BPPV Differential Diagnosis Checker
Use this skill when:
- Positional vertigo is present but Dix-Hallpike is atypical or negative
- Patient has not responded to repositioning maneuvers after 2–3 attempts
- Clinical features don't quite fit classic posterior canal BPPV
Step 1 — Confirm the Core BPPV Pattern First
Classic posterior canal BPPV has ALL of the following:
| Feature |
Expected in BPPV |
| Trigger |
Specific head movements — lying down, rolling in bed, looking up, bending forward |
| Duration of each episode |
< 1 minute (usually 30–60 seconds) |
| Dix-Hallpike response |
Latency 2–20s, upbeat-torsional nystagmus, duration <1 min, fatigues with repetition, severe vertigo |
| Hearing |
Normal — no hearing loss, no tinnitus |
| Neurologic exam |
Normal |
| Between attacks |
Mild imbalance possible; NO sustained dizziness |
If ANY of the above is atypical → work through the mimics below.
Step 2 — Mimic 1: Postural (Orthostatic) Hypotension
Key distinguishing features:
|
BPPV |
Postural Hypotension |
| Sensation |
Vertigo (spinning/tilting) |
Near-faint, lightheadedness, "nearly blacking out" |
| Triggered by lying down / rolling in bed |
✅ Yes |
❌ No |
| Triggered by standing up |
❌ Rarely |
✅ Yes — the key trigger |
| Dix-Hallpike nystagmus |
Present |
Absent |
Confirm: Measure BP and pulse lying → standing. Drop ≥20 mmHg systolic = orthostatic hypotension.
⚠️ Both can cause dizziness on arising from bed — but postural hypotension is triggered by the act of standing, not by the head position itself.
Step 3 — Mimic 2: Chronic Unilateral Vestibular Hypofunction
Key distinguishing features:
|
BPPV |
Unilateral Vestibular Hypofunction |
| Episode duration |
30–60 seconds |
Very brief — 1 to 2 seconds only |
| Trigger |
Any positional change (lying, rolling, looking up/down) |
Rapid head turns only |
| Looking up / bending forward triggers it |
✅ Yes |
❌ No |
| Dix-Hallpike |
Positive (typical pattern) |
Usually negative |
The fleeting 1–2 second duration with rapid head turns is the giveaway for vestibular hypofunction.
Step 4 — Mimic 3: Vestibular Paroxysmia
Key distinguishing features:
|
BPPV |
Vestibular Paroxysmia |
| Episode duration |
30–60 seconds |
1 to several seconds — very brief |
| Frequency |
Episodic, often weeks between bouts |
Multiple times per day |
| Triggers |
Head position changes |
Sometimes head turn, sometimes unprovoked |
| MRI finding |
Normal |
May show neurovascular compression |
Very brief attacks recurring many times daily → think vestibular paroxysmia, not BPPV. MRI of the posterior fossa is warranted.
Step 5 — Mimic 4: Vestibular Migraine
Key distinguishing features:
|
BPPV |
Vestibular Migraine |
| Episode duration |
< 1 minute |
Minutes to hours (occasionally seconds) |
| Recurrence pattern |
Weeks to months between bouts |
More frequent recurrences |
| Associated symptoms |
None during attack |
Headache, photophobia, phonophobia (may be subtle) |
| Age of onset |
Any age, more common >60 |
Often younger patients |
| Positional nystagmus |
Typical BPPV pattern |
Atypical — does not fit BPPV criteria |
| Response to Epley |
✅ Usually resolves |
❌ Does not resolve |
⚠️ Vestibular migraine can mimic BPPV closely, including positional provocation. Clues: younger age, recurrences over hours-to-days (not weeks-to-months), migrainous symptoms (even subtle), atypical nystagmus on Dix-Hallpike.
Step 6 — Mimic 5: Central Positional Vertigo
Key distinguishing features:
|
BPPV |
Central Positional Vertigo |
| Nystagmus on Dix-Hallpike |
Upbeat-torsional, latency 2–20s, <1 min, fatigues, severe vertigo |
Static, persists as long as position maintained; often downbeat; no latency; nonfatiguing |
| Effect of visual fixation on nystagmus |
Suppressed |
Not suppressed |
| Other neurologic signs |
Absent |
May be present (ataxia, dysarthria, diplopia) |
| Cause |
Otoconia in posterior canal |
Cerebellar lesion (especially vermis); demyelination; Chiari malformation |
🚨 Classic central sign: Downbeat positional nystagmus that is static (persists throughout the head-down position, does not fatigue). This needs neuroimaging.
