NCT06848205 · University of Minnesota
Percept Transitions in FOG and PD
What this study is about
The purpose of this research is to examine the possible causes and signs of freezing of gait (FOG) secondary to Parkinson's disease (PD).
View original scientific description
The purpose of this research is to examine the possible causes and signs of freezing of gait (FOG) secondary to Parkinson's disease (PD). To achieve this, the study will use the novel (on-label and FDA-approved) local field potential (LFP) measuring capability of the Medtronic Percept™ deep brain stimulation (DBS) system to compare oscillatory activity in people who have Parkinson's disease, with and without freezing of gait (FOG). This will be conducted as three separate experiments, participants may volunteer for one or more experiments: Experiment 1: The first experiment will compare LFPs during gait initiation with and without a cue, in people with (PD+FOG) and without FOG (PD-FOG). Experiment 2: The second experiment will compare LFPs during the successful movement transitions vs. freezing-events during a FOG provocation course in people with FOG.
Interventions
OTHER
OFF Parkinson's Medication(s)
Participants will be asked to withhold Parkinson's medications 12 hours prior to their testing visit (if extended-release Parkinson's medications are taken by the participant, they will be asked to withhold these for 24 hours prior to their testing visit).
OTHER
OFF Deep Brain Stimulation
Participants will have their deep brain stimulation turned off at the beginning of their testing visit.
Primary outcome measures
Quantification of the anticipatory postural adjustments magnitudes (cm)
Time frame: During the intervention
Blocks of 10 successful step initiation trials will be performed. Ground reaction forces (Kistler Inc.) will be recorded.
Quantification of the anticipatory postural adjustments duration (sec)
Time frame: During the intervention
Blocks of 10 successful step initiation trials will be performed. Ground reaction forces (Kistler Inc.) will be recorded.
Step characteristics of the first two steps, length (cm)
Time frame: During the intervention
Blocks of 10 successful step initiation trials will be performed. Ground reaction forces (Kistler Inc.) and bipolar surface electromyographic (EMG) signals will be recorded bilaterally from seven muscles (tibialis anterior, soleus, lateral gastrocnemius, rectus femoris, biceps femoris, semimembranosus, gluteus medius) (Delsys, Trigno) at 1000 Hz and synchronized to whole body kinematics (8-camera motion capture system, SIMI Inc. or Qualisys Inc.) collected at 100 or 120 Hz and with 128-channels of EEG data (BioSemi, Amsterdam) collected at 2000 Hz according to the 10:20 international system 35. Additionally, resting-state EEG will be collected, to reference and remove walking artifact 36 . Local field potentials (LFPs) will be recorded on the Medtronic Percept system and synchronized to the other data collection systems by briefly turning the device on and off.
Step characteristics of the first two steps, width (cm)
Time frame: During the intervention
Blocks of 10 successful step initiation trials will be performed. Ground reaction forces (Kistler Inc.) and bipolar surface electromyographic (EMG) signals will be recorded bilaterally from seven muscles (tibialis anterior, soleus, lateral gastrocnemius, rectus femoris, biceps femoris, semimembranosus, gluteus medius) (Delsys, Trigno) at 1000 Hz and synchronized to whole body kinematics (8-camera motion capture system, SIMI Inc. or Qualisys Inc.) collected at 100 or 120 Hz and with 128-channels of EEG data (BioSemi, Amsterdam) collected at 2000 Hz according to the 10:20 international system 35 . Additionally, resting-state EEG will be collected, to reference and remove walking artifact 36 . Local field potentials (LFPs) will be recorded on the Medtronic Percept system and synchronized to the other data collection systems by briefly turning the device on and off.
Step characteristics of the first two steps, duration (sec)
Time frame: During the intervention
Blocks of 10 successful step initiation trials will be performed. Ground reaction forces (Kistler Inc.) and bipolar surface electromyographic (EMG) signals will be recorded bilaterally from seven muscles (tibialis anterior, soleus, lateral gastrocnemius, rectus femoris, biceps femoris, semimembranosus, gluteus medius) (Delsys, Trigno) at 1000 Hz and synchronized to whole body kinematics (8-camera motion capture system, SIMI Inc. or Qualisys Inc.) collected at 100 or 120 Hz and with 128-channels of EEG data (BioSemi, Amsterdam) collected at 2000 Hz according to the 10:20 international system 35 . Additionally, resting-state EEG will be collected, to reference and remove walking artifact 36 . Local field potentials (LFPs) will be recorded on the Medtronic Percept system and synchronized to the other data collection systems by briefly turning the device on and off.
The coherence magnitudes between the cortex and globus pallidus (dB)
Time frame: During the intervention
Blocks of 10 successful step initiation trials will be performed. Ground reaction forces (Kistler Inc.) and bipolar surface electromyographic (EMG) signals will be recorded bilaterally from seven muscles (tibialis anterior, soleus, lateral gastrocnemius, rectus femoris, biceps femoris, semimembranosus, gluteus medius) (Delsys, Trigno) at 1000 Hz and synchronized to whole body kinematics (8-camera motion capture system, SIMI Inc. or Qualisys Inc.) and with 128-channels of EEG data (BioSemi, Amsterdam) collected at 2000 Hz according to the 10:20 international system 35. Additionally, resting-state EEG will be collected, to reference and remove walking artifact 36. Local field potentials (LFPs) will be recorded on the Medtronic Percept system and synchronized to the other data collection systems by briefly turning the device on and off. Coherence will be calculated between the cortex and basal ganglia, and the magnitudes will be calculated at different frequencies (power, decibels, dB).
