Plantarflexor PAS - Stroke

NCT ID: NCT04515407

Last Updated: 2024-02-22

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 10 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2021-10-01
• Study Completion Date: 2023-09-30

Brief Summary

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.

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.

Conditions

Stroke; Hemiparesis; Gait Dysfunction

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: OTHER
• Blinding Strategy: DOUBLE

Study Groups

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.

Group Type: OTHER

PAS at Rest

Intervention Type: OTHER

Paired Associative Stimulation will be delivered while the participant is seated and resting.

PAS - Active

Intervention Type: OTHER

Paired Associative Stimulation will be delivered while the participant is seated and producing submaximal background activity in the plantarflexor muscles.

PAS - Walking

Intervention Type: OTHER

Paired Associative Stimulation will be delivered while the participant is walking, during the late stance phase of the gait cycle.

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.

Group Type: OTHER

PAS at Rest

Intervention Type: OTHER

Paired Associative Stimulation will be delivered while the participant is seated and resting.

PAS - Active

Intervention Type: OTHER

Paired Associative Stimulation will be delivered while the participant is seated and producing submaximal background activity in the plantarflexor muscles.

PAS - Walking

Intervention Type: OTHER

Paired Associative Stimulation will be delivered while the participant is walking, during the late stance phase of the gait cycle.

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.

Group Type: OTHER

PAS at Rest

Intervention Type: OTHER

Paired Associative Stimulation will be delivered while the participant is seated and resting.

PAS - Active

Intervention Type: OTHER

Paired Associative Stimulation will be delivered while the participant is seated and producing submaximal background activity in the plantarflexor muscles.

PAS - Walking

Intervention Type: OTHER

Paired Associative Stimulation will be delivered while the participant is walking, during the late stance phase of the gait cycle.

Interventions

PAS at Rest

Paired Associative Stimulation will be delivered while the participant is seated and resting.

Intervention Type: OTHER

PAS - Active

Paired Associative Stimulation will be delivered while the participant is seated and producing submaximal background activity in the plantarflexor muscles.

Intervention Type: OTHER

PAS - Walking

Paired Associative Stimulation will be delivered while the participant is walking, during the late stance phase of the gait cycle.

Intervention Type: OTHER

Other Intervention Names

REST; Active; Walking

Eligibility Criteria

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

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

VA Office of Research and Development

FED

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Carolynn Patten, PhD

Role: PRINCIPAL_INVESTIGATOR

Martinez Outpatient Clinic and Community Living Center, Martinez, CA

Locations

Martinez Outpatient Clinic and Community Living Center, Martinez, CA

Martinez, California, United States

Countries

United States

Provided Documents

Document Type: Informed Consent Form

View Document

Other Identifiers

1I21RX003609-01

Identifier Type: NIH

Identifier Source: secondary_id

View Link

B3609-P

Identifier Type: -

Identifier Source: org_study_id