The Long-lasting Effects of Repetitive Neck Muscle Vibrations on Postural Disturbances in Standing Position in Chronic Stroke Patients

Study Overview
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Brief Summary
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One of the causes of disability in patients suffering from a stroke is postural imbalance. Sensory stimulation improves the postural symmetry of the subject transitorily and they are thought to have an effect on the spatial frame of reference through a sensory recalibration. Studies have shown that sensory stimulation by vibration of neck muscles have an immediate effect on static balance and when walking. The objective of this preliminary study is to test the long-lasting effects of repetitive neck muscle vibrations on postural disturbances in standing position and on spatial frame reference in chronic patients.

Detailed Description
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The hypothesis of this study is that the proprioceptive repeated stimulation by vibration of neck muscles in the long term improved postural asymmetry in connection with the egocentric representation of body disorders. The effect of vibration simultaneously on improving postural asymmetry and on improving markers of the perception of the body in space (LBA, SSA, Subjective Visual Vertical (SVV), Rod and frame) will be assessed.

Official Title
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The Long-lasting Effects of Repetitive Neck Muscle Vibrations on Postural Disturbances in Standing Position and on Spatial Frame Reference in Chronic Stroke Patients

Conditions
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Hemiplegia, Stroke

Intervention / Treatment
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* Other: Vibration sessions


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult (age ≥ 18 years) under 80 years, Right or left unilateral supratentorial ischemic or hemorrhagic lesion The first symptomatic episode Stroke older than 12 months with or without hemianopsia with or without visuospatial hemineglect Standing balance ≥ 30 sec unaided Percentage of weight bearing asymmetry on the hemiplegic lower limb (on a force platform) Written informed consent of the patient or a member of his entourage (in the case of patients with motor difficulties) Exclusion Criteria: Orthopaedic, rheumatologic, neurologic, vestibular or visual disorders affecting the distribution of the centre of pressure while standing on the force platform Visual disorder that does not allow assessment of the spatial frame of reference test Difficulty with understanding protocol procedures

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 79 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Left-brain damaged chronic patients<br> | Other: Vibration sessions<br>* The patients will undergo a program of 10 sessions of vibrations of the neck muscle, each of 10 minutes, during a period of 15 days at the rate of one session per day.<br>|
| Right-brain damaged chronic patients<br> | Other: Vibration sessions<br>* The patients will undergo a program of 10 sessions of vibrations of the neck muscle, each of 10 minutes, during a period of 15 days at the rate of one session per day.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes from baseline Weight Bearing Asymmetry at Day 15 | The primary evaluation criteria is the percentage of the Weight Bearing Asymmetry on the hemiparetic lower limb (WBA) calculated as the mean of 4 trys, each based on a 30 seconds duration with the two eyes open (OP) and then again with the two eyes closed. This evaluation is realized on a force platform. | Before and after the intervention program (Day 15) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Haptic and visual Subjective Straight Ahead (SSA) test | The effect on spatial reference frame evaluated by haptic and visual Subjective Straight Ahead (SSA) test | 7 days and 15 days after the start of the intervention | 
| Subjective Visual Vertical (SVV) test | The effect on spatial reference frame is evaluated by Subjective Visual Vertical (SVV) test | 7 days and 15 days after the start of the intervention | 
| Evaluation of Longitudinal Body Axis (LBA) | The effect on spatial reference frame is evaluated on Longitudinal Body Axis (LBA) | 7 days and 15 days after the start of the intervention | 
| Rod and Frame Test | The effect on spatial reference frame is evaluated by the Rod and Frame Test | 7 days and 15 days after the start of the intervention | 
| Change from baseline of patients' motor skills | Assessment of motor skills with simple motor tasks | 1 month after the end of the program | 
| Change from baseline of patients' sensitivity | Assessment of superficial tact on the hemiplegic lower limb compared to the safe limb | 1 month after the end of the program | 
| Change from baseline of patients' spasticity | Assessment of spasticity with Ashworth Modified scale | 1 month after the end of the program | 
| Change from baseline of patients' functional capacity | Functional capacity is a composite index made of sensitivity test, motor scale and spasticity scale | 1 month after the end of the program |