Module 3D ENT - Conditions Flashcards
Acute epiglottitis (aka. supraglottitis) - Aetiology + what group is at risk?
Usually a bacterial infection (Strep. pneumonia, group A streptococci, and Staph. aureus)
- Epiglottitis is now rare due to the HiB vaccine - be suspicious in unvaccinated children
Acute epiglottitis - Clinical features
- Sore throat, stridor, and drooling
- Muffled voice (‘hot potato’ voice) - characteristic change
- Respiratory distress - tachypnoea +/- use of accessory muscles
- Tripod position
- High-grade fever (if bacterial)
Acute epiglottitis - Investigations
Diagnosis is clinical and investigations should only be done once pt is stable:
- Lateral X-ray of neck: ‘thumb sign’
- Blood cultures and throat swabs: causative pathogen (guides antibx therapy)
Acute epiglottitis - Management
- Keep pt calm and do not examine the throat due to risk of acute airway closure
- Call for senior pediatrician + anaesthesist + ENT surgeon
- Steroids (dexamethasone) +/- oxygen
- Monitor in ICU and intubation/tracheostomy (if need) +/- adrenaline
(5. If bacterial –> IV antibiotics - empiric broad-spectrum (eg. ceftriaxone) –> adjust based on culture + local guidelines)
(6. Vaccination - HiB vaccine to prevent paediatric cases of acute epiglottitis)
What is a common complication of epiglottitis?
Epiglottic abscess - collection of pus around the epiglottis
Tonsillitis - aetiology
- Viral (more common) - adenoviruses
OR - Bacterial - Strep. pyogenes
In the pharynx, at the back of the throat, there is a ring of lymphoid tissue. There are six areas of lymphoid tissue in Waldeyer’s ring, comprising of the adenoids, tubal tonsils, palatine tonsils and the lingual tonsil.
Which tonsils are typically infected and enlarged in tonsillitis?
Palatine tonsils (on either side at back of throat)
Tonsillitis - Clinical features
Symptoms:
- Sore throat
- Fever (above 38ºC)
- Pain on swallowing
.
Signs:
- Red, inflamed tonsils
- +/- Exudates - small white patches of pus
- +/- Tender and enlarged anterior cervical lymph nodes (anterior triangle)
Tonsillitis - what are the 2 criterias used to assess whether the tonsilitis is bacterial and therefore antibiotics should be given
CENTOR criteria (≥ 3):
- Fever over 38ºC
- Tonsillar exudates
- Absence of cough
- Tender anterior cervical lymph nodes (lymphadenopathy)
.
FeverPAIN score (≥ 4):
- Fever during previous 24hrs
- P - Purulence (pus on tonsils)
- A - Attended withing 3 days of onset of symptoms
- I - Inflamed tonsils (severely inflamed)
- N - No cough or coryza
Tonsillitis - Management
- Reassure/safety net - return if fever > 38.3ºC or symptoms persist more than 3 days
- Paracetamol or ibuprofen - to control pain and fever
- Use CENTOR or FeverPAIN (bacterial?) - antibiotics
- (Penicillin V, 10-day course OR erythromycin if penicillin allergy)
- (Delayed prescription - educate pt that it is likely viral, but if symptoms worsen or do not improve in 2-3 days then can pick up antibiotics)
Tonsillitis - complcaitions
- Peritonsillar abscess (quinsy)
- Otitis media (if infection spreads to the inner ear)
- Scarlet fever
- Rheumatic fever (rare)
- Post-streptococcal glomerulonephritis (very rare)
- Streptococcal toxic shock syndrome (very rare, but life-threatening)
What is chronic rhinosinusitis (CRS)?
