Cholesteatoma and mastoiditis

Question 1

What is a cholesteatoma?

Answer 1

It is a three-dimensional collection of epidermal and connective tissues within the middle ear. Its significance lies in the fact that it grows independently and can be locally invasive and destructive, particularly affecting the bones of the middle ear.

Question 2

What is the pathophysiology of cholesteatoma?

Answer 2

Chronic negative middle-ear pressure due to dysfunction of the eustachian tube causes the tympanic membrane to be sucked back and retract. As this process continues, there is bone erosion.

Bone erosion (epitympanum) occurs mainly by pressure but release of osteolytic enzymes has been detected at the peripheral margins of the lesion. This erosion produces a slowly expanding defect.

A ‘retraction pocket’ lined by squamous, non-keratinising epithelium is thus formed. The erosion often goes on, as the ball of epithelium grows, to surround the ossicles and may extend into the mastoid bone, the lateral semicircular canal, the middle cranial fossa and the posterior cranial fossa.

The (usually) unilateral lesion can give rise to a spectrum of problems, ranging from painless otorrhoea (discharge from the ear) through to serious central nervous system complications.

Question 3

What are the different types of cholesteatoma?

Answer 3

Congenital
Primary acquired
Secondary acquired

Question 4

What is congenital cholesteatoma?

Answer 4

Occurs when squamous epithelium becomes trapped within the temporal bone during embryogenesis. It expands, resulting in conductive hearing loss either through obstruction of the Eustachian tube.

Question 5

What is primary acquired cholesteatoma?

Answer 5

Accounts for 80% of all cases.

Follows pathophysiology of cholesteatoma

Question 6

What is secondary acquired cholesteatoma?

Answer 6

Arises as a result of insult to the tympanic membrane such as perforation secondary to acute otitis media or trauma.

Question 7

What is the presentation of cholesteatoma?

Answer 7

Progressive conductive hearing loss
Vertigo
Headache
Facial nerve palsy
Ear discharge (which may be foul-smelling)
Recurrent otitis poorly responsive to treatment
Tympanic membrane perforation

Question 8

What are the risk factors for cholesteatoma?

Answer 8

Cleft palate

Ear trauma

Question 9

What are the differentials of cholesteatoma?

Answer 9

Otitis media with effusion
Otitis externa
Tympanosclerosis
Osteonecrosis

Question 10

What are the investigations for cholesteatoma?

Answer 10

CT imaging

MRI scan if there is concern about soft tissue involvement such as herniated brain or epidural abscess

Question 11

What is the management of cholesteatoma?

Answer 11

Medical therapy is reserved for those patients who refuse surgery or for whom a general anaesthetic would be too dangerous owing to comorbidity. In these patients, regular ear cleaning with treatment of infections (topical ± systemic antibiotics) is advised but, ultimately, this will not prevent cholesteatoma growth with its consequences.

Surgery to remove the cholesteatoma and leave a safe, dry ear.

Question 12

What are the complications of cholesteatoma?

Answer 12

Perichondritis 
Chondritis 
Ear canal stenosis 
Facial nerve injury 
Long-term dizziness

Question 13

Where is the mastoid process?

Answer 13

The mastoid process is an inferior extension of the petrous temporal bone of the skull and provides a structural function as an anchor point for the large muscles of the neck. It contains multiple air cells that develop from a single main cavity (the antrum), after the age of about 2.

Question 14

What is mastoiditis?

Answer 14

Mastoiditis occurs when suppurative infection extends from a middle ear affected by otitis media to the mastoid air cells. The infective process causes inflammation of the mastoid and surrounding tissues and may lead to bony destruction.

The mastoid air cells are related superiorly to the middle cranial fossa and posteriorly to the posterior cranial fossa. This means that suppuration in the mastoid may, rarely, spread to cause meningitis or a cerebral abscess.

Question 15

What is the classification of mastoiditis?

Answer 15

Acute mastoiditis is defined as an acute inflammation of the mastoid with colliquation of the air-filled mastoidal bone.

