TABLE OF CONTENTS
KEY
🔍 | Deep Dive |
📌 | Clinical Application |
🔸 | Weak Evidence |
🔹 | Strong Evidence |
📑 | Evidence summaries |
✅ | Recommended treatment |
⚠️ | Critical Information |
💡 | Extra Reading |
❗ | Caveats |
Recently, I listened to a podcast by Scott Weingart and it made me rethink a few things. Many of us hear “giddiness” and jump to ordering an MRI
Just to be safe.
But maybe there’s a better way to approach this.
What is “Giddiness”?
Let’s start by defining a few words.
I’m not bringing this up to be academic. I’m bringing it up because what our patients call “giddiness” can mean a whole range of very different things.
Broadly, these symptoms fall into four groups:
- Vertigo
- Internal vertigo → A false or distorted sensation of self-motion
- External vertigo → A false or distorted sensation that the environment is moving
- Dizziness → The sensation of disturbed or impaired spatial orientation without a distorted sense of motion
- Vestibulo-visual symptoms
- Postural symptoms → The sensation of disturbed or impaired spatial orientation without a false or distorted sense of motion
Remember Hickam’s dictum here
Patients may have more than one type of symptom at the same time.
Patients may have more than one type of symptom at the same time.
Spinning vertigo that changes direction during a single episode is classically described in Ménière’s disease.
Now that we’ve defined all this, it’s tempting to think that asking, “What do you mean by dizzy?” will neatly sort patients into categories. And for a long time, that’s exactly how we approached it.
But patients don’t read textbooks. They don’t neatly separate vertigo from dizziness or unsteadiness.
What’s become clearer over time is that how the symptom behaves matters more than how it’s described. This is where the GRACE-3 guidelines [2] come in, focusing on timing and triggers.
And this now forms the backbone of how we approach dizziness today.
The assessment in ER, of course, should start with ruling out the most life-threatening first
Step 1: Are there any neurologic red flags?
Look for any of these:
- Significant headache or neck pain
- Motor or sensory deficits
Especially the face or upper limbs
- The 5 Deadly Ds
- Diplopia
- Dysarthria
- Dysphagia
- Dysphonia
- Dysmetria
- Any cranial nerve dysfunction
Especially spontaneous nystagmus at rest
- Any cerebellar dysfunction
- Truncal ataxia
- Severe gait ataxia/inability to walk unaided
Remember: many dizzy patients feel unsteady, but the inability to walk unaided is the key red flag
If any red flag is present, evaluate for a possible central cause.
Step 2 - Is this actually vertigo?
My earlier approach was to ask patients to explain what they meant by “vertigo.” But over time, and with newer evidence, I’ve started to question how useful that really is, as we discussed earlier.
Studies suggest many patients change how they describe dizziness when asked again minutes later, and many report more than one type of symptom [3]
So instead of relying only on symptom labels, take a careful history and perform a focused clinical examination to look for an obvious medical (non-vestibular) cause.
Common examples include:
- Toxicological causes
- Hypovolaemia
- Cardiac arrhythmia
- Anemia
- Hypoglycaemia
- Infection/sepsis
- Electrolyte disturbance
If a clear medical cause explains the symptoms, manage that first before labelling it as vertigo.
Step 3 - Attempt to classify the vestibular syndrome
The GRACE-3 Guidelines approach classifies vestibular presentations into three main syndromes [2]
- Acute Vestibular Syndrome (AVS)
Acute onset of continuous, persistent dizziness lasting >24 hours
- Spontaneous Episodic Vestibular Syndrome (s-EVS)
Recurrent episodes of dizziness without a clear trigger
- Triggered Episodic Vestibular Syndrome (t-EVS)
Brief episodes of dizziness clearly triggered by movement or position change
It is important to recognise the likely differentials for each syndrome, as serious conditions can mimic benign vertigo, though this is not an exhaustive list.
