Integrating tDCS into routine inpatient rehabilitation practice to boost post-stroke recovery

Abstract

Transcranial direct current stimulation (tDCS), a non-invasive brain modulation tool, has gained popularity due to the portability, ease-of-use, and low cost. A majority of stroke recovery studies using tDCS have been focused on the chronic stage of recovery, as this time frame is relatively easy to conduct clinical trials and measure efficacy. However, studies during the chronic stage likely miss a window of opportunity where dynamic brain plasticity is occurring, the acute and subacute stages after stroke. The recent article by Bornheim et al. [[1]Bornheim S. Croisier J.L. Maquet P. Kaux J.F. Transcranial direct current stimulation associated with physical-therapy in acute stroke patients - a randomized, triple blind, sham-controlled study.Brain Stimul. 2020; 13: 329-336Abstract Full Text Full Text PDF PubMed Scopus (17) Google Scholar] investigated the effects of tDCS applied during the first month post-stroke on functional recovery in a small, single-center, randomized, triple-blinded sham-controlled trial. Fifty patients were randomized to receive anodal tDCS (intervention) or sham tDCS (control) for 20 minutes per day, 5 days per week over 4 weeks starting 48 hours post-stroke onset. After the morning stimulation session, all subjects received targeted rehabilitation therapy to address their deficits for a total of 2 hours per day, 5 days per week in the inpatient rehabilitation setting. Outcomes were assessed longitudinally and included measures for motor impairment (Upper and Lower Extremity section of Fugl Meyer Test [FM]), sensation (somatosensory section of the FM Test and Semmes Weinstein Monofilament Test [SWMT]), motor function (Wolf Motor Function Test [WMFT]), disability (Barthel Index [BI]), anxiety and depression (Hospital Anxiety and Depression Scale [HADS]), and quality of life (Stroke Impact Scale [SIS]). Per-protocol analysis showed statistically significant “time by treatment” effect in almost all the outcomes measures, proving that the seamless integration of tDCS into daily rehabilitation in the inpatient rehabilitation setting can lead to significant improvements in a number of key aspects of stroke recovery. Significant improvements were observed at pre to post intervention time points between the treatment groups in the assessments for motor impairment (FM), upper extremity function (WMFT), and anxiety and depression (HADS) but not in sensation, disability (BI) or quality of life (SIS). As motor impairment reduced and function improved, there appeared to be an associated improvement in depression status (HADS), which is consistent with the FLAME study [[2]Chollet F. Tardy J. Albucher J.F. Thalamas C. Berard E. Lamy C. et al.Fluoxetine for motor recovery after acute ischaemic stroke (FLAME): a randomised placebo-controlled trial.Lancet Neurol. 2011; 10: 123-130Abstract Full Text Full Text PDF PubMed Scopus (615) Google Scholar]. The sustained benefits seen in this trial are likely attributable to the prolonged application of tDCS for 20 sessions with a total of 400 minutes of brain stimulation time starting as early as 48 hours post-stroke, which is substantially longer than the majority of tDCS studies except for one [[3]Hesse S. Waldner A. Mehrholz J. Tomelleri C. Pohl M. Werner C. Combined transcranial direct current stimulation and robot-assisted arm training in subacute stroke patients: an exploratory, randomized multicenter trial.Neurorehabilitation Neural Repair. 2011; 25: 838-846Crossref PubMed Scopus (173) Google Scholar]. While the outcome measures assessing motor impairment are encouraging, functional independence measured by the BI and quality of life measured by the SIS provide a better estimate of clinically meaningful treatment effect. The authors cite a study by Lin et al. [[4]Lin K.C. Hsieh Y.W. Wu C.Y. Chen C.L. Jang Y. Liu J.S. Minimal detectable change and clinically important difference of the Wolf Motor Function Test in stroke patients.Neurorehabilitation Neural Repair. 2009; 23