Otology 2

Question 1

What is viral labryrinthitis?

Answer 1

Inflammatory disorder of the membranous labyrinth, affecting both the vestibular and cochlear end organs
Viral, bacterial or associated with systemic diseases
Vesrtibular nerve and labyrinth are involved, resulting in vertigo and hearing impairment
Average age 40-70 years

Question 2

How does viral labryrinthitis present?

Answer 2

vertigo: not triggered by movement but exacerbated by movement
nausea and vomiting
hearing loss: may be unilateral or bilateral, with varying severity
tinnitus
preceding or concurrent symptoms of upper respiratory tract infection

Question 3

What are the signs of labyrinthitis?

Answer 3

spontaneous unidirectional horizontal nystagmus towards the unaffected side
sensorineural hearing loss: shown by Rinne’s test and Weber test
abnormal head impulse test: signifies an impaired vestibulo-ocular reflex
gait disturbance: the patient may fall towards the affected side
normal skew test
abnormality on inspection of the external ear canal and the tympanic membrane e.g. vesicles in herpes simplex infection

Question 4

What are the investigations for labyrinthitis?

Answer 4

diagnosis is largely based on history and examination
glucose is helpful in excluding hypoglycaemia.
in most patients with suspected viral labyrinthitis, no other investigation is necessary

Question 5

What is osteosclerosis?

Answer 5

Disease of the ottic capsule or bony labyrinth
Progressive conductive deafness
Bilateral hearing loss begins at 30 (worse during pregnancy)
The hard, compact bone of the labyrinth is replaced by patches of spongy bone this abnormal bone is thought to produce toxins which can affect the cochlear
Secondary to fixation of the stapes in the oval window
Treatment is with stapedectomy (replace with teflon piston) and insertion of a prosthesis

Question 6

What is acoustic neuroma?

Answer 6

Benign tumours that arise from the auditory nerve- unilateral HL or tinnitus
Symptoms of gradually
progressive unilateral perceptive deafness and tinnitus
Involvement of the vestibular nerve may cause vertigo
Extension to involve the facial nerve may cause weakness and then paralysis.
Investigations: pure tone audiometry
MRI imaging or CT scanning
Treatment- gamma–knife a sophisticated x-ray gun requiring one treatment surgery is now reserved for patients with tumours greater than 3.5cm and patient preference watch and wait on smaller tumours

Question 7

What is pre auricular sinus?

Answer 7

Common congenital condition in which an epithelial defect forms around the external ear
Small sinuses require no treatment
Deeper sinuses may become blocked and develop episodes of infection, they may be closely related to the facial nerve and are challenging to excise

Question 8

What is presbycusis?

Answer 8

Type of sensorineural hearing loss that affects elderly individuals
high-frequency hearing is affected bilaterally
progresses slowly, as sensory hair cells and neurons in the cochlea atrophy over time.

Question 9

What are the causes of presbycusis?

Answer 9

Arteriosclerosis 
Diabetes 
Accumulated exposure to noise 
Drug exposure (Salicylates, chemotherapy agents)
Genetic

Question 10

What are the investigations for presbycusis?

Answer 10

Otoscopy: Normal, to rule out otosclerosis, cholesteatoma and conductive hearing loss (Foreign body, impacted wax etc.)
Tympanometry: Normal middle ear function with hearing loss (Type A)
Audiometry: Bilateral sensorineural pattern hearing loss
Blood tests including inflammatory markers and specific antibodies: Normal

Question 11

What assessment does a patient need before receiving a cochlear implant?

Answer 11

Anatomy: needs enough spiral ganglion neutrons after degeneration of the organ of Corti to be affective
Vaccinations against streptococcus and haemophilus

Question 12

What are the contraindications to consideration for cochlear implant?

Answer 12

Lesions of cranial nerve VIII or in the brain stem causing deafness
Chronic infective otitis media, mastoid cavity or tympanic membrane perforation
Cochlear aplasia

Question 13

What are the relative contraindications for cochlear implant?

