Background Losing the ability to move voluntarily can have devastating consequences for the independence and quality of life of a person. Stroke and spinal cord injury (SCI) are two important causes of paralysis which affect thousands of individuals around the world. Extraordinary efforts have been made in an attempt to mitigate the effects of paralysis. In recent years, rehabilitation of voluntary movement has been enriched by the constant integration of new neurophysiological knowledge about the mechanisms behind motor function recovery. One central concept that has improved neurorehabilitation significantly is neuroplasticity, the ability of the central nervous system to reorganize itself during the acquisition, retention, and consolidation of motor skills [1]. In this document, we present one of the interventions that has flourished as a consequence of our increased understanding of the plasticity of the nervous system: functional electrical stimulation

We report the therapeutic effects of integrating brain-computer interfacing technology and functional electrical stimulation therapy to restore upper limb reaching movements in a 64-year-old man with severe left hemiplegia following a hemorrhagic stroke he sustained six years prior to this study. He completed 40 90-minute sessions of functional electrical stimulation therapy using a custom-made neuroprosthesis that facilitated 5 different reaching movements. During each session, the participant attempted to reach with his paralyzed arm repeatedly. Stimulation for each of the movement phases (e.g., extending and retrieving the arm) was triggered when the power in the 18 Hz–28 Hz range (beta frequency range) of the participant's EEG activity, recorded with a single electrode, decreased below a predefined threshold. The function of the participant's arm showed a clinically significant improvement in the Fugl-Meyer Assessment Upper Extremity (FMA-UE) subscore (6 points) as well as moderate improvement in Functional Independence Measure Self-Care subscore (7 points). The changes in arm's function suggest that the combination of BCI technology and functional electrical stimulation therapy may restore voluntary motor function in individuals with chronic hemiplegia which results in severe upper limb deficit (FMA-UE ≤ 15), a population that does not benefit from current best-practice rehabilitation interventions.