What physical exam and tests can differentiate between central and peripheral vertigo?

Differentiating Central from Peripheral Vertigo

Use the HINTS examination (Head Impulse, Nystagmus, Test of Skew) in patients with acute vestibular syndrome, as it demonstrates 92.9% sensitivity and 83.4% specificity for identifying central causes, making it superior to individual neurologic examination findings. 1

Categorize by Timing Pattern First

Before examining nystagmus characteristics, classify vertigo into one of four syndromes based on timing and triggers 2:

• Acute vestibular syndrome: Continuous dizziness lasting days to weeks with nausea, vomiting, and intolerance to head motion (includes vestibular neuritis, labyrinthitis, or posterior circulation stroke) 2
• Triggered episodic vestibular syndrome: Brief episodes (<1 minute) triggered by specific head/body position changes (includes BPPV or postural hypotension) 2
• Spontaneous episodic vestibular syndrome: Episodes lasting minutes to hours without triggers (includes vestibular migraine, Ménière's disease, or vertebrobasilar TIA) 2
• Chronic vestibular syndrome: Dizziness lasting weeks to months (includes anxiety disorders, medication side effects, or posterior fossa masses) 2

Nystagmus Characteristics: The Primary Differentiator

Peripheral Vertigo Nystagmus 2:

• Horizontal with rotatory/torsional component
• Unidirectional (beats in same direction regardless of gaze)
• Suppressed by visual fixation
• Fatigable with repeated testing
• Brief latency period before onset (typically 5-20 seconds)

Central Vertigo Nystagmus 2:

• Pure vertical (upbeating or downbeating) without torsional component
• Direction-changing without changes in head position
• Direction-switching with gaze (gaze-evoked nystagmus)
• Not suppressed by visual fixation
• Persistent without modification on repositioning maneuvers
• Baseline nystagmus present without provocative maneuvers

The HINTS Examination: Gold Standard for Acute Vestibular Syndrome

HINTS should only be performed in patients with acute vestibular syndrome (continuous symptoms), not in episodic vertigo. 1 The examination consists of three components:

1. Head Impulse Test (HIT) 1:

• Abnormal (corrective saccade) = peripheral cause (sensitivity 76.8%, specificity 89.1%)
• Normal = suggests central cause in the context of acute vestibular syndrome
• Perform by rapidly rotating the patient's head 10-20 degrees while they fixate on your nose

2. Nystagmus Type 1:

• Bidirectional, vertical, direction-changing, or pure torsional = central (sensitivity 50.7%, specificity 98.5%)
• Unidirectional horizontal-torsional = peripheral

3. Test of Skew 1:

• Skew deviation present = central (sensitivity 23.7%, specificity 97.6%)
• Perform alternate cover test looking for vertical refixation saccade

Complete HINTS examination achieves 92.9% sensitivity and 83.4% specificity for central causes when performed by trained clinicians. 1

HINTS+ (Add Hearing Assessment) 1:

• Adding acute hearing loss assessment increases sensitivity to 99.0% and maintains 84.8% specificity
• New hearing loss with otherwise "benign" HINTS = consider labyrinthitis (peripheral) or anterior inferior cerebellar artery stroke (central)

Dix-Hallpike Maneuver Interpretation

Peripheral (BPPV) Pattern 2:

• Latency of 5-20 seconds before nystagmus onset
• Torsional and upbeating nystagmus
• Crescendo-decrescendo pattern
• Fatigability on repeat testing
• Resolution within 60 seconds

Central Pattern 2:

• Immediate onset without latency
• Persistent nystagmus that doesn't fatigue
• Purely vertical without torsional component
• Downbeating nystagmus is particularly concerning for central pathology

Critical Red Flags Demanding Immediate Neuroimaging

Approximately 25% of patients with acute vestibular syndrome have cerebrovascular disease, rising to 75% in high vascular risk cohorts. 2 Red flags include:

• Severe postural instability with falling (central causes produce significantly more severe balance impairment than peripheral disorders) 2
• New-onset severe headache with vertigo (may indicate vertebrobasilar stroke or hemorrhage) 2
• Any additional neurological symptoms: dysarthria, dysmetria, dysphagia, sensory or motor deficits, diplopia, or Horner's syndrome 2
• Downbeating nystagmus on Dix-Hallpike without torsional component 2
• Limb weakness or hemiparesis (sensitivity 11.4%, specificity 98.5%) 1
• Truncal/gait ataxia (increasing severity correlates with central etiology; sensitivity 69.7%, specificity 83.7%) 1
• Failure to respond to appropriate peripheral vertigo treatments 2
• Apogeotropic horizontal nystagmus on supine roll test 3
• Isolated positional downbeat nystagmus 3

Additional Neurologic Examination Findings

General Neurologic Examination 1:

• Pooled sensitivity 46.8%, specificity 92.8% for central causes
• Low sensitivity means normal exam does not rule out central pathology

Dysmetria Signs 1:

• Sensitivity 24.6%, specificity 97.8%
• Finger-to-nose and heel-to-shin testing

Limb Weakness/Hemiparesis 1:

• Sensitivity 11.4%, specificity 98.5%
• Highly specific but very insensitive—absence does not exclude central cause

Common Clinical Pitfalls to Avoid

• Do not rely on general neurologic examination alone: 46.8% sensitivity means over half of central causes will have normal findings 1
• Do not perform HINTS in episodic vertigo: HINTS is only validated for acute vestibular syndrome with continuous symptoms 1
• Do not assume BPPV based on positional symptoms alone: Central pathologies can mimic BPPV, particularly with apogeotropic nystagmus or isolated downbeat nystagmus 3
• Do not miss subtle neurological signs: Careful assessment without confirmatory bias is essential to identify rare central causes presenting as peripheral vertigo 3
• Consider vertebrobasilar insufficiency: Isolated transient vertigo may precede stroke by weeks or months, with episodes typically lasting <30 minutes without hearing loss 2
• Recognize that 10% of cerebellar strokes present similarly to peripheral vestibular disorders 2

When to Order Additional Testing

Do NOT Order Routine Testing 4:

• Neuroimaging should not be routinely used in diagnosed BPPV without red flags
• Vestibular testing should not be ordered in patients meeting diagnostic criteria for BPPV without additional vestibular signs/symptoms inconsistent with BPPV

DO Order Testing When 4:

• Clinical presentation is atypical
• Dix-Hallpike testing elicits equivocal or unusual nystagmus findings
• Additional symptoms suggest accompanying CNS or otologic disorder
• Multiple concurrent peripheral vestibular disorders suspected
• Any red flags for central pathology present