Syndrome | Common benign cause | Potentially serious cause |
AVS | Vestibular neuritis | Posterior circulation stroke |
s-EVS | Vestibular migraine, Ménière’s disease | Posterior circulation TIA |
t-EVS | BPPV | Central positional vertigo due to posterior circulation stroke or posterior fossa mass |
Once the syndrome is identified, the next step is to distinguish benign from urgent/emergent causes.
1. Acute vestibular syndrome (AVS)
🔹 In patients with nystagmus, trained clinicians should use HINTS testing to distinguish central (stroke) from peripheral (inner ear, usually vestibular neuritis) diagnoses.
What is the HINTS exam? [4]
- HI – Head Impulse Test
Ask the patient to fix their gaze on your nose. Rapidly rotate the head about 15–20° to each side. - Normal test → gaze remains fixed despite symptoms
(Intact vestibulo-ocular reflex → Concerning for central cause) - Abnormal test → unable to maintain gaze and have corrective saccade
(Impaired vestibulo-ocular reflex →Suggests peripheral cause)
- N – Nystagmus
Assess in primary gaze and lateral gaze. - Peripheral pattern
- Unidirectional horizontal nystagmus
- Fast phase remains the same direction regardless of gaze
- Central pattern
- Direction-changing horizontal nystagmus
- Vertical nystagmus
- Pure torsional nystagmus
Pure torsional or vertical spontaneous nystagmus strongly suggests a central neurological cause.
- TS – Test of Skew
Ask the patient to maintain fixation on your nose. Cover one eye, then quickly uncover it while covering the other eye, alternating sides repeatedly. At no point should both eyes be uncovered during the manoeuvre. - Vertical or diagonal corrective realignment on uncovering → highly concerning for a central cause.
- No skew deviation → consistent with a peripheral cause.
Feature | Peripheral Vertigo | Central Vertigo |
Head Impulse Test | Abnormal – corrective saccade to midline with head rotation | Normal – no corrective saccade |
Nystagmus | Unidirectional, horizontal | Direction-changing; can be horizontal, vertical, or torsional |
Test of Skew | No skew deviation | Skew deviation present |
The key point is that HINTS should only be used in patients with
- Acute vestibular syndrome patients who have continuous ongoing vertigo/dizziness
And
- Spontaneous nystagmus
As the exam is reliable only when symptoms are present.
No single part of the HINTS exam is enough on its own to exclude a central cause, but when all three findings are reassuring, it strongly suggests a peripheral diagnosis.
In the original study, HINTS identified ischemic stroke in AVS with higher sensitivity than an initial MRI-DWI (100% vs 88%).
Why use HINTS Plus?
However, an important limitation of HINTS exam is that AICA territory ischemia can mimic a peripheral pattern, especially in patients with vascular risk factors, sudden onset symptoms, or associated ipsilateral hearing loss.
🔹That is why GRACE 3 recommends that in patients with nystagmus, assess hearing by finger rub to distinguish central from peripheral diagnoses.
Why does this matter? Because new unilateral hearing loss in Acute Vestibular Syndrome (AVS) should raise concern for Anterior Inferior Cerebellar Artery (AICA) ischemia.
The inner ear is highly vulnerable to reduced blood flow because it is supplied by the internal auditory artery, essentially an end artery with limited backup circulation. If that vessel is compromised, auditory symptoms may appear before or along with stroke signs.
Sometimes the warning comes earlier. Brief episodes of vertigo with tinnitus or one-sided hearing loss lasting minutes may represent AICA TIAs before a completed stroke.
So when a patient presents with continuous vertigo and nystagmus, HINTS alone are not enough if hearing is abnormal.
That is where HINTS Plus comes in:
- Head Impulse
- Nystagmus
- Test of Skew
- Plus bedside hearing assessment
It is a small addition, but clinically important. Because occasionally, the ear gives away what the eyes do not.
But have you actually tried doing this on a real patient in a busy emergency department?
If yes, you may understand the slightly exhausted feeling some clinicians have when HINTS is presented as a simple solution to dizziness. On paper, it looks elegant. At the bedside, it is often far messier.
The original HINTS study was performed by highly trained neuro-ophthalmologists with substantial expertise in eye movement examination. [4]
Real-world data reflects this gap.
