ENT Flashcards
two parts of the external ear
- auricle/pinna
2. external auditory canal
what causes cauliflower ear deformity?
Accumulation of blood between cartilage and overlying perichondrium can disrupt the blood supply to the cartilage. If untreated can result in avascular necrosis of the cartilage, resulting in a ‘cauliflower ear’ deformity
significance of external auditory canal being S-shaped
This means you will have to pull back the auricle when examining the canal to attempt to straighten this
what is the light reflex when using an otoscope and what is its significance?
Light shining from the otoscope on the tympanic membrane is known as the ‘light reflex’ - use this to tell which ear we are looking at:
A light reflex at 5 o’clock is a RIGHT SIDED EAR
A light reflex at 7 o’clock is a LEFT SIDED EAR
imp structures of tympanic membrane
The pars flaccida is the weakest part of the tympanic membrane and is flaccid
Pars tensa forms the rest of the membrane
the middle ear contains?…
1 nerve (facial nerve) 2 muscles (stapedius and tensor tympani, both useful to protect the ears from loud noise to avoid damage) 3 bones (the ossicles - malleus, incus and stapes. These attach in a chain from the tympanic membrane to the oval window)
what is the mastoid process and significance of being close to the middle ear?
The mastoid process is the area of the temporal bone located behind the ear and contains air cells that both protect the ear and can equalise ear pressure
These mastoid air cells sit posterior to the middle ear and are therefore vulnerable to infection from the middle ear
purpose of eustachian tube
When atmospheric pressures changes, pressure differences can develop between the outer and middle ear. The eustachian tube opens allowing pressure to equalise. this can happen when swallowing, performing the valsalva manoeuvre
contents of the vestibular system and importance
3 semicircular canals and utricle and saccule.The semicircular canals are in three different positions; horizontal, superior and posterior. Each contain endolymph and sensory hair cells
The vestibular system detects balance and positioning
what ducts make up the cochlea?
Vibrations received from the ossicles via the oval window continue via this system to be translated as sound by the brain
The cochlea is made up of three ducts; scala media, scala tympani and scala vestibuli. Vibrations work across the membranes between these ducts to transmit this into an electrical signal via the Organ of Corti
which part of the nasal cavity can the olfactory nerve be found?
The olfactory nerve sits at the superior aspect of the nasal cavity
what are the lateral walls of the nasal cavity covered by and what purpose does this serve?
The lateral walls of the nasal cavity are covered by a superior, middle and inferior turbinate or concha
These are projections that increase the surface area within the nasal cavity
This allows for improved humidification, temperature change and filtration of inspired air
what are the clinically important plexuses in the nose?
anterior and posterior,
Anterior is known as Little’s area or Kiesselbach’s plexus (arterial) and has a rich blood supply that is the frequent source of epistaxis (nose bleeds)
Posterior is Woodruff’s plexus (venous) and is the site of posterior nose bleeds
bleeding from little’s area
more common
occurs in children/young adults
usually due to mucosal dryness
less severe
bleeding from woodruff’s area
less common older population hypertension/atherosclerotic disease more severe use of aspirin and warfarin
what are the 2 triangles of the neck and what are they divided by
anterior and posterior traingle of the neck. divided by the sternocleidomastoid
boundaries of the anterior triangle of the neck
superior: mandible
medial: midline of the neck
lateral: sternocleidomastoid
key structures in the anterior triangle of the neck
Thyroid and parathyroid glands
Cranial Nerve IX, X and XII
Carotid artery and internal jugular
Salivary glands
boundaries of the posterior triangle of the neck
Anterior - Sternocleidomastoid
Inferior- Clavicle
Posterior- Trapezius
key structures in the psoterior triangle of the neck
Subclavian artery and vein
External jugular vein
Cranial Nerve XI
Brachial Plexus
cystic hygroma vs branchial cyst
Both are benign, malformations that result in a neck lump however branchial cysts are found in the anterior triangle and cystic hygromas in the posterior triangle
what is the most common site of salivary gland tumours?
parotid glands
what can be affected by any pathology of the parotid gland?
The motor branch of the facial nerve runs through this structure and is thus affected by any pathology to the parotid gland
which gland produces most of our saliva when not eating?
Submandibular gland
which salivary gland which produces the most mucous secretions
sublingual. However, this does mean that mucocoele formation is more likely at this gland and these are called ranula
where is the problem in conductive hearing loss?
external or middle ear
where is the problem in sensorineural loss?
inner ear or cranial nerve VIII.
