Labyrinthitis
Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management
Definition
Labyrinthitis is an inner ear disorder characterised by inflammation of the labyrinth, affecting both the vestibular and auditory systems, leading to vertigo and hearing impairment.
Aetiology
- Viral infections (most common): herpes simplex virus, influenza, varicella-zoster.
- Bacterial infections: otitis media extension, meningitis.
- Autoimmune conditions: autoimmune inner ear disease.
- Ototoxic drugs: aminoglycosides, loop diuretics.
Pathophysiology
- Inflammation of the labyrinth disrupts the function of the vestibular and cochlear nerves.
- Leads to vertigo, nausea, and sensorineural hearing loss.
- Viral infections typically cause self-limiting inflammation, while bacterial infections may lead to permanent damage.
Risk Factors
- Recent viral upper respiratory tract infection.
- Chronic otitis media.
- Head trauma or ear surgery.
- Ototoxic medication exposure.
Signs and Symptoms
- Acute onset vertigo: persistent and not triggered by movement.
- Hearing loss: typically unilateral and sensorineural.
- Tinnitus: ringing in the affected ear.
- Nausea and vomiting: common due to vestibular dysfunction.
- Gait instability: difficulty maintaining balance.
Investigations
- Clinical diagnosis: based on characteristic symptoms.
- Pure tone audiometry: assesses degree of hearing loss.
- MRI brain: to exclude central causes (e.g., stroke, multiple sclerosis).
- Blood tests: inflammatory markers if bacterial labyrinthitis suspected.
Management
1. Symptomatic Treatment:
- Vestibular suppressants: prochlorperazine or cinnarizine for short term relief.
- Antiemetics: metoclopramide or ondansetron for nausea.
2. Underlying Cause Management:
- Viral: supportive care, as viral labyrinthitis is self-limiting.
- Bacterial: urgent IV antibiotics if suspected bacterial labyrinthitis.
3. Rehabilitation:
- Vestibular rehabilitation exercises: physiotherapy to aid compensation.
- Hearing aids: for persistent hearing loss.
4. Referral:
- ENT specialist: for persistent or severe cases.
- Neurology: if central causes of vertigo are suspected.
- Audiology: for hearing assessment and management.