Effects of Different Montages of Transcranial Direct Current Stimulation on Haemodynamic Responses and Motor Performance in Acute Stroke: A Randomized Controlled Trial (original) (raw)

2022, Journal of Rehabilitation Medicine

Transcranial direct current stimulation (tDCS) has shown positive results in neurorehabilitation. However, there is limited evidence on its use in acute stroke, and unclear evidence regarding the best tDCS montage (anodal-, cathodal-, or dual-tDCS) for stroke recovery. This study investigated the effects of these montages combined with physical therapy on haemodynamic response and motor performance. Methods: Eighty-two eligible acute stroke participants were allocated randomly into anodal, cathodal, dual, and sham groups. They received 5 consecutive sessions of tDCS combined with physical therapy for 5 days. Cerebral mean blood flow velocity (MFV) and motor outcomes were assessed preand post-intervention and at a 1-month follow-up. Results: None of the groups showed significant changes in the MFV in the lesioned or non-lesioned hemispheres immediately post-intervention or at a 1-month follow-up. For motor performance, all outcomes improved over time for all groups; betweengroup comparisons showed that the dual-tDCS group had significantly greater improvement than the other groups for most of the lower-limb performance measures. All 5-day tDCS montages were safe. Conclusion: MFV was not modulated following active or sham groups. However, dual-tDCS was more efficient in improving motor performance than other groups, especially for lower-limb performance, with after-effects lasting at least 1 month. A fter a unilateral stroke, the excitability of the affected hemisphere is decreased. This is coupled with an increase in the excitability of the unaffected hemisphere and abnormally high interhemispheric inhibition (IHI) from the intact to the lesioned hemisphere (1, 2). This reorganization of neuronal plasticity begins in the early stages after stroke (3). Transcranial direct current stimulation (tDCS) can induce changes in cortical excitability, which modulates brain plasticity in humans, and positive and safe results have been reported for tDCS in stroke neurorehabilitation (4, 5). Unilateral and dual-tDCS are used to induce poststroke motor recovery. Anodal-tDCS has been shown to increase cortical excitability, and cathodal-tDCS decreases cortical excitability, based on polarityspecific effects with limited doses (i.e. 0.5-1.5 mA) (8-13). Unilateral anodal-tDCS is used to restore excitability in the ipsilesional hemisphere by anodal stimulation, while cathodal-tDCS is used to decrease LAY ABSTRACT Different methods (anodal, cathodal, dual, or sham) of transcranial direct current stimulation (tDCS) combined with physical therapy were randomly provided to patients with acute stroke for 5 consecutive daily sessions. The outcome measures were evaluated before the intervention, post-intervention, and at 1-month followup using clinical motor assessments and transcranial colour-coded Doppler ultrasonography to measure blood flow velocity in the middle cerebral artery. The results showed no significant changes in cerebral blood flow in the lesioned and non-lesioned brain in all groups. For motor outcomes, dual-tDCS was more efficient for improving motor performance, especially lower-limb performance, than other montages, with a positive effect lasting for at least 1 month. All tDCS montages combined with physical therapy were safe for use in patients with acute stroke.