Chronic, latent, or masked, mastoiditis presents in a chronic, or subclinical, fashion. It is usually associated with chronic suppurative otitis media or cholesteatoma.

Question 16

What are the risk factors for mastoiditis?

Answer 16

Young children
Immunosuppressed patients
Cholesteatoma
Most common organism is s. pneumoniae. Others include H. influenzae, pseudomonas, Moraxella catarrhalis

Question 17

What is the presentation of mastoiditis?

Answer 17

History of acute or recurrent episodes of otitis media.
Intense otalgia and pain behind the ear.
Fever.
Infants may present with irritability, intractable crying and feeding problems.
Swelling, redness or a boggy, tender mass behind the ear.
The external ear may protrude forwards; fluctuance can sometimes be demonstrated behind the ear (examine from behind).
Ear discharge may be present and the eardrum may be perforated.
Tympanic membrane bulges and is erythematous.
The patient is unwell.

Question 18

What are the differentials of mastoiditis?

Answer 18

Otitis media or externa
Trauma 
Meningitis 
Cellulitis 
Parotid swelling 
Bone cysts

Question 19

What are the investigations for mastoiditis?

Answer 19

Blood tests inc. FBC, ESR 
Blood cultures 
CT
LP if brain spread suspected 
MRI 
Skull X-ray
Audiogram to monitor the hearing loss

Question 20

What is the management of mastoiditis?

Answer 20

Managed in a hospital setting

The usual initial therapy is high-dose, broad-spectrum intravenous (IV) antibiotics, given for at least 1-2 days (eg, with a third-generation cephalosporin).

Oral antibiotics are usually used after this, starting on IV treatment after 48 hours without a fever and continuing for at least 1-2 weeks.

Paracetamol, ibuprofen and other agents may be given as antipyretics and/or painkillers.

Myringotomy ± tympanostomy tube insertion may be performed in some cases as a therapeutic procedure, or to collect middle ear fluid for culture.

Immediate mastoidectomy is usually the method of choice to treat acute mastoiditis with subperiosteal abscess formation

Question 21

What are the complications of mastoiditis?

Answer 21

Labyrinthitis 
Osteomyelitis 
Subperiosteal abscess 
Cranial nerve palsies
Petrositis 
Lateral sinus thrombosis

Question 22

What is otosclerosis?

Answer 22

Otosclerosis describes the replacement of normal bone by vascular spongy bone.

It causes progressive conductive deafness due to fixation of the stapes at the oval window. Otosclerosis is autosomal dominant and typically affects young adults.

Question 23

What are the risk factors for otosclerosis?

Answer 23

Race- more common in white and Asian populations.
Sex- more commonly diagnosed in women
Age- presents between teen years and middle age.

Question 24

What is the presentation of otosclerosis?

Answer 24

Onset is usually at 20-40 years - features include:
Progressive conductive deafness
Tinnitus worsens as hearing loss worsens
Vestibular symptoms are usually absent
Tuning fork tests reveal conductive pattern deafness
Normal tympanic membrane*
Positive family history

*10% of patients may have a ‘flamingo tinge’, caused by hyperaemia- the Schwartze sign

Question 25

Whare are the investigations for otosclerosis?

Answer 25

Audiometry is the primary investigation of choice.

Tuning fork test

Question 26

What is the management of otosclerosis?

Answer 26

Hearing aid

Stapedectomy

• Can cause total unilateral sensorineural hearing loss (rare)
• Facial nerve injury may occur
• Disturbance of taste sensation

Question 27

What is viral labyrinthitis?

Answer 27

Labyrinthitis is an inflammatory disorder of the membranous labyrinth, affecting both the vestibular and cochlear end organs. Labyrinthitis can be viral, bacterial or associated with systemic diseases. Viral labyrinthitis is the most common form of labyrinthitis.

Labyrinthitis is used when both the vestibular nerve and the labyrinth are involved, usually resulting in both vertigo and hearing impairment.

Question 28

What is the difference between labyrinthitis and vestibular neuronitis?

