Optimizing tDCS to Improve Dual Task Gait and Balance

Summary

The objective of this study is to determine the acute effects of single sessions of optimized tDCS, conventional tDCS, and sham stimulation on dual task standing and walking in older adults who are free of overt disease yet who present with poor baseline dual task performance.

Conditions

• Aging

Interventions

DEVICE

Conventional tDCS

The anode will be placed over F3 and the cathode over the contralateral supraorbital margin. At the beginning of stimulation, the current will be increased from 0.1 mA, in 0.1 mA increments over 60 seconds, up to a maximum of 1.8 mA. At the end of each session, current will be automatically ramped down to 0.0 mA over a 60 second period.

DEVICE

Optimized tDCS

This intervention will utilize eight gel electrodes with placement and current parameters optimized to the cohort, with the goal of generating an average nE over the left dlPFC of the same size as the one delivered by a conventional montage using sponges. The direct current delivered by any one electrode will however never exceed 2.0 mA; the total amount of current from all electrodes will not exceed 4 mA. Each 20- minute session will begin and end with a 60-second ramp up/down of current amplitude to maximize comfort.

DEVICE

Conventional Sham

Conventional sham will be used to maximize blinding of conventional sponge-based stimulation. The same sponge placement, ramp-up procedure, and session duration described above will be used; however, current will be automatically ramped down 60 seconds after ramp-up.

DEVICE

Optimized Sham

An active sham will be used in which very low-level currents (0.5 mA max) are transferred between the same electrodes used in the active condition throughout the entire 20-minute session. This intervention will be optimized to deliver currents designed to not significantly influence their cortical tissue, but still mimic the cutaneous sensations induced by tDCS. We have shown that this active sham effectively blinds participants and operators to stimulation condition and does not affect functional outcomes.

Sponsors & Collaborators

• Hebrew SeniorLife

  lead OTHER

Principal Investigators

• Brad Manor, PhD · Hebrew SeniorLife

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

QUADRUPLE

Model

CROSSOVER

Eligibility

Min Age

65 Years

Max Age

85 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2020-02-10

Primary Completion

2023-03-02

Completion

2023-03-02

Countries

• United States

Study Locations