Decoding the Neural Mechanisms Underlying Postural Instability and Gait Dysfunction in Parkinson's Disease

July 31, 2026 updated by: Jay Alberts, The Cleveland Clinic
The purpose of this study is to learn how brain signals are related to freezing of gait (FOG) and balance problems in Parkinson's disease (PD) and to study how different deep brain stimulation (DBS) settings may affect these symptoms.

Study Overview

Detailed Description

PD is a progressive neurodegenerative disorder characterized by motor symptoms including tremor, rigidity, and bradykinesia. While DBS is an effective treatment for many of these motor symptoms, postural instability and gait dysfunction (PIGD), including FOG, frequently persist and are a major source of falls, loss of independence, and reduced quality of life.

The neural mechanisms underlying PIGD and FOG remain poorly understood, particularly in real-world conditions where these symptoms are most likely to occur. Conventional clinical assessments often fail to reliably provoke these gait disturbances, limiting the ability to study their underlying neurophysiology. At the same time, recent advances in DBS technology - specifically systems capable of recording brain signals, or neural activity - provide a unique opportunity to directly examine brain signals associated with gait impairment.

This study is designed to characterize the neural mechanisms associated with PIGD and FOG in individuals with PD who have an implanted sensing-enabled DBS system (Medtronic Percept™). By integrating neural recordings from the subthalamic nucleus (STN) with detailed biomechanical measurements during walking tasks, the study aims to identify patterns of neural activity that precede, accompany, and follow gait disturbances.

To address the challenge of eliciting ecologically valid gait disturbances, participants will complete walking and balance tasks within a fully immersive virtual reality platform. This system simulates real-world scenarios that are meant to provoke FOG and PIGD, including situations involving environmental constraints, anxiety-inducing contexts, and dual-task cognitive demands.

Additional assessments will include stair ambulation and functional mobility tasks using an instrumented gait platform which provides quantitative measures of temporal, kinematic, and kinetic aspects of walking and balance.

During these tasks, neural activity recorded from the DBS device will be synchronized with motion capture and biomechanical data. This integrated dataset will allow investigators to examine how neural activity relates to gait performance and to identify neural patterns associated with FOG episodes.

Participants will undergo multiple testing sessions under varying DBS conditions, including their clinically optimized DBS therapy and other programmed conditions. These comparisons will enable evaluation of how different stimulation approaches influence neural activity and gait performance.

The knowledge gained from this study is expected to advance understanding of the neural mechanisms underlying gait dysfunction in PD and may inform the development of more personalized and adaptive neuromodulation strategies to better treat these disabling symptoms in the future.

Study Type

Interventional

Enrollment (Estimated)

5

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

    • Ohio
      • Cleveland, Ohio, United States, 44195
        • Cleveland Clinic
        • Contact:
        • Principal Investigator:
          • Jay L Alberts, PhD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • You have been diagnosed with Parkinson's disease
  • You already have a deep brain stimulation (DBS) device implanted as part of your medical care - specifically, the Medtronic Percept DBS device
  • Your DBS settings have been stable for at least 3 months
  • You experience freezing of gait (sudden inability to move your feet when trying to walk)
  • You are able to walk on your own for at least 10 minutes without assistance
  • You are willing to temporarily stop your Parkinson's medications and have your DBS settings adjusted for study testing
  • You are able to understand the study and provide consent to participate

Exclusion Criteria:

  • You have a neurological condition other than Parkinson's disease (such as stroke or multiple sclerosis)
  • You have been diagnosed with dementia or have difficulty understanding the study or giving consent
  • You currently have alcohol or substance abuse problems
  • You have hearing or vision problems that would make it difficult to use a virtual reality headset
  • You have any medical or mental health condition that, in the opinion of the study doctor, would make it unsafe or difficult for you to participate

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Participants With Parkinson Disease Undergoing Multi-Condition DBS Assessments

All participants undergo repeated assessments under multiple deep brain stimulation (DBS) conditions in a randomized order. Each participant serves as their own control and completes testing under clinically optimized stimulation, as well as alternative stimulation paradigms. An additional baseline condition without stimulation is performed prior to randomized testing.

