Computational Modeling of 60 Hz Subthalamic Nucleus Deep Brain Stimulation for Gait Disorder in Parkinson's Disease

Not Applicable

Completed

Brief Summary: The objective of this study is to further the understanding and application of 60Hz subthalamic deep brain stimulation (STN-DBS) in Parkinson's patients with gait disorder. The investigators will achieve this through 2 study aims:

1. Determine the impact of 60Hz subthalamic deep brain stimulation on gait kinematics using wearable sensors

2. Develop machine learning models to predict optimal subthalamic deep brain stimulation frequency based on wearable sensors

Detailed Description: Gait disorder, which manifests as shuffling, reduction in speed, multistep turning, and/or freezing of gait (FOG), can arise later in the Parkinson's disease (PD) course and cause significant disability. Ultimately, patients are at risk for falls and can become socially isolated due to their mobility limitations. These symptoms tend not to respond to high frequency STN-DBS. However, lower frequency stimulation (60-80Hz) of the STN in treating gait disorder and/or freezing of gait has demonstrated benefit. This study potentially can expand knowledge of 60hz DBS while improving its utilization in combination with PD medications-enabling sustainable and possibly predictable therapeutic benefit.

Recruitment & Eligibility

Inclusion Criteria

Male or female, aged 21-80
Patients diagnosed with Parkinson's disease (PD)
PD subjects who have bilateral STN-DBS (greater than 3 months) or in the preoperative stage of being implanted with bilateral STN-DBS
Have underlying gait disorder
Currently treated with oral levodopa therapy
Willingness to comply with all study procedures

Exclusion Criteria

Cognitive deficits based on historical record that limit participant compliance with study protocol
Vestibular disorder or musculoskeletal problems affecting gait or balance

Arm && Interventions

Group	Intervention	Description
Deep Brain Stimulation(DBS) OFF Medication	Deep Brain Stimulation	Subthalamic-DBS in the Levodopa OFF state.
Deep Brain Stimulation(DBS) ON Medication	Deep Brain Stimulation	Subthalamic-DBS in the Levodopa ON state.

Primary Outcome Measures

Name	Time	Method
Gait Kinematic Response for 180 and 60Hz DBS	1-2 minute period with each stimulation condition in the Medicated and Unmedicated states.	The measurements of interest were captured during the instrumented walk. Interaction of DBS Frequency and Levodopa on gait kinematics was assessed using LM-ANOVA.
Accuracy of Discriminating STN-DBS (60hz vs. High Frequency) and Medication States With Machine Learning(ML)	2 years	We apply ML techniques to a data set of gait kinematics acquired from instrumented walking assessments and utilize random forest ML algorithms to identify participants' stimulation frequency/medication condition.

Secondary Outcome Measures

Name	Time	Method
Change in Speed of Limb Movements for 180 and 60Hz DBS	1 minute test session for each stimulation condition	The difference in the speed of limb movements (e.g. hand grasps and leg lifts) will be measured with the kinesia sensor for each DBS electrode stimulation pair (60hz or High Frequency) in both the medicated and unmedicated states on a severity scale of 0-4. Higher values = worse outcome.
Change in Hand Tremor Severity for 180 and 60Hz DBS	1 minute test session for each stimulation condition	The difference in tremor (e.g. rest, postural) severity will be measured with the kinesia sensor for each DBS electrode stimulation pair (60hz or High Frequency) in both the medicated and unmedicated states on a severity scale from 0-4. Higher number = worse outcome