Otology Flashcards
What is otorrhoea?
Ear discharge
When is a Rinne’s test positive and negative?
Positive when air conduction is greater than bone conduction
(in the case of a normal ear, or in the case where there is a sensorineural hearing loss)
Negative when there is a conductive hearing loss
What portion of the ear is responsible for sensironeural hearing loss and conductive hearing loss?
Sensironeural - problems with the inner ear
Conductive - problems with the middle ear
Which way does the sound lateralise in a webers test with sensorineural hearing loss?
Lateralises to the side without the hearing loss
What direction does the sound lateralise in the Weber’s test on a patient with conductive hearing loss?
Lateralises to the side with the conductive hearing loss
What do the types A, B and C indicate?
A - Normal
B - Tympanic membrane immobile
C - Middle ear pressure is low
What does tympanometry measure?
Tympanometry is an examination used to test the condition of the middle ear and mobility of the eardrum(tympanic membrane) and the conduction bones by creating variations of air pressure in the ear canal.
What is tympanometry used to determine?
Can be used to establish the difference between conductive hearing loss and sensorineural hearing loss, when results from the weber or Rinne test are unclear.
Can be used to help in the diagnosis of otitis media, used to determine the presence of fluid in the middle ear
What are the common pathologies of the outer ear?
Auricular haematoma, foreign body, Otitis externa, malignant otitis externa
What is an auricular haematoma?
Shearing forces to the anterior auricle can lead to separation of the anterior auricular perichondrium from the underlying, tightly adherent cartilage. This may lead to tearing of the perichondrial blood vessels and subsequent hematoma formation.
What is otitis externa?
Inflammation of the ear canal
What causes otitis externa?
Acute cases are typically due to bacterial infection, and chronic cases are often due to allergies and autoimmune disorders
What is malignant otitis externa?
Aggressive otitis externa - The infection spreads from the floor of the ear canal to the nearby tissues and into the bones at the base of the skull. The infection and swelling may damage or destroy the bones. The infection may affect the cranial nerves, brain, or other parts of the body if it continues to spread.
Involves osteomyelitis of the temporal bone
What are the pathologies of the middle ear?
Otitis media
Tympanosclerosis
Osteosclerosis
Cholesteatoma
Why does otits media lead to effusion?
Eustachain tube doesn’t work, middle ear lining continues to absorb air, pressure becomes less and therefore secretes fluid to fill the vacuum
What is the purpose of a grommet?
Bypasses eustachian tube to equalise pressure.
What are the symptoms of acute otitis media?
earache
a high temperature (fever)
being sick
a lack of energy
slight hearing loss – if the middle ear becomes filled with fluid, hearing loss may be a sign of glue ear, also known as otitis media with effusion
What is chronic suppurative otitis media?
Chronic suppurative otitis media (CSOM) is middle ear inflammation of greater than two weeks that results in episodes of discharge from the ear.
What can happen to the tympanic membrane as a result of otitis media?
Rupture
What is a cholesteatoma?
Growth of skin in the middle ear
What can the skin of a cholesteatoma erode?
May erode the base of the skull (mastoid bone), ossicles, brain and the facial nerve
What is typical history for cholesteatoma?
Smelly discharge from the ear, hearing loss
What is tympanosclerosis?
Hyalinization and subsequent calcification of subepithelial connective tissue of TM and middle ear, sometimes resulting in a detrimental effect to hearing
What kind of hearing loss does ostosclerosis cause?
Conductive hearing loss
Sounds reach the ear drum but are incompletely transferred via the ossicular chain in the middle ear, and thus partly fail to reach the inner ear (cochlea).
On audiometry, the hearing loss is characteristically low-frequency, with higher frequencies being affected later.
What are the pathologies associated with the inner ear?
Presbyacusis
Noise induced haring loss
Ototoxic medications
Meniere’s disease
Head injury
Infections
Vestibular schwannoma
What is presbyacusis?
Hearling loss associated with age - begins over the age of 30 - associated with high frequency loss
What is Ménière’s disease?
A disease of unknown cause affecting the membranous labyrinth of the ear, causing progressive deafness and attacks of tinnitus and vertigo.
Attacks usually last hours
What is vestibular schwannoma?
A vestibular schwannoma (VS) is a benign primary intracranial tumor of the myelin-forming cells of the vestibulocochlear nerve (8th cranial nerve). A type ofschwannoma, this tumor arises from the Schwann cells responsible for the myelin sheath that helps keep peripheral nerves insulated.
What are the symptoms of vestibular schwannoma?
The primary symptoms of vestibular schwannoma are unexplained progressive unilateral hearing loss and tinnitus, and vestibular (disequilibrium) symptoms.
What is the investigation for schwannoma?
MRI
What is the treatment for vestibular schwannoma?
Treatment of the condition is by surgery or radiation, and often results in substantial or complete hearing loss in the affected ear. Observation (non-treatment) over time also usually results in hearing loss in the affected ear.
Why is unilateral tinitus on one ear often reffered for an MRI scan?
Risk of vestibular schwannoma
What are the important factors in the pathology of tinnitus?
No directly treatable pathology in vast majority of patients - hearing loss and stress are important in the development of tinnitus
What is the treatment of tinnitus?
Sound enrichment and sound management
What is the differential diagnosis for vertigo?
benign positional vertigo
Ménières disease
vestibular neuritis / labyrinthitis
migraine
What is vestibular neuritis?
Vestibular neuronitis, or neuritis, is an infection of the vestibular nerve in the inner ear. It causes the vestibular nerve to become inflamed, disrupting your sense of balance.
What is the difference between vestibular neuritis and labrynthitis?
Labrynthitis also has associated hearing loss
What are the causes of vestibular neuritis?
The vestibular nerve usually becomes inflamed because of a viral infection, which may have started with a sore throat, cold or flu.
Vestibular neuronitis can also be caused by a bacterial infection, such as a middle ear infection or meningitis, although this is much less common. Bacteria can also get into your inner ear if you have a head injury.
What are the common symptoms of vestibular neuritis?
Dizziness and vertigo
Nystagmus is indicative of the malfunction of the bodies balance system
Describe the vertigo present in vestibular neuritis
Residual motion - provoked
What is treatment for vestibular neuritis?
Acute - vestibular sedatives
Chronic - vestibular rehabilitation
What is the pathology of Ménière’s disease?
Raising pressure in endolymphatic portions of the cochlea
‘endolymphatic hydrops’
What is the treatment for Ménière’s disease?
betahistine
bendrofluazide
intratympanic dexamethasone
intratympanic gentamicin
What are the clinical features of migraine?
spontaneous vertigo
duration: variable
frequency: variable
± headache, sensory sensitivity, auras
± precipitated by migraine triggers
± past history of migraine
What is the treatment for migraines?
Avoid triggers
Prophylactic medication
What are the temporal and intratemporal causes of facial palsy?
Intratemporal: Cholesteatoma
Extratemporal: Patorid gland tumour
What is Bell’s palsy?
Facial palsy with no apparent cause
What is the onset of bells palsy?
Acute
