Movement related cortical potentials change after EEG-BMI rehabilitation in chronic stroke

Movement related cortical potentials (MRCPs) have been studied for many years and proposed as reliable and immediate indicators of cortical reorganizations in motor learning and after stroke. It has been reported that decrease in amplitude and later onset of MRCPs reflect less mental effort and shorter planning time during a motor task. In this study MRCPs preceding hand movements in severe chronic stroke were investigated in an EEG screening paradigm (patients performed hand open and close for paretic and healthy hand) before and after a one-month online-EEG-Brain-Machine-Interface neurorehabilitation intervention coupled with physiotherapy. Five severely impaired (no residual finger extension) chronic stoke patients were enrolled in the study. We observed that MRCPs peak amplitude over Cz during paretic hand movement attempts decreased significantly after compared to before intervention. Furthermore, MRCP onset was significantly later over central regions during paretic hand movements after compared to before intervention. There were no significant pre-post differences during healthy hand movements. Our results suggest that our patients needed less mental effort and shorter planning time after intervention. We demonstrated for the first time significant MRCP changes after a neurorehabilitation intervention (BMI + physiotherapy) in severe chronic stroke patients.