Neural Underpinnings of Turning

NCT05475236 | Completed Results

• 2 other identifiers: N3954-M1IK1RX003954-01A1
• Study Type: interventional
• Target: 16
• Locations: 1 country
• Sites: 1

Brief Summary

Older adults and stroke survivors often have difficulty performing complex walking tasks, due in part to changes in the brain. One task often overlooked is turning, which can lead to injury when performed poorly. The investigators will use non-invasive brain stimulation to assess brain activity and relate those observations to turning performance in older adults and stroke survivors.

Conditions

Aging

Keywords

Aging; Walking; Brain; Transcranial Magnetic Stimulation; Turning

Outcome Measures

Primary Outcomes (4)

• Duration of Cortical Silent Period (CSP) (ms)

  Cortical Silent Period (CSP) is a single-pulse TMS measure of GABA-mediated cortical inhibition, in which stimulation is applied to the motor cortex while participants are activating a target muscle (here, the tibialis anterior muscle), resulting in a brief reduction in muscle activity. CSP is measured as the time during which the muscle activity is less than the pre-simulation muscle activity level until the return of voluntary muscle activity. CSP is measured in milliseconds (ms).

  30 minutes, Measured at Baseline

• 360 Degree Turn Duration From Baseline

  Change in 360 degree turn duration during a 360 degree turn test

  Measured at follow up visit (approximately three weeks after baseline)

• 180 Degree Turn Duration From Baseline

  Change in 180 degree turn duration as measured during a 2 minute walking task where participants walk back and forth down a corridor.

  Measured at follow up visit (approximately three weeks after baseline)

• Resting Motor Threshold (Percent of Machine Output)

  Resting motor threshold (rMT) is obtained by single-pulse TMS and assesses voltage-gated sodium-channel-mediated cortical excitability. rMT is the minimum intensity (% machine output) of stimulation needed to repeatedly evoke a motor evoked potential (MEP) of at least 50 microvolts in over 50% of trials. It is reported as a percentage of total machine output.

  20 minutes, Measured at Baseline

Secondary Outcomes (1)

• Katz Independence Questionnaire

  Baseline

Study Arms (2)

Sham Stimulation

SHAM COMPARATOR

Participants will undergo 30 seconds of 2 mA electrical current to the head through saline soaked electrodes.

Behavioral: Experimental: Locomotor Learning

Transcranial Direct Current Simulation

EXPERIMENTAL

Participants will undergo 20 minutes of 2 mA electrical stimulation to the head through saline soaked electrodes.

Behavioral: Experimental: Locomotor Learning

Interventions

Experimental: Locomotor Learning BEHAVIORAL

Participants will undergo four sessions of locomotor and turn learning. Locomotor learning will involve practicing walking over different terrains (i.e., soft and firm mats) and obstacles at different walking speeds (slow or fast) and turning practice at each end of the walking course. The full cohort will undergo either transcranial direct current stimulation or sham stimulation.

Sham Stimulation; Transcranial Direct Current Simulation

Eligibility Criteria

• Age: 65 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Older Adult (65+)

You may qualify if:

• age 65 years or older
• preferred 10m walking speed \< 1.1 m/s
• self-report of "some difficulty with walking tasks, such as becoming tired when walking a quarter mile, or when climbing two flights of stairs, or when performing household chores."
• Willingness to be randomized to either study group and to participate in all aspects of study assessment and intervention

You may not qualify if:

• Diagnosed neurological disorder or injury of the central nervous system, or observation of symptoms consistent with such a condition (Alzheimer's, Parkinson's, stroke, etc.)
• Contraindications to non-invasive brain stimulation (e.g., metal in head, wound on scalp)
• Contraindications to magnetic resonance imaging (e.g., metal in body, claustrophobia, etc).
• Use of medications affecting the central nervous system
• severe arthritis, such as awaiting joint replacement
• severe obesity (body mass index \> 35)
• current cardiovascular, lung or renal disease; diabetes; terminal illness
• myocardial infarction or major heart surgery in the previous year
• cancer treatment in the past year, except for nonmelanoma skin cancers and cancers having an excellent prognosis (e.g., early stage breast or prostate cancer)
• current diagnosis of schizophrenia, other psychotic disorders, or bipolar disorder
• uncontrolled hypertension at rest (systolic \> 180 mmHg and/or diastolic \> 100 mmHg)
• bone fracture or joint replacement in the previous six months
• current participation in physical therapy for lower extremity function or cardiopulmonary rehabilitation
• current enrollment in any clinical trial
• difficulty communicating with study personnel, and/or non-English speaking

Sponsors & Collaborators

• VA Office of Research and Development: lead

Study Sites (1)

North Florida/South Georgia Veterans Health System, Gainesville, FL

Gainesville, Florida, 32608-1135, United States

Location

Limitations and Caveats

Technical challenges during TMS data collection led to incomplete or unreliable neurophysiological data for several participants, limiting the interpretability of outcomes. Additionally, the overall sample size was small, which constrains the generalizability of the findings. The TMS component of the protocol required an FDA risk determination, which delayed the initiation of data collection and further contributed to the limited number of participants available for analysis.

Results Point of Contact

• Title: Dr. Clayton Swanson
• Organization: Veterans Health Administration

clayton.swanson@va.gov

3523761611

Study Officials

• Clayton W Swanson, PhD

  North Florida/South Georgia Veterans Health System, Gainesville, FL

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Masking Details: Participants will not be told which group (tDCS or sham) they are assigned to. Outcomes Assessors will not be told which group the participant was randomized to.
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: FED
• Responsible Party: SPONSOR

Model Details: Participants will randomized to either receive transcranial direct current stimulation (tDCS) or sham

Study Record Dates

• First Submitted: July 15, 2022
• First Posted: July 26, 2022
• Study Start: February 28, 2023
• Primary Completion: June 28, 2024
• Study Completion: June 28, 2024
• Last Updated: June 11, 2025
• Results First Posted: June 11, 2025

Record last verified: 2025-06

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, ICF
• Time Frame: The Limited Dataset will be completed after the study is completed and primary/secondary data accepted for publication

Locations

US (1)