The acute syndrome
Acute Vestibular Syndrome & TiTrATE
Stop asking "what kind of dizziness?" Ask "how long, and what set it off?" The temporal framing of acute dizziness is reproducible across clinicians and maps directly to the bedside test that comes next.
Patients describe dizziness inconsistently. Pinning the diagnosis to the word the patient uses ("vertigo", "lightheadedness", "off-balance") gives the same picture a different name every time and misclassifies stroke as anxiety.
The modern frame is simpler: ask timing (how long has it been going on?), triggers (does anything set it off?) and then do the targeted bedside exam that matches the answers.
Hotson and Baloh's 1998 NEJM piece defined the modern acute vestibular syndrome: acute, sustained vertigo with spontaneous nystagmus, gait unsteadiness, nausea and head-motion intolerance lasting more than 24 hours.1 It is the presentation where stroke and neuritis are the main competitors and where bedside testing has the highest leverage per minute of clinician time.
Edlow, Gurley and Newman-Toker's TiTrATE framework — Timing, Triggers, Targeted Examination — operationalises the AVS concept into a three-way triage with concrete testing pathways for each branch.2
The Bárány Society's vestibular-symptom classification provides the controlled vocabulary that lets the TiTrATE branches map onto international diagnostic criteria.3 The aPVS / EVS framing is the operational version of that vocabulary: spontaneous vs triggered is the discriminating temporal axis, and sustained vs episodic sorts the syndrome from the symptom.
The pay-off is that the next bedside test follows from the triage branch without further deliberation: HINTS for AVS, Dix-Hallpike + supine roll for t-EVS, a focused history (and migraine / aural inventory) for s-EVS.
The three branches
Sustained vertigo lasting hours to days with spontaneous nystagmus and gait unsteadiness.
- Vestibular neuritis
- Posterior-circulation stroke
- Labyrinthitis
Why timing and triggers, not symptom quality
Asking patients to describe their dizziness as "vertigo" vs "lightheadedness" produces unreliable labels. The same patient labels the same sensation differently on different occasions, and clinicians map those labels inconsistently onto diagnoses. Timing and triggers are reproducible across clinicians and map to the bedside test that follows.
Population data show that ~3–5% of dizzy ED patients are having a stroke, but stroke accounts for a disproportionate share of poor outcomes when missed.4 The TiTrATE triage is built to find that minority efficiently without dragging every dizzy patient through the same imaging algorithm.