- include time and the 2 types of CRS
- a persistent inflammatory condition affecting the paranasal sinuses and nasal passages
- lasting longer than 12 weeks
1. CRS with nasal polyps
2. CRS without nasal polyps
Chronic rhinosinusitis - aetiology/risk factors
- Atopy: hay fever, asthma
- Nasal obstruction: eg. septal deviation or nasal polyps
- Recent local infection: eg. rhinitis or dental extraction
- Swimming/diving
- Smoking
Chronic rhinosinusitis - Clinical features
Symptoms lasting for longer than 12 weeks…
- Cardinal symptoms: Nasal obstruction + facial pain or pressure + purulent nasal discharge
- Other symptoms: fatigue, headache, dental pain, cough, hearing changes
Chronic rhinosinusitis - 2 main investigations
- Nasal Endoscopy - to assess nasal cavity and sinuses (polyps, mucopurulent discharge, oedema/inflammation)
- CT scan of paranasal sinuses
Chronic rhinosinusitis - Management
Medical:
1. Nasal saline irrigation (clears nasal secretions and improves mucociliary function)
2. Intranasal steroids
3. Oral corticosteroids (for severe cases)
(4. Antibiotics - if evidence of bacterial infection - Staph. A)
Surgical:
5. Functional endoscopic sinus surgery (FESS)
Chronic rhinosinusitis - complications
- Mucosal polyp formation - build up of nasal and sinus mucosa can lead to polyp formation (further exacerbates symptoms)
- Orbital cellulitis or abscess - due to close proximity
- Intracranial complications (rare) - eg. meningitis, brain abscess
Rhinitis VS Rhinosinusitis - locations affected
- Rhintitis - nasal mucosa
- Rhinosinusitis - nasal mucosa + paranasal sinuses
Allergic rhinitis - what type of reaction is it?
IgE-mediated type 1 hypersensitivity reaction
Allergic rhinitis - main triggers
- Tree pollen or grass allergy - seasonal symptoms (hay fever)
- House dust mites and pets
- Other allergens
Allergic rhinitis - Classification (3 types)
- Seasonal - eg. hay fever
- Perennial (year-round) - eg. house dust mite allergy
- Occupational - associated with school/work environment
Allergic rhinitis - Clinical features + investigation
- Runny (rhinorrhoea), blocked, and itchy (pruritus) nose
- Sneezing
- Itchy, red, and swollen eyes (allergic conjunctivitis)
- associated with a personal or family hx of atopy
- skin prick testing can be useful
Allergic rhinitis VS Non-allergic rhinitis vs Infective sinusitis
- Non-allergic rhinitis - similar presentation, but lacks the IgE response + doesn’t respond well to antihistamines + no ocular symptoms
- Infective sinusitis - has additional symptoms such as facial pain/pressure + fever + purulent nasal discharge (nasal swab to test)
Allergic rhinitis - Management
- Allergen avoidance
- Oral/Intranasal antihistamines
- Non-sedating - cetirizine, loratadine, and fexofenadine
- Sedating - chlorphenamine and promethazine - Nasal corticosteroid sprays - eg. fluticasone and mometasone
Head and neck cancer - locations affected
- Nasal cavity
- Paranasal sinuses
- Mouth
- Salivary glands
- Pharynx (throat)
- Larynx (epiglottis, supraglottis, vocal cords, glottis and subglottis)
. - head and neck cancers usually spread to the lymph nodes first
Head and neck cancers - what cell type is usually affected?
Squamous cell carcinomas - arising from the squamous cells of the mucosa
Head and neck cancer - Risk factors
- Smoking
- Alcohol
- chewing betel quid (a hbit in south-east Asia)
- HPV-16 (strain 16)
- EBV
Head and neck cancers - red flags
- Lump in mouth or on lip
- Unexplained ulceration in the mouth lasting more than 3 weeks
- Erythroplakia or erythroleukoplakia (premalignant conditions)
- Persistent neck lump
- Unexplained hoarseness of voice
- Unexplained thyroid lump
Referral criteria for laryngeal cancer (2-week wait)
- Persistent unexplained hoarseness
- OR an unexplained lump in the neck
Head and neck cancer - Staging + Management
Staging (TNM) or stages 1-4:
- Tumour (size of tumour): 1 = small, 4 = large
- Node involvement (has cancer spread to lymph nodes): 0 = no lymph nodes containing cancer cells, 3 = lots of lymph nodes containing cancer cells
- Metastases (whether cancer has spread to another part of the body): M0 = cancer hasn’t spread, M1 = cancer has spread
.
Management:
1. Chemotherapy +/- Radiotherapy
2. Surgery
3. Targeted cancer drugs (ie. monoclonal antibodies - eg. Cetuximab for SCCs)
4. Palliative care
How do laryngeal tumours typically present?
- Glottic tumours
- Supraglottic tumours
- Subglottic tumours
- General symptoms
- Glottic tumours (most common):
- Hoarseness +/- dysphonia +/- stridor (advanced disease) - Supraglottic tumours:
- Dysphagia/Odynophagia +/- referred otalgia (ear pain) +/- neck mass - Subglottic tumours:
- Dyspnoea/airway obstruction +/- stridor (advanced disease)
- General symptoms: persistent sore throat, weight loss
What is leukoplakia?
