BPPV Clinical Simulator

What is BPPV?

Benign paroxysmal positional vertigo (BPPV) typically causes brief episodes of dizziness or triggered by changes in head position relative to gravity. A patient might say, “The room moves when I roll over in bed,” or simply, “I get dizzy when I lie back.” Both descriptions are worth following up.

What to ask when a patient says “I get dizzy”

. “Does it start when you lie back, roll over, look up, or stand up? If you roll in bed, does it happen on one side or both?”
. “If you hold still in that position, how long does the main sensation of movement last? What lingers afterward?”
. “How do you feel before you move again? Does a new episode ever start while you’re already still?”

Bárány Society · BPPV diagnostic criteria and history notes, printed pp. 108–110

Brief, repeatable episodes that start with a position change support testing for BPPV when screening and positioning allow it. Dizziness that is already present at rest and worsens with movement calls for a broader assessment. Use the positional exam to identify the likely canal and side.

What happens in the inner ear?

Each inner ear has three : horizontal, posterior, and anterior. They sense head rotation. Nearby, the helps sense head tilt and linear motion, such as when a car accelerates.

The utricle sits at the base of the canals.

In the utricle, otoconia sit at the surface of the gel layer. Hair bundles extend into it from below.Anatomy reference · OpenStax, fig. 14.11

Tiny calcium carbonate particles called from the utricle and enter a semicircular canal.

How the particles affect the signal

Each canal has a , a flexible structure that bends when fluid shifts. That bend changes how often the canal’s nerve sends signals to the brain. The brain uses those signals to sense head rotation and move the eyes to keep vision steady.

. Loose particles can keep moving after the head stops. They shift the fluid and briefly bend the cupula. As the particles settle, fluid movement slows and the cupula returns toward its resting position. The feeling of movement and the eye beats can fade while the patient is still in the test position.

. Particles attached to the cupula add weight. In some head positions, gravity can keep it bent even while the head is still. The changed nerve signal can persist, so the patient may still feel movement and the clinician may still see eye beats while holding the position.

What do you look for during an exam?

Positional tests can reproduce vertigo and elicit an involuntary eye movement called . Watch which way the eyes beat to help identify the canal. Time when the beats start and how long they last to help interpret what the particles may be doing. Ask how long the patient feels movement and record that separately.

AAO-HNSF BPPV guideline · Bárány Society · Positional nystagmus

How a head turn becomes an eye movement

As the head starts to turn, fluid in the canals () initially lags behind. It bends the cupula, a flexible structure in the widened end of the canal, called the . The bend moves the tiny hair bundles on the sensory cells. The vestibular nerve carries the resulting change in signal from the inner ear to the brain.

Cross section of a canal ampulla with the cupula upright at rest and bending during head rotation — Compare the cupula at rest and during rotation.OpenStax Anatomy and Physiology, fig. 14.12

Both ears send signals at rest. means firing increases above that baseline. means firing decreases. The brain compares signals from pairs of canals in opposite ears. As the head starts turning right, the right horizontal canal sends more signals and the left sends fewer. The brain reads that difference as a rightward turn. The moves the eyes left to help keep an object in view.

Watch the horizontal canals work together

Head still. Both canals fire at baseline.

Normal response to head rotation

Right horizontal canal

No relative flow Resting rate

Left horizontal canal

No relative flow Resting rate

Front view. The eyes move in the opposite direction to the head turn. The patient’s right is on your left.

Watch the pale cupula bend inside the gold ampulla. Its edges stay attached, and the dashed line marks its resting shape. The bend is exaggerated so you can see it.

Each tick is one nerve signal. Compare both rows over the same amount of time. The tick counts are illustrative.

What the patient feels. The brain uses the difference between the two canals’ firing rates as a cue that the head is turning. Here, that cue matches the actual turn.

This paired increase and decrease is called . During the head turn, one horizontal canal sends more signals while its partner sends fewer.

What changes when debris enters a canal?

The previous demo showed the normal reflex during an actual head turn. For BPPV, watch for positional nystagmus after the head reaches the test position. In this roll test, the patient lies on their back. The examiner turns the head to the right and holds it there. Loose particles in the right horizontal canal can keep moving under gravity, shifting the fluid and bending the cupula. The brain reads that changed signal as rotation, so the patient may feel motion and the eyes can drift even while the head is held still.

