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

NCT ID: NCT06771531

Last Updated: 2025-12-16

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: PHASE2
• Total Enrollment: 20 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-12-19
• Study Completion Date: 2026-10-31

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

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: TREATMENT
• Blinding Strategy: TRIPLE

Study Groups

tDCS group

Participants in this arm will receive the real tDCS intervention.

Group Type: EXPERIMENTAL

transcranial direct current stimulation

Intervention Type: 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.

sham group

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

Group Type: SHAM_COMPARATOR

active sham stimulation

Intervention Type: 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.

Interventions

transcranial direct current stimulation

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.

Intervention Type: DEVICE

active sham stimulation

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.

Intervention Type: DEVICE

Eligibility Criteria

Inclusion Criteria

1. Aged ≥65 years.

2. Self-reported feeling of unsteadiness or difficulty when standing and walking.

3. Mild-to-moderate foot-sole somatosensory impairment: the ability to perceive 75g monofilament but inability to perceive 10g monofilament.

Exclusion Criteria

1. self-reported inability to stand or walk continuously for one minute without personal assistance (canes or walkers allowed);

2. history or presence of foot ulceration, amputation, or deformities;

3. self-reported uncontrolled pain or pain that is associated with mobility disability;

4. uncontrolled diabetes mellitus;

5. hospitalization within the past three months due to acute illness, or as the result of a musculoskeletal injury significantly affecting balance;

6. persistent severe pain of lower extremity when standing or walking;

7. diagnosis of dementia, Parkinson's disease, or stroke that affects balance;

8. unstable medical condition;

9. legal blindness or deafness;

10. uncontrolled hypertension (i.e., systolic BP >180, diastolic BP >100 mm Hg, or prescription of ≥3 anti-hypertensive medications);

11. functionally limiting nephropathy, severe diseases or transplant of the kidney or liver, renal or congestive heart failure;

12. active cancer treatment;

13. balance disorders due to past use of chemotherapy or history of Guillain-Barré syndrome;

14. use of neuro-active or recreational drugs (e.g., sedatives, anti-psychotics), or alcohol abuse, which may affect the brain excitability;

15. contraindications to MRI or tDCS (e.g., personal or family history of seizures or epilepsy, metallic or electric bio-implants, claustrophobia, brain surgery);

16. persistent vertigo;

17. history of Charcot-Marie-Tooth nerve disease.

• Minimum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

National Institute on Aging (NIA)

NIH

Sponsor Role: collaborator

Hebrew SeniorLife

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Locations

Hebrew SeniorLife

Roslindale, Massachusetts, United States

Site Status: RECRUITING

Countries

United States

Central Contacts

Junhong Zhou, PhD

Role: CONTACT

junhongzhou@hsl.harvard.edu

617-971-5346

Facility Contacts

Kathy Tasker

Role: primary

KathyTasker@hsl.harvard.edu

617-971-5351

Other Identifiers

K01AG075180

Identifier Type: NIH

Identifier Source: secondary_id

View Link

Pro00044674

Identifier Type: -

Identifier Source: org_study_id