Peripheral Vs Central Vertigo

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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".
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# 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.

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## Step 1 — Assess the Nystagmus

Nystagmus is the single most informative bedside sign. Examine for:
1. Spontaneous nystagmus (at rest, eyes forward)
2. Gaze-evoked nystagmus (looking left, right, up, down)
3. 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

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## 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

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## 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.

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## 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 |

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## 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 |

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## 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.

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*Source: Barton JS. "Approach to the patient with dizziness." UpToDate. Last updated Dec 11, 2025.*