Vestibular Diseases
Conditions
Keywords
Bilateral vestibular hypofunction, Video Head Impulse Test, Covert-saccades, Quality of life, Dynamic visual acuity
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 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.
Interventions
OTHERHead 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.
OTHERDynamic 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.
OTHERVEMPs & 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.
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
OTHEROscillopsia severity questionnaire
Oscillopsia severity questionnaire is a 9 items questionnaires that identify oscillopsia in different circumstances.
Sponsors
Hospices Civils de Lyon
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 90 Years
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Frequency of covert-saccades | Day 0 | Frequency of covert saccades corresponds to the total amount of covert-saccades divided by the total amount of head impulse tests multiplied by 100. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Latency of covert-saccades | Day 0 | Latency of covert saccades correspond to the time between the beginning of head impulse and the initiation of the first covert-saccade |
| Quality of life assessed with the Dizziness Handicap Inventory | Day 0 | 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 |
| Dynamic visual acuity | day 0 | Dynamic visual acuity is a measure of threshold for binocular reading of letters that are presented on a screen during head impulse test |
| Oscillopsia severity questionnaire score | day 0 | 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 |
Countries
France
Outcome results
None listed