain (otosclerosis)
what are some causes of sensorineural deafness?
Bilateral progressive loss: Presbyacusis, drug ototoxicity, noise damage.
Unilateral progressive loss:
Meniere’s disease (endolymphatic hydrops), acoustic neuroma.
Sudden loss: Trauma, viral
infections (mumps, measles, VZ), impaired vascular flow (CVA), acoustic neuroma, barotrauma and leakage of perilymph fluid from inner ear.
physiology of the ear??
Sound waves require a medium, such as air or water. The compression in a sound wave is channelled down the ear canal to the tympanic membrane. Vibrations of the tympanic membrane are then transmitted by the ossicular chain through the oval window into the cochlea. The vibrations of the cochlea cause a fluid wave, which stimulates hair cells within the cochlea, generating an electrical impulse, which is transmitted along the cochlear nerve to the brain, where it is heard/interpreted. Mechanical energy is thereby converted to electrical energy. Anything that interferes with the movement of sound from the external ear to the middle ear to the inner ear, and then to the brain, can cause a hearing loss. The external ear and middle ear may appear normal on examination if the cause is in the inner ear or brain. It is possible for hearing loss to be permanent if not treated in a timely fashion.
what investigations would you perform for hearing loss?
clinical examination - ear exam and neurological examination - cranial nerves and cerebellar
pure tone audiogram
tympanometry
what is presbycusis?
Presbycusis describes age-related sensorineural hearing loss. Patients may describe difficulty following conversations
Audiometry shows bilateral high-frequency hearing loss
what is otosclerosis?
how is it managed?
Autosomal dominant, replacement of normal bone by vascular spongy bone. Onset is usually at 20-40 years - features include:
conductive deafness
tinnitus
tympanic membrane - 10% of patients may have a ‘flamingo tinge’, caused by hyperaemia
positive family history
management: hearing aid, stapedectomy.
flouride may inhibit sclerotic progression
if severe a cochlear implant is another option
what is glue ear?
Also known as otitis media with effusion
peaks at 2 years of age
hearing loss is usually the presenting feature
secondary problems such as speech and language delay, behavioural or balance problems may also be seen
what are ototoxic drugs?
gentamicin furosemide aspirin co-trimoxazole metronidazole
how is a perforated tympanic membrane managed?
Tympanoplasty - Cartilage or temporalis fascia is used to repair a perforation in tympanic membrane. N.B. This surgery is normally done for recurrent ear infections or to waterproof theear; hearing improvement often occurs when a perforation is
closed but cannot be guaranteed.
what surgical procedure if performed in otosclerosis?
Stapedectomy - Prosthesis used to bypass fixed
stapes/footplate in otosclerosis and allow transmission of sound
into inner ear
what is a bone anchored hearing aid?
Bone anchored hearing aid – a transcutaneous or percutaneous
device can be surgically implanted under general or local
anaesthesia for a conductive, mixed conductive /sensorineural
hearing loss or unilateral dead ear
what are the different types of hearing aid?
bone anchored hearing aid
cochlear implantation
middle ear implant - suitable for conductive and mixed hearing loss
how is excessive ear wax managed?
topical ear drops (warm olive oil, sodium bicarb) - softens impacted earwax allowing it to migrate naturally out of the canal
Microsuction - evacuates softened wax and wax tightly adherent to the ear canal
Syringing - sometimes performed in primary care setting
what is tinnitus?
Tinnitus is a term used to describe the perception of sound when no
external sound is present.
what are the two types of tinnitus?
non-pulsatile tinnitus (referred to as a false perception of sound.It is often described as a buzzing, high pitched tone or a clicking or popping. It can be associated with noise induced hearing loss, prebycusis, Meiere’s disease, head injury, otitis media and drug related causes)
Pulsatile Tinnitus - defined by a heart sound heard by an individual that is synchronous with their heartbeat and is usually caused by turbulent blood flow that reaches the cochlear. It may be associated with a treatable cause
what are the causes of pulsatile tinnitus?
vascular causes (atherosclerosis on the internal carotid, vascular malformations, glomus tumours)
non-vascular causes (page’s disease, otosclerosis, myoclonus of the middle ear muscles or palatal muscles )
how would you investigate tinnitus?
if unilateral and associated with hearing loss, MRI should be performed exclude acoustic neuroma
pulsatile tinnitus may be investigated using MR or CT angiography. Caroitd duplex scanning may also be helpful if carotid artery stenosis is suspected
how is tinnitus managed?
often patient just needs reassurance that it is common and they will adapt to it.
address any underlying causes
a hearing aid may improve tinnitus if hearing loss is preset through a masking effect.
what is otalgia?
otalgia is ear pain that can originate from the ear itself or can also be referred from elsewhere in the head or neck
what are some causes otalgia?
acute otitis media otitis externalities Necrotising otitis externalities (malignant otitis externalities, skull base osteomyelitis) TMJ dysfunction referred pain
what can caused referred pain in the ear?
any pathology involving the cranial nerves V,VII, IX, and X and the upper cervical nerves C2 and C3 can cause the sensation of referred otalgia.