Precacnerous condition (increases risk of SCC of the mouth)
- characterised by white patches in the mouth, often on the tongue or insides of the cheeks (buccal mucosa) - won’t come off with scraping
Leukoplakia - management
- Biopsy - to exclude SCC
- Conservative: smoking cessation + reducing alcohol intake
- Close monitoring +/- laser removal or surgical excision
What is erythroplakia and what is erythroleukoplakia?
- Erythroplakia = similar to leukoplakia, except the lsions are red
- Erythroleukoplakia = refers to lesions that are a mixture of red and white
(both precancerous lesions - high risk of progression to SCC)
What is Lichen planus + appearance?
Lichen planus = an autoimmune condition that causes localised chronic inflammation of the skin, hair, nails, and mucous membranes
- Appearance: shiny, purplish, flat-topped raised areas, with white lines across the surface called Wickham’s striae
(often it only affects the mouth and can be reticular, erosive, or plaque)
Lichen planus - management
- Good oral hygeine
- Stopping smoking
- Topical steroids
What is gingivitis?
Gingivitis refers to inflammation of the gums
- can present with swollen gums, bleeding after brushing, painful gums, and bad breath (halitosis)
- can lead to periodontitis (severe and chronic inflammation of the gums and tissues that support the teeth - leads to loss of teeth)
Gingival hyerplasia
- abnormal growth of the gums
Aphthous ulcers - what are they + management
- Very common, small, painful ulcers of the mucosa in the mouth
- have a well-circumscribed, punched-out, white appearance
- Management (usually heal within 2 weeks on their own)
1.Choline salicylate (eg. Bonjela) OR Benzydamine (eg. Difflam spray)
2. Topical corticosteroids (for severe ulcers)
3. If last more than 3 weeks –> 2 week wait referral
What is glossitis?
- Inflamed tongue - red, sore, and swollen
- Papillae of tongue atrophy, giving the tongue a smooth appearance (“beefy”)
Glossitis - causes
- Iron-deficiency anaemia
- B12 deficiency
- Folate deficiency
- Coeliac disease
- Injury or irritant exposure
Angioedema - what is it + top 3 causes
Angioedema = refers to fluid accumulating in the tissues, resulting in swelling (can affect the tongue)
.
- Allergic reactions
- ACE inhibitors
- C1 esterase inhibitor deficiency (hereditary angioedema)
Oral candidasis (oral thrush) - what is it + causes + management
Refers to an overgrowth of candida (type of fungus) in the mouth
- results in white spots/patches that coat the surface of the tongue and palate
.
Causes:
- Inhaled corticosteroids (not rinsing mouth afterwards)
- Antibiotics
- Diabetes
- Smoking
.
Management:
1. Miconazole gel
2. Nystatin suspension
Strawberry tongue - 2 key causes
- Scarlet fever
- Kawasaki disease
Black, hairy tongue
Results from decresed shedding (exfoliation) of keratin from the tongue’s surface
- due to dehydration, dry mouth, poor oral hygiene, and smoking
What are the key features of laryngitis?
- Definition
- Causes
- Symptoms
- Management
- Definition: Inflammation of the larynx, often affecting the vocal cords
- Causes:
- Acute: Viral infections (most common), bacterial infections, voice strain
- Chronic: Smoking, GORD, chronic irritants (e.g., dust, chemicals) - Symptoms:
- Hoarseness or loss of voice.
- Sore throat or discomfort.
- Cough and dysphonia. - Management: Rest voice, treat underlying cause (e.g., infections, reflux)
What are reactive nodules (vocal cord polyps) and their features?
- Definition
- Causes
- Symptoms
- Management
- Definition: Benign growths on the vocal cords due to chronic voice overuse or irritation.
- Causes:
- Vocal strain (e.g., singers).
- Smoking or chronic irritation. - Symptoms:
- Hoarseness or rough voice.
- Loss of vocal range.
- No associated pain. - Management:
- Vocal rest, speech therapy.
- Surgery if persistent or large.
What are the key features of laryngeal papilloma?
- Definition
- Symptoms
- Age groups
- Management
- Definition: Benign tumours caused by human papillomavirus (HPV), commonly types 6 and 11.
- Symptoms:
- Hoarseness (most common).
- Stridor or airway obstruction (if severe).
