Transcranial direct current stimulation (tDCS) for improving capacity in activities and arm function after stroke: a network meta-analysis of randomised controlled trials.

The included studies were mostly small phase II trials, which are prone to baseline imbalances and overestimation of treatment effects. There was significant heterogeneity in stimulation parameters (current, duration, electrode location) and concurrent treatments across the trials. Risk of bias in the individual studies was rated as low to unclear, and reporting of adverse events was often unsatisfactory. The analysis only looked at immediate post-intervention effects, so the long-term sustainability of any benefits is unknown. The finding that ADL capacity improved without arm function improving raises questions about whether the effect is due to a generalized treatment effect or chance rather than specific neural plasticity mechanisms.

There was no funding source for this study.

Do not interpret the improvement in activities of daily living as evidence that tDCS restores arm movement. The study found no effect of any tDCS type on arm function, so the ADL benefit may not be driven by motor recovery of the paretic limb.