Transcranial Direct Current Stimulation for Stroke Motor Recovery: What the TRANSPORT2 Trial Taught Us

Over the past 2 decades, transcranial direct current stimulation has attracted substantial interest as an adjunctive strategy to enhance poststroke motor recovery. In addition to its potential neuromodulatory effects on motor cortical networks, transcranial direct current stimulation devices are low-cost, easy to use, and compatible with concurrent rehabilitation. Yet, despite its promise, several barriers hinder translation into routine clinical practice, including neutral results from several recently completed multicenter trials, such as TRANSPORT2 (Transcranial Direct Current Stimulation for Post-Stroke Motor Recovery). Moving forward, progress will depend on addressing issues in 3 broad domains: device-related (stimulation parameters and montage), disease-related (patient characteristics and timing), and trial design (outcomes, analytical approaches, adjunctive therapy, and trial infrastructure). In this topical review, we critically examine these challenges and outline strategies to refine transcranial direct current stimulation application, with the goal of more effectively leveraging its neuromodulation properties to promote neuroplasticity and enhance motor recovery after stroke.