# Direct Measurement of Motor Cortical Oscillations in Response to Transcranial Direct Current Stimulation

> **NIH NIH P20** · MEDICAL UNIVERSITY OF SOUTH CAROLINA · 2021 · $228,717

## Abstract

Neuromodulatory approaches for chronic stroke patients are limited. Transcranial direct current stimulation 
(tDCS) has shown the potential to improve motor deficits in this population; however, its effects have not been 
consistent in randomized studies to date, limiting widespread adoption. A critical gap in our knowledge is a 
detailed understanding of how tDCS affects motor cortical oscillations, which are important in guiding voluntary 
movement. Our long-term goal is to develop effective neuromodulation-based therapeutic systems in chronic 
stroke patients based on a better understanding of how neuromodulation of cortical signals can improve recovery 
of motor behavior in this population. In a previous study, we recorded subdural electrocorticography (sECoG) in 
akinetic-rigid Parkinson’s disease (PD) patients undergoing DBS surgery, and observed significant modulation 
of motor cortical oscillations in relation to an arm-reaching task. Thus, changes in cortical oscillations supported 
improved motor performance in this group. Based on these results, our central hypothesis is that modulation of 
motor cortical oscillations both prior to and during movement may be one mechanism by which tDCS promotes 
recovery after chronic motor stroke. To test this hypothesis, in PD patients undergoing DBS surgery, we will 
measure cortical beta (13-30 Hz) and broadband gamma (70-200 Hz) oscillations during a cued arm-reaching 
task (Aim 1) and a motor imagery task (Aim 2) before and after anodal tDCS activation of primary motor cortex. 
In these patients, simultaneous sECoG and EEG will be performed. In order to ensure that our findings in PD 
will be directly translatable to a stroke model, in Aim 3 we will collect pilot data using combined tDCS and EEG 
in a cohort of chronic stroke patients performing the same arm task as PD patients in Aim 1. Aims 1 and 2 will 
be performed in the operating room, while Aim 3 will take place in the NI Core EEG lab. We anticipate that tDCS 
will modulate motor cortical oscillations in a way that biases movement planning and initiation in both populations. 
This proposal to combine tDCS with sECoG and EEG during neurosurgery is novel. If our hypotheses are 
confirmed, the findings may have use in developing a closed-loop form of tDCS for stroke recovery, for which 
we will have pilot data (from Aim 3) to inform such an approach. Furthermore, the measurement of EEG in both 
PD and chronic stroke patients, using an identical experimental paradigm and recording modality, ensures that 
the results will be directly interpretable between both models. Finally, our sECoG recordings will provide detailed 
spatial and frequency domain (above 70 Hz) information not captured by EEG. In the future, these results may 
potentially set the stage for an invasive system in chronic stroke patients based on sensing and responding to 
pathological oscillations, as is already commercially available for epilepsy patients and currently in devel...

## Key facts

- **NIH application ID:** 10232471
- **Project number:** 5P20GM109040-08
- **Recipient organization:** MEDICAL UNIVERSITY OF SOUTH CAROLINA
- **Principal Investigator:** Nathan C. Rowland
- **Activity code:** P20 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $228,717
- **Award type:** 5
- **Project period:** 2021-02-22 → 2024-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10232471

## Citation

> US National Institutes of Health, RePORTER application 10232471, Direct Measurement of Motor Cortical Oscillations in Response to Transcranial Direct Current Stimulation (5P20GM109040-08). Retrieved via AI Analytics 2026-05-28 from https://api.ai-analytics.org/grant/nih/10232471. Licensed CC0.

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