The effects of combined repetitive transcranial magnetic stimulation and transcranial direct current stimulation on motor function in patients with stroke

Background: Both transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS), when provided to stroke patients in combination with motor training, enhance therapeutic efficacy and motor function. However, the majority of previous studies have only examined a single treatment modality. Objective: The authors investigated the modulating influence of combination dual-mode brain stimulation upon bihemispheric stimulation with motor training in stroke patients. Methods: Twenty stroke patients with hemiparesis underwent five randomly arranged sessions of diverse combinations of rTMS and tDCS. We applied cathodal or anodal tDCS over the contralesional primary motor cortex (cM1) and 10Hz rTMS over the ipsilesional primary motor cortex (iM1) in a simultaneous or preconditioning method including sham stimulation. Immediately after dual-mode stimulation, sequential hand motor training was performed for 5 minutes. The total pulses of rTMS and the duration of tDCS and motor training were the same for all sessions. Cortical excitability and sequential motor performance were evaluated before and after each session. Results: Motor function and corticomotor excitability following simultaneous stimulation via cathodal tDCS over the cM1 combined with 10Hz rTMS over the iM1 were significantly increased after the intervention, with significantly greater motor improvement than seen with other treatment conditions (P<0.05). Conclusion: For the combination of bihemispheric rTMS and tDCS, simultaneous stimulation of cathodal tDCS and 10Hz rTMS results in better motor performance in stroke patients than other combination methods. This result seemed to be related to effective modulation of interhemispheric imbalance of cortical excitability by dual-mode stimulation.