- Dysphonia. - Age Groups:
- Juvenile onset: Transmitted during childbirth.
- Adult onset: Often linked to HPV exposure. - Management:
- Surgery (e.g., laser excision).
- Recurrence common, requiring multiple interventions.
Laryngeal dysplasia
- Definition
- Causes
- Symptoms
- Management
- Definition: Pre-malignant changes in the laryngeal epithelium.
- Causes:
- Smoking (major risk factor).
- Alcohol use. - Symptoms:
- Hoarseness or voice changes.
- No pain or systemic symptoms. - Diagnosis:
- Visualisation via laryngoscopy.
- Biopsy for histopathology (to confirm dysplasia grade) - Management:
- Smoking cessation, regular monitoring.
- Surgery or laser excision for severe dysplasia.
What are the clinical features and management of squamous cell carcinoma (SCC) of the larynx?
- Definition
- Risk factors
- Symptoms
- Diagnosis
- Management
- Definition: Malignant tumour arising from the squamous epithelium of the larynx.
- Risk Factors:
- Smoking (strongest risk factor).
- Alcohol, HPV, chronic laryngitis. - Symptoms:
- Glottic SCC: Hoarseness (early symptom).
- Supraglottic SCC: Dysphagia, neck mass, odynophagia.
- Subglottic SCC: Dyspnoea, stridor (often advanced).
- Weight loss in late stages. - Diagnosis:
- Laryngoscopy with biopsy.
- Imaging (CT/MRI) for staging. - Management:
- Early-stage: Surgery or radiotherapy.
- Advanced-stage: Combined chemoradiotherapy or total laryngectomy.
Anterior cervical triangle - borders
- Mandible forms the superior border
- Midline of the neck forms the medial border
- Sternocleidomastoid forms the lateral border
Posterior cervical triangle - borders
- Clavicle forms the inferior border
- Trapezius forms the posterior border
- Sternocleidomastoid forms the lateral border
Neck lump/swellling differentials
- Reactive lymphadenopathy (most common) - hx of infection/virus
- Lymphoma - rubbery, painless lymphadenopathy
- Thyroid swelling (goitre) - moves upwards on swelling
- Thyroglossal cyst
- Cystic hygroma (congenital lymphatic lesion - lymphangioma) - usually presents < 2yrs of age
- Branchial cyst - oval, mobile cystic mass between sternocleidomastoid and pharynx (presents during childhood)
- Carotid aneurysm - pulsatile lateral neck mass which doesn’t move on swallowing
- Carotid body tumour
- Salivary gland stones or infection
- lipoma
Neck lump red-flag referral criteria
2-week wait referral if:
- unexplained neck lump in > 45yrs
- persistent unexplained neck lump at any age
- USS if growing in size
What causes infectious mononucleosis?
Epstein Barr virus (EBV)
Infectious mononucleosis - investigations
- Monospot test - heterophile antibody test
- IgM (acute infection) and IgG (immunity) to EBV
Salivary glands - 3 locations + 3 reasons for enalrgement
- Stones blocking the drainage of the glands through the ducts (sialolithiasis)
- Infection
- Tumours (benign or malignant)
Which salivary glands are usually affected in salivary gland stones + symptoms of salivary gland stones?
Submandibular glands
.
Symptoms:
- pain and swelling (usually triggered when salivary flow is stimulated - eg. eating or chewing)
- can be asymptomatic
- can present with a hard, palpable lump within the salivary duct or orifice
Salivary gland stones - management
- Advise pt to remain well hydrated
- Stop medications (if able to) that impair saliva flow - eg. amitriptyline
- Encourage saliva flow - suck on citrus fruits/sweets
- NSAIDs - to relieve pain
Epistaxis (nosebleeds) - where does the bleeding usually originate from (anterior) and what about posterior nosebleeds?
Kiesselbach’s plexus, located in Little’s area
- this is an area of the nasal mucosa at the front of the nasal cavity that contains a lot of blood vessels
.
Posterior epistaxis - arises from branches of sphenopalatine artery (tends to be more severe)
Epistaxis - Triggers
Anterior nosebleeds are usually unilateral:
- nose picking
- colds
- sinusitis
- vigorous nose-bloing
- trauma
- changes in weather
- coagulation disorders (eg. Von Willebrand’s, thrombocytopenia)
- Anticoagulation (eg. aspirin, DOACS, or warfarin)
- snorting cocaine
- tumours (eg. SCC)
How does a posterior nosebleed (epistaxis) present?
