ENT - Ear Flashcards
Describe what happens during Weber’s test
1. Tap a 512Hz tuning fork and place in the midline of the forehead.
2. Ask the patient “Where do you hear the sound?
What is a normal result of Weber’s test?
Sound is heard equally in both ears.
What is the result of Weber’s test in conduction deafness?
Sound is heard louder on the side of the affected ear.
What is the result of Weber’s test in sensorineural (nerve) deafness?
Sound is heard louder on side of intact ear
Describe the steps of Rinne’s test
1. Place a vibrating 512 Hz tuning fork firmly on the mastoid process (apply pressure to the opposite side of the head to make sure the contact is firm). This tests bone conduction.
2. Confirm the patient can hear the sound of the tuning fork and then ask them to tell you when they can no longer hear it.
3. When the patient can no longer hear the sound, move the tuning fork in front of the external auditory meatus to test air conduction.
4. Ask the patient if they can now hear the sound again. If they can hear the sound, it suggests air conduction is better than bone conduction, which is what would be expected in a healthy individual (this is often confusingly referred to as a “Rinne’s positive” result).
What would a Rinne’s negative result indicate?
Conductive deafness → Bone conduction > air conduction (Rinne’s negative)
What would a Rinne’s positive result indicate?
- Normal result: air conduction > bone conduction (Rinne’s positive)
- Sensorineural deafness: air conduction > bone conduction (Rinne’s positive) – due to both air and bone conduction being reduced equally
What is conductive hearing loss?
Caused by the obstruction of sound waves at any point in the outer ear and the foot plate of the stapes in the middle ear.
What is the most common cause of conductive hearing loss?
Fluid accumulation is the most common cause of conductive hearing loss in the middle ear, especially in children e.g. ear infections
Give some causes of conductive hearing loss
- Wax impaction
- Otitis media with effusion (glue ear)
- Eustachian tube dysfunction
- Ear infections
- Perforations of tympanic membrane
- Chronic suppurative otitis media
Would wax impaction cause a conductive or sensorineural hearing loss?
Conductive
Would otitis media with effusion (glue ear) cause a conductive or sensorineural hearing loss?
Conductive
What is audiometry?
measurement of the range and sensitivity of a person’s sense of hearing
How would conductive hearing loss present on audiometry?
This will present through indifferences in air conduction level and bone conduction level on the audiogram, with bone conduction being greater than air conduction
Does otosclerosis cause conductive or sensorineural hearing loss?
Conductive
What is an audiometric characteristic of otosclerosis?
Carhart’s notch where there is an apparent loss of bone conduction at 2000 Hz
What is sensorineural hearing loss?
Caused by malfunction** or **disease within the cochlea or auditory nerve (i.e. inner ear)
What is the most common cause of sensorineural hearing loss?
Presbycusis
What is presbycusis?
Gradual loss of hearing in both ears, common problem linked to ageing
Give some other causes of sensorineural hearing loss
- Noise-induced hearing loss
- Congenital infections e.g. rubella, CMV
- Neonatal complications (e.g. kernicterus or meningitis)
- Drug induced deafness (aminoglycosides)
- Vascular pathology (stroke, TIA)
Which Abx can be responsible for drug-induced deafness?
Aminoglycosides e.g. gentamicin
Audiogram results in sensorineural hearing loss?
- Sensorineural hearing loss on an audiogram presents with loss of hearing at high frequencies
- Characterised by symmetrical, progressive hearing loss over many years and can be seen on audiograms
Audiogram results in sensorineural hearing loss?
- Sensorineural hearing loss on an audiogram presents with loss of hearing at high frequencies
- Characterised by symmetrical, progressive hearing loss over many years and can be seen on audiograms
What type of frequencies are lost in sensorineural hearing loss?
High
What is vertigo?
A hallucination of movement of oneself or one’s surroundings. This movement is often rotatory, e.g. one may feel as though the floor is tilting.
Causes of vertigo?
- Benign positional paroxysmal vertigo (BPPV)
- Acute labyrinthitis
- Meniere’s disease
- Acoustic neuroma features
- Ramsay hunt syndrome
- Ototoxicity – caused by aminoglycoside antibiotics (e.g. gentamicin, vancomycin) and loop diuretics (e.g. furosemide) most commonly
What is the most common cause of vertigo?