Trigeminal neuralgia is the most common cranial neuralgia linked to referred otalgia.
what is Otorrhoea?
discharge from the ear
the ear can discharge wax, pus, blood, mucus and even CSF.
Discharging wax should be reassured as normal.
what is otitis Externa?
infection of the external ear
typically affects the eternal auditory canal
the skin become erythematous, swollen, tender and warm leading to debris and discharge accumulation. The narrowing of the canal, in combination with the accumulation of the debris, leads to further entrapment of pathogens and propagating the infective process.
what is the most common causative pathogens in otitis externa?
Pseudomonas Aeruginosa (around 40%), S. Epidermidis, S. Aureus, and anaerobes
what are risk factors for otitis externa?
- frequent water contact
- humid environments
- presence of ear polyps or foreign bodies
- narrow ear canals
- ear eczema or psoriasis
- local trauma
what are the clinical features of otitis externa?
- progressive ear pain with purulent discharge
- itchiness and ear fullness may also be preset
less commonly
- hearing loss
- tinnitus
- swollen ear
on examination: the external ear canal will appear swollen and erythematous.
what types of ear discharge might suggest bacterial, fungal otitis externa infection or otitis media?
White-yellow – related to bacterial infection
Thick white grey with visible hyphae or spores – fungal infection
Clear grey – otitis media
what differential diagnosis would you want to consider for anyone presenting with ear discharge?
Otitis media with perforation – usually clear discharge or bloody followed by relief of pain, with an inflamed tympanic membrane with perforation.
Ramsay Hunt syndrome – may present with symptoms of otitis externa, yet has evidence of vesicular eruptions within 2 days of first onset of pain.
Furuncle – a painful ear canal due to localised abscess formation from infection of the hair follicle in the lateral third of ear canal. A visible bulge is present when examining with an otoscope.
Less common conditions include ear canal malignancy, branchial cyst, atopic dermatitis, and exostosis.
what investigations would you perform for otitis externa?
usually a clinical diagnosis based on a history and examination of the ear ring an otoscope.
if otitis externa is not resolving with antibiotics or there is signs of fungal disease on otoscope swabs of the discharge can be sent for culture.
complicated cases of otitis externa may warrant a high resolution CT (HRCT) scan to investigate the extent of the disease.
what risk scoring can be used to quantify the severity of otitis externa?
the Brighton grading system
Grade 1 - Localised canal inflammation with mild pain, no hearing loss and tympanic membrane visible
Grade 2- Debris in ear canal (not completely occluded) and erythematous ear canal, tympanic membrane may be partially obscured
Grade 3 - The ear canal is oedematous, erythematous, and occluded (often completely closed), and the tympanic membrane cannot be seen
Grade 4 - The tympanic membrane is obscured, perichondritis and pinna cellulitis, and signs of systemic involvement.
how do you manage otitis externa?
topical antibiotics combined with a steroid - ciprofloxacin/dexamethasone otic
simple analgesia
if there is canal debris then consider removal
micro suction
if infection is spreading consider oral antibiotics - flucloxacillin
if fungal give acetic acid/hydrocortisone otic
what is malignant otitis externa ?
it is an uncommon type of otitis externa that is found in immunocompromised individuals (90% of cases are found in diabetics)
where otitis externa extends into the mastiidand temporal bones
what is malignant otitis externa usually caused by?
pseudomonas aeruginosa
infection commences in the soft tissues of the external auditory meatus, then progresses to involve the soft tissues and into the bony ear canal
what are the key features in a history which suggest malignant otitis extra ?
Diabetes (90%) or immunosuppression (illness or treatment-related)
Severe, unrelenting, deep-seated otalgia
Temporal headaches
Purulent otorrhea
Possibly dysphagia, hoarseness, and/or facial nerve dysfunction
how is malignant otitis externa diagnosed ?
usually a CT scan is done