Right-beating
Right-Beating Horizontal Nystagmus
Fast phase to the right. Classically seen with left peripheral vestibular hypofunction or right lateral canal excitation.
Visual Diagnostic Reference
Nystagmus Video Library: Types and Diagnostic Insights
A curated visual reference to the involuntary eye movements seen in vestibular and central nervous system disorders. Each pattern is illustrated with annotated motion so clinicians, trainees, and patients can recognize the signature dynamics that point toward a precise diagnosis.
Diagnostic Insights
Why nystagmus is the most important sign at the bedside.
Nystagmus — rhythmic, involuntary eye movement — 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.
Horizontal Nystagmus
Lateral canal & brainstem origin
Left-beating
Left-Beating Horizontal Nystagmus
Fast phase to the left. Mirror counterpart — suggests right peripheral hypofunction or left lateral canal excitation.
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.
Downbeat
Pure Downbeat Nystagmus
Fast phase downward. Strong indicator of a craniocervical junction or cerebellar process until proven otherwise.
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.
Counterclockwise torsion
Pure Counterclockwise Torsional Nystagmus
Upper pole of the iris rotates toward the patient's left shoulder — the mirror image of clockwise torsion.
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.
CW + Downbeat
Clockwise Downbeat Nystagmus
Downbeat with clockwise torsion — pattern associated with left anterior canal involvement.
CCW + Upbeat
Counterclockwise Upbeat Nystagmus
Upward fast phase with counterclockwise torsion — the mirror beat of right-sided posterior canal BPPV (i.e., left posterior canal).
CCW + Downbeat
Counterclockwise Downbeat Nystagmus
Downbeat with counterclockwise torsion — consistent with right anterior canal involvement.
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.
Left Lateral BPPV
Left Lateral Canal BPPV
Mirror-image lateral canal pattern — direction-changing horizontal nystagmus across the supine head-roll test.
Right Posterior Canalithiasis
Right Posterior Canalithiasis
Upbeat + clockwise torsional nystagmus on right Dix-Hallpike — the textbook signature of the most common BPPV subtype.
Left Posterior Canalithiasis
Left Posterior Canalithiasis
Upbeat + counterclockwise torsional nystagmus on left Dix-Hallpike — mirrors the right-sided pattern.
Reference Key
Abbreviations used in clinical notation.
These shorthand codes appear throughout VNG reports, exam notes, and the patterns in this library. Use them to 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
If your nystagmus has a name, we can plan around it.
Recording, classifying, and treating nystagmus is the daily work of our otoneurology clinic. If you or a patient is experiencing dizziness or unexplained eye movements, an evaluation pairs these video patterns with VNG, head-impulse testing, and precision repositioning when indicated.