Identifying Targets for Fall-prevention Rehabilitation in People with Parkinson’s Disease

PROJECT SUMMARY The long-term goal of this line of research is to improve physical therapy for fall prevention in people with Parkinson’s disease (PD). Falls place an enormous burden on people with PD, leading to injury, isolation, and often, death. Physical therapy can improve balance; however, its effect on falls is often limited. Barriers to developing effective rehabilitative approaches include a lack of knowledge regarding 1) which specific aspects of balance should be targeted to reduce falls in this group, and 2) how neural deficits contribute to altered balance. For example, therapists are aware that reactive stepping (i.e., the quick steps to regain balance after a loss of balance) are related to falls. However, there is limited evidence directly relating reactive stepping responses to falls in people with PD, and no evidence regarding which aspects of stepping (e.g., size, speed, latency) should be targeted during therapy to have the greatest impact on falls. Similarly, while there is some evidence that standing balance (i.e., sway) relates to falls, the specific aspects of sway (e.g., area, relation to base of support) most related to falls in people with PD are unclear. Finally, the brain changes that lead to altered sway and reactive balance deficits in people with PD are poorly understood. These gaps impede our ability to deliver effective fall-prevention interventions and develop targeted neurostimulation protocols to improve balance in people with PD. This project will identify the specific aspects of reactive and standing balance that are related to prospectively measured falls, as well as the brain regions that contribute to altered balance. These data are necessary to design effective clinical trials to test rehabilitation approaches for fall reduction. The goals of this project will be achieved by assessing reactive & standing balance, as well as neuroimaging outcomes in 100 people with PD at risk for falls. We will then follow these individuals for 12 months to prospectively track falls. Aim 1 will assess the individual relationship between 1) reactive and 2) standing balance to prospectively assessed falls. Balance outcomes will be collected under dual-task conditions, given that falls often occur when attention is divided. Aim 2 will assess the relative and cumulative importance of reactive and standing balance for fall prediction in 1 model. To facilitate a better understanding of the PD-specific pathophysiology leading to poor balance in people with PD, exploratory Aim 3 will identify the neural correlates of poor reactive and standing balance in this cohort. This work is a critical step in understanding and treating balance deficits & falls in people with PD; addressing the question: “Which aspects of balance should clinicians target for fall-prevention therapy in people with PD?” Data will provide information to clinicians regarding rehabilitative targets for fall-prevention balance interventions, as well as a deeper understanding of the neural signatures of balance deficits in people with PD.