Optimizing Motor Training in Parkinson Disease Through Neural Mechanisms (NEURODEGEN)

Persons with Parkinson's disease (PD) have impaired mobility, which adversely affects their quality of life. The effectiveness of adapted tango dance, in which participants both lead (internally guide: IG) and follow (externally guide: EG) movement has been shown. To improve outcomes in those with PD, the underlying brain mechanisms for both motor impairments and improvement must be studied. IG and EG movements have distinct brain activity patterns. Individuals with PD have trouble with IG movement but this problem is helped by strategies used while "leading." During "following", participants with PD can use many external cues, which helps movement in PD, because EG tasks bypass the basal ganglia, the part of the brain affected by PD. In older persons with PD, the investigators aim to:

• determine brain activation patterns during IG and EG foot movement.
• look into effects of IG and EG training on brain activation along with mobility improvements.

The investigators will begin with a functional Magnetic Resonance Imaging test in a scanner. The investigators will look at brain area correlates of a clinically-used foot-tapping task, during IG and EG conditions in older persons with and without PD. Then, the investigators will assess the relative effectiveness of IG versus EG training during an adapted tango class, compared to a group that participates in health education, for improved mobility and foot tapping. Participants with PD will be assessed for disease severity. They will receive tests of outcome measures while "OFF" and "ON" PD-specific medications at the following time points:

• 1 week before training
• 1 week after training
• 1 month after training Participants must attend 20 lessons of IG or EG adapted tango in 12 weeks, taught by an experienced instructor. In the functional MRI (fMRI) scanner, the investigators will assess participants for improved foot tapping after training. The investigators will also look at changes in activation in specific brain circuits along with training effects upon mobility.

The long-term goal is to improve motor training as much as possible for persons with PD by understanding foot movement brain circuitry in PD as well as brain changes in circuitry through which training is effective. This work proposes to illumine information about brain function that is very important to continued progress in rehabilitative care of persons with PD.