At the bedside

Diagnosis & differential

There is no test that says “AIED”. The diagnosis is built from a suggestive history, audiovestibular testing, supportive serology, imaging that excludes mimics — and, often, the response to steroids.

It starts with suspicion

Diagnosis is clinical and rests on a high index of suspicion, particularly for rapidly progressive bilateral SNHL with vestibular symptoms. Features that raise it: bilateral subacute progression over weeks to months, fluctuation, responsiveness to corticosteroids, and any history of systemic autoimmune disease.1

Audiovestibular testing

  • Pure-tone audiometry — documents bilateral (often asymmetric) SNHL and tracks fluctuation during active phases; the foundation for monitoring response.
  • Speech discrimination — word-recognition scores are often disproportionately poor for the audiogram.
  • Videonystagmography (VNG) — caloric testing may show unilateral or bilateral vestibular hypofunction.
  • Video head impulse test (vHIT) — reduced VOR gain or corrective saccades indicate canal-specific dysfunction, often horizontal.
  • VEMPs — abnormal or absent responses reflect otolith end-organ involvement and help separate peripheral from central disease.

Together these localise the lesion — cochlear, vestibular or combined — and support an immune-mediated process when they fit the clinical picture and serology.

Serology

No blood test confirms AIED, but serology identifies systemic disease and inflammatory activity. ESR and CRP are non-specific markers of inflammation; autoantibody profiling — ANA, anti-dsDNA, ENA panel (anti-Ro/La, Sm, RNP), rheumatoid factor and anti-CCP, and ANCA — detects connective-tissue disease and vasculitis with inner-ear involvement.3 Inner-ear–specific antibodies (anti-68-kDa/HSP-70, anti-cochlin) remain investigational and are not standardised for routine use.2

Imaging

Imaging is mainly to exclude alternatives and occasionally to support active inflammation. Gadolinium MRI may show labyrinthine or vestibulocochlear-nerve enhancement indicating blood–labyrinth-barrier breakdown, and crucially excludes retrocochlear lesions such as vestibular schwannoma.4 High-resolution CT assesses bone — otosclerosis, labyrinthitis ossificans, and the bony erosion of granulomatous disease — and checks cochlear patency before implantation. Imaging is frequently normal in early or inactive AIED.

Differential diagnosis

AIED overlaps with several commoner disorders; the distinguishing axes are rate of progression, laterality, systemic autoimmune associations, steroid response and imaging.

Distinguishing AIED from its mimics
ConditionDistinguishing features
Ménière's diseaseFluctuating hearing loss, episodic vertigo, tinnitus, fullness — usually unilateral initially and slowly progressive; MRI may show hydrops
Vestibular migraineEpisodic vertigo with migraine features (photophobia, phonophobia, aura); no progressive auditory decline; normal imaging
Multiple sclerosisVertigo with other CNS signs; central hearing loss is rare; T2/FLAIR white-matter lesions on MRI
LabyrinthitisOften post-viral, acute monophasic vertigo with hearing loss; no systemic autoimmune markers
Vestibular schwannomaProgressive unilateral SNHL and imbalance; gadolinium MRI shows a CPA/IAC mass

Ménière’s disease is the commonest confusion — but it starts unilaterally and progresses slowly, and hydrops may be shown on MRI.5 Vestibular migraine lacks progressive auditory decline,6 multiple sclerosis brings other CNS signs and white-matter lesions,7 and a schwannoma shows a CPA/IAC mass.8

Key points

  • AIED is a clinical diagnosis — no confirmatory test exists; suspicion is everything.
  • Audiometry plus VNG/vHIT/VEMP localise cochlear and vestibular involvement.
  • Serology finds systemic disease (ANA, ANCA, RF/anti-CCP); inner-ear antibodies are investigational.
  • MRI excludes schwannoma and may show labyrinthine enhancement; imaging is often normal early.
  • Differentiate from Ménière’s, vestibular migraine, MS, labyrinthitis and schwannoma by tempo, laterality, systemic clues and imaging.