🚨 Patients with static positional nystagmus without prior typical BPPV should be investigated for central disease.
Summary Decision Table
| Feature |
BPPV |
Postural Hypotension |
Vestibular Hypofunction |
Vestibular Paroxysmia |
Vestibular Migraine |
Central Positional Vertigo |
| Duration |
30–60s |
Seconds–minutes |
1–2s |
1–several s |
Minutes–hours |
Persists in position |
| Dix-Hallpike |
Typical |
Negative |
Negative |
Variable |
Atypical |
Atypical/static |
| Hearing loss |
No |
No |
Possible |
No |
No |
Usually no |
| Neurologic signs |
No |
No |
No |
No |
No |
Possible |
| Response to Epley |
Yes |
N/A |
N/A |
No |
No |
No |
Clinical Guardrails
- Non-response to Epley after 2–3 sessions = reassess the diagnosis. The most common reasons are wrong canal (horizontal or anterior), wrong side, or a mimic — not treatment failure per se.
- Atypical Dix-Hallpike (no latency, non-fatiguing, persistent, minimal vertigo, or downbeat nystagmus) = central cause until proven otherwise → MRI brain.
- Vestibular migraine is underdiagnosed — ask specifically about headaches, photophobia, or phonophobia during or around dizzy episodes; these may be subtle.
- Subjective BPPV (typical history but no nystagmus on exam) — empiric repositioning is reasonable if history is convincing, but other diagnoses should be considered if treatment fails within a few days.
Source: Barton JS. "Benign paroxysmal positional vertigo." UpToDate. Last updated Nov 04, 2024.
1---2name: bppv-differential-diagnosis3description: BPPV Differential Diagnosis Checker4---56# BPPV Differential Diagnosis Checker78> Use this skill when:9> - Positional vertigo is present but Dix-Hallpike is atypical or negative10> - Patient has not responded to repositioning maneuvers after 2–3 attempts11> - Clinical features don't quite fit classic posterior canal BPPV1213---1415## Step 1 — Confirm the Core BPPV Pattern First1617**Classic posterior canal BPPV has ALL of the following:**1819| Feature | Expected in BPPV |20|---|---|21| Trigger | Specific head movements — lying down, rolling in bed, looking up, bending forward |22| Duration of each episode | < 1 minute (usually 30–60 seconds) |23| Dix-Hallpike response | Latency 2–20s, upbeat-torsional nystagmus, duration <1 min, fatigues with repetition, severe vertigo |24| Hearing | Normal — no hearing loss, no tinnitus |25| Neurologic exam | Normal |26| Between attacks | Mild imbalance possible; NO sustained dizziness |2728> If ANY of the above is atypical → work through the mimics below.2930---3132## Step 2 — Mimic 1: Postural (Orthostatic) Hypotension3334**Key distinguishing features:**3536| | BPPV | Postural Hypotension |37|---|---|---|38| Sensation | Vertigo (spinning/tilting) | Near-faint, lightheadedness, "nearly blacking out" |39| Triggered by lying down / rolling in bed | ✅ Yes | ❌ No |40| Triggered by standing up | ❌ Rarely | ✅ Yes — the key trigger |41| Dix-Hallpike nystagmus | Present | Absent |4243**Confirm:** Measure BP and pulse lying → standing. Drop ≥20 mmHg systolic = orthostatic hypotension.4445> ⚠️ Both can cause dizziness on arising from bed — but postural hypotension is triggered by the act of standing, not by the head position itself.4647---4849## Step 3 — Mimic 2: Chronic Unilateral Vestibular Hypofunction5051**Key distinguishing features:**5253| | BPPV | Unilateral Vestibular Hypofunction |54|---|---|---|55| Episode duration | 30–60 seconds | Very brief — 1 to 2 seconds only |56| Trigger | Any positional change (lying, rolling, looking up/down) | Rapid head turns only |57| Looking up / bending forward triggers it | ✅ Yes | ❌ No |58| Dix-Hallpike | Positive (typical pattern) | Usually negative |5960> The fleeting 1–2 second duration with rapid head turns is the giveaway for vestibular hypofunction.6162---6364## Step 4 — Mimic 3: Vestibular