Making the diagnosis
Diagnosis & criteria
Unlike most vertigo, this diagnosis is defined by numbers. The symptoms raise the question; quantitative testing across the frequency range answers it.
The Bárány Society criteria
To diagnose bilateral vestibulopathy, doctors need three things together: the typical symptoms (unsteadiness worse in the dark, blurred vision on head movement); proof on balance tests that both ears are under-working; and confidence that nothing else explains it better.
The 2017 consensus requires all three limbs: (A) a chronic vestibular syndrome with the characteristic symptoms; (B) documented bilateral hypofunction — horizontal vHIT gain <0.6 on both sides, or a reduced caloric response (sum <6°/s per ear), or rotational-chairgain <0.1 with a phase lead >68°; and (C) the picture is not better explained by another disease.1
Test across frequencies, because a deficit can be missed at one and seen at another — caloric probes the very low end, the chair the middle, vHIT the high (functional) end.2 Earlier criteria captured the same construct and underlined the heterogeneity of presentation and severity, from partial hypofunction to complete areflexia.3
The test battery
Each test interrogates a different frequency of the VOR, so the battery is complementary rather than redundant — and a normal result on one does not exclude the deficit.
- Video head impulse test (vHIT)Bilateral horizontal VOR gain <0.6 with catch-up saccades — high-frequency, functional confirmationdecisive
- Bithermal caloricSum of slow-phase velocities <6°/s per ear — the low-frequency criteriondecisive
- Rotational chairGain <0.1 at 0.1 Hz with phase lead >68° (short time constant) — whole-system, mid-frequencydecisive
- Dynamic visual acuityA drop of ≥3 lines with head movement quantifies the functional impact of the VOR losssupportive
- AudiometryOften normal; abnormal hearing points toward a specific cause (Ménière's, ototoxicity, autoimmune)supportive
- MRI + aetiology work-upSearches for a cause — bilateral schwannoma (NF2), CANVAS, autoimmune/infective screens, drug historysupportive
Caloric, vHIT and rotational-chair testing each interrogate a different frequency of the VOR, so testing across all three is what establishes — or excludes — a bilateral deficit. Dynamic visual acuity adds the functional impact, and audiometry helps point to a specific cause.
The tests have their own chapters — vHIT, rotational chair, and the caloric component of VNG. Dynamic visual acuity adds the functional impact, and audiometry helps point to a specific cause.
Apply the criteria
All three limbs are required. Symptoms without objective testing cannot diagnose it; confirmed hypofunction still needs the alternatives excluded before the label is settled.
Bárány criteria checker
Switch on each strand that is present. All three — symptoms, documented bilateral hypofunction, and exclusion of a better cause — are required to meet the criteria.
Key points
- Diagnosis (Bárány 2017) requires all three: symptoms + documented bilateral hypofunction + no better explanation.
- Thresholds: vHIT gain <0.6 both sides, caloric sum <6°/s per ear, or chair gain <0.1 with phase lead >68°.
- Test across frequencies — caloric (low), chair (mid), vHIT (high) — as a deficit can be missed on one alone.
- Severity ranges from partial hypofunction to complete areflexia.