Development of a Combined, Sequential Real-Time fMRI and fNIRS Neurofeedback System Enhance Motor Learning After Stroke

Congratulations Dr. Janis Daly on the publication of “Development of a Combined, Sequential Real-Time fMRI and fNIRS Neurofeedback System Enhance Motor Learning After Stroke,” which appeared in the May 18th online edition of Journal of Neuroscience Methods.

Abstract

Background. After stroke, wrist extension dyscoordination precludes functional arm/hand. We developed a more spatially precise brain signal for use in brain computer interface (BCI’s) for stroke survivors.

New Method

Combination BCI protocol of real-time functional magnetic resonance imaging (rt-fMRI) sequentially followed by functional near infrared spectroscopy (rt-fNIRS) neurofeedback, interleaved with motor learning sessions without neural feedback. Custom Matlab and Python code was developed to provide rt-fNIRS-based feedback to the chronic stroke survivor, system tester.

Results

The user achieved a maximum of 71% brain signal accuracy during rt-fNIRS neural training; progressive focus of brain activation across rt-fMRI neural training; increasing trend of brain signal amplitude during wrist extension across rt-fNIRS training; and clinically significant recovery of arm coordination and active wrist extension.

Comparison with existing methods

Neurorehabilitation, peripherally directed, shows limited efficacy, as do EEG-based BCIs, for motor recovery of moderate/severely impaired stroke survivors. EEG-based BCIs are based on electrophysiological signal; whereas, rt-fMRI and rt-fNIRS are based on neurovascular signal.

Conclusion

The system functioned well during user testing. Methods are detailed for others’ use. The system user successfully engaged rt-fMRI and rt-fNIRS neurofeedback systems, modulated brain signal during rt-fMRI and rt-fNIRS training, according to volume of brain activation and intensity of signal, respectively, and clinically significant improved limb coordination and active wrist extension. fNIRS use in this case demonstrates a feasible/practical BCI system for further study with regard to use in chronic stroke rehab, and fMRI worked in concept, but cost and patient-friendly issues make it less feasible for clinical practice.