# Brain areas that control reaching movements after stroke: Task-relevant connectivity and movement-synchronized brain stimulation

> **NIH VA I01** · VETERANS HEALTH ADMINISTRATION · 2022 · —

## Abstract

As stroke is a leading cause of disability among veterans, there is a compelling need to develop
treatments that improve motor ability after a stroke affects those brain networks relevant to motor function.
Our goal is to improve motor function after stroke through methods that combine brain stimulation with
practice. To advance this goal we need an understanding of the network changes that underlie recovery of
useful motor behaviors such as reaching. Non- primary cortical motor areas have been shown to have
strong connections with other motor areas, including the primary motor cortex, and there is some evidence
that their functional role changes after stroke. We and others have also demonstrated the ability to influence
reaching behavior with focal cortical stimulation, and to influence the cortical representation of reaching
movement through the combination of cortical stimulation with reaching practice.
We will use this new knowledge and increase our understanding of brain network changes and the effects
of brain stimulation and practice by completing the following three aims: 1. Quantify effects of disrupting
activity in PMd and PMv in each hemisphere during reaching tasks in participants with and without
capsular stroke. The functional role of each region will be assessed through the effects of brief trains of
repetitive transcranial magnetic stimulation in the dorsal and ventral premotor areas of each hemisphere
during reaching tasks in human participants with and without capsular stroke. The specifics of white
matter damage will influence which region on each side affects connectivity most. 2. Quantify connectivity
with M1 and other motor regions in human participants with and without capsular stroke. This will be
assessed by resting state & task-related connectivity using fMRI, and will demonstrate differences between
the three types of functional connectivity measures: TMS regional effects on motor output, resting state
fMRI, and dynamic causal models of task-related fMRI. The relationship between motor function and
functional connectivity will therefore have been tested. 3. Evaluate the effects of movement-
synchronized TMS of the most facilitatory region on the effects of practice on motor output and
behavioral performance. TMS of the most functionally relevant premotor region will be synchronized with
practice of the affected upper extremity. An innovative feature of this work is the study of internal capsule
stroke, which is a more homogeneous and appropriate population than the overall set of stroke types that
affect movement, which has a great deal of variety. These findings will allow us to formulate clear
hypotheses about which premotor area should be modulated after stroke, and when, in the context of
movement practice. We will be able to design a novel treatment protocol that delivers precisely timed
stimulation during practice of reaching movements.

## Key facts

- **NIH application ID:** 10316643
- **Project number:** 1I01RX003511-01A2
- **Recipient organization:** VETERANS HEALTH ADMINISTRATION
- **Principal Investigator:** GEORGE F. WITTENBERG
- **Activity code:** I01 (R01, R21, SBIR, etc.)
- **Funding institute:** VA
- **Fiscal year:** 2022
- **Award amount:** —
- **Award type:** 1
- **Project period:** 2021-11-01 → 2025-10-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10316643

## Citation

> US National Institutes of Health, RePORTER application 10316643, Brain areas that control reaching movements after stroke: Task-relevant connectivity and movement-synchronized brain stimulation (1I01RX003511-01A2). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10316643. Licensed CC0.

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