Repeated tDCS of the left dorsolateral prefrontal cortex for acute DoC: a pilot randomized controlled trial

This study aimed to investigate the safety and feasibility of transcranial direct current stimulation (tDCS) in patients with acute disorders of consciousness (DoC), and to preliminarily explore its potential intervention effects. In this sham-controlled randomized trial, participants with acute DoC within 7-28 days post-onset were randomly assigned (1:1) to either the active or sham stimulation group. The active-stimulation group received 2-mA direct current stimulation at the left dorsolateral prefrontal cortex (DLPFC) for 20 min per session, twice daily, over 10 consecutive working days. Primary outcomes were safety and feasibility. Exploratory efficacy outcomes included the Coma Recovery Scale-Revised (CRS-R), Glasgow Coma Scale (GCS), and Full Outline of UnResponsiveness (FOUR) scale, assessed at baseline, after 5 days, and upon completion of the intervention. Between May 2022 and May 2023, 22 eligible patients were enrolled and randomly assigned to the active (n = 11) or sham (n = 11) group. All participants completed the full protocol without dropouts. No severe adverse events were reported; transient skin redness occurred in six patients (54.55%) in the active-stimulation group. After 10 days, the active-stimulation group showed significantly higher scores on exploratory neurobehavioral measures (CRS-R: 15.91 ± 6.56 vs. 7.64 ± 5.22, t = 3.27, p < 0.01; FOUR: 13.73 ± 2.97 vs. 9.36 ± 4.65, t = 2.62, p = 0.01). Compared with sham stimulation, the tDCS protocol demonstrated favorable safety and feasibility in patients with acute DoC, with preliminary signals of neurobehavioral improvement. These findings support the conduct of larger, adequately powered trials to confirm therapeutic efficacy.Trial registration This trial was prospectively registered in the Chinese Clinical Trial Registry (identifier: ChiCTR2200060209) on 22-05-22.