Plantarflexor PAS - Stroke (PAS - Stroke)

February 20, 2024 updated by: VA Office of Research and Development

Paired Associative Stimulation to Facilitate Plantarflexor Power Following Stroke

The current project investigates a method called paired associative stimulation (PAS) which is known to influence nervous system function through a process called neuroplasticity. Here the investigators will target function of the ankle plantarflexor muscles because they are critically important to walking. The investigators will study adults who have walking dysfunction resulting from stroke. The study will test three ways of delivering PAS targeted towards brain-muscle connections serving the ankle plantarflexors. The overall goal is to improve functioning of the plantarflexors. The investigators believe that improving plantarflexor function will increase the likelihood of positive effects from gait retraining programs for people post-stroke. Participants will experience all three PAS methods in separate sessions. The investigators will compare differences in the size of these effects to identify the optimal method for delivery of PAS to the ankle plantarflexors. This study is a preliminary step to help us design a better clinical trial of combined PAS and gait retraining.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The current project builds on preliminary work in which the investigators have observed a relationship between efficacy of the corticospinal tract serving the plantarflexors and walking function, specifically ankle plantarflexor power, in individuals with chronic post-stroke hemiparesis. The investigators have observed robust associations between: i) PF corticospinal efficacy, and ii) modulation of corticospinal drive, and PF power, particularly in individuals poststroke. Importantly, clinical and demographic factors including: age, stroke chronicity, and lesion location, neither explain, nor modify, these associations. In combination, these findings lead to the investigators' central premise, that improved efficacy of the corticospinal tract serving the plantarflexors will enable augmentation of ankle PF power and contribute to improved walking function in individuals post-stroke. Here the team will investigate use of paired associative stimulation (PAS) to enhance corticospinal efficacy and to the plantarflexors through targeted neuroplasticity. Specifically the team will investigate three approaches to PAS to determine its efficacy for enhancing: i) neural responses, ii) biomechanical effects (A2), and iii) retention of neural and biomechanical effects.

Objectives. This SPiRE project focuses on methodological variables required to optimize efficacy of PAS on:

a) corticospinal efficacy to the plantarflexors, and b) walking function (quantified as A2) in Veterans and adults with poststroke walking dysfunction. By achieving the aims, data generated from this SPiRE will contribute to development of more focused and relevant hypotheses to be tested in future studies supported through competitive Merit Review. However, before motivating a larger study, the investigators first seek to determine the salience and magnitude of effects of PAS. In addition to exploring methodological issues related to PAS, data generated from the proposed SPiRE will enable us to determine the appropriate scope of a future project including sample size and dosing. The investigators seek to develop the methodology, determine feasibility, and generate preliminary/exploratory data for sake of determining effect sizes and computing statistical power for future large scale studies in human subjects. The investigators will compare effects of PAS targeting ankle plantarflexion when delivered: at rest, during submaximal activity, and during walking.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
10

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United States
    • California
      • Martinez, California, United States, 94553
        • Martinez Outpatient Clinic and Community Living Center, Martinez, CA

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • hemiparesis resulting from stroke
  • single, unilateral, hemispheric stroke (cortical or sub-cortical areas)
  • stroke confirmed by neuroimaging (CT or MRI)
  • stroke 3 months prior to enrollment
  • ability to walk, independently at least 25' on level ground, even if requiring brace or assistive device (cane)
  • Veteran Status prioritized

Exclusion Criteria:

  • lower extremity pain affecting ability to bear weight on legs
  • contractures limiting normal range of motion in major lower extremity joints
  • other neurological conditions (e.g., Parkinson's Disease, Multiple Sclerosis, ALS), prior traumatic brain injury, severe osteoarthritis or prior pathological fracture
  • cardiovascular conditions contraindicative to walking or light exercise
  • severe hypertension (i.e., >200/110 at rest that cannot be controlled in resting range of 180/110 mmHg)
  • perceptual or cognitive deficits affecting ability to: comprehend, follow three step directions, or provide consent

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Other: Order 1
All participants will receive PAS in three experimental conditions, randomized to the order of condition. Experimental order will be counterbalanced across participants. Order 1 will be: Seated@Rest, Seated@Active, Walking.
Other: PAS at Rest
Paired Associative Stimulation will be delivered while the participant is seated and resting.
Other Names:
  • REST
Other: PAS - Active
Paired Associative Stimulation will be delivered while the participant is seated and producing submaximal background activity in the plantarflexor muscles.
Other Names:
  • Active
Other: PAS - Walking
Paired Associative Stimulation will be delivered while the participant is walking, during the late stance phase of the gait cycle.
Other Names:
  • Walking
Other: Order 2
All participants will receive PAS in three experimental conditions, randomized to the order of condition. Experimental order will be counterbalanced across participants. Order 2 will be: Seated@Active, Walking, Seated@Rest.
Other: PAS at Rest
Paired Associative Stimulation will be delivered while the participant is seated and resting.
Other Names:
  • REST
Other: PAS - Active
Paired Associative Stimulation will be delivered while the participant is seated and producing submaximal background activity in the plantarflexor muscles.
Other Names:
  • Active
Other: PAS - Walking
Paired Associative Stimulation will be delivered while the participant is walking, during the late stance phase of the gait cycle.
Other Names:
  • Walking
Other: Order 3
All participants will receive PAS in three experimental conditions, randomized to the order of condition. Experimental order will be counterbalanced across participants. Order 3 will be: Walking, Seated@Rest, Seated@Active.
Other: PAS at Rest
Paired Associative Stimulation will be delivered while the participant is seated and resting.
Other Names:
  • REST
Other: PAS - Active
Paired Associative Stimulation will be delivered while the participant is seated and producing submaximal background activity in the plantarflexor muscles.
Other Names:
  • Active
Other: PAS - Walking
Paired Associative Stimulation will be delivered while the participant is walking, during the late stance phase of the gait cycle.
Other Names:
  • Walking

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
change in Motor Evoked Potential (MEP) size
Time Frame: immediately post-PAS
The difference in MEP size (area) post-PAS compared to pre-PAS will be quantified as the primary outcome for Aim 1. MEP size is considered an indicator of cortical/neural excitability. An increase in MEP size would suggest that PAS enhanced cortical excitability. MEP size can be expressed in either absolute/raw values or percentage change relative to baseline. A single session of PAS lasts 30-45 minutes.
immediately post-PAS
change in ankle plantarflexor power (A2)
Time Frame: immediately post-PAS
The difference in A2 post-PAS compared to pre-PAS will be quantified as the primary outcome for Aim 2. A2 quantifies the dynamic force producing capacity and is critical to forward progression during walking. An increase in A2 amplitude, area, or slope would suggest that PAS enhanced cortical excitability/neural connectivity enabling production of greater, more effective plantarflexor power during walking. A2 is expressed relative to the individual subject's body weight. Change in A2 can be expressed in either these normalized units or percentage change relative to baseline. A single session of PAS lasts 30-45 minutes.
immediately post-PAS

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
VA Office of Research and Development

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Carolynn Patten, PhD, Martinez Outpatient Clinic and Community Living Center, Martinez, CA

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
October 1, 2021

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
August 31, 2023

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
September 30, 2023

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 30, 2020

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 12, 2020

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 17, 2020

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
February 22, 2024

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 20, 2024

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
February 1, 2024

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • B3609-P
  • 1I21RX003609-01 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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