Paroxysmia6566**Key distinguishing features:**6768| | BPPV | Vestibular Paroxysmia |69|---|---|---|70| Episode duration | 30–60 seconds | 1 to several seconds — very brief |71| Frequency | Episodic, often weeks between bouts | Multiple times per day |72| Triggers | Head position changes | Sometimes head turn, sometimes unprovoked |73| MRI finding | Normal | May show neurovascular compression |7475> Very brief attacks recurring many times daily → think vestibular paroxysmia, not BPPV. MRI of the posterior fossa is warranted.7677---7879## Step 5 — Mimic 4: Vestibular Migraine8081**Key distinguishing features:**8283| | BPPV | Vestibular Migraine |84|---|---|---|85| Episode duration | < 1 minute | Minutes to hours (occasionally seconds) |86| Recurrence pattern | Weeks to months between bouts | More frequent recurrences |87| Associated symptoms | None during attack | Headache, photophobia, phonophobia (may be subtle) |88| Age of onset | Any age, more common >60 | Often younger patients |89| Positional nystagmus | Typical BPPV pattern | Atypical — does not fit BPPV criteria |90| Response to Epley | ✅ Usually resolves | ❌ Does not resolve |9192> ⚠️ Vestibular migraine can mimic BPPV closely, including positional provocation. Clues: younger age, recurrences over hours-to-days (not weeks-to-months), migrainous symptoms (even subtle), atypical nystagmus on Dix-Hallpike.9394---9596## Step 6 — Mimic 5: Central Positional Vertigo9798**Key distinguishing features:**99100| | BPPV | Central Positional Vertigo |101|---|---|---|102| Nystagmus on Dix-Hallpike | Upbeat-torsional, latency 2–20s, <1 min, fatigues, severe vertigo | Static, persists as long as position maintained; often downbeat; no latency; nonfatiguing |103| Effect of visual fixation on nystagmus | Suppressed | Not suppressed |104| Other neurologic signs | Absent | May be present (ataxia, dysarthria, diplopia) |105| Cause | Otoconia in posterior canal | Cerebellar lesion (especially vermis); demyelination; Chiari malformation |106107> 🚨 **Classic central sign:** Downbeat positional nystagmus that is **static** (persists throughout the head-down position, does not fatigue). This needs neuroimaging.108>109> 🚨 **Patients with static positional nystagmus without prior typical BPPV should be investigated for central disease.**110111---112113## Summary Decision Table114115| Feature | BPPV | Postural Hypotension | Vestibular Hypofunction | Vestibular Paroxysmia | Vestibular Migraine | Central Positional Vertigo |116|---|---|---|---|---|---|---|117| Duration | 30–60s | Seconds–minutes | 1–2s | 1–several s | Minutes–hours | Persists in position |118| Dix-Hallpike | Typical | Negative | Negative | Variable | Atypical | Atypical/static |119| Hearing loss | No | No | Possible | No | No | Usually no |120| Neurologic signs | No | No | No | No | No | Possible |121| Response to Epley | Yes | N/A | N/A | No | No | No |122123---124125## Clinical Guardrails126127- **Non-response to Epley after 2–3 sessions** = reassess the diagnosis. The most common reasons are wrong canal (horizontal or anterior), wrong side, or a mimic — not treatment failure per se.128- **Atypical Dix-Hallpike** (no latency, non-fatiguing, persistent, minimal vertigo, or downbeat nystagmus) = central cause until proven otherwise → MRI brain.129- **Vestibular migraine is underdiagnosed** — ask specifically about headaches, photophobia, or phonophobia during or around dizzy episodes; these may be subtle.130- **Subjective BPPV** (typical history but no nystagmus on exam) — empiric repositioning is reasonable if history is convincing, but other diagnoses should be considered if treatment fails within a few days.131132---133134*Source: Barton JS. "Benign paroxysmal positional vertigo." UpToDate. Last updated Nov 04, 2024.*
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