Covert Saccade Triggers in Bilateral Vestibular Hypofunction (CS-TRIGGER)

• ClinicalTrials.gov Identifier: NCT04268615
• Recruitment Status: Completed
• First Posted: February 13, 2020
• Last Update Posted: July 28, 2022
• Sponsor: Hospices Civils de Lyon
• Information provided by (Responsible Party): Hospices Civils de Lyon

Study Description

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.

Condition or disease	Intervention/treatment	Phase
Reflex, Abnormal; Bilateral Vestibulopathy; Healthy Volunteers	Other: Covert Saccades and Virtual Reality; Other: Actives versus passives Head Impulses; Other: Visually guided saccades	Not Applicable

Study Design

• Study Type: Interventional (Clinical Trial)
• Actual Enrollment: 32 participants
• Allocation: Non-Randomized
• Intervention Model: Parallel Assignment
• Masking: None (Open Label)
• Primary Purpose: Basic Science
• Official Title: Covert Saccade Triggers in Bilateral Vestibular Hypofunction
• Actual Study Start Date: December 15, 2020
• Actual Primary Completion Date: March 21, 2022
• Actual Study Completion Date: March 21, 2022

Arms and Interventions

Arm	Intervention/treatment
Experimental: Patients; Patients suffering from chronic bilateral vestibular hypofunction	Other: 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.; 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.; 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.
Active Comparator: healthy subject group	Other: 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.; 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.; 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.

Outcome Measures

Primary Outcome Measures :

1. Latency of covert-saccades [ Time Frame: Day 1 ]
   Latency of covert saccades correspond to the time between the beginning of head impulse and the initiation of the first covert-saccade

Secondary Outcome Measures :

1. Frequency of covert-saccades [ Time Frame: Day 1 ]
   Frequency of covert saccades corresponds to the total amount of covert-saccades divided by the total amount of head impulse tests multiplied by 100.
2. Velocity of covert-saccades [ Time Frame: day 1 ]
   Velocity of covert saccades correspond to the maximal velocity of the first covert-saccade
3. Amplitude of covert-saccades [ Time Frame: Day 1 ]
   Amplitude of covert saccades correspond to amplitude of the first covert-saccade
4. Latency of visually-guided saccades [ Time Frame: Day 1 ]
   Latency of visually guided saccades correspond to the time between the appearance of target and the initiation of the first saccade

Eligibility Criteria

• Ages Eligible for Study: 18 Years to 90 Years (Adult, Older Adult)
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: Yes

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

Contacts and Locations

Locations

France

Hospices Civils de Lyon

Bron, France, 69500

Sponsors and Collaborators

Hospices Civils de Lyon

Investigators

• Principal Investigator: Caroline FROMENT, MD; Hospices Civils de Lyon

More Information

• Responsible Party: Hospices Civils de Lyon
• ClinicalTrials.gov Identifier: NCT04268615
• Other Study ID Numbers: 69HCL19_0998; 2020-A00184-35 ( Other Identifier: ID-RCB )
• First Posted: February 13, 2020
• Last Update Posted: July 28, 2022
• Last Verified: July 2022

• Studies a U.S. FDA-regulated Drug Product: No
• Studies a U.S. FDA-regulated Device Product: No

Keywords provided by Hospices Civils de Lyon:

Saccadic Eye Movements; Bilateral Vestibulopathy; Bilateral Vestibular Hypofunction

Additional relevant MeSH terms:

Bilateral Vestibulopathy; Reflex, Abnormal; Vestibular Diseases; Labyrinth Diseases; Ear Diseases; Otorhinolaryngologic Diseases; Neurologic Manifestations; Nervous System Diseases