In one emergency department review, 96.9% of patients who received HINTS did not actually meet the criteria used in validation studies. Most commonly [5]
- No documented spontaneous nystagmus
- Symptoms were intermittent rather than continuous
- Patients received both HINTS and Dix-Hallpike, even though these tests are designed for different clinical syndromes
And perhaps the most striking finding: no central cause of dizziness was identified using HINTS in that cohort.
The authors concluded that although HINTS was widely used in the ED, its practical diagnostic value was limited because it was often applied to the wrong patients, and further physician training would likely be needed to improve accuracy.
What if the patient has no nystagmus?
GRACE 3 suggests
🔹 In patients without nystagmus, assess the severity of gait unsteadiness to distinguish central from peripheral diagnoses.
🔹 In patients without nystagmus, assess the severity of gait unsteadiness to distinguish central from peripheral diagnoses.
When AVS is caused by a peripheral vestibular lesion, imbalance is usually mild to moderate, and most patients can still walk unaided with encouragement.
By contrast, in AVS without spontaneous nystagmus, gait ataxia should not be assumed to have a benign cause.
Spontaneous Episodic Vestibular Syndrome (s-EVS)
In spontaneous episodic vestibular syndrome, bedside eye findings are often absent by the time the patient is examined, so diagnosis relies heavily on history and a focused neurologic exam.
So GRACE 3 says
🔹Clinicians should perform a history and physical exam with emphasis on cranial nerves, visual fields, eye movements, limb coordination, and gait assessment to distinguish between central (TIA) and peripheral (vestibular migraine, Menière disease) diagnoses.
Triggered Episodic Vestibular Syndrome (t-EVS)
When dizziness is brief, positional, and reliably triggered by head movement, think BPPV first. In this group, the correct bedside test is not HINTS, but the Dix-Hallpike manoeuvre, used to diagnose posterior canal BPPV.
A positive Dix-Hallpike reproduces vertigo and causes a characteristic nystagmus that is:
- Latent – begins after a short delay of a few seconds (sometimes longer)
- Transient – gradually settles, usually within 15–30 seconds
- Typical in direction – classically upbeat torsional
Interestingly, gaze position can change how it appears: looking toward the downward ear may make it look more torsional, while looking upward may make it appear more vertical. This is expected physiology, not a red flag.
If Dix-Hallpike is negative on both sides, or if the nystagmus is horizontal, consider lateral canal BPPV (horizontal canal). In that situation, perform the Supine Roll test.
Anterior canal BPPV is uncommon, but worth remembering. It can present with bilateral downbeat nystagmus during Dix-Hallpike.
Treatment should match the canal involved:
- Posterior canal → Epley manoeuvre
- Lateral canal → Gufoni manoeuvre
One practical tip: keep the patient in each position of the Epley manoeuvre for at least 30 seconds before moving to the next step.
Standing Algorithm
Another structured way to approach vertigo is the STANDING algorithm (SponTAneous Nystagmus, Direction, head Impulse test, standing) [7]
It is a four-step emergency department tool designed to differentiate central from peripheral causes of acute vertigo.
It is a four-step emergency department tool designed to differentiate central from peripheral causes of acute vertigo.
- Is there nystagmus? What type?
Start by looking for nystagmus (ideally with Frenzel lenses, though rarely available in ED reality).
- Spontaneous nystagmus present → move to the direction of assessment
- No nystagmus → provoke it:
- Dix-Hallpike → posterior canal
- Pagnini–McClure (Supine Roll) → lateral canal
If positional nystagmus is triggered, this strongly points toward BPPV
- What is the direction?
If spontaneous nystagmus is present, classify its direction:
- Horizontal unidirectional
- Multidirectional / direction-changing
- Vertical
This is an important decision point.
- Vertical or multidirectional nystagmus raises immediate concern for a central cause and should prompt further investigation.
- Horizontal unidirectional nystagmus may still be peripheral, and the algorithm proceeds to the Head Impulse Test.
