Multimodal physical training combined with tDCS improves physical fitness components in people after stroke: a double-blind randomized controlled trial

Abstract

ABSTRACT Background Transcranial direct current stimulation (tDCS) seems to be a potential tool to optimize the long-term effects of multimodal physical training (MPT) on fitness components in post-stroke patients. Objective We investigated the effects of cortical tDCS combined with MPT on motor function reflected by strength, motor performance, and cardiorespiratory capacity in chronic stroke patients. Methods This double-blind randomized controlled trial included 18 volunteers (55 ± 10 y, 72 ± 13 kg), who underwent MPT preceded by either sham stimulation (SHAM) or 2 mA bi-hemispheric tDCS. MPT consisted of 24 sessions of 60–70 min performed 2 d/wk within 12–16 weeks, with individualized intensity. Outcomes were Fugl-Meyer scores for lower limbs (FM-LL), and total (FM-Total); speed in the 10-m walk test (10MWT); oxygen uptake and work output at maximal effort (VO2max and Wmax), and gas exchange threshold (VO2-GET and W-GET); peak torque of isokinetic knee extension (PT-EXT) and flexion (PT-FLEX) of paretic and non-paretic limbs; bilateral strength deficit during knee extension (DS-EXT) and flexion (DS-FLEX). Results Pre- vs. post-intervention improvements were detected in tDCS vs. SHAM (p < 0.05) for FM-total (29.6% vs. 15.9%; effect size [ES] = 0.78), FM-LL (35.9% vs. 9.0%; ES = 1.23), 10MWT (10.6% vs. 3.8%; ES = 0.67), Wmax (75.0% vs. 4.3%; ES = 1.68), W-GET (91.6% vs. 12.4%; ES = 1.62), PT-EXT (25.6% vs. −6.5%; ES = 1.94) and PT-FLEX (26.3% vs. 9.8%; ES = 0.65) of the paretic limb, and DS-EXT (−13.7% vs. 2.5; ES = 1.43). Conclusion Bi-hemispheric cortical tDCS optimized the effects of MPT performed with moderate volume and intensity upon muscle strength, motor function, and cardiorespiratory performance in stroke hemiparetic survivors. (Registration number RBR-22rh3p).