Labyrinthitis

Question 1

What is labyrinthitis?

Answer 1

Labyrinthitis is an inflammatory condition affecting the contents of the otic capsule. This includes the cochlea, three orthogonal semi-circular canals, and the otolith organs (utricle, saccule).

Question 2

What are the contents of the otic capsule?

Answer 2

This includes the cochlea, three orthogonal semi-circular canals and the otolith organs (utricle, saccule).

Question 3

Briefly describe the pathophysiology of labyrinthitis

Answer 3

The inflammation is usually attributed to a viral upper respiratory tract infection.

Rarely labyrinthitis can be caused by a bacterial infection. This may be an inflammatory response to a nearby infection or the result of bacteria or bacterial toxins entering the labyrinth. It is usually secondary to otitis media or meningitis.

Question 4

What viruses cause labyrinthitis?

Answer 4

Viral labyrinthitis is typically associated with a preceding upper respiratory tract infection. Aetiological viral agents include varicella zoster virus, cytomegalovirus, mumps, measles, rubella and HIV

Question 5

What bacteria cause labyrinthitis?

Answer 5

Potential bacterial causes include Treponema pallidum, Haemophilus influenzae, Streptococcus species, Staphylococcus species and Neisseria meningitidis.

Question 6

How can viral and bacterial labyrinthitis be differentiated?

Answer 6

Unlike viral labyrinthitis, the bacterial form may affect both ears simultaneously.

In addition to this, bacterial labyrinthitis is associated with acute or chronic otitis media, meningitis, and cholesteatoma (a collection or growth of epidermal and connective tissues within the middle ear).

Question 7

What are the clinical features of labyrinthitis?

Answer 7

• Vertigo
• Dizziness
• Nausea and vomiting
• Hearing loss
• Otorrohea

Question 8

How does the presentation of labyrinthitis and vestibular neuronitis differ?

Answer 8

Unlike vestibular neuronitis, labyrinthitis can also be associated with:

• Hearing loss
• Tinnitus

Question 9

How is labyrinthitis diagnosed?

Answer 9

A clinical diagnosis is based on history and examination findings. It is important to exclude a central cause of the vertigo.

The head impulse test can be used to diagnose peripheral causes of vertigo, resulting from problems with the vestibular system (e.g. vestibular neuronitis or labyrinthitis).

Rinne and Weber’s and audiogram testing also show sensorineural hearing loss.

Question 10

What type of hearing loss is shown in labyrinthitis?

Answer 10

Sensorineural hearing loss.

Question 11

Briefly describe the management of labyrinthitis

Answer 11

Management is the same as with vestibular neuronitis, with supportive care and short-term use (up to 3 days) of medication to suppress the symptoms. Options for managing symptoms are:

• Prochlorperazine
• Antihistamines (e.g. cyclizine, cinnarizine and promethazine)

Antibiotics are used to treat bacterial labyrinthitis. The underlying infection (e.g. otitis media or meningitis) needs appropriate treatment.

Question 12

What are the complications of labyrinthitis?

Answer 12

• Delayed endolymphatic drops
• Mastoiditis
• Cochlear ossification
• Hearing loss
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Question 13

Is permanent hearing loss more common in viral or bacterial labyrinthitis?

Answer 13

Patients rarely have lasting symptoms, including permanent hearing impairment. This is more common after bacterial labyrinthitis, particularly associated with meningitis.

Question 14

What differentials should be considered for labyrinthitis?

Answer 14

• Vestibular neuronitis
• Benign paroxysmal positional vertigo
• Meniere’s disease
• Vestibular schwannoma (acoustic neuroma)