Improving Recovery After Stroke Via Electrical Stimulation of Proprioceptors

Study Overview
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Brief Summary
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The overall objective of the study is to test whether the use of small electrical currents to stimulate proprioceptors of the upper limb has potential for improving robot-assisted upper-limb rehabilitation in stroke survivors.

Detailed Description
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Study participants will be instructed to perform upper-limb movements using a system designed for upper-limb rehabilitation (Armeo Spring by Hocoma AG). The system provides subjects with unloading of the stroke-affected arm thus facilitating the performance of upper-limb movements. The system will be used to track the movements of the stroke-affected arm. Simultaneously, a custom-designed system (a prototype developed by the investigators) will be used to deliver small electrical currents to the arm. We hypothesize that the currents delivered to the arm will improve the accuracy of the movements performed by study participants. To assess if delivering small currents to the arm has an effect on the accuracy of the movements performed by the study participants, they will receive actual stimulation for some trials and sham stimulation for other trials. Because the investigators will deliver very small currents, study participants will be unable to perceive such currents and hence tell if they are performing the movements while receiving actual or sham stimulation. By comparing trials performed while subjects receive actual stimulation with trials performed while subjects received sham stimulation, the investigators will determine if the stimulation has an effect on the accuracy of the movements performed by the subjects. It is worth noticing that the investigators collected primary outcome data to assess changes associated with the use of actual stimulation vs sham stimulation. Data during a follow-up session was also collected, but not for the purpose of collecting outcome measures.

Official Title
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Improving Recovery After Stroke Via Electrical Stimulation of Proprioceptors

Conditions
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Chronic Stroke Survivors

Intervention / Treatment
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* Device: Current stimulator


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: unilateral and cortical, subcortical, or cerebellar stroke 6 months post-stroke Upper extremity impairments but able to move upper extremity against gravity 25% of the range Ability to understand directions and follow simple instructions Medically stable Upper Extremity Fugl-Meyer between 28 and 55 At least four (4) months since last botox treatment Mini-Mental State Examination (MMSE) ≥ 23 Exclusion Criteria: Participation in other forms of therapy/ intervention for upper extremity motor recovery Upper extremity or trunk fractures Severe fixed contractures affecting the upper limbs Severe perceptual deficits or visual field impairments Severe cognitive deficits Pregnant women Presence of an implanted electrically operated medical device Evidence of more than one clinical stroke Serious medical or neurological illness History of head trauma or cerebral infectious disease

Ages Eligible for Study
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Minimum Age: 18 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: Basic Science
Intervention Model: Single Group Assignment
Interventional Model Description: The investigators will use a system to inject small currents in the arm while subjects perform upper-limb movements. Subjects will perform multiple trials. During half of the trials, subjects will receive actual stimulation. During the other half, subjects will receive sham stimulation.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Current stimulator<br>The investigators have developed a device to deliver very small currents to the arm. The device will be used while subjects perform upper-limb movements using a device for upper-limb rehabilitation. Subjects will perform multiple trials of movement. During half of the trials, they will receive actual stimulation. During the other half, they will receive sham stimulation. | Device: Current stimulator<br>* This is a device developed by the investigators to produce sub-sensory electrical stimulation delivered via subcutaneous electrodes placed on the skin.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Fugl-Meyer Assessment | Subjects are asked to perform upper-limb movements from which a therapist can assess the severity of movement abnormalities (e.g. flexion synergies) | Changes in Fugl-Meyer Assessment score with vs without stimulation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Jebsen-Taylor Hand Function Test | Subjects are asked to perform a set of functional movements from which a therapist can assess subjects' functional limitations | Changes in Jebsen-Taylor Hand Function Test score with vs without stimulation | 
| Motor Activity Log | Subjects are asked about the amount and quality of use of their stroke-affected arm during the performance of daily activities | Change in Motor Activity Log score with vs without stimulation | 
| Modified Ashworth Scale | A therapist examines subjects to assess the severity of spasticity | Change in Modified Ashworth Scale score with vs without stimulation | 
| Box and Block test | Subjects are asked to move as many small wooden blocks as possible from one to box to another in a set amount of time | Change in Box and Block test score with vs without stimulation | 
| Grip strength | A hand dynamometer is used to measure grip strength | Change in grip strength with vs without stimulation | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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stroke, electrical stimulation