| name | peripheral-vs-central-vertigo |
| description | Differentiates peripheral from central causes of vestibular dizziness using nystagmus characteristics, Dix-Hallpike findings, hearing loss, and brainstem signs. Use after vestibular dizziness is confirmed and you need to decide whether this is a benign peripheral cause (BPPV, neuritis) or a central cause (stroke, cerebellar lesion) requiring urgent neuroimaging. Trigger phrases: "is this central or peripheral vertigo", "could this be a stroke", "differentiating vestibular neuritis from stroke", "BPPV vs central", "what type of nystagmus". |
Peripheral vs Central Vertigo Differentiator
Prerequisite: Dizziness has already been classified as vestibular (worsened by head movement, nystagmus present or Dix-Hallpike positive). Use this skill to determine if the cause is peripheral or central.
Step 1 — Assess the Nystagmus
Nystagmus is the single most informative bedside sign. Examine for:
- Spontaneous nystagmus (at rest, eyes forward)
- Gaze-evoked nystagmus (looking left, right, up, down)
- Positional nystagmus (after Dix-Hallpike)
Tip: Subtle nystagmus may only be visible with fixation blocked — have the patient gaze through a white sheet of paper held close to the eyes.
| Feature | Peripheral | Central |
|---|
| Direction | Unidirectional; fast component toward the normal ear; never reverses | May reverse direction when patient looks in direction of slow component; can be purely vertical or torsional |
| Type | Horizontal with torsional component; never purely torsional or vertical | Any direction; purely vertical or purely torsional = central sign |
| Effect of visual fixation | Suppressed by fixation | Not suppressed — persists or worsens with fixation |
| Postural instability | Mild-moderate; walking preserved | Severe; patient may fall when walking |
| Deafness / tinnitus | May be present | Usually absent |
| Other neurologic signs | Absent | Often present (diplopia, ataxia, dysarthria, dysphagia, focal weakness) |
🚨 Central red flags in nystagmus:
- Direction-changing nystagmus
- Purely vertical or purely torsional nystagmus
- Nystagmus NOT suppressed by visual fixation
Step 2 — Perform and Interpret Dix-Hallpike
Technique: Move patient rapidly from sitting → lying with head tilted 45° off the table and rotated 45° to one side. Observe eyes for nystagmus.
| Feature | Peripheral (BPPV) | Central |
|---|
| Latent period | 2–20 seconds | None (immediate onset) |
| Duration of nystagmus | < 1 minute | > 1 minute |
| Fatigability | Fatigues with repetition | Nonfatiguing |
| Intensity of vertigo | Severe | Less severe, sometimes none |
✅ BPPV diagnosis: Typical Dix-Hallpike response (latency 2–20s, duration <1 min, fatigues, severe vertigo) = 80% sensitivity for BPPV
⚠️ Atypical Dix-Hallpike (immediate onset, non-fatiguing, duration >1 min, minimal vertigo) = central cause until proven otherwise
Step 3 — Look for Brainstem / Cerebellar Signs
Perform a focused neurologic exam:
Central signs (any one of these = flag for neuroimaging):
- Cranial nerve abnormalities (diplopia, facial sensory loss, dysarthria, dysphagia)
- Horner syndrome
- Motor or sensory deficits (especially hemibody)
- Dysmetria on finger-nose or heel-shin testing
- Severely ataxic gait — patient falls or cannot walk
- Skew deviation (vertical misalignment of eyes)
- Abnormal head impulse test (HIT) when combined with direction-changing nystagmus or skew (HINTS exam)
⚠️ Absence of other neurologic signs does NOT fully exclude a central process. Isolated cerebellar strokes can present with dizziness alone.
Step 4 — Assess Hearing
| Finding | Interpretation |
|---|
| Unilateral hearing loss + vertigo | Strongly suggests peripheral cause (labyrinthitis, Ménière's disease) |
| Tinnitus + ear fullness + recurrent attacks | Ménière's disease — peripheral |
| No hearing loss | Does NOT exclude peripheral disease |
| Sudden hearing loss + vertigo | Consider labyrinthine infarct — urgent imaging |
Step 5 — Pattern-Based Diagnosis
| Clinical Pattern | Most Likely Diagnosis | Action |
|---|
| Acute prolonged severe vertigo, normal neuro exam, normal HIT | Vestibular neuritis | Peripheral; supportive management |
| Acute prolonged vertigo + ataxic gait or brainstem signs | Cerebellar/brainstem stroke | Urgent neuroimaging |
| Recurrent brief positional spells, positive Dix-Hallpike (typical) | BPPV | Epley maneuver |
| Atypical Dix-Hallpike response + hearing loss | Posterior fossa lesion | Further investigation |
| Recurrent attacks + hearing loss/tinnitus/fullness | Ménière's disease | Peripheral; refer audiology/ENT |
| Recurrent unprovoked attacks + migrainous features | Vestibular migraine | Peripheral; neurology/migraine workup |
Clinical Guardrails
- HINTS exam (Head Impulse, Nystagmus direction, Test of Skew) — when all three are assessed together in acute prolonged vertigo, an abnormal HIT + unidirectional nystagmus + no skew = peripheral. Any component suggesting central = neuroimaging urgently.
- "Normal" MRI does not exclude early posterior fossa stroke — MRI within 24–48 hours of cerebellar stroke may be falsely negative. Clinical suspicion should drive management.
- Positional vertigo ≠ BPPV by default — atypical Dix-Hallpike warrants imaging for posterior fossa lesion.
- Vestibular dizziness ≠ peripheral — always complete a neurologic exam before labelling as benign.
Source: Barton JS. "Approach to the patient with dizziness." UpToDate. Last updated Dec 11, 2025.
