Covert Saccade Triggers in Bilateral Vestibular Hypofunction

NCT ID: NCT04268615

Last Updated: 2025-09-02

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 32 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2020-12-15
• Study Completion Date: 2022-03-21

Brief Summary

Patients with chronic bilateral vestibular hypofunction may suffer from a visual instability during head movement called oscillopsia. Visual consequence of vestibular deficit can lead to a severe impairment of their quality of life. However, correcting saccades during rapid head movement, called covert-saccades, have been more recently identified. These saccades, which occur during the head movement in patients with vestibular hypofunction, present a very short latency. They could compensate for the lack of vestibular-ocular reflex and greatly decrease oscillopsia and visual impairment. The triggering of these covert-saccade is still not known. They could be of visual origin but the short latency is unusual. The objective of this study is to evaluate the potential role of visual trigger in 12 patients with chronic bilateral areflexia, using different visuo-vestibular conditions. The latency of simple visually guided saccades will also be tested in the group of patients and a group of 12 healthy controls.

Conditions

Reflex, Abnormal; Bilateral Vestibulopathy; Healthy Volunteers

Study Design

• Allocation Method: NON_RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

Patients

Patients suffering from chronic bilateral vestibular hypofunction

Group Type: EXPERIMENTAL

Covert Saccades and Virtual Reality

Intervention Type: OTHER

During this intervention, patients will undergo head impulse testing while wearing virtual reality Headsets. During the head impulse tests the visual information will be modified in order to create a conflict between head rotation and rotation of the visual scene. Recording of head and eye movement will be done during these head impulses in order to verify if visual information modifies compensatory eye movements during head impulses.

Actives versus passives Head Impulses

Intervention Type: OTHER

Patients will undergo classic passive head rotation as well as active head rotation in order to compare latencies of covert saccades in both conditions.

Visually guided saccades

Intervention Type: OTHER

Patients as well as healthy control subjects will undergo testing of visually guided saccades in different conditions (step, gap, overlap) in order to compare latencies of covert saccades between both groups.

healthy subject group

Group Type: ACTIVE_COMPARATOR

Covert Saccades and Virtual Reality

Intervention Type: OTHER

During this intervention, patients will undergo head impulse testing while wearing virtual reality Headsets. During the head impulse tests the visual information will be modified in order to create a conflict between head rotation and rotation of the visual scene. Recording of head and eye movement will be done during these head impulses in order to verify if visual information modifies compensatory eye movements during head impulses.

Actives versus passives Head Impulses

Intervention Type: OTHER

Patients will undergo classic passive head rotation as well as active head rotation in order to compare latencies of covert saccades in both conditions.

Visually guided saccades

Intervention Type: OTHER

Patients as well as healthy control subjects will undergo testing of visually guided saccades in different conditions (step, gap, overlap) in order to compare latencies of covert saccades between both groups.

Interventions

Covert Saccades and Virtual Reality

During this intervention, patients will undergo head impulse testing while wearing virtual reality Headsets. During the head impulse tests the visual information will be modified in order to create a conflict between head rotation and rotation of the visual scene. Recording of head and eye movement will be done during these head impulses in order to verify if visual information modifies compensatory eye movements during head impulses.

Intervention Type: OTHER

Actives versus passives Head Impulses

Patients will undergo classic passive head rotation as well as active head rotation in order to compare latencies of covert saccades in both conditions.

Intervention Type: OTHER

Visually guided saccades

Patients as well as healthy control subjects will undergo testing of visually guided saccades in different conditions (step, gap, overlap) in order to compare latencies of covert saccades between both groups.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• For all :

• Age from 18 to 90
• Understanding of the experimental instructions
• Informed Consent
• For Patients :

Bilateral vestibular hypofunction with regards to the criteria of the of the Barany Society A. Chronic vestibular syndrome with at least three of the following symptoms

1. Postural imbalance

2. Unsteadiness of gait

3. Movement-induced blurred vision or oscillopsia during walking or quick head/body movements

4. Worsening of postural imbalance or unsteadiness of gait in darkness and/or on uneven ground B. No symptoms while sitting or lying down under static conditions C. Bilaterally reduced or absent angular VOR function documented by

• bilaterally pathological horizontal angular VOR gain < 0.6, measured by the video-HIT5or scleral-coil technique and/or
• reduced caloric response (sum of bithermal max. peak SPV on each side < 6°/sec7)and/or
• reduced horizontal angular VOR gain < 0.1 upon sinusoidal stimulation on a rotatorychair (0.1 Hz, Vmax = 50°/sec).

D. Not better accounted for by another disease

• For Healthy control No ENT or neurological disorders

Exclusion Criteria

• Corrected Visual Acuity lower than 5/10
• Other conditions leading to oscillopsia or ataxia
• Oculomotor palsy, ocular instability in primary position
• Treatment that may affect ocular motility (psychotropes)
• Cervical rachis pathology with instability
• Cochlear Implants
• Non-stabilized medical disease
• Pregnant women
• Patients under tutelage
• Patient without social security

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 90 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Hospices Civils de Lyon

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Caroline FROMENT, MD

Role: PRINCIPAL_INVESTIGATOR

Hospices Civils de Lyon

Locations

Hospices Civils de Lyon

Bron, , France

Countries

France

References

Lagadec V, Pelisson D, Koun E, Robert C, Froment Tilikete C, Hermann R. Oculomotor compensatory strategies in bilateral vestibulopathy: Predictive and active conditions of head movements. J Vestib Res. 2025 Nov;35(6):290-299. doi: 10.1177/09574271251355180. Epub 2025 Jun 21.

Reference Type: BACKGROUND

PMID: 40543046 (View on PubMed)

Hermann R, Ramat S, Colnaghi S, Lagadec V, Desoche C, Pelisson D, Froment Tilikete C. Catch-Up Saccades in Vestibulo-Ocular Reflex Deficit: Contribution of Visual Information? Ear Hear. 2025 May-Jun 01;46(3):719-728. doi: 10.1097/AUD.0000000000001616. Epub 2024 Dec 18.

Reference Type: BACKGROUND

PMID: 39690450 (View on PubMed)

Desoche C, Verdelet G, Salemme R, Farne A, Pelisson D, Froment C, Hermann R. Virtual reality set-up for studying vestibular function during head impulse test. Front Neurol. 2023 Mar 29;14:1151515. doi: 10.3389/fneur.2023.1151515. eCollection 2023.

Reference Type: BACKGROUND

PMID: 37064179 (View on PubMed)

Other Identifiers

2020-A00184-35

Identifier Type: OTHER

Identifier Source: secondary_id

69HCL19_0998

Identifier Type: -

Identifier Source: org_study_id