Definition
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Labyrinthitis: Inflammation of the labyrinth in the inner ear, affecting both the vestibular (balance) and cochlear (hearing) structures, leading to vertigo, balance issues, and hearing loss.
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Vestibular neuritis: Inflammation of the vestibular nerve, affecting balance but not hearing, as the cochlea is not involved.
Both are acute peripheral vestibular disorders, usually self-limiting but can be disabling in the acute phase.
Causes and Pathophysiology
Common Causes
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Viral infections (most frequent): herpes simplex virus type 1, influenza, adenovirus.
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Bacterial causes (labyrinthitis more than vestibular neuritis):
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Secondary to otitis media (Streptococcus pneumoniae, Haemophilus influenzae).
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Bacterial meningitis with spread to inner ear.
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Post-viral inflammatory response.
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Autoimmune inner ear disease (rare).
Pathophysiology
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Inflammation disrupts normal vestibular input from the affected ear, causing mismatch with the unaffected ear and triggering vertigo.
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Labyrinthitis includes cochlear inflammation, impairing sound transmission and causing sensorineural hearing loss.
Clinical Presentation
Shared Features (Labyrinthitis & Vestibular Neuritis)
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Sudden-onset severe vertigo lasting hours to days.
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Nausea and vomiting.
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Gait instability and unsteadiness.
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Nystagmus (usually horizontal).
Labyrinthitis Specific
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Unilateral hearing loss.
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Tinnitus.
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Aural fullness.
Vestibular Neuritis Specific
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No hearing loss or tinnitus.
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Isolated vestibular symptoms.
Diagnosis
Clinical Assessment
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History and examination are usually sufficient.
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Differentiate from central causes of vertigo (stroke, multiple sclerosis).
Key Diagnostic Points
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Positive head impulse test (peripheral lesion).
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Absence of other focal neurological signs (central causes excluded).
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In labyrinthitis: audiometry confirms sensorineural hearing loss.
Investigations (if needed)
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Audiometry.
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MRI brain/inner ear if atypical or central lesion suspected.
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Blood tests and ear cultures if bacterial cause suspected.
Management
General Principles
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Symptomatic control of vertigo, nausea, and vomiting.
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Reduce inflammation in the acute phase.
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Treat underlying infection if present.
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Promote vestibular compensation with early mobilization.
Pharmacological Treatment
1. Symptomatic Relief (Acute Phase – usually 1–3 days)
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Prochlorperazine: 5–10 mg orally every 6–8 hours, or 12.5 mg IM/IV every 8 hours if severe.
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Cyclizine: 50 mg orally or IM every 8 hours.
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Ondansetron: 4–8 mg orally or IV every 8 hours for nausea/vomiting.
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Diazepam: 2–5 mg orally every 8 hours for severe vertigo (short-term use only).
Note: Vestibular suppressants should be avoided after the acute phase to allow vestibular adaptation.
2. Anti-inflammatory Therapy
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Prednisolone: 50 mg orally daily for 5 days, then taper over the next 5 days (some studies show benefit, especially in vestibular neuritis).
3. Antiviral Therapy (if strong suspicion of viral cause)
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Acyclovir: 800 mg orally five times daily for 7 days (limited evidence, considered in herpes zoster oticus).
4. Antibiotic Therapy (for bacterial labyrinthitis)
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Amoxicillin: 500 mg orally every 8 hours for 7–10 days.
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Ceftriaxone: 1–2 g IV once daily for severe cases or meningitis-associated labyrinthitis.
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Antibiotic choice guided by culture results when possible.
5. Vestibular Rehabilitation
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Begin as soon as tolerated (after acute phase) to promote central compensation.
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Gaze stabilization, balance training, and walking exercises.
Complications
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Persistent imbalance (chronic vestibular dysfunction).
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Permanent sensorineural hearing loss (in labyrinthitis).
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Recurrent vertigo episodes (rare).
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Anxiety or depression secondary to chronic symptoms.
Prognosis
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Most cases improve within 2–6 weeks.
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Early mobilization and vestibular rehabilitation improve recovery.
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Hearing recovery in labyrinthitis depends on severity and cause; bacterial cases often have poorer prognosis.
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