- Head Impulse Test (HIT)
This evaluates the vestibulo-ocular reflex (VOR).
Interpretation:
- Positive HIT on the side of unidirectional nystagmus suggests a peripheral vestibular lesion
- Normal HIT despite spontaneous nystagmus raises suspicion for a central lesion
Both sides should be tested.
- Standing and Gait
The final step is applied to all patients, but becomes particularly important in those with no spontaneous or positional nystagmus.
The patient is asked to stand and walk.
If the patient is:
- Unable to stand unsupported
- Unable to walk independently
- Markedly unstable out of proportion to symptoms
Then a central cause of vertigo should be suspected, particularly cerebellar pathology.
Limitations
Like many bedside algorithms, it sounds easier than it is.
- Frenzel lenses are uncommon in many EDs
- Detecting subtle nystagmus requires experience
- Correctly performing Dix-Hallpike, Supine Roll, and HIT still requires skill
- No formal test of skew
- No hearing assessment
- Poor fit for episodic dizziness when symptoms have resolved.
- Uses gait as a catch-all late step.
A prospective multicentre study of 456 ED patients with vertigo found the STANDING algorithm had strong performance for detecting central vertigo: sensitivity 88.2%, specificity 91.6%, and negative predictive value 99%. Compared with usual care, it was also associated with fewer non-contrast head CT scans (48.3% vs 66.8%) and a shorter ED length of stay.
That said, nearly half of patients still underwent non-contrast head CT, which reminds us of a recurring truth in dizziness medicine: even promising bedside algorithms do not completely eliminate uncertainty, imaging, or the need for clinical judgment.
Sudbury Vertigo Risk Score
I cannot end this article without mentioning the Sudbury Vertigo Risk Score [6] ,though it is not my favourite way to risk-stratify the dizzy patient.
Predictor | Points |
Stroke Risk Factors | ㅤ |
Male | 1 |
Age > 65 | 1 |
Diabetes | 1 |
Hypertension | 3 |
Neurologic Deficits | ㅤ |
Motor/Sensory | 5 |
Cerebellar | 6 |
BPPV Diagnosis | -5 |
Derivation study in adults showed 100% sensitivity, 72% specificity, and excellent discrimination (C-statistic 0.97) for serious central causes (stroke, TIA, vertebral-artery dissection, or brain tumour).
Interpretation
- Low risk (<5): Imaging is usually unnecessary if no red flags are present. Treat likely benign causes, give symptom relief, and discharge with safety-net advice.
- Moderate risk (5–8): If a peripheral cause is not clear, consider MRI ± vascular imaging. Further work-up should depend on clinical context and comorbidities.
- High risk (>8): Urgent evaluation and neuroimaging for a central cause are warranted. Consider admission and address vascular risk factors.
The most obvious limitation is that the Sudbury Vertigo Risk Score has not been externally validated, something the authors themselves acknowledge repeatedly. Until that happens, it is hard to justify using it routinely in clinical practice.
Another issue is how stroke and TIA were defined. Many patients never had imaging, let alone an MRI. A significant amount of outcome data came from follow-up phone calls using broad WHO definitions. That may have overestimated vascular events, while also potentially missing small posterior circulation strokes.
But honestly, my bigger concerns are the components themselves.
- BPPV diagnosis is part of the score, but if we already know it is BPPV, why do we need the score?
- Much of it is essentially a list of familiar stroke risk factors.
- And if there are clear neurologic deficits, most of us are getting an MRI anyway.
Having said all that, I still think it has some practical value. If a dizzy patient stacks up multiple risk factors on the score, it may be wiser to get an MRI than place too much faith in your own HINTS or Dix-Hallpike skills
Understanding Nystagmus in “Dizzy” patients
Broadly, we assess nystagmus in three settings:
- Spontaneous nystagmus at rest
- Gaze-evoked nystagmus (during HINTS/HINTS+ assessment)
- Positional nystagmus triggered during bedside tests for BPPV
1. Spontaneous Nystagmus at Rest
This is nystagmus present while the patient is looking straight ahead.
