Objective:
The purpose of this study was to investigate the effect of dual-mode noninvasive brain stimulation (NBS) by combining transcranial direct current stimulation (tDCS) over the unaffected primary motor cortex (uM1) and high-frequency repetitive transcranial magnetic stimulation (rTMS) over the affected M1 (aM1) on motor functions and corticomotor excitability in chronic stroke patients.
Methods:
Seventeen chronic stroke patients (12 men; mean age 58.7 years; 12 infarctions and 5 hemorrhages) participated in this double blinded random-order crossover study. All participants received three randomly arranged, dual-mode stimulations with 24 hours of washout period; Condition 1, simultaneous application of 10 Hz rTMS over the aM1 and cathodal tDCS over the uM1; Condition 2, simultaneous application of 10 Hz rTMS over the M1a and anodal tDCS over the uM1; Condition 3, 10 Hz rTMS over the aM1 and sham tDCS over the uM1. Corticomotor excitability using motor evoked potential (MEP) amplitude and hand motor functions using the sequential motor task were assessed before and after stimulation.
Results:
MEP amplitude was significantly increased after condition 1 and 3, respectively (p<0.05). The changes of MEP amplitude were significantly higher in condition 1 than condition 2 (p<0.05). In sequential motor task, the movement time was significantly decreased after condition 1 and 3, respectively (p<0.05). The change of movement time was significantly larger in condition 1 than the other conditions (p<0.05).
Conclusions:
Simultaneous stimulation of cathodal tDCS over the uM1 produced enhancement of 10 Hz rTMS effect over the aM1 in patients with stroke. These results suggest the dual-mode NBS as a method of enhancing motor function probably by inducing interhemispheric interaction of bilateral primary motor cortices in chronic stroke patients (Supported by the National Research Foundation of Korea grant (No.2011-0016960) and a KOSEF grant (M10644000022-06N4400-02210)).
Fibrinogen Reduction and Motor Function Improvement by Hematopoietic Growth Factor Treatment in Chronic Stroke in Aged Mice: A Treatment Frequency Study
