What is the best approach to perform a physical exam to differentiate central from peripheral vertigo in a patient?

Physical Examination to Differentiate Central from Peripheral Vertigo

The physical exam should focus on nystagmus characteristics during the Dix-Hallpike maneuver, presence of additional neurological signs, and severity of postural instability—with central causes showing pure vertical nystagmus without torsional component, immediate onset without latency, no fatigability, and associated neurological deficits. 1

Nystagmus Examination: The Primary Distinguishing Feature

Peripheral Vertigo Nystagmus Pattern

• Horizontal with rotatory (torsional) component 1
• Unidirectional (beats in same direction regardless of gaze) 1
• Suppressed by visual fixation (ask patient to focus on object) 1
• Fatigable with repeated testing (diminishes with repeated Dix-Hallpike maneuvers) 1
• Brief latency period (3-10 seconds) before onset 1

Central Vertigo Nystagmus Pattern

• Pure vertical (upbeating or downbeating) without torsional component 2, 1
• Direction-changing without head position changes (periodic alternating nystagmus) 2, 1
• Direction-switching with gaze (beats right with right gaze, left with left gaze) 2, 1
• Not suppressed by visual fixation 1, 3
• Baseline nystagmus present without provocative maneuvers 2, 1
• Does not fatigue with repeated testing 2, 1

Dix-Hallpike Maneuver Interpretation

Peripheral (BPPV) Response

• Latency of 3-10 seconds before nystagmus onset 1
• Torsional and upbeating nystagmus with crescendo-decrescendo pattern 1
• Resolution within 60 seconds 1
• Fatigability on repeat testing 1

Central Cause Response

• Immediate onset without latency 1
• Persistent nystagmus that does not resolve 1
• Purely vertical without torsional component 1
• Downbeating nystagmus particularly concerning for central pathology 2, 1

Neurological Examination: Critical for Central Causes

Associated Neurological Signs Indicating Central Pathology

• Dysarthria (speech difficulty) 1
• Dysmetria (finger-to-nose testing abnormality) 1
• Dysphagia (swallowing difficulty) 1
• Sensory or motor deficits 1
• Diplopia (double vision) 1
• Horner's syndrome 1
• Limb weakness or hemiparesis 1
• Truncal or gait ataxia 1

Postural Stability Testing

Severity Assessment

• Severe postural instability with falling strongly suggests central causes, particularly vertebrobasilar insufficiency or cerebellar lesions 1, 3
• Central causes produce significantly more severe balance impairment compared to peripheral disorders 1
• Peripheral vestibular disorders allow patients to maintain some degree of postural control 1

Gaze Testing

Central Pattern

• Gaze-evoked nystagmus (nystagmus that appears or intensifies with lateral gaze) is typical of central lesions 2, 1
• Nystagmus not suppressed by gaze fixation indicates central pathology 2, 1

Peripheral Pattern

• Nystagmus suppressed when patient focuses on a visual target 1, 4

Red Flags Demanding Immediate Neuroimaging

• Downbeating nystagmus on Dix-Hallpike without torsional component 2, 1
• Baseline nystagmus without provocative maneuvers 2, 1
• New-onset severe headache with vertigo (vertebrobasilar stroke or hemorrhage) 1
• Any additional neurological symptoms 1
• Severe postural instability with falling 1
• Limb weakness or hemiparesis 1
• Truncal/gait ataxia 1
• Apogeotropic horizontal nystagmus on supine roll test 1
• Isolated positional downbeat nystagmus 1

Duration and Timing Assessment

Episode Duration Patterns

• Less than 1 minute: BPPV (peripheral) 1
• Less than 30 minutes: Vertebrobasilar insufficiency (central) 2, 1
• Hours: Ménière's disease (peripheral) 1
• Days to weeks: Vestibular neuritis (peripheral) or cerebellar infarction (central) 1

Critical Pitfall to Avoid

Cerebellar infarction can masquerade as peripheral vestibular lesion because vertigo and severe imbalance may be the only presenting features—MRI is indicated in any patient with acute vertigo and profound imbalance 3. Approximately 25% of patients with acute vestibular syndrome have cerebrovascular disease, rising to 75% in high vascular risk cohorts 1. The combination of vertigo with severe postural instability warrants immediate neuroimaging, as isolated transient vertigo may precede vertebrobasilar stroke by weeks or months 1.

Response to Treatment Assessment

• Peripheral vertigo responds to canalith repositioning procedures or vestibular rehabilitation 1
• Central vertigo does not respond to these interventions 1
• Failure to respond to appropriate peripheral vertigo treatments is a red flag for central causes 2, 1