- blood can go down throat - causes coughing/vomiting due to swallowed blood
- bilateral bleeding
Epistaxis (nose bleeds) - Management
- First aid measures: sit up and tilt head forwards (to reduce blood in pharynx and prevent aspiration) + squeeze the soft part of the nostrils together for 10-15 mins
- Topical vasoconstrictor (eg. phenylephrine or oxymetazoline)
(Tranexamic acid - can soak gauze and apply to bleeding site)
- Nasal packing - using nasal tampons or inflatable packs
- Nasasl cautery - silver nitrate sticks
(5. Naseptin nasal cream (chlorhexidine and neomycin) QDS for 10 days to reduce any crusting/inflammation/infection)
Who should you not give Naseptin nasal cream to?
contradicted in peanut or soya allergy
What conditions are nasal polyps associated with?`
- chronic sinusitis/rhinitis
- asthma
- Samter’s triad (nasal polyps, asthma, and aspiring intolerance/allergy)
- Cystic fibrosis
- Eosinophilic granulomatosis with polyangiitis
Nasal polyps - Presentation
Nasal polyps may be found on examination in pts presenting with:
- chronic rhinosinusitis
- difficulty breathing through nose
- snoring
- nasal discharge
- loss of sense of smell (ansomia)
.
Examination:
- Use a nasal speculum (holds nostrils open) - unilateral polyps are a RED FLAG (tumours)
- Nasal endoscopy - to visualise nasal cavity in detail
Nasal polyps - Management
- Medical management:
- intranasal tpoical steroid drops (to reduce inflammation)
- intranasal saline irrigations (can provide symptomatic relief) - Surgical intervention:
- Intranasal polypectomy - used when polyps are visible close to the nostrils
- Endoscopic nasal polypectomy - used where the polyps are further in nose/sinuses
(NOTE: Unilateral polyps - refer to exclude malignancy)
What is a peritonsillar abscess (quinsy)?
a serious complication of tonsilitis or can arise on its own
- a collection of pus in the tissue surrounding the tonsils, usually caused by a bacterial infection
Peritonsillar abscess (quinsy) - Presentation
Pts present similarly to tonsillitis:
- sore throat
- painful swallowing
- fever
- neck pain
- referred ear pain
- swollen tender lymph nodes
.
Additional symptoms that indicate a peritonsillar abscess include:
- Trismus (unable to open mouth)
- Change in voice - due to pharyngeal swelling (“hot potato” voice)
- Swelling and erythema - in area beside tonsils
- deviation of uvula to unaffected side
Pleomorphic adenoma (parotid gland) - Clinical features
- Swelling, erythema, and tenderness within the parotid gland
- free-moving structure - not tethered
- NO facial nerve involvement (this would suggest a malignant cause as the tumour invades local structures)
What is a thyroglossal cyst - pathophysiology
- During fetal development, the thyroid gland starts at the base of the tongue
- From here it gradually travels down the neck to its final position in front of the trachea, beneath the larynx
- It leaves a track behind called the thyroglossal duct, which then disappears
- When part of the thyroglossal duct persists it can give rise to a fluid-filled cyst –> this is called a thyroglossal cyst
Branchial cyst - presentation
- round, soft, cystic swelling usually anterior to the sternocleidomastoid muscle (in anterior triangle of the neck)
- non-tender, but can become infected or inflamed
What is otitis media?
- Infection in the middle ear (space that sits between the tympanic membrane (eardrum) and the inner ear)
- Bacteria enter from the back of the throat through the eustachian tube
What is otitis media with effusion (glue ear) + main presenting symptom
Where the middle ear becomes full of fluid
- causing a loss of hearing in that ear
What is otitis externa (aka. ‘swimmer’s ear’)?
an inflammatory condition affecting the external auditory canal and pinna
- acute (< 3 weeks) or chronic (> 3 weeks)
How does the vestibular system (vestibular apparatus) let the brain know that the head is turning in a particular direction
- Vestibular apparatus is located in the inner ear, consists of 3 loops called the semicircular canals that are filled with endolymph
- These semiciruclar canals are orientated in different direction to detect various movements of the head - as the head turns, the fluid shifts inside the canala
- Stereocilia (tiny hairs) in the ampulla detect the fluid shift and transmit to the brain by the vestibular nerve, which then lets the brain know that the head is moving in a particular direction
Vertigo - Central VS Peripheral CAUSE
When a pt presents with ‘dizziness’, it is important to first distinguish between vertigo and lightheadedness - ask whether the “room is moving” (vertigo)
HINTS examination - explain the head impulse, nystagmus, and test of skew components
Head impulse:
- pt sitting upright and fixing their gaze on the examiner’s nose 9ensure they have no neck pain before performing)
- examiner holds pts head and rapidly jerks it 20 degrees in one direction while the pt continues looking at the examiner’s nose
- head is moved slowly back to the centre before repeating in the opposite direction
.
