rTMS to Improve Cognition in Parkinson's

Repetitive transcranial magnetic stimulation (rTMS) shows promise as an effective cognitive neurorehabilitation treatment. To date, no rTMS studies have assessed the effect of rTMS on cognitive function in PD-MCI. Nor has there been PD neurophysiological studies using rTMS to examine neural plasticity in cognitive neural networks. This study seeks to fill this gap by conducting a small scaled pilot randomized controlled trial (RCT) designed to assess the safety and therapeutic effects of rTMS on cognitive outcomes as well as on brain connectivity in Veterans with PD-MCI. PD-MCI participants will be randomized to either active rTMS or sham rTMS. Participants will complete a standardized neurocognitive battery assessment at baseline, endpoint and at a one month follow-up. The primary outcome is change in executive function. Secondary outcomes include performance on other cognitive domain tasks and a proximal measure of real-life function that captures relevant functional changes related to cognitive impairment in PD. Multi-modal neuroimaging, in a subsample of participants, will be used to study neural connectivity changes induced by rTMS. Changes in resting state functional connectivity, grey matter volume via voxel-based morphometry and white matter integrity via diffusion tensor imaging will be assessed at baseline and endpoint. To inform how to optimize rTMS treatment in PD-MCI, these changes will be correlated with changes in cognitive performance.