Multi-session anodal transcranial direct current stimulation enhances lower extremity functional performance in healthy older adults.

Abstract

The aim of this study was to examine the effects of 5days of anodal-transcranial direct current stimulation (a-tDCS) over the primary motor cortex (M1) on lower extremity functional performance in healthy elderly people. This was a randomized, double-blinded, sham-controlled study whereby 32 healthy older individuals participated in two groups. The intervention group received 20min of a-tDCS (1mA) over the M1 on five consecutive days. The sham group received the same stimulation, but the tDCS device was turned off after 30s of stimulation. Participants were asked to perform the Timed Up and Go (TUG), 30-s Chair Stand Test (30-s CST), and a Modified Figure of Eight Walk Test (MFEWT) on the first day before tDCS application, immediately, 30min, and 1week after the last session of stimulation. Results of the a-tDCS group showed that most of the test values had significant changes in post-test assessments compared to the pre-test (p < 0.05). When comparing the anodal and sham tDCS groups, the results showed a significant improvement in TUG and time-MFEWT immediately after (p = 0.02, p = 0.01), 30min after (p = 0.04, p = 0.01) and 1week after the last session of stimulation (p = 0.01, p = 0.01). Improvements in performance of the 30-s CST and the number of steps-MFEWT were not significant, except at 1week after the last session for the steps-MFEWT (p = 0.04). The application of 20min a-tDCS over the M1 for 5 consecutive days improves lower extremity functional performance in the healthy older participants.