Transcranial direct current stimulation and suppression of contralesional primary motor cortex post-stroke: a systematic review and meta-analysis

ABSTRACT

Objective: The purpose of this systematic review and meta-analysis was to investigate the therapeutic effects of cathodal tDCS (ctDCS) that suppresses the contralesional primary motor cortex (cM1) activity for individuals with stroke in different recovery phases.

Methods: Fifteen studies that used ctDCS for suppressing the cM1 activity were included in this meta-analysis. Twenty total comparisons from the qualified studies identified motor function changes between ctDCS and sham protocols. We divided recovery stages into two categories: (a) acute and subacute phases (time since stroke ≤6 months): eight comparisons and (b) chronic phase (time since stroke >6 months): 12 comparisons.

Results: Random-effects meta-analysis models revealed motor improvements after applying ctDCS on the cM1 as indicated by a significant standardized effect size (ES = 0.61; P < 0.001). The moderator variable analysis showed that acute and subacute patients revealed no significant effect size of ctDCS (ES = 0.46; P = 0.07), whereas the ctDCS protocol significantly improved motor functions in chronic patients (ES = 0.71; P < 0.001).

Conclusion: This comprehensive meta-analysis indicates that the treatment effects of ctDCS on the cM1 are different between patients in the acute and subacute phases and patients in the chronic phase post-stroke.

KEYWORDS:

• tDCS
• stroke
• motor rehabilitation
• contralesional hemisphere
• primary motor cortex

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

None.