Right supine roll test

Face up. Choose a version of the same head turn.

What the patient may feel. Compare what happens after the head stops.

Head position

Canals and debris

Face up · same view as the table

Eyes from the front

During a beat, the eyes drift slowly toward the patient’s left, then reset quickly to the right.

The white dot marks the nose in both head-end views. The highlighted canal is the right horizontal canal. Gold particles represent loose otoconia. The patient’s right is on your left in the eye close-up. Playback timing and motion are illustrative.

Watch the eyes drift toward the patient’s left, then snap back toward the right. When this cycle repeats, it’s called . The quick reset is the , so this example is called .

Name the vertical fast phase relative to the patient’s face. Toward the forehead is upbeat. Toward the chin is downbeat. For , watch the tops of the irises twist toward the patient’s right or left ear.

Before positional testing, watch the eyes with the head still

The roll-test example showed beats after the head changed position. In a clinical exam, first establish what the eyes are doing before you move the head. An oculomotor screen checks how the eyes hold gaze, line up, and follow or shift between targets. Findings at this stage can point to a need for a broader assessment before you interpret the positional response.

Start with straight-ahead gaze. With the head still, look for . Note which way the eyes beat.

Then compare right and left gaze. Keep the head still and ask the patient to look to either side at a comfortable angle. Watch for and compare the fast phase. With , right-beating nystagmus grows stronger on right gaze and weakens on left gaze. If the fast phase keeps reversing with the direction of gaze at moderate angles, consider a problem in how the brain holds the eyes steady. Brief beats at extreme gaze can occur normally.

In the examples below, compare Alexander’s law and Direction-changing with gaze. On each side, ask whether the beats change strength or actually reverse.

How to check eye alignment and tracking

Alignment. Alternate the cover from one eye to the other while the patient looks at a target. Watch the newly uncovered eye for a vertical correction, which can indicate .

Tracking. Ask the patient to follow a slowly moving target to check . Repeated catch-up movements can show that the eyes are falling behind.

Target changes. Ask the patient to look back and forth between two stationary targets to check . Watch for consistent overshooting or undershooting. Consider these findings alongside the history and the rest of the exam.

Choose a test and interpret the response

Which canal will you see most often?

The posterior canal is usually the most common, followed by the horizontal canal. Anterior-canal BPPV is uncommon. In a multicenter study of 1,692 patients with BPPV, 60.9% had posterior-canal BPPV, 31.9% horizontal-canal BPPV, 2.2% anterior-canal BPPV, and 5.0% a mixed pattern.

The mix varies across clinics. This gives you a starting expectation. Use the pattern of eye movements during positional testing to identify the canal in the patient in front of you.

Multicenter study of 1,692 patients · Comparison cohort of 314 patients

Before you position the patient

Use the history and the eye screen to decide whether positional testing fits. Check whether the patient can safely tolerate the neck motion, transfers, and head support. Use a suitable modification or seek help when positioning is limited. New focal neurologic signs, severe new headache or neck pain, or inability to sit or stand unaided warrant urgent assessment.

Choose the positional test

Use to check for posterior-canal BPPV. If the first side produces no characteristic upbeat and twisting response, check the other side as tolerated. If the history still fits and Dix–Hallpike brings out horizontal beats or no nystagmus, use the to check the horizontal canals. Vertigo without visible nystagmus leaves the canal and side uncertain.

Start by asking what brought on the beats. Did the patient move only their eyes, or did their head change position relative to gravity? Then describe where the eyes snap, which position gives the stronger response, and how long the beats last. A horizontal reversal between right- and left-ear-down roll positions can be expected in horizontal BPPV. A reversal when only gaze changes is a different finding.

Right Dix–Hallpike: upward beats with a twist

After the patient reaches the right Dix–Hallpike position, there is a short pause. The eyes then snap upward toward the forehead while the tops of the irises twist toward the patient’s right ear, which is closer to the floor. The beats build and fade while the head stays in position.

What it suggests. This is the classic pattern for right posterior-canal BPPV due to canalithiasis, in which loose particles move and then settle. Excitation of the right posterior canal drives a slow downward and twisting movement. The fast reset goes upward and twists toward the right ear.

