# Paired Associative Stimulation to Facilitate Plantarflexor Power Following Stroke

> **NIH VA I21** · VA NORTHERN CALIFORNIA HEALTH CARE SYS · 2024 · —

## Abstract

Project Summary/Abstract
The proposed SPiRE builds on preliminary work in which we 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. We have observed robust associations between: i) PF
corticospinal efficacy, and ii) modulation of corticospinal drive, and PF power, particularly in individuals post-
stroke. Importantly, clinical and demographic factors including: age, stroke chronicity, and lesion location, neither
explain, nor modify, these associations. In combination, these findings lead to our 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 we propose to investigate use of
paired associative stimulation (PAS) to enhance corticospinal efficacy and to the plantarflexors through targeted
neuroplasticity. We will explore 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. The proposed SPiRE focused 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 with post-
stroke walking dysfunction. By achieving our 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, we 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. Our objectives are consistent with the programmatic guidelines of the SPiRE (RX-20-009),
particularly as they relate to senior investigators. Specifically: i) this work has not previously been funded; ii) the
question to be addressed in this proposal represents a new area of research, and a new collaboration, for the
PI, and iii) we seek to develop our 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. We will compare effects of PAS targeting ankle plantarflexion when delivered: at rest, during
submaximal activity, and during walking.

## Key facts

- **NIH application ID:** 10933424
- **Project number:** 5I21RX003609-04
- **Recipient organization:** VA NORTHERN CALIFORNIA HEALTH CARE SYS
- **Principal Investigator:** Carolynn Patten
- **Activity code:** I21 (R01, R21, SBIR, etc.)
- **Funding institute:** VA
- **Fiscal year:** 2024
- **Award amount:** —
- **Award type:** 5
- **Project period:** 2020-10-01 → 2025-09-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10933424

## Citation

> US National Institutes of Health, RePORTER application 10933424, Paired Associative Stimulation to Facilitate Plantarflexor Power Following Stroke (5I21RX003609-04). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10933424. Licensed CC0.

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