Motor priming to enhance the effect of physical therapy in people with spinal cord injury.

Context: Brain-Computer Interface (BCI) is an emerging neurorehabilitation therapy for people with spinal cord injury (SCI).

Objective: The study aimed to test whether priming the sensorimotor system using BCI-controlled functional electrical stimulation (FES) before physical practice is more beneficial than physical practice alone.

Methods: Ten people with subacute SCI participated in a randomized control trial where the experimental (N = 5) group underwent BCI-FES priming (∼15 min) before physical practice (30 min), while the control (N = 5) group performed physical practice (40 min) of the dominant hand. The primary outcome measures were BCI accuracy, adherence, and perceived workload. The secondary outcome measures were manual muscle test, grip strength, the range of motion, and Electroencephalography (EEG) measured brain activity.

Results: The average BCI accuracy was 85%. The experimental group found BCI-FES priming mentally demanding but not frustrating. Two participants in the experimental group did not complete all sessions due to early discharge. There were no significant differences in physical outcomes between the groups. The ratio between eyes closed to eyes opened EEG activity increased more in the experimental group (theta P_θ= 0.008, low beta P_lβ= 0.009, and high beta P_hβ= 1.48e-04) indicating better neurological outcomes. There were no measurable immediate effects of BCI-FES priming.

Conclusion: Priming the brain before physical therapy is feasible but may require more than 15 min. This warrants further investigation with an increased sample size.