Abstract W P103: Modulation of Motor Network Activities by Dual-mode Non-invasive Brain Stimulation in Stroke Patients
Objective: Combination of two non-invasive brain stimulation (NBS) modes, repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS), have been tried to enhance motor function in stroke patients. We aimed to investigate the changes of motor network after dual-mode NBS using Electroencephalogram (EEG).
Methods: Seven subacute ischemic stroke patients (mean age of 60.6 years; 4 males) and 8 healthy controls (mean age of 29.3 years; 4 males) participated. Participants received simultaneous application of 2mA cathodal tDCS over contralesional M1 and 10 Hz rTMS over the ipsilesional M1. Motor function was assessed before and after stimulation by serial reaction time task (SPTT). Eyes-closed resting state EEG was measured for 5 mins using the Neuroprax® EEG system (NeuroConn GmbH, Germany) before and after stimulation, respectively. The EEG signals were preprocessed using the SPM12b (http://www.fil.ion.ucl.ac.uk/spm/). In stroke patients, we flipped EEG signals from affected hemisphere to the left side. We confirmed event-related dynamics of brain oscillations through topography, and connectivity between ipsilesional M1 and contralesional M1 in mu band (8-12Hz) showing resting-state motor neurons over the bilateral M1s.
Results: Pre-simulation Event-related desynchronization (ERD) topographic map showed balancing between both hemispheres in heathy controls, however in stroke patients, ipsilesional M1 appeared more ERD, with unbalancing between both hemispheres. After dual-mode NBS, ERD topographic map showed balanced ERD between bilateral hemispheres in both healthy and stroke groups. In other words, stroke patients showed more ERS over the ipsilesional M1 after NBS. Furthermore, in stroke patients, connectivity between ipsilesional M1 (C3) and contralesional M1 (C4) increased after NBS, whereas connectivity between C3 and C4 decreased in healthy controls.
Conclusions: These results revealed that there were a balanced ERD and increase of connectivity between bilateral hemispheres after dual-mode NBS in stroke patients. The dual-mode NBS may modulate the pre-existing inter-hemispheric imbalance of both hemispheres in stroke patients.
Author Disclosures: Y. Kim: Research Grant; Significant; the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (NRF-2014R1A2A1A01005128) and the Brain Research Program through the National Research Foundation of Korea (. M. Lee: None. A. Lee: None. J. Cho: None. W. Chang: None.
- © 2015 by American Heart Association, Inc.