Nystagmus:
- unilateral –> peripheral cause
- bilateral or vertical –> central cause
.
Test of skew (alternate cover test):
- examiner covers one eye at a time, alternating between covering either eye
- the eyes should remain fixed on the examiner’s nose with no deviation
- if there is a vertical correction when an eye is covered (eye has drifted up or down) and needs to move vertically to fix on the nose when uncovered, this indicates a central cause of vertigo
BPPV - Dix-Hallpike manouevre
Used to diagnose BPPV - it involves moving the patient’s head in a way that moves endolymph through the semicircular canals and triggers vertigo in patients with BPPV:
- (ensure pt has no neck pain)
1. Pt sits upright on a flat examination couch with their head turned 45 degrees to one side (turned to the right to test the right ear and left to test the left ear)
2. Support the patient’s head to stay in the 45 degree position while rapidly lowering the patient backwards until their head is hanging off the end of the couch, extended 20-30 degrees
3. Hold the patient’s head still, turned 45 degrees to one side and extended 20-30 degrees below the level of the couch
4. Watch the eyes closely for 30-60 seconds, looking for nystagmus
Repeat the test with the head turned 45 degrees in the other direction
.
+ve test: triggers rotational nystagmus and symptoms of vertigo
- the eye will have rotational beats of nystagmus towards the affected ear (clockwise with left ear and anti-clockwise for right ear BPPV)
What forms the inner ear + vestibular system + which nerves form the vestibulocochlear nerve?
Inner ear (contains the bony labyrinth - bony structure containing perilymph and endolymph):
- semicircular canals
- vestibule (middle section)
- cochlear - responsible for hearing
.
Vestibular system:
- Semicircular canals - detect rotation of the head
- Otolith organs - detect gravity and linear acceleration
.
Vestibulocochlear nerve (CN VIII):
- Vestibular nerve - transmits signals from the vestibular system to the brain to help with balance
- Cochlear nerve - transmits signals from the cochlear to provide hearing
What is an acoustic neuroma (vestibular schwannoma)?
- Benign tumours of the Schwann cells surrounding the auditory nerve (vestibulocochlear nerve) that innervates the inner ear
- also called vestibular schwannomas
- Schwann cells are found in the peripheral NS and provide the myelin sheath around neurones
Note: Acoustic neuromas (vestibular schwannomas) are a subtype of a broader category which are cerebellopontine angle (CPA) tumours. Acoustic neuromas make up around 85% of CPA tumours
CPA tumours include meningiomas and other types of tumours
Acoustic neuromas (vestibular schwannomas) are usually unilateral, what are bilateral acoustic neuromas heavily associated with?
Neurofibromatosis type II
Acoustic neuroma (vestibular schwannoma) - Investigations
- Audiometry - to asses hearing loss (sensorineural pattern)
- MRI brain - to establish diagnosis and features of tumour
MRI brain images of acoustic neuromas (vestibular schwannomas)
- Left: vestibular schwannoma at the right cerebellopontine angle
- Right: MRI showing a vestibular schwannoma
Acoustic neuroma (vestibular schwannoma) - Management
- Observation: monitoring
- Surgery: to remove the tumour (partial or total removal)
- Radiotherapy: to reduce the growth
(risks of surgery: vestibulocochlear nerve injury (with hearing loss or dizziness) +/- facial nerve injury (with facial weakness))
Describe the basic structures of the ear (from outside in)
- Pinna - the external portion of the ear
- External auditory canal - the tube into the ear
- Tympanic membrane - the eardrum
- Eustachian tube - connects the middle ear with the throat to equalise pressure
- Malleus, incus and stapes (ossicles) - the small bones in the middle ear that connect the tympanic membrane to the structures of the inner ear
- Semicircular canals - responsible for sensing head movement (the vestibular system)
- Cochlea - responsible for converting the sound vibration into a nervous signal
- Vestibulocochlear nerve - transmits nerve signals from the semicircular canals and cochlea to the brain
Describe how to perform Rinne’s test
- Strike the tuning fork to make it vibrate and hum
- Place the flat end on the mastoid process (boney lump behind ear) - this tests bone conduction
- Ask the pt to tell you when they can no longer hear the humming noise
- When they can no longer hear the noise, remove the tuning fork (still vibrating) and hover it 1cm from the same ear
- Ask the patient if they can hear the sound now – this tests air conduction
(6. Repeat the process on the other side)
.
