Author's School

School of Medicine


Author's Department/Program

Movement Science


English (en)

Date of Award


Degree Type


Degree Name

Doctor of Philosophy (PhD)

Chair and Committee

Gammon M. Earhart

Committee Members

Linda van Dillen, Michael Harris, Catherine Lang, Pietro Mazzoni


People with PD often report signs and symptoms that negatively impact quality of life. Among these are balance difficulties, impaired gait, and FOG. New treatment and assessment strategies for these signs and symptoms are needed, as current techniques are limited. While new treatment and assessment strategies continue to emerge, gaps in knowledge persist. Deep brain stimulation (DBS) has been utilized in many people with PD throughout the 21st century, but it is unknown specifically how subthalamic nucleus deep brain stimulation (STN-DBS) affects balance. Alternative treatment strategies, such as a dental mouthpiece, have also been proposed. While dental mouthpieces have shown promise in improving PD-related signs and symptoms in a small number of people with PD, it is unknown whether this treatment will show any benefit in a larger group of people with PD. Wearable sensors can be used in the laboratory setting to assess FOG, but it is unclear whether they can be successfully utilized to assess FOG in the real world.The primary purposes of this dissertation were to determine: 1) the specific effects of STN-DBS and levodopa on balance, 2) the effects of a dental mouthpiece on motor signs and symptoms and quality of life in people with PD, and 3) the feasibility of our sensor-based FOG assessment method for use in the real world.

In Chapter 2, we used a comprehensive balance assessment to determine the effects of STN-DBS and levodopa on overall balance and on components of balance. We noted that the combination of STN-DBS and levodopa improves overall balance and four of six components of balance. This work is a critical first step toward more thorough understanding of the effects of STN-DBS and levodopa on balance in people with PD and can inform clinical care for this population.

In Chapter 3, we examined whether a dental mouthpiece has acute benefits on motor signs and symptoms of PD or quality of life benefits in people with PD after one month of use. We observed no significant benefits of mouthpiece use in people with PD after correcting for multiple comparisons. Our results directly contradict prior literature on the effects of a dental mouthpiece in people with PD, as we found no benefits of mouthpiece use in a larger sample of people with PD. Future studies are necessary to determine whether other treatment strategies can provide benefits for people with PD by acting on a similar mechanism.

In Chapter 4, we assessed the performance of our sensor-based FOG assessment method during traditional laboratory-based gait and turning tasks, simulated real world activities performed in the laboratory, and during real world use. We determined that our sensor-based method is feasible for assessing FOG in the real world.

Our results indicate that a larger real world validation study of our sensor-based FOG assessment method is warranted. The success of our sensor-based method suggests that wearable sensors may eventually be useful for assessment and even treatment of various signs and symptoms of PD in the real world.