Labyrinthitis versus vestibular neuritis
Labyrinthitis is inflammation of the labyrinth, the maze of fluid-filled channels in the inner ear, so vertigo (a spinning sensation) comes with hearing loss or ringing.
Remember
After a viral illness, sudden, continuous vertigo with hearing loss or ringing points to labyrinthitis, while vertigo with normal hearing suggests vestibular neuritis (inflammation of the balance nerve alone).
The labyrinth is a maze of fluid-filled channels in the inner ear, and it does two jobs. Its vestibular part (the balance part) holds the semicircular canals, which are loops that sense head rotation, and the utricle and saccule, the otolith organs that sense straight-line movement. Its cochlear part is the cochlea, the coiled organ of hearing.
Labyrinthitis means that the whole labyrinth is inflamed, usually triggered by a viral infection, such as an upper respiratory tract infection. Both parts are affected, so the person has acute, persistent vertigo with imbalance, together with reduced hearing, tinnitus (hearing a sound, such as ringing, that is not there) or both. The vertigo persists even at rest, rather than occurring in brief episodes triggered by head movement.
Vestibular neuritis is the close relative. Only the vestibular nerve is inflamed. This is the balance branch of the vestibulocochlear nerve (cranial nerve VIII, the nerve that carries both hearing and balance signals). The vertigo looks very similar, but hearing stays normal and there is no tinnitus, and that detail tells the two conditions apart.
Both conditions are usually self-limiting, settling over days to weeks, and treatment is supportive, for example anti-sickness medicines. Balance often returns over about 2 to 6 weeks. Sudden hearing loss in one ear needs urgent assessment. If there are other neurological symptoms or abnormal examination findings, a central cause, such as a problem in the brainstem relay for balance signals, becomes more likely and calls for further investigation.
Key facts
- Labyrinthitis
- both the balance and hearing parts of the inner ear are inflamed, so vertigo is joined by hearing loss, tinnitus or both.
- Vestibular neuritis
- only the balance nerve is inflamed, so there is vertigo but hearing stays normal and there is no tinnitus.
- Telling them apart
- hearing loss or tinnitus points to the labyrinth rather than the nerve.
- Usual cause
- both conditions usually follow a viral infection.
- Course
- both usually ease over days to weeks, and balance often returns over about 2 to 6 weeks.
- Red flag
- sudden hearing loss in one ear needs urgent assessment.
- Positional vertigo
- in benign paroxysmal positional vertigo (BPPV), short spells of vertigo are brought on by moving the head, unlike the persistent vertigo of labyrinthitis.
Exam traps
- Vestibular neuritis causes sudden, constant vertigo after a viral illness, but it does not account for hearing loss or tinnitus, because hearing signals travel in a separate branch of the nerve.
- Otoconia (small calcium carbonate crystals) that drift into a semicircular canal cause BPPV, which gives brief spells of vertigo triggered by head movement, without hearing loss or tinnitus, so it does not fit continuous vertigo at rest with hearing symptoms.
- Disease of the middle-ear ossicles (the three tiny middle-ear bones) reduces hearing, but the balance organs and the cochlea lie deeper in the inner ear, so middle-ear disease does not by itself explain severe vertigo with ringing.
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