Facilitating skilled right hand motor function in older subjects by anodal polarization over the left primary motor cortex

Abstract

Healthy aging is accompanied by limitations in performance of activities of daily living and personal independence. Recent reports demonstrated improvements in motor function induced by non-invasive anodal direct current stimulation (tDCS) of the primary motor cortex (M1) in young healthy adults. Here we tested the hypothesis that a single session of anodal tDCS over left M1 could facilitate performance of right upper extremity tasks required for activities of daily living (Jebsen-Taylor Hand function Test, JTT) in older subjects relative to sham in a double-blind crossover study design. We found (a) significant improvement in JTT function with tDCS relative to sham that outlasted the stimulation period by at least 30 minutes, (b) that the older the subjects the more prominent this improvement appeared and (c) that consistent with previous results in younger subjects, these effects were not accompanied by any overt undesired side effect. We conclude that anodal tDCS applied over M1 can facilitate performance of skilled hand functions required for activities of daily living in older subjects.

Preconditioning tDCS facilitates subsequent tDCS effect on skill acquisition in older adults

“…This result confirms previous work reporting that older adults maintain the ability to learn new motor skills (Seidler 2007, Swinnen et al 1998. Previous studies have demonstrated the effect of tDCS with the anode placed over M1 on motor behaviour when the stimulation was applied during training of a functional motor task (Hummel et al 2010), sequence learning (Zimerman et al 2013), and visuo-motor tracking tasks (Goodwill et al 2015, Goodwill et al 2013). Here we demonstrated that tDCS with the anode placed over M1 also improved a unimanual isometric force control task (Reis et al 2009, Saucedo Marquez et al 2013 in both age groups.…”

“…However, the utilization of two mechanistically opposing tDCS protocols has never been investigated in the context of aging. There is good evidence to suggest that the responsiveness to tDCS (in terms of improving motor behaviour) is greater in older adults compared to younger adults (Hummel et al 2010, Zimerman et al 2013) and corticospinal excitability increases following tDCS with the anode placed over M1 are comparable between young and older adults ). As such, tDCS may have substantial potential as a clinical intervention tool to facilitate motor learning in older adults thereby potentially maintaining functional independence.…”

Effects of tDCS on motor learning and memory formation: A consensus and critical position paper

“…A series of studies have looked at online learning and adaptation effects over the life span (Goodwill, Reynolds, Daly, & Kidgell, 2013;Hardwick & Celnik, 2014;Hoff et al, 2015;Hummel et al, 2010;Zimerman et al, 2013). Hummel and colleagues (2010) investigated motor performance effects of tDCS using a crossover design in a cohort of older adults (Hummel et al, 2010).…”

“…Hummel and colleagues (2010) investigated motor performance effects of tDCS using a crossover design in a cohort of older adults (Hummel et al, 2010). When contralateral anodal or sham tDCS was applied concurrently with performance of the Jebsen-Taylor hand function test (JTT) they observed that anodal tDCS resulted in significant performance improvement relative to sham that lasted for over 30 min, and that the size of the effect correlated positively with age.…”

La stimulation transcrânienne à courant continu : un nouvel outil de neurostimulation

“…En revanche, la stimulation de l'hé misphè re dominant n'a induit aucune amé lioration de la dexté rité de la main droite. Une autre é tude a mis en é vidence un bé né fice majoré de la tDCS du cortex M1 pour les sujets â gé s par rapport aux sujets jeunes (Hummel et al, 2010). Ces ré sultats montrent que la stimulation est davantage performante pour des fonctions qui peuvent encore ê tre amé lioré es et moins pour celles dont la performance est dé jà é levé e (Desrosiers et al, 1999).…”