Abstract TP321: Testing a Neural Activity Triggered Device for Stroke Rehabilitation

Abstract

Background: In this ongoing study we are testing a closed-loop neurological feedback device that can facilitate functional recovery in stroke patients with upper extremity motor deficits. Methods: This device combines Brain Computer Interface (BCI) and functional electrical muscle stimulation (FES), together with tongue stimulation (TS) in order to utilize the subject’s intention-to-move with the stimulated output. FMRI is used to examine the brain plasticity changes secondary to the rehabilitation. Subjects, wearing a 16-channel EEG cap, are first trained to voluntarily modulate beta and mu rhythms as they use motor imagery or execution of left and right hand squeezing task and then trained to use this imagery or execution to control the movement of a cursor, either to the right or the left depending on the presentation of a target rectangle shown on the screen. Once subjects achieve consistent accuracy in doing this task, FES in conjunction with TS is used. The subject is then asked to perform the task with the stimulation of FES and TS linked to their task performance. Results: Two chronic stroke patients (mean age=57, 1 male, more than 1 year postonset) were able to complete the entire 3-week BCI training course and to perform the tasks at a > 70% success rate. Cortical activation recorded by EEG in response to attempted paretic arm movement became concentrated over the contralateral motor areas. Similar changes were confirmed by fMRI measures (Figure 1). Although neither subject showed any improvement on the Action Research Arm Test (ARAT), subjects self-reported increased strength, less spasticity and a greater range of movement in their paretic arm. Conclusion: Our preliminary results indicate that training with the device may lead to brain plasticity changes toward normalization of cortical activation patterns and promote behavioral improvements for stroke patients even in their chronic stage.