# Brain stimulation to alleviate weakness and maladaptive plasticity in SCI

> **NIH VA IK1** · LOUIS STOKES CLEVELAND VA MEDICAL CENTER · 2020 · —

## Abstract

Less than one percent of individuals with a spinal cord injury (SCI) experience complete functional recovery
by hospital discharge. Functional deficits can be improved after discharge by combining rehabilitation with a
promising experimental technique known as non-invasive brain stimulation. Non-invasive brain stimulation is
believed to further improve recovery by promoting advantageous plasticity across neural substrates that survive
in the majority of SCIs. Specifically, we have recently shown that a form of non-invasive brain stimulation, called
transcranial direct current stimulation (tDCS), can improve muscle strength up to 15% more than rehabilitation
alone by increasing the excitability of pathways to the weaker muscles.
 The rationale of this proposal is that optimizing the application of tDCS would lead to an even better
enhancement of outcomes in those with SCI. My work, similar to others, has shown that in the presence of an
SCI, cortical areas representing stronger muscles are larger than those devoted to weaker muscles. Because of
such neurophysiological changes, the broad distribution of current from conventional tDCS would not just excite
areas devoted to weak muscles but also those of over-represented strong muscles. Here, I test the premise that
reducing extraneous excitation of motor cortical areas that represent strong muscles, by using focal tDCS, I
would increase corticospinal excitability to pathways devoted to weak muscles and improve their contribution to
movement control of the paretic upper extremity compared to conventional tDCS.
 My preliminary data provides support for my central premise. I have found that individuals receiving the largest
current density from conventional tDCS to cortical areas devoted to weak muscles demonstrate the most
improvements in hand dexterity. Therefore, my revised application will build off my previous study in SCI to
determine if using a more focal form of tDCS can improve movement control of the paretic upper extremity. To
test my premise, eighteen subjects with C2-C8 incomplete SCI will receive single sessions of conventional tDCS
or focal tDCS, with a new approach called high-definition tDCS (HD-tDCS), during upper-limb movement training
in a randomized, sham-controlled crossover experiment.
 From my cross-over study, I will quantify how focality of tDCS affects corticospinal excitability to pathways
devoted to the weak muscles compared to conventional tDCS. Changes in corticospinal excitability will be
assessed with transcranial magnetic stimulation. Next, I will measure how focal tDCS affects movement control
of the upper extremity in comparison to conventional tDCS. Kinematic movement control will be quantified as
change in upper limb movement speed and smoothness of movement. Finally, I will utilize computational
modeling to determine the overlap between the tDCS electric field and motor cortical representations devoted to
weak and strong muscles. Completion of my CDA-1 will inform...

## Key facts

- **NIH application ID:** 9837353
- **Project number:** 5IK1RX002428-02
- **Recipient organization:** LOUIS STOKES CLEVELAND VA MEDICAL CENTER
- **Principal Investigator:** Kelsey Potter-Baker
- **Activity code:** IK1 (R01, R21, SBIR, etc.)
- **Funding institute:** VA
- **Fiscal year:** 2020
- **Award amount:** —
- **Award type:** 5
- **Project period:** 2019-01-01 → 2020-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9837353

## Citation

> US National Institutes of Health, RePORTER application 9837353, Brain stimulation to alleviate weakness and maladaptive plasticity in SCI (5IK1RX002428-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9837353. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*