Supine roll: use both sides to work out the likely ear

Compare right and left turns of similar size and speed. Say the fast phase beats right with the right ear down and left with the left ear down. Both beat toward the floor, so the pattern is . If it is clearly stronger with the right ear down, the right horizontal canal is more likely involved. In the usual geotropic form, the right-ear-down turn moves fluid toward the ampulla of that canal and excites it. With the left ear down, the affected canal is inhibited and the beats are usually weaker.

If the beats go toward the ceiling on both sides, the pattern is . For this form of horizontal-canal BPPV, the weaker side is usually the affected side. If the responses are similar, side assignment from intensity alone is uncertain.

While holding the position: when do the beats start and stop?

Clinically, ask whether the patient still feels movement after the head is held still, and how long it lasts. Record what they feel and what you see in the eyes separately. Use the eye pattern across test positions to help identify the canal and side.

is the delay from reaching the test position to the first beat. is how long the beats continue while the position is held. In the brief posterior-canal example above, both the pause and the fading response fit free-moving particles.

If the same upbeating and torsional pattern continues beyond a minute, consider posterior-canal cupulolithiasis, where particles attached to the cupula can keep it deflected. The can help assess this possibility. Interpret the duration alongside the direction, position, and rest of the exam, since persistent positional nystagmus can have other causes.

Downbeating on a positional test

Predominantly downward beats with a small twist can occur with rare anterior-canal BPPV. Downbeating positional nystagmus also raises concern for a central cause. Review the torsion, timing, and other exam findings before assigning a canal.

Ewald’s laws in the positional exam

A canal senses turns most strongly in the direction of its loop. That helps explain why a horizontal canal produces mostly side-to-side eye beats, while a tilted canal can produce vertical beats with a twist. In comparable roll positions, the turn that increases firing in the affected canal usually produces stronger beats than the turn that decreases it.

Horizontal canal

Side-to-side beats

Flow toward the ampulla () excites the canal.

Posterior and anterior canals

Vertical beats with a twist

Flow away from the ampulla () excites the canal.

In the geotropic roll example, the stronger right-ear-down response supports right horizontal-canal involvement. The beat direction tells you the pattern. The difference in strength helps you work out the side.

Bárány Society · Canal excitation and slow eye movements, Fig. 3 · Experimental study · Horizontal canal response and Ewald’s second law

Sources and page numbers

Bárány Society consensus on nystagmus (Eggers et al., 2019)

Match the maneuver to the findings

Before choosing a maneuver, identify the likely canal and ear from the eye movements. Use their direction and timing to judge whether the findings fit free-moving particles or need further assessment. A uses a sequence of positions to guide free-moving particles out of the canal. Positioning and head support affect which maneuver a patient can tolerate.

Typical posterior-canal canalithiasis: Use an on the affected side when appropriate. For example, brief upbeat and rightward torsional beats on right Dix–Hallpike support a right Epley.
Geotropic horizontal-canal BPPV: or the are options when the affected side is clear. For geotropic Gufoni, the patient first lies onto the unaffected side. A right-sided diagnosis therefore starts with left side-lying.
Apogeotropic horizontal pattern: Check the weaker side and compare duration on both sides. Several mechanisms can produce this pattern. An apogeotropic maneuver such as may be appropriate when the findings and positioning support it. If repeat roll testing now brings out beats toward the floor, the pattern has changed to geotropic. Compare the new responses on both sides before choosing the next maneuver.
Unclear, sustained, or atypical findings: Review the observed pattern and consider other causes before selecting treatment. If you cannot localize the canal or side, or the findings raise concern for a central cause, reassess or refer as appropriate.

Use the Technique library to review the setup and sequence for the test or maneuver you selected.

Reassess the response

Check whether the original trigger still brings on vertigo and whether the positional nystagmus has resolved, persisted, or changed direction. If the beats change direction or appear in a different position, use the new findings to work out which canal and ear are involved before repeating a maneuver. If symptoms persist, evaluate for unresolved BPPV and other vestibular or central causes.

Discuss fall safety and the possibility of recurrence. Arrange reassessment within one month after treatment or observation to document the outcome.

Clinical sources

Practice cases

Choose any case to practice. See the reasoning after each answer.

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Medium

Hard

Clinical references for the cases

BPPV Clinical Simulator

Evaluation

What to do next

What it suggests

Findings entered

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