Cortical Mechanisms and Modulation of Somatosensation in Older Adults With Foot Sole Somatosensory Impairments
Hebrew SeniorLife
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.
Eligibility
- Age range
- 65+ years
- Sex
- All
- Healthy volunteers
- No
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 mel…
Interventions
- Devicetranscranial 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.
- Deviceactive 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.
Location
- Hebrew SeniorLifeRoslindale, Massachusetts