High-Definition Transcranial Direct Current with Electrical Theta Burst on Post-Stroke Motor Rehabilitation: A Pilot Randomized Controlled Trial

Effectiveness of Intermittent Theta Burst Stimulation to Enhance Upper Extremity Recovery After Stroke: A Pilot Study

OBJECTIVES

To first investigate the effectiveness of modified constraint-ınduced movement therapy (mCIMT) in low-functioning patients with stroke (PwS). Second, we aimed to investigate the efficiency of intermittent theta-burst stimulation (iTBS), applied on intermittent days, in addition to the mCIMT in PwS.

DESIGN

A randomized, sham-controlled, single-blinded study.

SETTING

Outpatient clinic.

PARTICIPANTS

Fifteen PwS (age [mean±SD]: 66.3±9.2 years; 53% female) who were in the first 1 to 12 months after the incident were included in the study.

INTERVENTIONS

PwS were divided into 3 groups: (1) mCIMT alone; (2) mCIMT + sham iTBS; (3) mCIMT + iTBS. Each group received 15 sessions of mCIMT (1 hour/session, 3 sessions/week). iTBS was applied with 600 pulses on impaired M1 before mCIMT.

MAIN OUTCOME MEASURES

Upper extremity (UE) impairment was assessed with the Fugl-Meyer Test (FMT-UE), whereas the motor function was evaluated with the Wolf-Motor Function Test (WMFT). Motor Activity Log-28 (MAL-28) was used to evaluate the amount of use and how well (How Well Scale) the impaired UE movements.

RESULTS

With-in-group analysis revealed that all groups had statistically significant improvements based on the FMT-UE and MAL-28 (p<.05). However, the performance time and arm strength variables of WMFT were only increased in the mCIMT + iTBS group (p<.05). The only between-group difference was observed in the intracortical facilitation in favor of the mCIMT + iTBS group (p<.05). The effect size of iTBS was f=0.18.

CONCLUSIONS

Our findings suggest that mCIMT with and without the application of iTBS has increased the UE motor function in low-functioning PwS. iTBS applied on intermittent days may have additional benefits as an adjunct therapy for facilitating cortical excitability, increasing the speed and strength of the impaired UE as well as decreasing disability.

Clinical Comparison between HD-tDCS and tDCS for Improving Upper Limb Motor Function: A Randomized, Double-Blinded, Sham-Controlled Trial

Background

Stroke is a common and frequently occurring disease among middle-aged and elderly people, with approximately 55%-75% of patients remaining with upper limb dysfunction. How to promote the recovery of motor function at an early stage is crucial to the life of the patient.

Objectives

This study aimed to investigate whether high-definition transcranial direct current stimulation (HD-tDCS) of the primary motor cortex (M1) functional area in poststroke patients in the subacute phase is more effective in improving upper limb function than conventional tDCS.

Methods

This randomized, sham-controlled clinical trial included 69 patients with subcortical stroke. They were randomly divided into the HD-tDCS, anodal tDCS (a-tDCS), and sham groups. Each group received 20 sessions of stimulation. The patients were assessed using the Action Research Arm Test, Fugl-Meyer score for upper extremities, Motor Function Assessment Scale, and modified Barthel index (MBI) pretreatment and posttreatment.

Results

The intragroup comparison scores improved after 4 weeks of treatment. The HD-tDCS group showed a slightly greater, but nonsignificant improvement as compared to a-tDCS group in terms of mean change observed in function of trained items. The MBI score of the HD-tDCS group was maintained up to 8 weeks of follow-up and was higher than that in the a-tDCS group.

Conclusion

Both HD-tDCS and a-tDCS can improve upper limb motor function and daily activities of poststroke patients in the subacute stage. This trial is registered with ChiCTR2000031314.

Transcranial burst electrical stimulation contributes to neuromodulatory effects in the rat motor cortex

Background and objective

Transcranial Burst Electrical Stimulation (tBES) is an innovative non-invasive brain stimulation technique that combines direct current (DC) and theta burst stimulation (TBS) for brain neuromodulation. It has been suggested that the tBES protocol may efficiently induce neuroplasticity. However, few studies have systematically tested neuromodulatory effects and underlying neurophysiological mechanisms by manipulating the polarity of DC and TBS patterns. This study aimed to develop the platform and assess neuromodulatory effects and neuronal activity changes following tBES.

Methods

Five groups of rats were exposed to anodal DC combined with intermittent TBS (tBES+), cathodal DC combined with continuous TBS (tBES-), anodal and cathodal transcranial direct current stimulation (tDCS+ and tDCS-), and sham groups. The neuromodulatory effects of each stimulation on motor cortical excitability were analyzed by motor-evoked potentials (MEPs) changes. We also investigated the effects of tBES on both excitatory and inhibitory neural biomarkers. We specifically examined c-Fos and glutamic acid decarboxylase (GAD-65) using immunohistochemistry staining techniques. Additionally, we evaluated the safety of tBES by analyzing glial fibrillary acidic protein (GFAP) expression.

Results

Our findings demonstrated significant impacts of tBES on motor cortical excitability up to 30 min post-stimulation. Specifically, MEPs significantly increased after tBES (+) compared to pre-stimulation (p = 0.026) and sham condition (p = 0.025). Conversely, tBES (-) led to a notable decrease in MEPs relative to baseline (p = 0.04) and sham condition (p = 0.048). Although tBES showed a more favorable neuromodulatory effect than tDCS, statistical analysis revealed no significant differences between these two groups (p > 0.05). Additionally, tBES (+) exhibited a significant activation of excitatory neurons, indicated by increased c-Fos expression (p < 0.05), and a reduction in GAD-65 density (p < 0.05). tBES (-) promoted GAD-65 expression (p < 0.05) while inhibiting c-Fos activation (p < 0.05), suggesting the involvement of cortical inhibition with tBES (-). The expression of GFAP showed no significant difference between tBES and sham conditions (p > 0.05), indicating that tBES did not induce neural injury in the stimulated regions.

Conclusion

Our study indicates that tBES effectively modulates motor cortical excitability. This research significantly contributes to a better understanding of the neuromodulatory effects of tBES, and could provide valuable evidence for its potential clinical applications in treating neurological disorders.