Augmentation of Locomotor Adaptation Post-Stroke

Recruiting

Phase 1 Results N/A

Trial Description

This project will evaluate two different methods of normalizing the center of mass acceleration (COMa) in individuals post-stroke, specifically focusing on rates and pattern of recovery to analyze walking-specific adaptations as precursors to motor learning. In addition, the proposed project seeks to establish the optimal configuration of electrodes to activate neural circuits involved in post-stroke locomotion. Once the better method of training COMa and optimal parameters of electrode placement for tDCS are identified, the investigators will evaluate the effects of tDCS on locomotor adaptations during single sessions and over a five-day training period.

Detailed Description

The project seeks to establish the optimal configuration of electrodes to change the excitability of neural circuits involved in post-stroke locomotion, identify effective strategies for training a specific locomotor adaptation, and improve adaptations via adjunctive non-invasive brain stimulation. Tools to improve neural excitability may increase potential for locomotor skill learning, thereby improving rehabilitation outcomes. Non-invasive brain stimulation with transcranial direct current stimulation (tDCS) has recently emerged as a simple to administer, low-cost, and low-risk option for stimulating brain tissue. Cortical excitability is increased after application and preliminary results imply a relationship to increases in motor activity in those post-stroke. However, inhibition of the contralesional hemisphere is also shown to improve paretic motor output through inhibition of excessive maladaptive strategies, and combining the two electrode configurations may provide additional benefit for locomotor tasks requiring interlimb coordination. Furthermore, the effects of tDCS on walking function in conjunction with physical intervention strategies aimed at improving locomotor ability post-stroke are yet unstudied.

Conditions

Interventions

  • TDCS Device
    Intervention Desc: Constant non-invasive, low intensity, direct electrical current utilized to stimulate specific areas of the brain. Evaluating immediate effects of anodal/cathodal stimulation during 20 minutes of treadmill walking.
    ARM 1: Kind: Experimental
    Label: Uphill COMa training
    Description: Walking on an inclined treadmill, thus manipulating the permissive environment to elicit COMa adaptation, while receiving either tDCS or sham tDCS.
    ARM 2: Kind: Experimental
    Label: Downhill COMa training
    Description: Walking on a declined treadmill, thus manipulating the permissive environment to elicit COMa adaptation, while receiving either tDCS or sham tDCS.
  • Sham tDCS Device
    Intervention Desc: Per published protocols, tDCS will be administered for 30 secs allowing for sensory adaptation to occur and then turned off, so that the remaining sham "stimulation" will include zero current. Evaluating immediate effects during 20 minutes walking on a treadmill.
    ARM 1: Kind: Experimental
    Label: Uphill COMa training
    Description: Walking on an inclined treadmill, thus manipulating the permissive environment to elicit COMa adaptation, while receiving either tDCS or sham tDCS.
    ARM 2: Kind: Experimental
    Label: Downhill COMa training
    Description: Walking on a declined treadmill, thus manipulating the permissive environment to elicit COMa adaptation, while receiving either tDCS or sham tDCS.

Trial Design

  • Allocation: Randomized
  • Masking: Double Blind (Subject, Outcomes Assessor)
  • Purpose: Treatment
  • Endpoint: Efficacy Study
  • Intervention: Parallel Assignment

Outcomes

Type Measure Time Frame Safety Issue
Primary Center of Mass Acceleration Peak Pre (same as initial session) and post (immediately following final session) conducted within 5-10 days apart according to subject availability. No
Secondary Center of Mass Acceleration Impulse Pre (directly prior to initial session) and post (immediately following final session) conducted within 5-10 days apart according to subject availability. No

Sponsors