Abstract
Loss of motor function is a common deficit following stroke insult and often manifests as persistent upper extremity (UE) disability which can affect a survivor’s ability to participate in activities of daily living. Recent research suggests the use of brain–computer interface (BCI) devices might improve UE function in stroke survivors at various times since stroke. This randomized crossover-controlled trial examines whether intervention with this BCI device design attenuates the effects of hemiparesis, encourages reorganization of motor related brain signals (EEG measured sensorimotor rhythm desynchronization), and improves movement, as measured by the Action Research Arm Test (ARAT). A sample of 21 stroke survivors, presenting with varied times since stroke and levels of UE impairment, received a maximum of 18–30 h of intervention with a novel electroencephalogram-based BCI-driven functional electrical stimulator (EEG-BCI-FES) device. Driven by spectral power recordings from contralateral EEG electrodes during cued attempted grasping of the hand, the user’s input to the EEG-BCI-FES device modulates horizontal movement of a virtual cursor and also facilitates concurrent stimulation of the impaired UE. Outcome measures of function and capacity were assessed at baseline, mid-therapy, and at completion of therapy while EEG was recorded only during intervention sessions. A significant increase in r-squared values [reflecting Mu rhythm (8–12 Hz) desynchronization as the result of attempted movements of the impaired hand] presented post-therapy compared to baseline. These findings suggest that intervention corresponds with greater desynchronization of Mu rhythm in the ipsilesional hemisphere during attempted movements of the impaired hand and this change is related to changes in behavior as a result of the intervention. BCI intervention may be an effective way of addressing the recovery of a stroke impaired UE and studying neuromechanical coupling with motor outputs.Clinical Trial Registration: ClinicalTrials.gov, identifier NCT02098265.
Highlights
StrokeStroke is a leading cause of acquired adult long-term disability in the United States (Benjamin et al, 2017) and occurs when blood supply to the brain is compromised, leading to functional deficits that may affect activities of daily living (ADLs)
The maps for the right hand movements represent an average of these measures from impaired hand movements and non-impaired right hand movements
R-Squared The signed r-squared value for the Mu (8–12 Hz) rhythm significantly decreased in the post-therapy stage compared to the pre-therapy stage [onetailed paired t-test: t(20) = 1.85; p = 0.039; meanPRE = −0.142; meanPOST = −0.161], while the subject attempted movements of the impaired hand (Figure 4)
Summary
Stroke is a leading cause of acquired adult long-term disability in the United States (Benjamin et al, 2017) and occurs when blood supply to the brain is compromised, leading to functional deficits that may affect activities of daily living (ADLs). Previous studies suggest that change in the pattern of brain activity linked to attempted movements of the affected hand contributes to motor re-conditioning and induces brain plasticity or reorganization which, if properly directed and reinforced, should lead to improvement in a stereotyped motor function of interest (Daly et al, 2009; Caria et al, 2011; Muralidharan et al, 2011; Varkuti et al, 2013) This is of special importance for patients in the chronic phase (generally >6 months post stroke) of recovery who may have little to no residual function in the affected arm, in addition to learned compensatory motor strategies (Muralidharan et al, 2011). This interim analysis, of the larger ongoing prospective randomized crossover-controlled clinical trial, seeks to determine whether greater desynchronization of motor related SMRs in the ipsilesional hemisphere during attempted movements of the impaired hand are related to changes in behavior as a result of intervention
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