Improving Locomotor Learning With Brain Stimulation (ELLMITS)

Enhancing Locomotor Learning With Motor Imagery and Transcranial Direct Current Stimulation

The primary goal of this research was to assess the practicality and initial effectiveness of a motor imagery (MI) intervention combined with elements of action observation (AO), alongside active or sham transcranial direct current stimulation (tDCS) over the prefrontal cortex (PFC), on locomotor learning in healthy adults. Feasibility was determined by examining recruitment rates, participant engagement, and safety measures. The efficacy of the intervention was gauged by analyzing the time taken to complete tasks and changes in cerebral blood flow immediately after the intervention and one week later. The study was guided by three main hypotheses: (1) the intervention techniques would be well-received and safe for the participants; (2) compared to a control group, MI training would lead to better learning outcomes and retention of learning; (3) in comparison to the control and sham tDCS groups, active tDCS would result in superior learning outcomes and retention of learning.

Study Overview

• Status: Completed
• Conditions: Motor Learning
• Intervention / Treatment: Behavioral: Motor Imagery (MI); Device: Active tDCS; Device: Sham tDCS

Detailed Description

The study implemented a double-blind, randomized, controlled trial design. Participants were tested three times over 7 days. After study enrollment, the participants were randomly assigned to one of three groups: MIActive (receiving active tDCS stimulation and participating in MI protocol), MISham (receiving sham tDCS stimulation and participating in MI protocol), and Control (receiving no stimulation and participating in an unrelated video-watching task) by a research member not associated with data collection. Allocation ratio was 1:1:1 and a block randomization approach was employed to maintain an equal distribution of participants across the three groups throughout the study. Study participants and assessors were blinded to assignment of active or sham tDCS. The independent variables were time (pre, post, and retention trials) and group (MIActive, MISham and Control), and the dependent variables were time to completion of a complex obstacle course and the amount of change in oxygenated hemoglobin (ΔO2Hb) during performance of that task.

• Study Type: Interventional
• Enrollment (Actual): 38
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • North Carolina
    • Boone, North Carolina, United States, 28607
      • Appalachian State University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Male and female adults age 18 and older
• Freely ambulatory (no assistive walking aids)

Exclusion Criteria:

• Failure to meet specific inclusion criteria
• History or presence of any neurological disease
• Low visual ability, operationally defined as visual acuity less than 20/70 on the standard eye chart
• Extreme difficulty performing walking tasks due to low visual ability
• Clinical judgment of the investigative team
• Additionally, subjects who are determined to be at increased risk for adverse events during the tDCS procedure, as determined by the tDCS screening questionnaire

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: MI/Active tDCS; The participants received active tDCS current and participated in the Motor Imagery intervention.	Behavioral: Motor Imagery (MI); Participants watched a standardized video sequence that consisted of an individual completing twenty walking trials (twenty video clips-each clip represents one trial). Participants were instructed to place their focus intently on the person performing the obstacle course and try to imagine themselves doing the skill. Periodically, a reminder would appear to help focus and redirect participant's attention to different aspects of the video or different versions of imagery (visual or kinesthetic). Participants will watch the video first at normal play speed and then in slow motion after a short break (30 secs to 1 min). Total training time will be approximately 20 mins which is consistent with the duration of the locomotor intervention and duration of stimulation.; Device: Active tDCS; The participants received a 20-minute "active" session of tDCS at a 2-milliamp current.
Sham Comparator: MI/Sham tDCS; The participants received sham tDCS current and participated in the Motor Imagery intervention.	Behavioral: Motor Imagery (MI); Participants watched a standardized video sequence that consisted of an individual completing twenty walking trials (twenty video clips-each clip represents one trial). Participants were instructed to place their focus intently on the person performing the obstacle course and try to imagine themselves doing the skill. Periodically, a reminder would appear to help focus and redirect participant's attention to different aspects of the video or different versions of imagery (visual or kinesthetic). Participants will watch the video first at normal play speed and then in slow motion after a short break (30 secs to 1 min). Total training time will be approximately 20 mins which is consistent with the duration of the locomotor intervention and duration of stimulation.; Device: Sham tDCS; The participants received a 20-minute session of "sham" tDCS.
No Intervention: Control; The control group watched an unrelated (non stimulating) video for a duration equal to the MI groups' intervention tasks.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Prefrontal cortical activity	Functional near infrared spectroscopy (fNIRS) monitor (OctaMon by Artinis Medical Systems), changes in oxygenated hemoglobin concentration (O2Hb) relative to a baseline task	Baseline to 1 week follow up
Adherence to interventions	number of sessions attended	Baseline to 1 week follow up
Retention of participants	number of participants completing intervention and follow-up assessment	Baseline to 1 week follow up
Adverse events in each study arm	Number of unexpected and/or serious adverse events	Baseline to 1 week follow up
Time to completion	Recorded time to complete the obstacle course	Baseline to 1 week follow up
Gait velocity	Gait velocity, measured in meters/sec, was recorded using a zeno walkway gait analysis system. ProtoKinetics Movement Analysis Software was used to collect and analyze the data.	Baseline to 1 week follow up

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cognitive Assessment	The Montreal Cognitive Assessment (MoCA) is a widely used screening tool designed to assess various cognitive domains, including memory, attention, language, visuospatial skills, executive function, and orientation. During a MoCA test, individuals are presented with a series of tasks and questions that challenge different aspects of cognitive function. These tasks may include remembering a list of words, drawing a certain shape, following complex instructions, and identifying similarities between words or objects.	Baseline to 1 week follow up
Kinesthetic and Visual Imagery Questionnaire (KVIQ)	The ability to imagine movements was assessed with the Kinesthetic and Visual Imagery Questionnaire (KVIQ). This test evaluates the subject's ability to see (visual imagery) and feel (kinesthetic imagery) movements. The KVIQ consists of 10 items, (5 movements for each scale), each item being a separate movement followed by rating the ease or difficulty of generating those self-images on a 5-point Likert scale (where 1 = no image or sensation and 5 = Image as clear as seeing or as intense as executing the action). Higher scores reflected higher imagery abilities.	Baseline to 1 week follow up

Collaborators and Investigators

• Sponsor: Appalachian State University
• Investigators: Principal Investigator: Jared W Skinner, PhD, Appalachian State University

Publications and helpful links

General Publications

• Clark DJ, Chatterjee SA, Skinner JW, Lysne PE, Sumonthee C, Wu SS, Cohen RA, Rose DK, Woods AJ. Combining Frontal Transcranial Direct Current Stimulation With Walking Rehabilitation to Enhance Mobility and Executive Function: A Pilot Clinical Trial. Neuromodulation. 2021 Jul;24(5):950-959. doi: 10.1111/ner.13250. Epub 2020 Aug 18.

Study record dates

Study Major Dates

• Study Start (Actual): September 20, 2022
• Primary Completion (Actual): December 22, 2022
• Study Completion (Actual): December 22, 2022

Study Registration Dates

• First Submitted: May 3, 2024
• First Submitted That Met QC Criteria: May 9, 2024
• First Posted (Actual): May 16, 2024

Study Record Updates

• Last Update Posted (Actual): May 16, 2024
• Last Update Submitted That Met QC Criteria: May 9, 2024
• Last Verified: May 1, 2024

More Information

Terms related to this study

• Keywords: tDCS; motor imagery; randomized; controlled trial; double-blinded; functional near-infrared spectroscopy (fNIRS)
• Other Study ID Numbers: IRB-21-0198

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: There is not a plan to make Individual Participant Data (IPD) available.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: Yes