- Normal result (Rinne’s +ve): pt can hear sound again next to ear (it is normal for air conduction to be better than bone conduction)
- Abnormal result (Rinne’s -ve): sound not heard next to ear - indicates that bone conduction > air conduction, this suggests a conductive cause for the hearing loss
(When the tuning fork is placed on the mastoid process, sound is transmitted through the bones of the skull directly to the cochlear, meaning bone conduction is intact)
Describe how to perform Weber’s test
- Strike the tuning fork to make it vibrate and hum (use the palm of your hand or your knee – not the patient!)
- Place it in the centre of the patient’s forehead
- Ask the patient if they can hear the sound and which ear it is loudest in
.
- Normal result: pt hears sound equally in both ears
- Sensorineural hearing loss: sound will be louder in the normal ear (quieter in the affected ear) - the normal ear is better at sensing the sound
- Conductive hearing loss: sound will be louder in the affected ear - due to affected ear “turning up the volume” and becomes more sensitive (as sound has not been reaching that side as well due to the conduction problem (When the tuning fork’s vibration is transmitted directly to the cochlea, rather than having to be conducted, the increased sensitivity makes it sound louder in the affected ear)
Normal audiogram + details
Normal readings will be between 0 and 20 dB, at the top of the chart
.
Symbols used on audiograms:
- X – Left-sided air conduction
- ] – Left-sided bone conduction
- O – Right-sided air conduction
- [ – Right-sided bone conduction
.
(each ear is tested separately and air and bone conduction are tested separately too)
Sensorineural hearing loss audiogram
- both air and bone conduction readings will be more than 20 dB, plotted below the 20 dB line on the chart
- this may affect only one side, one side more than the other or both sides equally
Conductive hearing loss audiogram
- bone conduction readings will be normal (between 0 and 20 dB)
- However, air conduction readings will be greater than 20 dB, plotted below the 20 dB line on the chart
Mixed hearing loss audiogram
- Both air and bone conduction readings will be more than 20 dB
- However, there will be a difference of more than 15 dB between the two (bone conduction > air conduction)
(due to BC adding an additional barrier for sound transmitted through the air, increasing the AC thresholds relative to BC)
What is eustachian tube dysfunction?
-The Eustachian tube is present mainly to equalise the air pressure in the middle ear and drain fluid from the middle ear.
- When the Eustachian tube is not functioning correctly or becomes blocked, the air pressure cannot equalise properly and fluid cannot drain freely from the middle ear
- The air pressure between the middle ear and the environment can become unequal - the middle ear can fill with fluid.
. - Eustachian tube dysfunction may be related to a viral upper respiratory tract infection (URTI), allergies (e.g., hayfever) or smoking
What is tympanometry?
- Inserting a device into the external auditory canal (ear canal)
- Creating different air pressures in the canal
- Sending a sound in the direction of the tympanic membrane
- Measuring the amount of sound reflected back off the tympanic membrane
- Plotting a tympanogram (graph) of the sound absorbed (admittance) at different air pressures
.
- The amount of sound absorbed by the tympanic membrane and middle ear (not reflected back to the device) is known as the admittance
- Normally, sound is absorbed best when the air pressure in the ear canal matches the ambient air pressure
- The ambient air pressure is equal to the middle ear pressure in healthy ears.
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- When there is Eustachian tube dysfunction, the air pressure in the middle ear may be lower than the ambient air pressure because new air cannot get in through the tympanic membrane to equalise the pressures
- As a result, the tympanogram will show a peak admittance (most sound absorbed) with negative ear canal pressures
What is a cholesteatoma?
a non-cancerous skin growth (squamous epithelial cells) that develops in the middle ear
- usually caused by Eustachian tube dysfunction
Mastoiditis - complication + management
- Mastoiditis is usually as a result of a middle ear infection - can progress into an intracranial infection
- Management: IV antibx +/- surgery
