Brain Stimulation for Foot-sole Sensation in Older Adults With Foot-sole Somatosensory Deficits

NCT06771531 | Recruiting

• 2 other identifiers: Pro00044674K01AG075180
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

In older adults, diminished sensation of the legs and feet is highly prevalent and causes poor balance and reduced mobility. This type of sensation is not only dependent upon the receptors and nerves in the legs and feet, but also upon a complex central nervous system pathway that includes the cerebral cortex of the brain. This project will use a form of noninvasive brain stimulation called transcranial direct current stimulation (tDCS) to test whether increasing the excitability of the brain networks that process sensory feedback can augment foot sole sensation, balance, and mobility in older adults suffering from mild-to-moderate foot sole sensory impairments.

Conditions

Somatosensory Function; Balance Control; Mobility

Keywords

brain stimulation; balance and mobility; foot-sole somatosensory function

Outcome Measures

Primary Outcomes (4)

• postural sway area when standing with eyes closed on the foam

  This metric assesses the degree to which the soft support and cut-off of the vision diminishes the control of standing posture.

  Before and immediately after intervention

• Timed Up-and-Go (TUG) time

  This metric assesses mobility.

  Before and immediately after intervention

• On-target Blood oxygen level dependent (BOLD) signal intensity in response to foot sole stimulation

  This metric assesses the degree to which brain cortical regions activated by the walking-related foot-sole stimulation.

  Before and immediately after intervention

• Standing vibratory thresholds of each foot sole

  This metric assesses the degree to which the foot soles can sense the vibro-tactile stimuli when standing.

  Before and immediately after intervention

Secondary Outcomes (2)

• Postural sway speed when standing with eyes closed on the foam

  Before and immediately after intervention

• Gait speed of 10m walking test

  Before and immediately after intervention

Other Outcomes (1)

• BOLD signal intensity within other relevant cortical regions in response to foot sole stimulation

  Before and immediately after intervention

Study Arms (2)

tDCS group

EXPERIMENTAL

Participants in this arm will receive the real tDCS intervention.

Device: transcranial direct current stimulation

sham group

SHAM COMPARATOR

Participants in this arm will receive the sham stimulation as control.

Device: active sham stimulation

Interventions

transcranial direct current stimulation DEVICE

tDCS can safely and selectively modulate cortical excitability (specifically neuronal firing likelihood) by transferring weak electrical currents between scalp electrodes. The direct current delivered by any one electrode will not exceed 2.0 mA and the total amount of current from all electrodes will not exceed 4 mA in this study.

tDCS group

active sham stimulation DEVICE

sham stimulation will implement the same protocol of the tDCS intervention; however, only very low-level currents (no more than 0.5 mA) are transferred between the same electrodes used for the tDCS throughout the 20-minute session. This strategy effectively mimics the cutaneous sensations and skin redness induced by creating only micro cortical electric fields.

sham group

Eligibility Criteria

• Age: 65 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Older Adult (65+)

You may qualify if:

• Aged ≥65 years.
• Self-reported feeling of unsteadiness or difficulty when standing and walking.
• Mild-to-moderate foot-sole somatosensory impairment: the ability to perceive 75g monofilament but inability to perceive 10g monofilament.

You may not qualify if:

• self-reported inability to stand or walk continuously for one minute without personal assistance (canes or walkers allowed);
• history or presence of foot ulceration, amputation, or deformities;
• self-reported uncontrolled pain or pain that is associated with mobility disability;
• uncontrolled diabetes mellitus;
• hospitalization within the past three months due to acute illness, or as the result of a musculoskeletal injury significantly affecting balance;
• persistent severe pain of lower extremity when standing or walking;
• diagnosis of dementia, Parkinson's disease, or stroke that affects balance;
• unstable medical condition;
• legal blindness or deafness;
• uncontrolled hypertension (i.e., systolic BP \>180, diastolic BP \>100 mm Hg, or prescription of ≥3 anti-hypertensive medications);
• functionally limiting nephropathy, severe diseases or transplant of the kidney or liver, renal or congestive heart failure;
• active cancer treatment;
• balance disorders due to past use of chemotherapy or history of Guillain-Barré syndrome;
• use of neuro-active or recreational drugs (e.g., sedatives, anti-psychotics), or alcohol abuse, which may affect the brain excitability;
• contraindications to MRI or tDCS (e.g., personal or family history of seizures or epilepsy, metallic or electric bio-implants, claustrophobia, brain surgery);

Sponsors & Collaborators

• Hebrew SeniorLife: lead
• National Institute on Aging (NIA): collaborator

Study Sites (1)

Hebrew SeniorLife

Roslindale, Massachusetts, 02131, United States

RECRUITING

MeSH Terms

Interventions

Transcranial Direct Current Stimulation

Intervention Hierarchy (Ancestors)

Electric Stimulation Therapy; Therapeutics; Convulsive Therapy; Psychiatric Somatic Therapies; Behavioral Disciplines and Activities; Electroshock; Psychological Techniques

Central Study Contacts

Junhong Zhou, PhD

CONTACT

617-971-5346; junhongzhou@hsl.harvard.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 8, 2025
• First Posted: January 13, 2025
• Study Start: February 26, 2026
• Primary Completion (Estimated): July 1, 2026
• Study Completion (Estimated): December 31, 2026
• Last Updated: April 22, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)