Transcranial direct current stimulation plus concurrent activity may influence task prioritization during walking in people with Parkinson’s disease – initial findings

Abstract

Introduction: Walking for people with Parkinson's disease (PD) degrades during motor-cognitive interplay (ie, dual-task conditions). Current management of PD improves motor symptoms but inadequately addresses cognitive function, indicating a necessity for novel interventions. In this pilot study, we examined bi-hemisphere transcranial direct current stimulation (tDCS) with concurrent activity and dual-task walking in people with PD. Methods: Participants received 3 sessions (tDCS (sitting), tDCS (bike), tDCS(Wii)) of bilateral tDCS (dorsolateral prefrontal cortex; left = anode, right = cathode) at 2 mA and 1 sham session (tDCS(sham)). Sessions were randomized, single-blinded, and performed during medication ``ON{''} times separated by 7 +/- 2 days. Following each session, participants performed Timed Up and Go (TUG) single, dual-task conditions (TUG(alone), TUG(motor), TUG(cognitive)). Results: Sixteen participants with PD completed this study (mean age = 68.13 +/- 9.76 years, Unified Parkinson's Disease Rating Scale mean = 40.31 +/- 18.27, Repeatable Battery for the Assessment of Neuropsychological Status mean= 84.13 {[}13th percentile]). No differences were observed for TUG conditions between tDCS sessions. Dual task cost for TUG(motor), 14.73% (tDCS (Sitting)), 17.78% (tDCS(Bike)), 15.97% (tDCS (Wii))), 19.02% (tDCS (Sham)); for TUG(cognitive) (walking), 20.01% (tDCS (Sitting)), 18.7% (tDCS(Bike)), 31.18% (tDCS(Wii)), 20.01% (tDCS(Sham)); for TUG(cognitive) (cognitive), 33.72% (tDCS(Sitting)), 14.99% (tDCS(Bike)), 4.42% (tDCS(Wii)), 19.11% (tDCS(sham)). Conclusion: Our bi-hemisphere tDCS paired with concurrent activities did not lessen dual-task cost in participants with PD but appeared to influence task prioritization. Further investigation with a larger sample size is warranted.