How do you differentiate between central and peripheral vertigo?

Differentiating Central vs Peripheral Vertigo

The most reliable way to differentiate central from peripheral vertigo is through nystagmus characteristics combined with neurological examination findings, where peripheral vertigo produces horizontal-rotatory, unidirectional, fatigable nystagmus that suppresses with visual fixation, while central vertigo produces pure vertical or direction-changing nystagmus that persists with visual fixation and is accompanied by other neurological deficits. 1

Nystagmus Pattern Analysis (Most Critical Distinguishing Feature)

Peripheral Vertigo Nystagmus

• Horizontal with rotatory (torsional) component 1
• Unidirectional - beats in the same direction regardless of gaze 1
• Suppressed by visual fixation - diminishes when patient focuses on an object 1, 2
• Fatigable - decreases with repeated testing 1
• Brief latency period before onset after provocative maneuvers 1

Central Vertigo Nystagmus

• Pure vertical (upbeating or downbeating) without torsional component 1, 3
• Direction-changing - switches direction with different gaze positions 1
• Not suppressed by visual fixation - persists when patient focuses 1, 2
• Non-fatigable - persists without modification during repositioning maneuvers 1
• May be present at baseline without any provocative maneuvers 1

Associated Neurological Symptoms

Central Vertigo Red Flags

Central vertigo nearly always presents with additional neurological deficits, including: 1

• Dysarthria (speech difficulty) 1
• Dysmetria (coordination problems) 1
• Dysphagia (swallowing difficulty) 1
• Sensory or motor deficits 1
• Diplopia (double vision) 1
• Horner's syndrome 1
• Limb or gait ataxia 4

Peripheral Vertigo Characteristics

• Isolated vertigo without neurological signs 1
• May have auditory symptoms (hearing loss, tinnitus, aural fullness) 1
• Presence of syncope excludes peripheral causes 5

Dix-Hallpike Maneuver Interpretation

Peripheral Pattern (BPPV)

• Characteristic nystagmus with latency (delay before onset) 1
• Fatigability with repeated testing 1
• Horizontal-rotatory nystagmus 1

Central Pattern

• Immediate onset without latency 1
• Persistent, purely vertical nystagmus (especially downbeating) 1, 3
• No fatigability 1
• Downbeating nystagmus without torsional component is a major red flag 1

Duration of Vertigo Episodes

Episode duration is highly discriminatory: 3

• Vertebrobasilar insufficiency (central): typically lasts minutes (less than 30 minutes) 1, 3
• Peripheral causes: typically last hours 3
• BPPV: seconds to minutes with position changes 1
• Vestibular neuritis: days to weeks of continuous vertigo 1
• Ménière's disease: hours per episode 1

Response to Treatment

• Peripheral vertigo responds to canalith repositioning procedures (Epley maneuver) or vestibular rehabilitation 1
• Central vertigo does not respond to these interventions 1
• Failed sustained response to repositioning maneuvers is a red flag for central pathology 4

Critical Red Flags Requiring Urgent Imaging

Any of these findings mandate immediate MRI evaluation: 1, 3

• Downbeating nystagmus on Dix-Hallpike without torsional component 1
• Baseline nystagmus without provocative maneuvers 1
• New-onset severe headache with vertigo (suggests vertebrobasilar stroke or hemorrhage) 1
• Profound imbalance with acute vertigo (cerebellar infarction can masquerade as peripheral vertigo) 3
• Apogeotropic horizontal nystagmus on supine roll test 4
• Isolated positional downbeat nystagmus 4

Common Pitfalls to Avoid

• 10% of cerebellar strokes present identically to peripheral vestibular disorders - cerebellar infarction is the central lesion most likely to masquerade as peripheral vertigo 1, 3
• Overlooking subtle neurological signs that indicate central pathology 1
• Availability heuristic bias - assuming all positional vertigo is BPPV without proper examination 4
• Missing vertebrobasilar insufficiency - isolated vertigo attacks may precede stroke by weeks or months 1
• In elderly patients, vertigo is often multifactorial and requires careful evaluation 5