An interventional study of Frenzel Lens and Diagnostic Algorithm in Nystagmus, Acquired and Stroke, Acute, sponsored by CHU de Quebec-Universite Laval. Completed at 5 sites in Canada. Open to participants aged 18 Years to 100 Years. Per ClinicalTrials.gov, last updated 2026-03-18.
Sponsored by CHU de Quebec-Universite Laval · Not applicable, Interventional, and Diagnostic
This pilot study is perfomed to validate and document faisability of the use of Frenzel lens and the use of a diagnostic algorithm for the assessment of a special sign (nystagmus) observe in the eyes of patients consulting in the emergency department (ED) for an acute episode of vertigo/dizziness/imbalance.
This pilot study is a randomized controlled trial 2 by 2 design to allocated randomly the Frenzel lens and the diagnostic algorithm. There is no use of sham lens. The usual care opposed to the diagnostic algorithm will be questioned only on the perception of nystagmus by the clinician and the use of repositioning particles technique. The only blinding will be the patients about the use of the algorithm and the outcomes assessor about the use or not of Frenzel lens and the use or not of the diagnostic algorithm.
27 studies on the registry are indexed under Nystagmus, Pathologic; 3 are open to participants now.
This study's enrollment of 120 is above the median of 48 across 17 interventional studies indexed under Nystagmus, Pathologic.
Browse Nystagmus, Pathologic studies →CHU de Quebec-Universite Laval is the lead sponsor of 137 studies on the registry; 27 are open to participants now.
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Exclusion Criteria:
Frenzel lens will be applied on patients' eyes during different diagnostic maneuvers to assess if a nystagmus is present and if present describe its main characteristic. Without mentioning to patient, the emergency physician will use a diagnostic algorithm inspired from the TiTrATE approach to interpret the nystagmus and propose the need or the irrelevance for neuro-imaging
Device: Frenzel Lens · Diagnostic Test: Diagnostic Algorithm
Frenzel lens will be applied on patients' eyes during different diagnostic maneuvers to assess if a nystagmus is present and describe its main characteristics. No diagnostic algorithm will be used to interpret nystagmus.
Device: Frenzel Lens
Nystagmus assessment in different manoeuvres is performed without the use of Frenzel lens. Without mentioning to patient, the emergency physician will use a diagnostic algorithm inspired from the TiTrATE approach to interpret the nystagmus and propose the need or the irrelevance for neuro-imaging
Diagnostic Test: Diagnostic Algorithm
The emergency physician is performing the assessment of nystagmus and its interpretation as usual. The Frenzel lens and the diagnostic algorithm are not used.
pair of magnifying glasses (+20 dioptres) that are worn by the patient and an illuminating system. On using Frenzel goggles, the nystagmus is better seen as a result of eyes being magnified and inhibition of visual fixation.
A diagnostic algorithm using the TiTrate approach: continuous, Intermittent, trigger or spontaneous. The diagnostic algorithm use the REDCap software that include different videos to illustrate diagnostic tests and nystagmus types. Different maneuvers: HINTS+ battery, Dix-Hallpike test, Supine Roll test. Different Particle Repositioning Techniques will be proposed according to specific tests: Epley and Gufoni maneuvers. Risk Score is used to assess stroke risk for transient ischaemic attack (TIA): ABCD2 and the Canadian TIA Risk Score
Rate of Nystagmus detection per participant
During eye examination, nystagmus will be characterized according to prominent direction of the fast phase (patients' left, patients' right, up, down, rotational),with their clinical setting or trigger. Overall rate of nystagmus detection by participant. (Rate of typical nystagmus for benign paroxysmal positional vertigo in the Dix-Hallpike maneuver or Supine Head Roll Test. Rate of nystagmus detection in the initial physical exam)
Time frame: Day 0
Emergency Department Length of stay
Time spent at the emergency department from triage to time of departure for hospital admission or for home discharge assessed up to 48 hours
Time frame: Day 0, from triage time to Emergency Department departure (admission or home discharge)
Rate of neuro-imaging per participant
Any imaging to investigate acute intra-cerebral lesion and/or the neck/brain vascular. anomaly : computed tomography imaging; computed tomography angiogram; magnetic resonance angiography; magnetic resonance imaging, vascular neck ultrasound imaging.
Time frame: From day 0 to 12 weeks
Rate of acute stroke per participant
Any acute stroke, hemorrhagic or ischemic, diagnosed by neuro-imaging: computed tomography or magnetic resonance imaging
Time frame: From day 0 to 12 weeks
Rate of symptomatic central lesion per participant
Any central lesion diagnosed by computed tomography or magnetic resonance imaging that may be related to the initial presentation of vertigo/dizziness/imbalance
Time frame: From day 0 to 12 weeks
Rate of specialised consultations for vertigo/dizziness/imbalance per participant
Any specialised consultations (neurology, ear nose and throat (ENT), cardiology or similar) to investigate the acute vertigo/dizziness/imbalance with the final diagnosis. Sumarisation of final diagnosis.
Time frame: From day 0 to 12 weeks
Rate of acute vertigo/dizziness/imbalance related hospitalisation per participant
Admission to hospital directly related to vertigo/dizziness/imbalance may be immediate to initial visit or delayed.
Time frame: From day 0 to 12 weeks
Rate of subsequent Emergency Department Visit for Vertigo/dizziness/imbalance per participant
Return visit to the emergency department for vertigo/dizziness/imbalance as chief complaint.
Time frame: From day 0 t0 12 weeks
Rate of New Atrial Fibrillation
Atrial fibrillation detected by the initial visit electrocardiogram or by long-term cardiac rhythm monitoring (Holter or loop recorder).
Time frame: From day 0 to 12 weeks
Rate of New Stroke at 12 weeks
A stroke free status will be assessed by a validated questionnaire by telephone at tree months and all specialised consultations and neuroimaging will be reviewed for acute stroke diagnosis,
Time frame: At 12 weeks
Rate of the use of Particles Repositioning Technique
Once Paroxysmal Positional Vertigo diagnosis is being diagnosed with the Dix-Hallpike test or with the Supine Head Roll test, the use of particles repositioning technique, Epley or Gufoni maneuvers, will be noted with their immediate impact on acute vertigo.
Time frame: Day 0
Rate of Emergency Department Visit Return for Benign Paroxysmal Positional Vertigo according to Typical Nystagmus
Rate of Emergency Department Visit Return for Benign Paroxysmal Positional Vertigo according to Typical Nystagmus: direction, duration
Time frame: From day 0 to 12 weeks
Initial managment self appreciation of patient presenting in the ED for an acute episode of vertigo/dizziness/imbalance
Simple question answered on a likert scale at the end of the ED encounter. 0% worst, 100% best appreciation.
Time frame: Day 0
Adverse Events
Combination of stroke, death, neurosurgery, intervenional neuroradiology, thrombolytic therapy
Time frame: From day 0 to 12 weeks
Plan to share: No
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This study is completed, as verified in Mar 2026. You cannot join it, but the record below documents what was studied.
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