BRIEF REPORT: Chronic stroke recovery after combined BCI training and physiotherapy: A case report

A case of partial recovery after stroke and its associated brain reorganization in a chronic patient after combined brain computer interface (BCI) training and physiotherapy is presented. A multimodal neuroimaging approach based on fMRI and diffusion tensor imaging was used to investigate plasticity of the brain motor system in parallel with longitudinal clinical assessments. A convergent association between functional and structural data in the ipsilesional premotor areas was observed. As a proof of concept investigation, these results encourage further research on a specific role of BCI on brain plasticity and recovery after stroke. Descriptors: BCI, Chronic stroke, fMRI, DTI Spontaneous recovery of motor function in chronic stroke patients is reduced and often negligible. Functional recoverymainly occurs in response to intensive therapeutic intervention and rehabilitation such as constrained induced movement therapy, bilateral arm training, or robot-assisted training (Wolf et al., 2006; Prange et al., 2006; Page & Levine, 2007). However, the success of rehabilitation programs in chronic patients with severe hemiparesis is limited. Moreover, most of these treatments rely on the existence of residual hand/arm functionality; hence, patients with no or minimal motor function are excluded. New technologies such as the development of brain computer interfaces (BCI) that utilize neurophysiologic or metabolic brain activity to drive external devices offer promising strategies to modulate neuroplasticity and motor behavior in stroke survivors (Birbaumer & Cohen, 2007; Buch et al., 2008). Recently, a non-invasive BCI based on neurophysiological signals has been proposed to apply in patients with severe motor disability resulting from stroke. Using BCI, chronic stroke patients learned to control a mechanical orthosis affixed to the paralyzed hand, which moves in a hand-grasping or hand-opening fashion, depending upon sensorimotor rhythm activity (Buch et al., 2008). BCI training is hypothesized to induce brain reorganization by contingently linkingmotor commands to handmovements and thus providing afferent feedback to sensorimotor cortex. Here we report, as a proof of concept study, a case of partial recovery after stroke and its associated brain reorganization in a chronic patient after combined BCI training and physiotherapy. A multimodal neuroimaging approachwas used to study functional and structural plasticity. In parallel with the longitudinal clinical assessments, we applied fMRI and psycho-physiological interaction (PPI) analysis to assess functional connectivity and diffusion tensor imaging (DTI) to evaluate the structural integrity of the cortico-spinal tract (CST).