Effect of Mental Imagery Training on Brain Plasticity and Motor Function in Individuals With Parkinson's Disease

The functional connectivity strength between the subjects' right insula and dorsomedial frontal cortex will be measured at baseline and post-intervention as each group of subjects engages in their respective imagery tasks. Functional connectivity will be measured as the correlation value between the functional MRI signal time courses obtained from these two brain regions.

We will obtain resting-state functional MRI scans from the PD-neurofeedback and PD-control groups at baseline and post-intervention to examine the changes in intrinsic functional connectivity between the right insula and dorsomedial frontal cortex. Functional connectivity will be measured as the correlation value between the functional MRI signal time courses obtained from these two brain regions.

We will administer the Movement Disorders Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part III (motor exam) at baseline and post-intervention to the PD-neurofeedback and PD-control groups to measure the change in motor impairment. The MDS-UPDRS part III is a subscale that provides an objective assessment of motor impairment. The scores range between 0-132. Higher scores indicate more severe impairment.

We will administer standard motor function tests (e.g., timed up and go, 5 times sit-to-stand, 360-degree turn) at baseline and post-intervention to the PD-neurofeedback and PD-control groups to measure the change in motor function. The performance score on these tests is the time to complete the motor tasks. Shorter time indicates better performance. The motor function tests measure movement speed. Timed up and go test measures (seconds) how fast one can stand up from a chair, walk 3 meters, turn, walk back to the chair and sit down again. Five times sit-to-stand test measures (seconds) how fast one can stand up from a chair with arms crossed across the chest and sit back again 5 times in a row. 360-degree turn test measures (seconds) how fast one can turn around their own axis clockwise and counterclockwise. The composite motor function score is the sum of the durations (seconds) of all three tests.

In a group of PD patients who will not receive any intervention, we will collect functional MRI data during a mental imagery task with both motor and visual imagery components to investigate the functional connectivity between the motor and visual networks.