Patients were initially scanned on

Patients were initially scanned on a 1.5 Tesla (1.5 T) scanner until a 3 T machine became available (20/3 patients were scanned on the 1.5/3 T scanners, respectively). Total fMRI scan time did not exceed 30 min on the 1.5 T machine per labeling guidelines and within the standard of care (25). To examine the effects of DBS, the study utilized DBS cycling. Subjects came into the study visit with their normal DBS settings turned on. At the start of the study, their IPG was set for a cycling mode of 30 sec ON and 30 sec OFF with the ramp time turned off. Subjects were cycled for 5 min before imaging to equilibrate to this new setting. To synchronize cycling of the IPG to the acquisition of the MR scan, an electronics box was created to measure and lock onto the sub- jects’ DBS cycling. This was necessary as there are multisecond communication delays between when the programmer indicates the stimulator is on to when the stimulator is actually on