Timing-dependent effects of transcranial direct current stimulation with mirror therapy on daily function and motor control in chronic stroke: a randomized controlled pilot study

Abstract

Background: The timing of transcranial direct current stimulation (tDCS) with neurorehabilitation interventions may affect its modulatory effects. Motor function has been reported to be modulated by the timing of tDCS; however, whether the timing of tDCS would also affect restoration of daily function and upper extremity motor control with neurorehabilitation in stroke patients remains largely unexplored. Mirror therapy (MT) is a potentially effective neurorehabilitation approach for improving paretic arm function in stroke patients. This study aimed to determine whether the timing of tDCS with MT would influence treatment effects on daily function, motor function and motor control in individuals with chronic stroke. Methods: This study was a double-blinded randomized controlled trial. Twenty-eight individuals with chronic stroke received one of the following three interventions: (1) sequentially combined tDCS with MT (SEQ), (2) concurrently combined tDCS with MT (CON), and (3) sham tDCS with MT (SHAM). Participants received interventions for 90 min/day, 5 days/week for 4 weeks. Daily function was assessed using the Nottingham Extended Activities of Daily Living Scale. Upper extremity motor function was assessed using the Fugl-Meyer Assessment Scale. Upper extremity motor control was evaluated using movement kinematic assessments. Results: There were significant differences in daily function between the three groups. The SEQ group had greater improvement in daily function than the CON and SHAM groups. Kinematic analyses showed that movement time of the paretic hand significantly reduced in the SEQ group after interventions. All three groups had significant improvement in motor function from pre-intervention to post-intervention.

Timing-Dependent Effects of Transcranial Direct Current Stimulation on Hand Motor Function in Healthy Individuals: A Randomized Controlled Study

“…A recent study reported a time-dependent effect in stroke patients. The group that received tDCS before motor training exhibited better recovery of daily functions than the group with simultaneous tDCS application [21]. In another study involving stroke patients, the 20-min tDCS before physical exercise increased muscle strength and reduced upper limb motor dysfunction [52].…”

“…Our findings are consistent with previous studies. In a recent randomized controlled trial, which explored the time-dependent effects of tDCS on upper limb function using mirror therapy in patients with chronic stroke, tDCS before training improved daily function and kinematics compared with the concurrent stimulation [21]. In other studies investigating the time-dependent effects in healthy participants, the cortical excitability was enhanced when tDCS was applied before motor training [22].…”

“…Although several studies compared tDCS stimulation before or concurrently with motor training in healthy volunteers or the elderly, the optimal timing has not been established [19]. Research involving stroke patients and healthy volunteers reported that tDCS should be applied prior to motor training [21,22], but opposing results indicate that using tDCS concurrently with motor training is more effective [23].…”

Effect of Anodal Transcranial Direct Current Stimulation Combined With Cognitive Training for Improving Cognition and Language Among Children With Cerebral Palsy With Cognitive Impairment: A Pilot, Randomized, Controlled, Double-Blind, and Clinical Trial

“…In fact, tDCS-induced plasticity is highly dependent on the state of the subject during stimulation. Liao et al ( 42 ) showed that tDCS both before and during mirror therapy resulted in better motor function than tDCS alone among chronic stroke patients. However, studies comparing the effects of tDCS alone and concurrent or sequential use of tDCS and cognitive training are scarce so far, and future studies are warranted.…”

Bimanual Movements and Chronic Stroke Rehabilitation: Looking Back and Looking Forward

“…Establishing accepted procedures in administering tDCS should lead to individualized dose-controlled treatments [98]. Further, standardizing tDCS protocols for chronic stroke intervention must include when and duration of the anodal and cathodal stimulation combinations [106]. Questions on the optimal stimulation time are still being debated.…”