Dizziness Red Flag Screener

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name: dizziness-red-flag-screener
description: Screens any dizzy patient for features that mandate urgent neuroimaging or neurology referral — distinguishing benign peripheral dizziness from a central or life-threatening cause. Use when a patient presents with dizziness and you want to quickly rule out stroke, cerebellar lesion, or other dangerous aetiology before attributing symptoms to a benign cause. Trigger phrases: "could this dizziness be serious", "rule out stroke in dizzy patient", "when to image a dizzy patient", "red flags in dizziness", "urgent referral for dizziness".
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# Dizziness Red Flag Screener

> Run this checklist on EVERY patient presenting with new or acute dizziness before attributing it to a benign peripheral cause.

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## 🚨 Immediate Red Flags — Neuroimaging + Neurology Now

Any ONE of the following warrants urgent MRI brain (CT is insufficient for posterior fossa):

| Red Flag | Why It Matters |
|---|---|
| Severely ataxic gait — patient staggers, falls, or cannot walk | Cerebellar stroke until proven otherwise |
| Skew deviation (vertical misalignment of eyes) | Highly specific for central vestibular lesion |
| Direction-changing nystagmus | Central sign; peripheral nystagmus is unidirectional |
| Purely vertical or purely torsional nystagmus | Cannot be explained by peripheral vestibular disease |
| Nystagmus NOT suppressed by visual fixation | Peripheral nystagmus is suppressed; central is not |
| Abnormal HINTS exam in acute prolonged vertigo | Direction-changing nystagmus OR no corrective saccade on head impulse OR skew deviation |
| New brainstem signs: diplopia, dysarthria, dysphagia, facial numbness, Horner syndrome | Brainstem stroke or demyelination |
| New limb weakness, sensory deficit, or incoordination | Central lesion |
| Severe occipital / neck headache with acute vertigo | Vertebral artery dissection or posterior fossa haemorrhage |
| Sudden onset hearing loss + acute vertigo | Labyrinthine infarct — vascular emergency |

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## ⚠️ Concerning Features — Urgent Workup Required (Same Day / Next Day)

| Feature | Consider |
|---|---|
| Atypical Dix-Hallpike: immediate onset, non-fatiguing, duration >1 min, minimal vertigo | Posterior fossa lesion; MRI brain |
| Acute prolonged vertigo + any abnormal neuro finding | Central pathology |
| Dizziness in setting of new cardiac arrhythmia or palpitations | Cardiac cause; ECG, Holter |
| Dizziness while lying down (not positional) | Cardiac arrhythmia; ECG |
| Acute dizziness + orthostatic hypotension + new medication | Drug-induced; medication review + orthostatic vitals |
| First episode of severe vertigo in patient >60 with vascular risk factors | Posterior circulation TIA/stroke; urgent MRI + vascular imaging |
| Progressive imbalance over weeks (not acute) | CNS mass lesion, cerebellar degeneration |

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## ✅ Reassuring (Low-Risk) Features

The following features together suggest a benign peripheral aetiology:

- Unidirectional nystagmus, suppressed by fixation
- Typical Dix-Hallpike response (2–20s latency, <1 min duration, fatigues, severe vertigo)
- Normal neurologic examination (gait, cranial nerves, coordination)
- No new brainstem or cerebellar symptoms
- Dizziness worsened by head movement (vestibular pattern)
- Associated unilateral hearing loss / tinnitus (suggests peripheral labyrinthine cause)

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## Quick HINTS Exam (for Acute Prolonged Severe Vertigo)

Perform when the patient has acute, prolonged, severe dizziness that has NOT resolved:

| Test | Peripheral result | Central result |
|---|---|---|
| **H** — Head Impulse Test | Corrective saccade present (abnormal VOR) | No corrective saccade (normal-appearing VOR) |
| **I** — Nystagmus direction | Unidirectional | Direction-changing |
| **TS** — Test of Skew | No skew deviation | Skew deviation present |

> ✅ All three peripheral = vestibular neuritis (benign)
> 🚨 Any single central result = neuroimaging urgently

> ⚠️ **HINTS is only valid in acute continuous vertigo** — do not apply to episodic or resolved dizziness.

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## Clinical Guardrails

- **Normal MRI in first 24–48h does NOT exclude posterior fossa stroke** — DWI sensitivity is ~80% in the first 24 hours for cerebellar/brainstem infarcts. If clinical suspicion is high, repeat MRI at 48–72h or discuss with neurology.
- **HINTS exam requires training** — if you are not confident performing it, default to neuroimaging in any acute prolonged vertigo with vascular risk factors.
- **Dizziness alone can be the only presentation of a posterior circulation stroke** — do not require other neurologic signs to be present before imaging.
- **Older patients with vascular risk factors** (hypertension, diabetes, AF, prior TIA/stroke) have a much higher prior probability of central cause — lower your threshold for imaging.
- **Drug-induced dizziness** is common and remediable — always review the medication list (antihypertensives, antidepressants, anticonvulsants, anticholinergics, vestibulotoxic drugs).

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*Source: Barton JS. "Approach to the patient with dizziness." UpToDate. Last updated Dec 11, 2025.*