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

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.