Determine the Effect of Targeted High-definition Transcranial Direct Current Stimulation (tDCS) on Reducing Post-stroke Upper Limb Motor Impairments

Description

Significant motor impairments occur in 80% of individuals after moderate to severe stroke and impact the body side to the lesioned hemisphere. Typical motor impairments involve loss of dexterity with highly prevalent upper limb flexion synergy. Advances in treating flexion synergy impairments have been hampered by a lack of precision rehabilitation. Previous studies suggest and support the role of cortico-reticulospinal tract (CRST) hyperexcitability in post-stroke flexion synergy. CRST hyperexcitability is often caused by damage to the corticospinal tract (CST). We hypothesize that: 1) inhibiting the contralesional dorsal premotor cortex (cPMd) will directly reduce the CRST hyperexcitability and thus, reduce the expression of the flexion synergy; 2) facilitating the ipsilesional primary motor cortex (iM1) will improve the excitability of the damaged CST, therefore reducing the CRST hyperexcitability and the flexion synergy. we propose to use a novel targeted high-definition tDCS (THD-tDCS) to specifically modulate the targeted cortical regions for testing his hypothesis, via the following aims: Aim 1. Evaluate the effect of cathodal THD-tDCS over the cPMd on reducing the CRST hyperexcitability and the expression of flexion synergy. Aim 2. Evaluate the effect of anodal THD-tDCS over the iM1 on improving the excitability of the CST, and determine whether this, thus, also reduces the CRST hyperexcitability and the flexion synergy. Aim 3. Evaluate the confluence effect of bilateral THD-tDCS, i.e., simultaneous cathodal stimulation over the cPMd and anodal over the iM1.

Conditions

Stroke

Study Overview

Study Details

Study overview

Significant motor impairments occur in 80% of individuals after moderate to severe stroke and impact the body side to the lesioned hemisphere. Typical motor impairments involve loss of dexterity with highly prevalent upper limb flexion synergy. Advances in treating flexion synergy impairments have been hampered by a lack of precision rehabilitation. Previous studies suggest and support the role of cortico-reticulospinal tract (CRST) hyperexcitability in post-stroke flexion synergy. CRST hyperexcitability is often caused by damage to the corticospinal tract (CST). We hypothesize that: 1) inhibiting the contralesional dorsal premotor cortex (cPMd) will directly reduce the CRST hyperexcitability and thus, reduce the expression of the flexion synergy; 2) facilitating the ipsilesional primary motor cortex (iM1) will improve the excitability of the damaged CST, therefore reducing the CRST hyperexcitability and the flexion synergy. we propose to use a novel targeted high-definition tDCS (THD-tDCS) to specifically modulate the targeted cortical regions for testing his hypothesis, via the following aims: Aim 1. Evaluate the effect of cathodal THD-tDCS over the cPMd on reducing the CRST hyperexcitability and the expression of flexion synergy. Aim 2. Evaluate the effect of anodal THD-tDCS over the iM1 on improving the excitability of the CST, and determine whether this, thus, also reduces the CRST hyperexcitability and the flexion synergy. Aim 3. Evaluate the confluence effect of bilateral THD-tDCS, i.e., simultaneous cathodal stimulation over the cPMd and anodal over the iM1.

Determine the Effect of Targeted High-definition tDCS on Reducing Post-stroke Upper Limb Motor Impairments

Determine the Effect of Targeted High-definition Transcranial Direct Current Stimulation (tDCS) on Reducing Post-stroke Upper Limb Motor Impairments

Condition
Stroke
Intervention / Treatment

-

Contacts and Locations

Urbana

Carle Foundation Hospital, Urbana, Illinois, United States, 61801

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

For general information about clinical research, read Learn About Studies.

Eligibility Criteria

  • * Paresis confined to one side, with substantial motor impairment of the paretic upper limb
  • * Capacity to provide informed consent
  • * Muscle tone abnormalities and motor or sensory impairment in the non-paretic limb
  • * Severe wasting or contracture or significant sensory deficits in the paretic upper limb
  • * Severe cognitive or affective dysfunction that prevents normal communication and understanding of consent or instruction
  • * Severe concurrent medical problems (e.g. cardiorespiratory impairment)
  • * Using a pacemaker
  • * Metal implants in the head
  • * Known adverse reactions to TMS and tDCS
  • * Pregnant

Ages Eligible for Study

18 Years to 90 Years

Sexes Eligible for Study

ALL

Accepts Healthy Volunteers

No

Collaborators and Investigators

Carle Foundation Hospital,

Study Record Dates

2025-06-30