RecruitingPhase 4Diagnostic testImaging Biomarkers of FOG Response to DBSFor this study, the investigators are recruiting 54 individuals with Parkinson's Disease and Freezing of Gait (FOG) who are planning to undergo Deep Brain Stimulation (DBS). The objective of this study is to better understand the FOG response to DBS. Prior to DBS, participants will undergo an MRI scan, behavioral assessment related to walking, a cognitive evaluation, and assessment of other Parkinson's disease symptoms. Following DBS, participants will repeat these assessments at multiple timepoints over the period of one year. Overall, participants will complete a total of 7 visits over a period of approximately 1 year.