Suggestive of Peripheral Cause
- Horizontal unidirectional nystagmus (can rarely occur in central lesions such as AICA stroke)
- Can be combined with torsional nystagmus
Suggestive of Central Cause
- Vertical nystagmus (upbeat or downbeat)
- Pure torsional nystagmus
2. Gaze-Evoked Nystagmus
The patient looks left and right while you observe for changes.
Peripheral Pattern
- Horizontal unidirectional nystagmus
- The fast phase remains the same direction whether the patient looks left or right
Central Pattern
- Bidirectional horizontal gaze-evoked nystagmus
- Beats right on right gaze and left on left gaze
Mild nystagmus at the extreme end of lateral gaze can be a normal finding (end-gaze nystagmus) and should not be overcalled as pathological.
3. Positional Nystagmus (BPPV Testing)
This occurs only when triggered by head movement during manoeuvres such as Dix-Hallpike or Supine Roll testing.
BPPV Type | When Elicited | Nystagmus Pattern | Important Interpretation Points |
Posterior Canal BPPV | Dix-Hallpike | Upbeat torsional | Usually has a short latency and is transient. |
Lateral Canal BPPV | Supine Roll Test | Horizontal | Can be positive on both sides. May be toward the ground or away from the ground. |
Anterior Canal BPPV | Dix-Hallpike | Downbeat positional | Rare pattern. Can also be seen in the central cause. |
- BPPV does not usually cause spontaneous nystagmus. If nystagmus is present at rest, reconsider the diagnosis.
- Vertical or torsional nystagmus during BPPV testing is not necessarily central. When provoked by positional manoeuvres, it may represent typical peripheral BPPV.
How to Send a Patient with Constant Dizziness Home without an MRI and Still Sleep at Night
This part I shamelessly borrowed from Scott Weingart, inspired by Peter’ John’s video below.
- No new or presumed central features on a full neurological exam (Specifically check for the Dangerous D’s)
- Able to walk unaided
- If the patient has nystagmus
- Head Impulse test abnormal
- No vertical or torsional nystagmus at rest
- No direction-changing gaze-evoked nystagmus
- With or without nystagmus
- Normal Test of Skew
- No new hearing loss
What Matters…
Before you plan an MRI for your “dizzy” patient, ask these:
1️⃣ Are there any neurologic red flags?
Look for any of these:
- Significant headache or neck pain
- Motor or sensory deficits
Especially the face or upper limbs
- The 5 Deadly Ds
- Diplopia
- Dysarthria
- Dysphagia
- Dysphonia
- Dysmetria
- Any cranial nerve dysfunction
Especially spontaneous nystagmus at rest
- Any cerebellar dysfunction
- Truncal ataxia
- Severe gait ataxia/inability to walk unaided
→ If any red flag is present, evaluate for a possible central cause.
2️⃣ Is this actually vertigo?
Take a careful history and perform a focused clinical examination to look for an obvious medical (non-vestibular) cause.
Common examples include:
- Toxicological causes
- Hypovolaemia
- Cardiac arrhythmia
- Anemia
- Hypoglycaemia
- Infection/sepsis
- Electrolyte disturbance
→ If a clear medical cause explains the symptoms, manage that first before labelling it as vertigo.
3️⃣ Is the giddiness continuous?
→ If yes: think Acute Vestibular Syndrome (AVS)
Use HINTS Plus (only in ongoing AVS with spontaneous nystagmus) to help differentiate peripheral vs central causes.
→ If no: ask if it is triggered.
- No trigger → Spontaneous Episodic Vestibular Syndrome (s-EVS)
Use history + focused neuro exam to look for central causes.
- Triggered by position/head movement → Triggered Episodic Vestibular Syndrome (t-EVS)
Use the Dix-Hallpike or Supine Roll Test to diagnose BPPV.
Want to Read More?
- Kattah, Jorge C., et al. "HINTS to diagnose stroke in the acute vestibular syndrome: three-step bedside oculomotor examination more sensitive than early MRI diffusion-weighted imaging." Stroke 40.11 (2009): 3504-3510.
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