Perception of Electrical Stimuli in Individuals With Stroke

Study Overview
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Brief Summary
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To successfully manipulate objects in one's surroundings, such as when lifting a cup, one must accurately perceive their physical interactions. This includes accurately interpreting the tactile cues arising at one's fingertips when touching an object. Currently, tactile perception is assessed in individuals with stroke using passive protocols. Research has yet to explore whether activating one's muscles impacts the tactile perceptual process in individuals with stroke despite previous research demonstrating the effect of muscle activation on tactile perception in individuals who are neurologically intact. The proposed research will be the first to address the impact of muscle activation, in addition to stroke, on tactile perception. As such, the proposed research is significant for advancing our understanding of the extent to which tactile deficits occur in individuals with stroke, particularly during volitional movement.

Detailed Description
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Participants will detect an externally-applied electrical stimulus at their fingertip with the elbow: 1) relaxed and flexed to 2) 25% and 3) 50% of their maximum voluntary torque (MVT). We will compare the detection threshold for these three conditions between each arm of participants with stroke and similarly-aged controls. Based on pilot data, we hypothesize that the detection threshold will be largest at the paretic arm when flexing to 50% MVT due to the greatest inhibition of sensory signals. Findings will indicate whether stroke negatively impacts an individual's ability to detect tactile stimuli during volitional sensorimotor tasks.

Official Title
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Perception of Electrical Stimuli During Muscle Activation in Individuals With Stroke

Conditions
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Stroke

Intervention / Treatment
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* Behavioral: Torque Generation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: For the participants with stroke, i) a single unilateral cortical lesion that took place at least one year prior and ii) an absence of comorbid neurological impairments Ability to understand and complete the experimental tasks Capacity to provide informed consent At least 18 years of age Exclusion Criteria: Major injury to either arm Sensory neuropathy

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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Accepts Healthy Volunteers

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: We will compare outcome measures across three experimental conditions and each upper extremity in participants with stroke and similarly-aged controls.
Masking: None (Open Label)


Arms and Interventions

| Intervention/Treatment |
| --- |
|Behavioral: Torque Generation|Relaxed, or flexing about the elbow to 25% or 50% of the maximum elbow torque that one can generate.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Detection threshold | Minimum magnitude of current at which an electrical stimulus can be detected |  5 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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tactile perception, somatosensation, muscle activation