Covert-saccades, Dynamic Visual Acuity and Quality of Life (COSQOL)

Quality of Life and Dynamic Visual Acuity in Patients With Bilateral Vestibulopathy: the Impact of Covert-saccades

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 objective of this study is to evaluate the potential functional benefice of these compensatory movements in a population of 20 patients with chronic bilateral areflexia, in a cross-sectional study.

Study Overview

• Status: Completed
• Conditions: Vestibular Diseases
• Intervention / Treatment: Other: Head Impulse Tests; Other: Dynamic visual acuity Test (DVAT); Other: VEMPs & VEMPo; Other: Dizziness Handicap Inventory; Other: Oscillopsia severity questionnaire

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Not Applicable

Contacts and Locations

Study Locations

• France
  • Bron, France, 69500
    • Unité de Neuro-Ophtalmologie Hôpital Neurologique

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 90 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Bilateral Vestibular Hypofunction (BVH) with at least two of the tree following criteria

  • Mean peak slow phase velocity of 5°/s or less in bilateral bithermal (30 and 44°C) caloric irrigations
  • Pathologic Head-impulse test
  • VOR gain of <0.25 on rotatory chair tests
• Disorder present for over 6 month
• Comprehension of the experiments instructions
• Patient consent

Exclusion Criteria:

• Corrected Visual Acuity lower than 5/10
• Other conditions leading to oscillopsia or ataxia
• Oculomotor palsy, ocular instability in primary position
• Cervical rachis pathology with instability
• Cochlear Implants
• Non-stabilized medical disease
• Pregnant women
• Patients under tutelage

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Bilateral vestibular hypofunction; Patients suffering from chronic bilateral vestibular hypofunction.

Other: Head Impulse Tests; Head Impulse Tests are performed by the clinician who holds the patient's head in his hands, while he is looking straight at an earth-fixed target; then by turning the patient's head abruptly and unpredictably to the left or right, up or down through a small angle (only 10-20 degrees - not a large angle). 20 impulses in each directions (6) will be performed.; Other: Dynamic visual acuity Test (DVAT); Dynamic visual acuity Test (DVAT) assesses visual acuity during head movement relative to baseline static visual acuity. DVA will be assessed actively during self-generated rotations of the head in different directions.; Other: VEMPs & VEMPo; VEMPs & VEMPo are sound evoked muscular contractions of the neck or eye. They are recorded using an evoked response computer, a sound generator, and surface electrodes to pick up neck or eye muscle activation.; Other: Dizziness Handicap Inventory; Dizziness Handicap Inventory is a questionnaire that identify difficulties that patient may be experiencing because of dizziness, yielding to a score ranging from 0 to 100; Other: Oscillopsia severity questionnaire; Oscillopsia severity questionnaire is a 9 items questionnaires that identify oscillopsia in different circumstances.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Frequency of covert-saccades	Frequency of covert saccades corresponds to the total amount of covert-saccades divided by the total amount of head impulse tests multiplied by 100.	Day 0

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Quality of life assessed with the Dizziness Handicap Inventory	Dizziness Handicap Inventory is a questionnaire that identify difficulties that patient may be experiencing because of dizziness, yielding to a score ranging from 0 to 100	Day 0
Dynamic visual acuity	Dynamic visual acuity is a measure of threshold for binocular reading of letters that are presented on a screen during head impulse test	day 0
Oscillopsia severity questionnaire score	Oscillopsia severity questionnaire is a 9 items questionnaires that identify oscillopsia in different circumstances. A mean item score gives an oscillopsia severity score ranging from 1 to 5, yielding to a total score ranging from 0 to 45	day 0
Latency of covert-saccades	Latency of covert saccades correspond to the time between the beginning of head impulse and the initiation of the first covert-saccade	Day 0

Collaborators and Investigators

• Sponsor: Hospices Civils de Lyon
• Investigators: Principal Investigator: Caroline TILIKETE, MD, Institut National de la Santé Et de la Recherche Médicale, France

Publications and helpful links

General Publications

• Hermann R, Pelisson D, Dumas O, Urquizar C, Truy E, Tilikete C. Are Covert Saccade Functionally Relevant in Vestibular Hypofunction? Cerebellum. 2018 Jun;17(3):300-307. doi: 10.1007/s12311-017-0907-0.

Study record dates

Study Major Dates

• Study Start: May 1, 2016
• Primary Completion (Actual): January 1, 2017
• Study Completion (Actual): January 1, 2017

Study Registration Dates

• First Submitted: April 25, 2016
• First Submitted That Met QC Criteria: April 26, 2016
• First Posted (Estimated): April 27, 2016

Study Record Updates

• Last Update Posted (Estimated): September 4, 2025
• Last Update Submitted That Met QC Criteria: August 27, 2025
• Last Verified: August 1, 2025

More Information

Terms related to this study

• Keywords: Quality of life; Bilateral vestibular hypofunction; Video Head Impulse Test; Covert-saccades; Dynamic visual acuity
• Additional Relevant MeSH Terms: Otorhinolaryngologic Diseases; Ear Diseases; Labyrinth Diseases; Vestibular Diseases
• Other Study ID Numbers: 69HCL15_0746

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No