The Effect of Binasal Occlusion on Balance Following a Concussion

Study Overview
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Brief Summary
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This study evaluates the effect of binasal occlusion (BNO) glasses on balance and eye movement in adults with dizziness after a concussion. Participants will stand on a force plate while rapidly reading a series of numbers both with and without the BNO glasses. It is thought that the BNO glasses will improve both balance and the time to read the numbers.

Detailed Description
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While most individuals will recover within the first month after concussion, a significant number will continue to experience dizziness, balance problems, cognitive deficits, and vision problems. Single-task measures of static balance may not be sensitive enough, however, to capture mild postural changes still associated with incomplete recovery. Increasingly there is an interest in dual-task paradigms of balance assessment as a more accurate representation of functional postural control associated with activities of daily living and sport participation. Binasal occlusion (BNO) has been proposed as a means of providing visual stabilization to improve postural control in individuals with vision-related balance problems following a concussion.

Official Title
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The Effect of Binasal Occlusion on Balance Following a Concussion

Conditions
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Concussion Post Syndrome

Intervention / Treatment
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* Device: Binasal occlusion
* Device: No binasal occlusion


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Forty adults with persistent symptoms one month or more following a concussion will be recruited for the study. Individuals will be considered eligible if they have been diagnosed with a concussion as defined in the 2016 Berlin consensus statement (McCrory et al., 2017) as a traumatic brain injury induced by biomechanics forces, which was caused by either a direct or indirect blow to the head, face, neck or elsewhere on the body with an impulsive force transmitted to the head, which may or may not have involved loss of consciousness, and included one or more of the following clinical domains: Symptoms (e.g. headache, nausea, fatigue, feeling like in a fog, difficulty concentrating or remembering, and/or emotional lability) Physical signs (e.g. loss of consciousness, amnesia, neurological deficit); Balance impairment (e.g. gait unsteadiness) Behavioural changes (e.g. irritability) Cognitive impairment (e.g. slowed reaction times) Sleep/wake disturbance (e.g. somnolence, drowsiness) Participants must also meet the following inclusion criteria: (1) aged 18-65 years; (2) sustained the concussion 4 or more weeks ago; (3) report persistent dizziness or balance problems not accounted for by a pre-existing musculoskeletal, neurological, or vestibular condition; (4) have normal vision or visual impairments that can be corrected with contact lenses; (5) are proficient in English or French; (6) are able to provide informed consent. Exclusion Criteria: Do not meet criteria stipulated in the inclusion criteria

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Binasal occlusion<br>Participants will be fitted with glasses covered with occlusive tape from the inner canthi to the nasal border on each lens. | Device: Binasal occlusion<br>* Binasal occlusion glasses<br>|
| Active Comparator: No binasal occlusion<br>Participants will be fitted with non-occluded glasses. | Device: No binasal occlusion<br>* Non-occluded glasses<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postural sway | The primary outcome of interest is the mean medial/lateral and anterior/posterior velocity of centre of pressure, in addition to the 95% ellipse during different conditions of static balance. The minimal clinical difference considered to demonstrate a change in postural sway is 5cm based on previous validation of the Balance TrackS force plate in a concussed population. | After one month post-injury. Data collection will occur in one single session per participant upon enrolment in the study. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time to completion of the King-Devick Test (KDT) | The KDT is a vision-based test of rapid number naming speed that acts as a proxy measure for saccadic eye movement. The KDT consists of a demonstration card, plus a series of 3 increasingly more difficult test cards of variably spaced single digit numbers. Following completion of the demonstration card, participants are asked to read each test card from left to right, top to bottom, as quickly as possible without errors. A summary score of the test is recorded as the total time to complete all 3 test cards, measured in seconds. Time to completion for the KDT will be recorded. Any increase in time compared with a control condition, or any uncorrected errors are considered a significant change. | After one month post-injury. Data collection will occur in one single session per participant upon enrolment in the study. | 
| Saccadic eye movement | Saccadic eye movement will be assessed with a Tobii™ Pro wearable eye tracker. Tobii™ Pro wearable eye tracker uses infrared video-oculography to analyze patterns of eye movement in terms of fixations and saccades. Longer, more complicated visual tasks, such as rapid number naming, require longer processing times. The number of saccades completed during each balance condition will be recorded by the Tobii™ Pro. | After one month post-injury. Data collection will occur in one single session per participant upon enrolment in the study. | 
| Post-concussion symptom score (PCSS) | The PCSS is a standardized and easily administered 22-item self-report symptom scale that measures the severity of each symptom experienced that day. Symptoms are reported on a 7-point Likert scale, with 0 and 6 representing anchoring points from the absence of symptoms to the presence of severe symptoms. Results are conveyed as the total symptom score and range from 0-132, with a higher score associated with a higher level of symptoms. Total scores demonstrate high internal consistency in a concussion population (α=0.93), with a 6.8 point change (80% CI) associated with a clinical change in symptoms. | After one month post-injury. Data collection will occur in one single session per participant upon enrolment in the study. | 
| Neck Disability Index (NDI) | The NDI is the most commonly used self-report outcome measure for neck pain. The index is a simple and quickly administered 10-item questionnaire measured on a 6-point Likert scale from 0=no disability to 5 = full disability. Scores range from 0-50, with 50 representing the highest level of disability. Clinically important difference have been reported with a 5-7 point change in score depending on whether the pain was of musculoskeletal or neural origin. | After one month post-injury. Data collection will occur in one single session per participant upon enrolment in the study. | 
| Dizziness Handicap Inventory (DHI) | The DHI is a self-report measure of disability associated with dizziness. Internal consistency is high for total scores (α = 0.89). The presence of dizziness-related disability is scored as no (0), sometimes (2), or yes (4). Scores range from 0-100, with a higher score reflecting a greater disability associated with dizziness. Cut-off scores exist for mild (16-34), moderate (36-52), and severe (54+) disability, with an 18-point change in score considered clinically meaningful. | After one month post-injury. Data collection will occur in one single session per participant upon enrolment in the study. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Balance, Dual-task, King-Devick Test, Saccades, Binasal Occlusion