Is Labyrinthitis Unilateral?
Yes, labyrinthitis is typically unilateral, affecting one ear at a time, though bilateral cases can occur rarely. 1, 2
Clinical Presentation Pattern
- Labyrinthitis characteristically presents as a unilateral process with sudden hearing loss and concurrent vertigo affecting one ear 1
- The condition involves inflammation of the inner ear that disrupts sensory transmission from the affected ear to the brain 3
- Unilateral presentation is the standard pattern seen in clinical practice, with patients experiencing vestibular weakness on the affected side 1
Evidence from Clinical Studies
- A cohort study of 61 patients with idiopathic labyrinthitis documented that all patients presented with unilateral vestibular weakness at initial presentation 1
- Case reports consistently describe labyrinthitis as a unilateral phenomenon, including COVID-19-induced cases presenting with "right-sided severe hearing loss" and "right labyrinthine hypofunction" 2
- Suppurative labyrinthitis secondary to middle ear infections follows a unilateral pattern corresponding to the affected ear with otitis media 4
Bilateral Disease Considerations
- Bilateral labyrinthitis is rare but possible, particularly in the context of labyrinthitis ossificans where progressive bilateral sensorineural hearing loss can develop 3
- When bilateral hearing loss occurs, autoimmune inner ear disease should be considered as an alternative diagnosis, which presents with "progressive fluctuating bilateral hearing loss" 5
- The distinction between unilateral labyrinthitis and bilateral autoimmune processes is clinically important for treatment planning 5
Clinical Implications
- Unilateral presentation means contralateral ear function remains intact, which is crucial for counseling patients about hearing rehabilitation options 6
- Cochlear implantation can be considered for unilateral hearing loss due to labyrinthitis ossificans, with timing being critical before complete obliteration occurs 6
- The unilateral nature allows for comparison testing between affected and unaffected ears during diagnostic evaluation 1