Non-automatic Control of Gait and Posture in Obstructive Sleep Apnea Syndrome (CIH-Gait)

Study Overview
=================
Brief Summary
-----------------
The purpose of this randomised controlled study is to determine the impact of continuous positive airway pressure (CPAP) versus sub-therapeutic CPAP (placebo) on the control of gait upon severe sleep apnea patients, based on stride time variability.

Detailed Description
-----------------
As severe sleep apnea patients exhibit gait abnormalities, this is the first randomised controlled trial to our knowledge to assess the impact of CPAP upon gait and postural control in severe sleep apnea patients. Based on a dual-task paradigm, posture and gait analysis will be perform before and after 8 week of intervention. Beside gait parameters, the cerebral metabolism will be assessed using a Near Infrared Spectroscopy (fNIRS) device during normal walking and during walking while dual-tasking, using a visual and a verbal task.

Official Title
-----------------
Non-automatic Control of Gait and Posture in Obstructive Sleep Apnea Syndrome : a Randomised Controlled Trial of Continuous Positive Airway Pressure Effectiveness (CIH - Gait)

Conditions
-----------------
Obstructive Sleep Apnea Syndrome

Intervention / Treatment
-----------------
* Device: Effective CPAP
* Device: Sub-therapeutic CPAP


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Normally weighted or over-weighted patients (BMI < 30 kilograms/m²) Newly diagnosed Obstructive Sleep Apnea Syndrome (OSAS) (i.e. no previous treatment) Severe OSAS as defined by the American Academy of Sleep Medicine (AHI ≥ 30) To speak and understand french To be affiliated to social welfare Exclusion Criteria: Age criteria : <18 year old and >70 year old Obesity (BMI ≥ 30 kilograms/m²) Pathological conditions thought to be responsible of gait unsteadiness and postural sway or requiring an walking device : nervous system disease (Parkinson disease, chronic stroke), cerebellum syndrome, vestibular syndrome, orthopaedic and rheumatic diseases, Lower limb sensitivity impairment, Cognitive disorder (Folstein test score < 24), Ophthalmology disorder : uncorrected refractive disorder, disturbance of color vision, Psychotropic treatment intake, Alcoholism, Member of an at-risk occupation (car, bus, truck drivers...) mandating effective continuous positive airway pressure introduction.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Effective CPAP<br>Continuous Positive Airway Pressure (RESMED S9™ Series), all the nights, during 8 weeks. | Device: Effective CPAP<br>* Effective Continuous Positive Airway Pressure auto-regulated, worn all night long during 8 weeks<br>* Other names: Continuous positive airway pressure (RESMED S9™ Series);|
| Sham Comparator: Sub-therapeutic CPAP<br>Sub-therapeutic Continuous Positive Airway Pressure (RESMED S9™ Sham-Continuous Positive Airway Pressure System), validated placebo of Continuous Positive Airway Pressure, all the nights, during 8 weeks. | Device: Sub-therapeutic CPAP<br>* Sub-therapeutic Continuous Positive Airway Pressure (Sham-CPAP) worn all night long during 8 weeks<br>* Other names: Sham-CPAP (RESMED S9™ Sham-CPAP System);|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline of stride time coefficient of variation at 8 weeks | The stride time will be recorded during an overground walking test, under single (walking alone) and dual-task (walking while performing a cognitive task) condition. The cognitive task used in our protocol is an electronic Stroop test, displayed on a screen at the end of the 10 meters walkway. The coefficient of variation allows us to estimate stride time variability, known to be the reflect of gait control efficiency when it exhibits low values. | Baseline and 8 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline of single support time and percentage at 8 weeks | To assess gait stability, mean single support time will be assess under single (walking alone) and dual task condition (walking while performing a cognitive task) and its coefficient of variation calculate. | Baseline and 8 weeks | 
| Change from baseline of double support time and percentage at 8 weeks | To assess gait stability, mean double support time will be assess and its coefficient of variation calculate. | Baseline and 8 weeks | 
| Change from baseline of gait speed at 8 weeks |  | Baseline and 8 weeks | 
| Change from baseline of step length at 8 weeks |  | Baseline and 8 weeks | 
| Change from baseline of step width at 8 weeks |  | Baseline and 8 weeks | 
| Change from baseline of the center-of-pressure area at 8 weeks | Studying gait implies posture assessment as the link between gait stability and an efficient postural control is tenuous. | Baseline and 8 weeks | 
| Change from baseline of the center-of-pressure length at 8 weeks | Combined with center-of-pressure (CoP) area, the length (path of CoP) of CoP permits efficient measurement of CoP spatial variability. | Baseline and 8 weeks | 
| Change from baseline of the center-of-pressure mean speed at 8 weeks | The mean speed represents a good index of the amount of neuromuscular activity required to regulate postural control. | Baseline and 8 weeks | 
| Change from baseline of oxy-haemoglobin concentration of bilateral prefrontal cortices at 8 weeks | The oxyhaemoglobin concentration will be recorded during an treadmill walking test, under single (walking alone) and dual-task (walking while performing a cognitive task) condition. The cognitive task used in our protocol is an electronic Stroop test, displayed on a screen placed in front of the patient. We use a fNIRS (Near Infrared Spectroscopy) device, disposed bilaterally opposite to prefrontal cortices to assess the change of oxyhemoglobin concentration over different motor and cognitive tasks. | Baseline and 8 weeks | 
| Change from baseline of deoxy-haemoglobin concentration of bilateral prefrontal cortices at 8 weeks | The deoxyhemoglobin concentration will be recorded as oxyhaemoglobin concentration. | Baseline and 8 weeks | 
| Change from baseline of total haemoglobin concentration of bilateral prefrontal cortices at 8 weeks | The total haemoglobin concentration will be recorded as oxyhaemoglobin concentration. | Baseline and 8 weeks | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Obstructive Sleep Apnea Syndrome, Gait, Posture, Continuous Positive Airway Pressure