What are the key differences between central vertigo and peripheral vertigo in terms of presentation, diagnosis, and treatment?

Distinguishing Central from Peripheral Vertigo

The critical distinction between central and peripheral vertigo relies primarily on nystagmus characteristics, with peripheral vertigo producing horizontal-torsional nystagmus that fatigues and is suppressed by visual fixation, while central vertigo produces pure vertical or direction-changing nystagmus that persists without fatigue and is not suppressed by gaze fixation. 1

Nystagmus Characteristics: The Primary Differentiator

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
• Fatigable - decreases in intensity with repeated testing 1
• Brief latency period (5-20 seconds) before onset after provocative maneuvers 1

Central Vertigo Nystagmus

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

Associated Symptoms and Neurological Signs

Peripheral Vertigo

• Hearing loss may be present (Ménière's disease, labyrinthitis) 2
• Tinnitus and aural fullness (Ménière's disease) 1
• Isolated vertigo without other neurological deficits 2
• Patients can typically maintain some degree of postural control 1

Central Vertigo

• Additional neurological symptoms are the hallmark: dysarthria, dysmetria, dysphagia, sensory or motor deficits, diplopia, or Horner's syndrome 1
• Severe postural instability with falling - significantly more impaired balance than peripheral causes 2, 1
• Limb weakness or hemiparesis 1
• Truncal or gait ataxia 1
• New-onset severe headache may indicate vertebrobasilar stroke 1

Dix-Hallpike Maneuver Interpretation

Peripheral (BPPV) Pattern

• Characteristic nystagmus with 5-20 second latency 1
• Crescendo-decrescendo pattern 1
• Torsional and upbeating components 1
• Fatigues with repeat testing 1
• Resolves within 60 seconds 1

Central Pattern (Red Flags)

• Immediate onset without latency 1
• Persistent nystagmus that does not resolve 1
• Purely vertical without torsional component 1
• Downbeating nystagmus on Dix-Hallpike is particularly concerning 2, 1

Duration and Temporal Patterns

Episode Duration

• BPPV (peripheral): Less than 1 minute per episode 1
• Vertebrobasilar insufficiency (central): Typically less than 30 minutes 2, 3
• Ménière's disease (peripheral): Hours-long episodes 1, 3
• Vestibular neuritis (peripheral): Days to weeks of continuous symptoms 1

The duration of attacks is particularly helpful - vertebrobasilar insufficiency typically lasts minutes, whereas peripheral inner ear causes typically last hours 3

Response to Treatment: A Critical Distinguishing Feature

Peripheral Vertigo

• Responds to canalith repositioning procedures (Epley maneuver for BPPV) with 80% success after 1-3 treatments 1
• Responds to vestibular rehabilitation 1

Central Vertigo

• Does not respond to these interventions 1
• Failure to respond to appropriate peripheral vertigo treatments is a red flag demanding neuroimaging 1

Red Flags Requiring Urgent Neuroimaging

Any of the following mandate immediate MRI with diffusion-weighted imaging: 1

• Downbeating nystagmus on Dix-Hallpike without torsional component 2, 1
• Baseline nystagmus without provocative maneuvers 2
• Severe postural instability with falling 2, 1
• New-onset severe headache with vertigo 1
• Any additional neurological symptoms 1
• Limb weakness or hemiparesis 1
• Truncal/gait ataxia 1
• Failure to respond to appropriate peripheral vertigo treatments 2, 1
• Apogeotropic horizontal nystagmus on supine roll test 1, 4
• Isolated positional downbeat nystagmus 1, 4

Common Pitfalls to Avoid

Approximately 10% of cerebellar strokes present identically to peripheral vestibular disorders, making this the most dangerous diagnostic trap 1, 4. In acute vestibular syndrome, approximately 25% have cerebrovascular disease, rising to 75% in high vascular risk cohorts 1.

Overlooking subtle neurological signs is the most common error - always perform a complete neurological examination beyond just assessing nystagmus 1.

Assuming all positional vertigo is BPPV - central positional vertigo from fourth ventricular lesions can mimic BPPV but produces purely vertical nystagmus 3.

Missing vertebrobasilar insufficiency - isolated transient vertigo may precede stroke by weeks or months, and the nystagmus is typically gaze-evoked and does not fatigue 2.

Failing to recognize medication-induced vertigo - anticonvulsants (Mysoline, carbamazepine, phenytoin), antihypertensives, and cardiovascular medications can produce vestibular symptoms 2, 1.

Specific Central Causes to Distinguish

Vertebrobasilar Insufficiency

• Gaze-evoked nystagmus typical of central lesions 2
• Severe postural instability 2
• Nystagmus does not fatigue and is not suppressed by gaze fixation 2
• May present as isolated vertigo before stroke develops 2

Migraine-Associated Vertigo

• Accounts for up to 14% of vertigo cases 2, 1
• Requires migraine symptoms during at least two vertiginous episodes: migrainous headache, photophobia, phonophobia, or visual aura 2, 1
• More often central in nature, though can be peripheral 2

Intracranial Tumors

• Must be excluded in differential diagnosis 1
• Posterior fossa tumors and vestibular schwannomas require consideration 1