Most commonly caused by age-related changes
explain rinne’s test
In a normal ear, air conduction should be greater than bone conduction. This is a POSITIVE Rinne test
Due to obstruction of the ear canal, bone conduction is better in conductive hearing loss. This is a NEGATIVE Rinne test
explain weber’s test
Weber test should be equal in both ears in a normal patient
Again, because bone conduction is greater than air in conductive hearing loss, the sound lateralises to the affected ear
In sensorineural hearing loss, the reverse happens; sound is louder in their normal, unaffected ear
signs and symptoms of acute otitis media
otalgia (ear pain), inflammation of the tympanic membrane and malaise
pathophys of AOM
Caused by upper respiratory tract infections migrating via the Eustachian tube into the middle ear
Much more common in children as their Eustachian tube is shorter and wider therefore allowing easier transmission
Can be viral or bacterial. Common viruses involved are RSV, rhinovirus, enterovirus. Most common bacteria is s. pneumoniae
management of AOM
Mostly self-resolves, support with analgesia such as paracetamol
If worsening or significantly unwell can treat with amoxicillin
Children with recurrent acute otitis media infections are considered for grommets
complications of AOM
Tympanic membrane can perforate due to build up of pus
Recurrent infections can cause hearing loss
Severe complications include mastoiditis, facial nerve palsy and intracranial infection
presenting complaint of perforated tympanic membrane as a complication of AOM
Patients may complain of otorrhoea (discharge from the ear) and a sudden relief of pain
what is OME (otitis media with effusion) and what is the key presenting complaint?
A collection of NON-INFECTIVE fluid in the middle ear
Key presenting symptom will be hearing loss, in very young children this can manifest as delayed speech development
Sometimes known as glue ear and seen almost exclusively in children
Otoscopy - Classical findings are of a dull tympanic membrane with a light reflex reflected upwards or an absent light reflex
pathophys of OME
Most common cause is Eustachian tube dysfunction. In childhood, the wider and short eustachian tube is more prone to infection AND also poorer ventilation
Other exacerbating factos include other congenital structural malformations such as cleft palate and allergies
In adults, always consider malignancy causing obstruction of the Eustachian tube
management of OME
50% resolve in 3 months
Unresolved cases will be considered for hearing aids or grommet insertion
No indication for antibiotics. Remember this is non-infective
chronic otitis media signs and symptoms
Recurrent otitis media infections can cause tympanic membrane perforations
Symptoms are hearing loss and ongoing otorrhoea usually for > 6 weeks
There are usually no infective signs such as fever or otalgia
pathophys of chronic OM
Recurrent acute otitis media infections causing perforation of the tympanic membrane
Can also occur due to trauma to the ear resulting in perforation
Iatrogenic from grommet insertion
management of chronic OM
- Aural toilet - washing out the ear canal
- Topical antibiotics/steroids - allow the perforation to heal
- If the perforation is not healing/is too large to heal, can surgically repair it. This is called myringoplasty and involves taking cartilage from the tragus and using that to fill the space.
complications of chronic OM
Recurrent infections can cause hearing loss
Severe complications include mastoiditis, facial nerve palsy and intracranial infection
what is a cholestatoma?
A destructive, hyperproliferating growth of keratinazing squamous epithelial cells of the middle ear
Keratinazed squamous epithelium is essentially skin that has collected within the middle ear. This squamous epithelium is expansile and can erode into surrounding structures.
signs and symptoms of cholesteatoma?
Symptoms will vary depending on invasion of the cholesteatoma:
Otorrhoea (most common) - chronic in nature, classically brown in colour without otalgia or fever which differentiates this from infection
Conductive hearing loss - occurs if invasion damages the ossicles
Senosorineural hearing loss - invasion of the cochlea
Dizziness - damage to the semicircular canals
Facial nerve palsy - invasion of cranial nerve VII
Exam questions classicaly describe a ‘pearly white/grey appearance’ on otoscopy with painless, brown discharge.
pathophys of cholestatoma
This collection forms due to the presence of a ‘retraction pocket’; a space that forms behind the tympanic membrane that is prone to trapping squamous epithelial cells.
Risk factors for developing this retraction pocket are: recurrent acute otitis media, Eustachian tube dysfunction and previous ear surgery
management of cholestatoma
A CT scan of the temporal bone is required to confirm diagnosis and for pre-operative planning
The definitive treatment is complete surgical removal. All of it must be removed otherwise it will recur
complications of cholestatoma
Dependent on the site of invasion
Severe cases can result in intracranial invasion leading to infection
otitis externa signs and symptoms
Presenting symptoms are otalgia, otorrhoea with a swollen, erythematous ear
Patients are often very tender at the pinna on movement
May also complain of itching of the ear
risk factors for otitis externa
A very common condition sometimes called 'swimmer's ear'. Risk factors include: Increased water contact Humid conditions Excessive use of cotton buds Presence of hearing aids Immunocompromised patients eg. diabetics
pathophys of otitis externa
Disruption of the external ear canal’s protective mechanisms (through water, trauma etc) trap bacteria that results in infection of the external auditory canal
The most common bacteria is pseudomonas aeruginosa
management of otitis externa
Topical antibiotics and steroids
This may need to be inserted via a Pope Wick to ensure topical anibiotics are delivered effectively
Consider aural toilet and microsuction
complications of otitis externa
Necrotising otitis externa is a result of spreading infection into the mastoid and temporal bones which can cause cranial nerve palsies. If left untreated, can result in death
Treatment for this requires a prolonged course of iv antibiotics
what is dizzines/vertigo?
True vertigo is the inappropriate sensation of movement of the surroundings - “Like the room is spinning”
name 3 common otological causes and 3 central causes of vertigo
otological - BPPV, Meniere’s disease, vestibular neuronitis
central - stroke, MS, migraine