Answer 28

Labyrinthitis should be distinguished from vestibular neuritis as there are important differences: vestibular neuritis is used to define cases in which only the vestibular nerve is involved, hence there is no hearing impairment;

Question 29

What is the presentation of labyrinthitis?

Answer 29

The average age of presentation is 40-70 years

Patients typically present with an acute onset of:

• 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

Signs of labyrinthitis:

• 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

The diagnosis is largely based on history and examination.

Question 30

What is the management of viral labyrinthitis?

Answer 30

Episodes are usually self-limiting

Prochlorperazine or antihistamines may help reduce the sensation of dizziness

Question 31

What is vestibular neuronitis?

Answer 31

Vestibular neuronitis is a cause of vertigo that often develops following a viral infection.

Question 32

What is the presentation of vestibular neuronitis?

Answer 32

Recurrent vertigo attacks lasting hours or days

Nausea and vomiting may be present

Horizontal nystagmus is usually present

No hearing loss or tinnitus

Question 33

What are the differentials of vestibular neuronitis?

Answer 33

Viral labyrinthitis

Posterior circulation stroke: the HiNTs exam can be used to distinguish vestibular neuronitis from posterior circulation stroke

Question 34

What is the management of vestibular neuronitis?

Answer 34

Vestibular rehabilitation exercises are the preferred treatment for patients who experience chronic symptoms

Buccal or intramuscular prochlorperazine is often used to provide rapid relief for severe cases

A short oral course of prochlorperazine, or an antihistamine (cinnarizine, cyclizine, or promethazine) may be used to alleviate less severe cases

Question 35

What is Meniere’s disease?

Answer 35

Meniere’s disease is a disorder of the inner ear of unknown cause.

It is characterised by excessive pressure and progressive dilation of the endolymphatic system.

It is more common in middle-aged adults but may be seen at any age. Meniere’s disease has a similar prevalence in both men and women.

Question 36

What is the presentation of Meniere’s disease?

Answer 36

Recurrent episodes of vertigo, tinnitus and hearing loss (sensorineural). Vertigo is usually the prominent symptom

A sensation of aural fullness or pressure is now recognised as being common

Other features include nystagmus and a positive Romberg test

Episodes last minutes to hours

Typically symptoms are unilateral but bilateral symptoms may develop after a number of years

Question 37

What is the natural hx of Meniere’s disease?

Answer 37

Symptoms resolve in the majority of patients after 5-10 years

The majority of patients will be left with a degree of hearing loss

Psychological distress is common

Question 38

What is the management of Meniere’s disease?

Answer 38

ENT assessment is required to confirm the diagnosis

Patients should inform the DVLA. The current advice is to cease driving until satisfactory control of symptoms is achieved

Acute attacks: buccal or intramuscular prochlorperazine. Admission is sometimes required

Prevention: betahistine and vestibular rehabilitation exercises may be of benefit

Question 39

What is acoustic neuroma?

Answer 39

Vestibular schwannomas (sometimes referred to as acoustic neuromas) account for approximately 5% of intracranial tumours and 90% of cerebellopontine angle tumours.

Question 40

What is the presentation of acoustic neuroma?

Answer 40

The classical history of vestibular schwannoma includes a combination of vertigo, hearing loss, tinnitus and an absent corneal reflex.

Features can be predicted by the affected cranial nerves:
Cranial nerve VIII: vertigo, unilateral sensorineural hearing loss, unilateral tinnitus
Cranial nerve V: absent corneal reflex
Cranial nerve VII: facial palsy

Bilateral vestibular schwannomas are seen in neurofibromatosis type 2.

Question 41

What are the investigations and management of acoustic neuroma?

Answer 41

Patients with a suspected vestibular schwannoma should be referred urgently to ENT. It should be noted though that the tumours are often slow-growing, benign and often observed initially.

MRI of the cerebellopontine angle is the investigation of choice. Audiometry is also important as only 5% of patients will have a normal audiogram.

Management is with either surgery, radiotherapy or observation.