Improving Locomotor Learning With Brain Stimulation

Enhancing Locomotor Learning With Motor Imagery and Transcranial Direct Current Stimulation

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT06414213

Acronym

ELLMITS

Enrollment

Registered

2024-05-16

Start date

2022-09-20

Completion date

2022-12-22

Last updated

2025-02-03

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Motor Learning

Keywords

randomized, double-blinded, tDCS, motor imagery, functional near-infrared spectroscopy (fNIRS), controlled trial

Brief summary

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.

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.

Interventions

BEHAVIORALMotor 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.

DEVICEActive tDCS

The participants received a 20-minute active session of tDCS at a 2-milliamp current.

DEVICESham tDCS

The participants received a 20-minute session of sham tDCS.

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

SUPPORTIVE_CARE

Masking

DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender

ALL

Age

18 Years to 99 Years

Healthy volunteers

Yes

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

Design outcomes

Primary

Measure	Time frame	Description
Prefrontal Cortical Activity	Baseline to 1 week follow up	Functional near infrared spectroscopy (fNIRS) monitor (OctaMon by Artinis Medical Systems), changes in oxygenated hemoglobin concentration (O2Hb) relative to a baseline task
Adherence to Interventions	Baseline to 1 week follow up	number of sessions attended
Retention of Participants	Baseline to 1 week follow up	number of participants completing intervention and follow-up assessment
Adverse Events in Each Study Arm	Baseline to 1 week follow up	Number of unexpected and/or serious adverse events
Time to Completion	Baseline to 1 week follow up	Recorded time to complete the obstacle course

Secondary

Measure	Time frame	Description
Kinesthetic and Visual Imagery Questionnaire (KVIQ)	Baseline to 1 week follow up	The Kinesthetic and Visual Imagery Questionnaire (KVIQ-10) measures the ability to imagine movements. This test evaluates the subject's ability to see (visual imagery) and feel (kinesthetic imagery) movements. The KVIQ-10 total score ranges from 10 to 50 (visual and kinesthetic subscale scores each range from 5 to 25).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 reflect higher imagery abilities.

Countries

United States

Participant flow

Participants by arm

Arm	Count
MI/Active tDCS The participants received active tDCS current and participated in the Motor Imagery intervention. 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. Active tDCS: The participants received a 20-minute active session of tDCS at a 2-milliamp current.	13
MI/Sham tDCS The participants received sham tDCS current and participated in the Motor Imagery intervention. 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. Sham tDCS: The participants received a 20-minute session of sham tDCS.	12
Control The control group watched an unrelated (non stimulating) video for a duration equal to the MI groups' intervention tasks.	13
Total	38

Withdrawals & dropouts

Period	Reason	FG000	FG001	FG002
Overall Study	Lost to Follow-up	1	1	3

Baseline characteristics

Characteristic	MI/Active tDCS	MI/Sham tDCS	Control	Total
Age, Categorical <=18 years	0 Participants	0 Participants	0 Participants	0 Participants
Age, Categorical >=65 years	0 Participants	0 Participants	0 Participants	0 Participants
Age, Categorical Between 18 and 65 years	13 Participants	12 Participants	13 Participants	38 Participants
Age, Continuous	22.42 years STANDARD_DEVIATION 1.98	22.36 years STANDARD_DEVIATION 2.06	24.1 years STANDARD_DEVIATION 4.04	22.96 years STANDARD_DEVIATION 2.69
Race and Ethnicity Not Collected	—	—	—	0 Participants
Sex: Female, Male Female	11 Participants	11 Participants	10 Participants	32 Participants
Sex: Female, Male Male	2 Participants	1 Participants	3 Participants	6 Participants

Adverse events

Event type	EG000 affected / at risk	EG001 affected / at risk	EG002 affected / at risk
deaths Total, all-cause mortality	0 / 13	0 / 12	0 / 13
other Total, other adverse events	0 / 13	0 / 12	0 / 13
serious Total, serious adverse events	0 / 13	0 / 12	0 / 13