Interactive Diagnostic Reference

Nystagmus Video Library: Types & Diagnostic Insights

An interactive guide to the involuntary eye movements seen in vestibular and central nervous system disorders. Pair the simulator with annotated reference clips and a labeled inner-ear diagram to localize the lesion at the bedside.

Interactive eye-movement simulator 14 annotated clips · 12 simulator patterns Curated by Dr. Ian Purcell

Diagnostic Insights

Why nystagmus is the most useful sign at the bedside.

Nystagmus encodes the state of the vestibular and central ocular-motor systems in real time. The direction, plane, and provocation of the beat localize the lesion more reliably than imaging alone — this library pairs reference clips with the clinical logic Dr. Purcell uses in practice.

Peripheral vs. central

Peripheral nystagmus is unidirectional, suppresses with fixation, and is paired with vertigo. Central patterns change direction, are pure vertical or torsional, and persist with fixation.

Read the plane

Horizontal, vertical, and torsional components map onto specific semicircular canals. Combined directions reveal which canal is firing or being inhibited.

Provocation matters

Positional and head-impulse maneuvers convert a subtle finding into a diagnosis. The same beat can mean BPPV or a posterior fossa lesion depending on how it's elicited.

Otolith pattern recognition

Dr. Purcell's work in vestibular neurophysiology has refined the recognition of nystagmus patterns produced by dislodged otoliths — guiding precision repositioning with the Epley and TRV chairs.

Interactive Simulator

See the beat. Find the canal.

Choose a nystagmus pattern and watch the eye move in real time. The labeled inner-ear diagram highlights the semicircular canal most often responsible for that beat.

Selected pattern

Clockwise Upbeat Nystagmus

Upward fast phase combined with clockwise torsion — the classical beat of right posterior canal BPPV on Dix-Hallpike.

Plane: Vertical + Torsional
Localization: Right posterior canal
Provocation: Right Dix-Hallpike
Typical cause: Posterior canalithiasis (BPPV)

Eye movement Combined · torsional + upbeat

Affected anatomy Right ear · Posterior canal

Right vestibular labyrinth — semicircular canals mapped to the selected pattern

Horizontal

Vertical

Torsional

Lateral BPPV

Combined BPPV

Tip: highlighted canal = common peripheral source; central lesions can mimic it.

Horizontal Nystagmus

Lateral canal & brainstem origin

Right-beating

Right-Beating Horizontal Nystagmus

Fast phase to the right. Classically seen with left peripheral hypofunction or right lateral canal excitation.

HorizontalPeripheral

Left-beating

Left-Beating Horizontal Nystagmus

Fast phase to the left. Mirror counterpart — suggests right peripheral hypofunction or left lateral canal excitation.

HorizontalPeripheral

Vertical Nystagmus

Anterior & posterior canal · central pathway

Upbeat

Pure Upbeat Nystagmus

Fast phase directed upward. Suggests anterior canal excitation peripherally — or a medullary/pontomesencephalic lesion centrally.

VerticalCentral / Peripheral

Downbeat

Pure Downbeat Nystagmus

Fast phase downward. Strong indicator of a craniocervical junction or cerebellar process until proven otherwise.

VerticalCentral

Pure Torsional Nystagmus

Rotational eye motion · vertical canal localization

Clockwise torsion

Pure Clockwise Torsional Nystagmus

Upper pole of the iris rotates toward the patient's right shoulder. Implicates the contralateral posterior or ipsilateral anterior canal.

TorsionalVertical canal

Counterclockwise torsion

Pure Counterclockwise Torsional Nystagmus

Upper pole of the iris rotates toward the patient's left shoulder — the mirror image of clockwise torsion.

TorsionalVertical canal

Combined Torsional & Vertical Patterns

Signature beats of posterior- and anterior-canal BPPV

CW + Upbeat

Clockwise Upbeat Nystagmus

Upward fast phase combined with clockwise torsion — the classical beat of right posterior canal BPPV on Dix-Hallpike.

CombinedBPPV

CW + Downbeat

Clockwise Downbeat Nystagmus

Downbeat with clockwise torsion — pattern associated with left anterior canal involvement.

CombinedAnterior canal

CCW + Upbeat

Counterclockwise Upbeat Nystagmus

Upward fast phase with counterclockwise torsion — the mirror beat of left posterior canal BPPV.

CombinedBPPV

CCW + Downbeat

Counterclockwise Downbeat Nystagmus

Downbeat with counterclockwise torsion — consistent with right anterior canal involvement.

CombinedAnterior canal

Positional & BPPV Maneuvers

Provoked patterns — lateral & posterior canalithiasis

Right Lateral BPPV

Right Lateral Canal BPPV

Geotropic or apogeotropic horizontal nystagmus on supine head-roll, localizing otolith debris to the right horizontal canal.

PositionalLateral canal

Left Lateral BPPV

Left Lateral Canal BPPV

Mirror-image lateral canal pattern — direction-changing horizontal nystagmus across the supine head-roll test.

PositionalLateral canal

Right Posterior Canalithiasis

Upbeat + clockwise torsional nystagmus on right Dix-Hallpike — the textbook signature of the most common BPPV subtype.

BPPVDix-Hallpike

Left Posterior Canalithiasis

Upbeat + counterclockwise torsional nystagmus on left Dix-Hallpike — mirrors the right-sided pattern.

BPPVDix-Hallpike

Reference Key

Abbreviations used in clinical notation.

These shorthand codes appear throughout VNG reports, exam notes, and the patterns in this library — read a chart entry or your goggle tracings like a clinician.

YYaw

PPitch

UFUtricular Fugal

UPUtricular Pedal

+Excitatory response

−Inhibitory response

CWClockwise nystagmus

CCWCounterclockwise nystagmus

↑Upbeat nystagmus

↓Downbeat nystagmus

RBRight beat

LBLeft beat

BrBarrel roll

DixDix-Hallpike maneuver

ADRight ear

ASLeft ear

SUPSupine position

Clinical next step

Turn a confusing eye-movement pattern into a concrete treatment plan.

Our clinic uses recorded eye movements as part of a full vestibular workup—not as an isolated finding. If dizziness, oscillopsia, positional vertigo, or unexplained nystagmus is affecting daily life, we connect the bedside exam with VNG, canal-specific localization, and targeted treatment decisions.

Clarify the source
Differentiate peripheral vestibular findings from central warning signs.
Match testing to symptoms
Use the right diagnostic tools instead of a generic dizziness workup.
Plan what comes next
From repositioning maneuvers to follow-up imaging or therapy referrals.

Call (858) 223-2172 Read the nystagmus primer

For patients, families, or referring clinicians who want a specialist interpretation of what these patterns may mean.