Neurofeedback-guided kinesthetic motor imagery training in Parkinson’s disease: Randomized trial

Background Parkinson’s disease (PD) causes difficulty with maintaining the speed, size, and vigor of movements, especially when they are internally generated. We previously proposed that the insula is important in motivating intentional movement via its connections with the dorsomedial frontal cortex (dmFC). We demonstrated that subjects with PD can increase the right insula-dmFC functional connectivity using fMRI-based neurofeedback (NF) combined with kinesthetic motor imagery (MI). The current study is a randomized clinical trial testing whether NF-guided kinesthetic MI training can improve motor performance and increase task-based and resting-state right insula-dmFC functional connectivity in subjects with PD. Methods We assigned nondemented subjects with mild PD (Hoehn & Yahr stage ≤ 3) to the experimental kinesthetic MI with NF (MI-NF, n=22) and active control visual imagery (VI, n=22) groups. Only the MI-NF group received NF-guided MI training (10-12 runs). The NF signal was based on the right insula-dmFC functional connectivity strength. All subjects also practiced their respective imagery tasks at home daily for 4 weeks. Post-training changes in 1) task-based and resting-state right insula-dmFC functional connectivity were the imaging outcomes, and 2) MDS-UPDRS motor exam and motor function scores were the clinical outcomes. Results The MI-NF group did not show significant NF regulation and was not significantly different from the VI group in any of the imaging or clinical outcome measures. The MI-NF group reported subjective improvement in kinesthetic body awareness. There was significant and comparable improvement only in motor function scores in both groups. This improvement correlated with NF regulation of the right insula-dmFC functional connectivity only in the MI-NF group. Both groups showed specific training effects in whole-brain functional connectivity with distinct neural circuits supporting kinesthetic motor and visual imagery (exploratory outcome). Conclusions The functional connectivity-based NF regulation was unsuccessful in our cohort with mild PD. However, kinesthetic MI practice by itself or in combination with other imagery techniques is a promising tool in motor rehabilitation in PD. Highlights Parkinson’s disease (PD) causes difficulty with sustained motor performance Insula and dorsomedial frontal cortex (dmFC) are implicated in motivating movement Regulation of insula-dmFC functional connectivity with neurofeedback (NF) failed Motor imagery practice regardless of NF improved motor function and body awareness Motor imagery is a promising strategy for motor rehabilitation in PD