Bihemispheric Beta Desynchronization During an Upper-Limb Motor Task in Chronic Stroke Survivors

For severe motor paralysis patients, most rehabilitation strategies require residual movements that, however, are lacking in up to 30-50% of stroke survivors. In these patients, motor imagery based BCI systems might play a substantial role in rehabilitation strategies. 11 severely motor-injured stroke patients and 6 healthy participants participated in this study. During an unilateral upper-hand motor task, stroke patients shown significant modulation of sensorimotor rhythms in both hemispheres, shown that EEG signals of both hemispheres can be used for control of BMI systems. Main findings were that ERD amplitude was reduced in affected hemisphere, and that ERD when using affected hand was lateralized to and more marked in ipsilateral (unaffected) hemisphere. Significant activation differences between healthy and affected hemisphere were found, suggesting participation of different physiological mechanisms in both, that might be explored in future experimentation for improving the design and implementation of EEG-based BMI systems and use of these systems in neurorehabilitation of stroke.