What They Found
The authors recommend the TiTrATE approach: timing, triggers and targeted examination.
The initial distinction is between spontaneous and triggered transient vestibular symptoms.
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Feature
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Spontaneous episodes
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Triggered episodes
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Onset
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Without a specific provoking movement
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Associated with a reproducible trigger
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Important causes
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Vertebrobasilar TIA, vestibular migraine, arrhythmia, Ménière's disease
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BPPV, central positional vertigo, orthostatic hypotension
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Diagnostic priority
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Exclude vascular and cardiac causes
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Identify the trigger and reproduce the relevant findings
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A particularly useful distinction is whether movement actually triggers a new episode or merely worsens dizziness that is already present.
The review also emphasises that vestibular migraine and vertebrobasilar ischaemia can present with position-dependent symptoms. Positional symptoms alone do not establish BPPV.
Duration helps narrow the differential... but we must not rely on it.
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Episode duration
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Diagnoses to consider
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Seconds
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BPPV, vestibular paroxysmia, cardiac arrhythmia
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Minutes
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Vertebrobasilar TIA, arrhythmia, vestibular migraine
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Minutes to hours
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Vestibular migraine, Ménière's disease, vertebrobasilar ischaemia, toxic-metabolic causes
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Do not perform HINTS+ in resolved transient vertigo
HINTS+ is validated for patients with an acute vestibular syndrome who have ongoing symptoms and spontaneous or gaze-evoked nystagmus.
It is not validated in asymptomatic patients or those without nystagmus.
The authors explain that applying HINTS+ to an asymptomatic patient can generate a misleading central pattern because a normal head impulse test may be incorrectly interpreted in the absence of an appropriate acute vestibular syndrome.
The correct bedside examination depends on whether symptoms are ongoing or have resolved.
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Ongoing symptoms with nystagmus
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Symptoms resolved
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HINTS+ when appropriate
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Do not use HINTS+
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Detailed ocular motor examination
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Detailed ocular motor examination
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Gait and truncal stability
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Gait and truncal stability
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Assess spontaneous nystagmus
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Search for triggered nystagmus
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Evaluate hearing
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Perform positional testing
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The STANDING algorithm is a more versatile algorithm that can be considered in transient presentations.
Examine the eyes and gait
The review recommends assessment of gaze stability, spontaneous and gaze-evoked nystagmus, saccades, smooth pursuit, vestibulo-ocular reflex and focal neurological findings.
Two particularly concerning findings are vertical or torsional spontaneous nystagmus and severe truncal instability, especially inability to sit or stand independently.
Positional testing: An important recommendation
The authors recommend Dix–Hallpike and supine-roll testing in patients with transient vestibular symptoms, including those who do not report positional triggers, particularly once symptoms have resolved. Patients may fail to recognise or report positional triggers, and central positional nystagmus can provide diagnostic clues even when spontaneous nystagmus is absent.
Features supporting BPPV
Brief position-triggered episodes, characteristic canal-specific nystagmus and an immediate, sustained response to an appropriate repositioning manoeuvre.
Features raising concern for a central cause
Nystagmus inconsistent with the stimulated canal, positional vomiting or lack of sustained response to repositioning.
Vestibular migraine can also produce positional nystagmus that resembles BPPV, particularly lateral-canal BPPV.
The response to treatment therefore contributes important diagnostic information.
How often is transient vertigo actually stroke or TIA?
The review summarises several observational studies.
Selected study findings
15% Stroke
Selected acute transient vestibular syndrome cohort
12% TIA
Same selected cohort
In the subgroup whose symptoms had resolved, the reported rates were 17% for stroke and 14% for TIA.
These figures came from a selected observational population that excluded BPPV, general medical causes and known neurological disorders. They should not be applied directly to all patients presenting to the ED with dizziness.
In that study, HINTS+ could not be performed in 73% because symptoms had already ceased. Initial MRI-DWI was false-negative in 43% of confirmed strokes.
A separate cohort of episodic vestibular presentations reported 10% TIA and 2% stroke.
The important distinction: These are rates in selected study populations, not the probability that an individual patient with isolated transient vertigo has suffered a stroke.
Neuroimaging: A negative scan is not a diagnostic endpoint
MRI with diffusion-weighted imaging is preferred when a central cause is suspected.
However, there are limitations of early imaging. A negative early MRI must therefore be interpreted alongside the clinical history, examination and vascular imaging findings.
Early MRI-DWI false negatives
Up to 20%
Small brainstem strokes
Up to 50%
There is Low sensitivity for CT-based imaging in detecting acute vertebrobasilar ischaemia.
CT/CTA nevertheless has an important role when urgent vascular treatment decisions are required, particularly where basilar artery stenosis, dissection or occlusion is suspected.