Answer 13

Chronic infective otitis media or mastoid cavity infections
Tympanic membrane perforation
Patients that may be seen to demonstrate a lack of interest in using the implant to develop enhanced oral communication skills.

Question 14

What are pure tone audiograms?

Answer 14

Most commonly performed hearing test and help determine a patients hearing threshold
Tones are played through a set of headphones at varying volumes and the patient is asked to respond when they hear a noise- one ear is done at a time and sometimes masking can be used on the other ear
In the left ear air conduction is labelled X and bone conduction ] whilst in the right ear air conduction is O and bone conduction [
A normal picture is all frequencies between 0 and 20 dB in both air and bone conduction

Question 15

What is tympanometry?

Answer 15

Measures compliance/stiffness of the eardrum, as well as ear canal volume and pressure within the middle ear
Maximal sound energy passes through the ear drum when the pressure in the ear canal is the same as the middle ear, hence a peak should be seen on the graph at 0 but normal ranges between -100 and +100
A negative middle ear pressure forces the graph to the left and fluid in the middle ear gives a flat trace, an excessively tall peak can indicated a hyper mobile drum such as in ossicular discontinuity
>2ml canal volume suggests perforation
Heaight- compliance of ear drum/resistance behind
Location- amount of pressure in the middle ear

Question 16

What sis acute mastoiditis?

Answer 16

Complication of AOM
Infection spreads from the middle ear cavity and pus forms in the mastoid air cells causing bony erosion
Persistent otalgia, pyorrhoea and hearing loss
Sagging of the posters-superior canal wall
Tenderness over the bone immediately above the ear canal (McEwen’s triangle)
A unilateral headache should ring alarm bells as it may be a sign of the development of a intracranial complication

Question 17

What is the management for mastoiditis?

Answer 17

In the early stages the patient may be treated with high does IV antibiotics in hospital, but if it does not settle within 48hours or complications arise e.g. subperiosteal abscess, facial nerve palsy, labyrinthitis, petrositis (spread medially into the petrous bone causing Vth and VIth cranial nerve palsies) or spread outside the temporal bone, the patient should have a cortical mastoidectomy

Question 18

What is an unusual symptom of osteosclerosis?

Answer 18

Paracusis willsii
Hearing better with background noise) can occur in these patients, tinnitus and positional vertigo can also be additional problems

Question 19

How do the different types of diffuse otitis externa present?

Answer 19

Bacterial- pus and debris in EAM
Fungal- dry or wet debris or yellow or black spores (aspergillum flavum or niger)
Viral- vesicles around introitus of EAM (Herpes zoster), soft palate or haemorrhagic vesicles on tympanic membrane (‘bullous myringitis’) associated with thin, watery blood-stained discharge

Question 20

What are the features of diffuse otitis externa?

Answer 20

Facial oedema
Tragus is tender on movement
Skin may crack and crust, chronically skin may become thickened or fissured or permanently moist

Question 21

What is the treatment for diffuse otitis externa?

Answer 21

Aural toilet and local medication, such as antibiotics or steroid ear drops antifungal agents and glycerine (to withdraw moisture) can be used
systemic antibiotics can be used if the condition is severe
When the problems begin to clear it is important to check for a middle ear infection as this is a common cause of otitis externa

Question 22

What is malignant otitis externa?

Answer 22

More aggressive form of otitis externa usually seen in the elderly and diabetics
Caused by pseudomonas, spreads to the bone and causes osteomyelitis of the skull base
can damage the facial nerve and those exiting through the jugular foramen (9, 10 and 11)
This condition can be fatal- treatment needs to be prompt with high dose IV antibiotics and sometimes surgical debridement

Question 23

What is furuncle otitis media?

Answer 23

A furuncle is a painful infection of one of the hair follicles of the outer 1/3 of the EAM usually due to Staphylococcus it usually arises after one of the hairs has been plucked or the EAM scratched
red swelling arise from one aspect of the outer wall of the EAM bulging into the meatus
Treatment is with analgesia, astringents (such as glycerin and ichthammol) antibiotics may help in more severe infections when there is a lymphadenitis