Assessments include walking and balance tasks performed in a virtual reality environment designed to simulate real-world gait challenges, as well as stair ambulation and functional mobility tasks. Neural activity is recorded from the implanted DBS device and synchronized with biomechanical and kinematic data collected during task performance. This design enables within-subject comparisons of neural activity and gait performance across stimulation conditions.

Participants have the Medtronic Percept DBS system implanted as part of standard clinical care. During study sessions, stimulation is evaluated under different conditions, including clinically optimized stimulation, off stimulation, and alternative stimulation paradigms. Stimulation settings are temporarily adjusted for research assessments and are returned to clinically optimized settings at the end of each session. Effects of those conditions on task performance are being assessed.
Participants complete walking and balance tasks within a virtual reality environment designed to simulate real-world situations that provoke gait disturbances. Tasks include navigating environmental constraints, performing turning and stopping movements, and completing dual-task cognitive challenges while walking.
Participants complete stair ambulation and functional mobility tasks on an instrumented platform, including ascending and descending steps, walking, turning, and performing dual-task conditions. These assessments provide quantitative measures of gait performance, balance, and functional mobility.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in STN-LFP power fluctuations from single-task walking compared to FOG episode
Time Frame: Five sessions completed from enrollment to the end of testing, over an average of one week.
Participants will complete motor, cognitive and dual-task modules in a virtual reality environment that simulates a home-setting, allowing for acquisition of real-world, at-home behavior. They will also complete a stair navigation task under both single and dual-task conditions. During these assessments, neural activity (i.e., subthalamic nucleus local field potentials (STN-LFPs)) will be recorded from the Medtronic Percept Deep Brain Stimulation system. Freezing of gait (FOG) episodes will be marked by a clinician, and change in STN-LFP power fluctuations from single-task walking compared to FOG episodes will be analyzed as the primary outcome.
Five sessions completed from enrollment to the end of testing, over an average of one week.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Number of FOG episodes during the MOVE system modules under each of the four DBS conditions
Time Frame: Five sessions completed from enrollment to the end of testing, over an average of one week.
Participants will complete motor, cognitive and dual-task modules in a virtual reality setting, Moving Overground in Virtual Environments (MOVE). The MOVE system simulates a home-setting, allowing for acquisition of real-world, at-home behavior. It consists of four modules: 1) Reference, 2) Physical, 3) Anxiety, 4) Cognitive (dual-task). Freezing of gait (FOG) episodes usually occur under stressful circumstances which can be grouped into three broad categories: changes in physical environment, anxiety-provoking situations and dual-task environments. The modules in the MOVE system are designed to elicit FOG episodes in a research setting. FOG episodes will be marked by a clinician, and the number of episodes under each of the four DBS conditions will be compared.
Five sessions completed from enrollment to the end of testing, over an average of one week.
Overall time for SAFE-Gait task
Time Frame: Five sessions completed from enrollment to the end of testing, over an average of one week.
Participants will complete the Cleveland Clinic Stair Ambulation and Functional Evaluation of Gait (SAFE-Gait). The SAFE-Gait test requires participants to 1) ascend 3 standard steps, 2) walk on a flat surface for 3 meters, 3) turn and 4) walk back to the starting position which requires descending 3 steps. The time to complete this task will be recorded and compared for all tested DBS conditions.
Five sessions completed from enrollment to the end of testing, over an average of one week.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Collaborators

Investigators

  • Principal Investigator: Jay L Alberts, PhD, The Cleveland Clinic

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

September 18, 2026

Primary Completion (Estimated)

March 18, 2027

Study Completion (Estimated)

April 18, 2027

Study Registration Dates

First Submitted

July 27, 2026

First Submitted That Met QC Criteria

July 31, 2026

First Posted (Actual)

August 6, 2026

Study Record Updates

Last Update Posted (Actual)

August 6, 2026

Last Update Submitted That Met QC Criteria

July 31, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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