What clinical findings differentiate peripheral vertigo from central vertigo?

Differentiating Peripheral from Central Vertigo

Use the HINTS examination (Head Impulse, Nystagmus, Test of Skew) in patients with acute vestibular syndrome who have nystagmus—this is the most accurate bedside tool for distinguishing peripheral from central causes, with a positive likelihood ratio of 17.3 for peripheral patterns and 5.61 for central patterns when identifying stroke. 1, 2

Clinical Context and Timing-Based Approach

The differentiation strategy depends critically on the temporal pattern of vertigo presentation 2:

Acute Vestibular Syndrome (AVS)

Persistent vertigo with nausea/vomiting, gait instability, nystagmus, and head-motion intolerance 3:

For patients WITH nystagmus:

• Perform HINTS examination (if trained): This three-component test has superior diagnostic accuracy over neuroimaging 2
  • Head Impulse Test (HIT): Abnormal (corrective saccade) = peripheral; Normal = central 1
  • Nystagmus pattern: Unidirectional, horizontal = peripheral; Direction-changing or vertical = central 2
  • Test of Skew: Absent = peripheral; Present (vertical misalignment) = central 1
• Add finger rub test: Asymmetric hearing suggests peripheral cause 2
• The HINTS exam has a negative likelihood ratio of 0.06 for stroke when showing a peripheral pattern 1

For patients WITHOUT nystagmus:

• Assess gait severity: Severe gait unsteadiness suggests central cause 2
• Lower threshold for imaging as HINTS cannot be applied 2

Critical Caveat About HINTS

HINTS is only accurate when performed by specially trained clinicians (neurologists, neuro-otologists, or emergency physicians with specific training) 2. When applied by untrained emergency clinicians in routine practice, HINTS testing is inaccurate and not considered standard of care as of 2023 2. Most studies showing high accuracy involved neurologists or subspecialists 1.

Episodic Vestibular Syndrome (Triggered/Positional)

Perform Dix-Hallpike test to diagnose benign paroxysmal positional vertigo (BPPV) 2:

• Typical BPPV findings = peripheral: Brief latency, fatigable, rotatory nystagmus 4
• Red flags for central pathology 4:
  • Additional neurological symptoms (headache, vomiting beyond typical vertigo)
  • Limb or gait ataxia
  • Failed sustained response to repositioning maneuvers
  • Apogeotropic horizontal nystagmus on supine roll test
  • Isolated positional downbeat nystagmus

Episodic Vestibular Syndrome (Spontaneous)

Search for symptoms/signs of cerebral ischemia (transient ischemic attack) 2:

• Focal neurological deficits
• Vascular risk factors
• Consider CT angiography or MRI angiography if TIA suspected 2

Key Epidemiological Context

Do not be falsely reassured by absence of focal neurological deficits 3:

• 25% of patients with acute vestibular syndrome have cerebrovascular disease 3
• 75-80% of AVS patients with posterior circulation infarct have NO focal neurological deficits 3
• 11% of patients with isolated AVS (no focal signs) have acute infarct on imaging 3

Imaging Recommendations

Do NOT use CT brain for vertigo evaluation—detection rate of pathology is <1% in patients with normal neurological examination 3, 2:

• CT is not indicated for AVS 2
• CT is not indicated for episodic positional vertigo 2
• CT is not indicated for spontaneous episodic vertigo 2

MRI brain use 3, 2:

• NOT routine first-line if a HINTS-trained clinician is available 2
• Use as confirmatory test in patients with central or equivocal HINTS examinations 2
• Consider in atypical BPPV presentations 4, 2
• 11% of patients with central positional vertigo show acute brain lesions on MRI versus 6% on CT 3

Alternative Approach for Untrained Clinicians

If uncomfortable with HINTS examination 5:

• Focus on presence of additional neurological symptoms or signs beyond isolated vertigo 4
• Assess severity of gait disturbance (severe = central) 2
• Look for vascular risk factors 2
• Maintain lower threshold for MRI imaging 2, 5