Benign positional paroxysmal vertigo (BPPV)
What is otitis media?
A common infection causing inflammation of the middle ear.
Clinical features of otitis media?
Rapid onset of:
- Deep seated pain
- Systemic symptoms e.g. fever, irritability
- Vomiting
- Impaired hearing
- Onset is rapid with feeling of aural fullness followed by discharge when tympanic membrane perforates with relief of pain
- Tympanic membrane shows injection of blood vessels and then diffuse erythema
- Bacterial infection common particularly in young children
What does otitis media typically occur after?
A viral URTI
What is benign chronic otitis media?
Dry tympanic membrane perforation without chronic infection.
What feeling is often described in otitis media?
Aural fullness
Give some intra-cranial complications of otitis media
- Meningitis
- Sigmoid sinus thrombosis
- Brain abscess
Give some extra-cranial complications of otitis media
- Facial nerve palsy
- Mastoiditis
- Petrositis
- Labyrinthitis
How can otitis media lead to facial nerve palsy?
The nerve arises in the facial canal, and travels across the bones of the middle ear
How can otitis media lead to mastoiditis?
Infection spreads from middle ear to form abscess in the mastoid air spaces of the temporal bone
How can otitis media cause petrositis?
infection spreads to apex of petrous temporal bone
How can labyrinthitis caused by otitis media present?
can lead to inflammation of semiciruclar canals leading to vertigo, N&V and imbalance
What is the 1st line Abx in otitis media (when Abx indicated)?
High dose amoxicillin (oral NOT topical Abx unless 2ary otitis externa infection)
Give some indications for the requirement of Abx in otitis media
- Perforated eardrum
- <2 years old and bilateral
- Present for >/=4 days
- <3 months old
- Systemically unwell
- High risk of complications e.g. immunocompromised
How can grommets be useful in otitis media?
thin tubes sitting in ear drum that allow fluid to pass
What is glue ear?
Middle ear become full of fluid, causing a hearing loss (conductive) in that ear.
What type of hearing loss does glue ear cause?
Conductive
Pathophysiology behind glue ear?
Eustachian tube connects the middle ear to the back of the throat and helps drain secretions from the middle ear. When it becomes blocked, this causes middle ear secretions (fluid) to build up in the middle ear space.
Why is glue ear more common in children?
as Eustachian tube more horizontal.
What is the main symptom of glue ear?
Reduction of hearing in that ear (
Potential complications of glue ear?
- Conductive hearing loss → can lead to speech delay
- Infection (otitis media)
1st line investigation in glue ear?
Otoscopy
Treatment of glue ear?
- Treated conservatively – resolves within 3 months
- Children with co-morbidities affecting structure of ear (e.g. Down’s syndrome, cleft palate) → may require hearing aids or grommets
What are grommets?
Tiny tubes inserted into the tympanic membrane by an ENT surgeon
What is the purpose of grommets?
Allows fluid from middle ear to drain through membrane to the ear canal
How are grommets removed?
Usually fall out within a year
What is otitis externa?
Inflammation of the outer ear (pinna) and common cause of otalgia.
What is the most common cause of otalgia?
Otitis externa
What is perichondritis?
Infection of the skin and tissue surrounding the cartilage of the outer ear.
What are the 2 most common organisms causing otitis externa?
Pseudomonas spp. and Staph. aureus
What type of pathogen tends to cause chronic otitis externa?
Fungal
Clinical features of otitis externa?
- Unilateral ear pain due to acute inflammation of the skin of the external auditory meatus
- Can also have itch
- Minimal discharge
- Hearing only impaired if the meatus becomes blocked by swelling or discharge → conductive
What may be present in a patient’s history presenting with otitis externa?
Patient may have recently gone swimming (swimmer’s ear), recent trauma to ear or recent insect bite
What is swimmers ear?
Swimmer’s ear (otitis externa) is a bacterial infection typically caused by water that stayed in the outer ear canal for a long period of time, providing a moist environment for bacteria to grow.
Topical or oral Abx for otitis externa?
Topical NOT oral Abx (unless there are complications)