The coherence magnitudes between the cortex and EMG (dB)
Time frame: During the intervention
Blocks of 10 successful step initiation trials will be performed. Ground reaction forces (Kistler Inc.) and bipolar surface electromyographic (EMG) signals will be recorded bilaterally from seven muscles (tibialis anterior, soleus, lateral gastrocnemius, rectus femoris, biceps femoris, semimembranosus, gluteus medius) (Delsys, Trigno) at 1000 Hz and synchronized to whole body kinematics (8-camera motion capture system, SIMI Inc. or Qualisys Inc.) and with 128-channels of EEG data (BioSemi, Amsterdam) according to the 10:20 international system 35 . Additionally, resting-state EEG will be collected, to reference and remove walking artifact 36 . Local field potentials (LFPs) will be recorded on the Medtronic Percept system and synchronized to the other data collection systems by briefly turning the device on and off. Coherence will be calculated between the cortex and the muscle activity, and the magnitudes will be calculated at different frequencies (power, decibels, dB).
The coherence magnitudes between the globus pallidus and EMG (dB)
Time frame: During the intervention
Blocks of 10 successful step initiation trials will be performed. Ground reaction forces (Kistler Inc.) and bipolar surface electromyographic (EMG) signals will be recorded bilaterally from seven muscles (tibialis anterior, soleus, lateral gastrocnemius, rectus femoris, biceps femoris, semimembranosus, gluteus medius) (Delsys, Trigno) at 1000 Hz and synchronized to whole body kinematics (8-camera motion capture system, SIMI Inc. or Qualisys Inc.) and with 128-channels of EEG data (BioSemi, Amsterdam) according to the 10:20 international system 35 . Additionally, resting-state EEG will be collected, to reference and remove walking artifact 36 . Localfield potentials (LFPs) will be recorded on the Medtronic Percept system and synchronized to the other data collection systems by briefly turning the device on and off. Coherence will be calculated between the globus pallidus and the muscle activity, and the magnitudes will be calculated at different frequencies (power, decibels, dB).
Number of freezing episodes
Time frame: During the intervention
Kinematics will be measured using 6 inertial measurement units (IMUs, Opal sensors, APDM), containing triaxial accelerometers, gyro-scopes, and magnetometers, on each foot and wrist, the fifth lumbar vertebra, and the sternum. This system has been validated for use in PD gait to provide measures of gait (velocity, stride length mean and SD, cadence, and stride time mean and SD), gait initiation (measures of APA and 1 st step characteristics) and turning. Kinematic data will be collected at 128 Hz and synchronized to video recordings and LFP data. LFP and kinematic data will be classified by transition type: initiation, turning, and doorways, and compared during successful transitions, and freezing episodes (unsuccessful transitions). Number of freezing episodes will be identified and rated qualitatively from the videotape by a blinded rater.
Rapid Alternating Movements of Wrist Pronation/Supination (degrees)
Time frame: During the intervention
Participants will perform rapid alternating movements of the wrist or ankle while a manipulandum measures their angular position, with EMG of the moving limb, EEG and LFPs are recorded synchronously. Movements will be cued using a series of beeps that will change randomly between a low and a high- frequency. RMS of the amplitude will be calculated.
Rapid Alternating Movements of Supination or Ankle plantar/dorsi-flexion (degrees)
Time frame: During the intervention
Participants will perform rapid alternating movements of the wrist or ankle while a manipulandum measures their angular position, with EMG of the moving limb, EEG and LFPs are recorded synchronously. Movements will be cued using a series of beeps that will change randomly between a low and a high- frequency. RMS of the amplitude will be calculated.
Peak power of local field potential oscillations (dB)
Time frame: During the intervention
Average changes in peak alpha and beta power derived from power spectral density analysis of the local field potential signal recorded by the implanted Medtronic Percept™ device.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Diagnosis of idiopathic PD.
- Age 21-75 (see Inclusion of Individuals across the Lifespan for justification of age range).
- Able to ambulate independently without the use of an assistive device (e.g. cane) for 50 meters.
- Implanted Medtronic Percept TM Device.
- At least 3 months since the initial activation of the neurostimulator.
- Undervalued, under-represented, or disenfranchised social group may be included.
- Active members of the military (service members), DoD personnel (including civilian employees) may be included.
- Individual or group that is disadvantaged in the distribution of social goods and services such as income, housing, or healthcare may be included.
Exclusion criteria
- Meet criteria for dementia with Lewy bodies, Multiple Systems Atrophy, Alzheimer's disease, or other neurodegenerative disorder.
- History of seizures or other significant neurological disorders that may affect participation or performance in the study.
- History of musculoskeletal disorders that significantly affect walking or movement of limb(s) that would affect the participation in the experimental task (Participants will be excluded from that task, but may participate in other tasks, for example, may be excluded from Experiment 1 if the disorder affects walking, but may still participate in Experiment 3).
- History of muscular conditions of the neck and back, including whiplash that would affect walking experiments.
- History of visual and/or vestibular conditions that may affect participation or performance in the study.
- Reduced capacity to consent. This will be assessed using a 2-stage process. Initially, participants will be tested using the University of California, San Diego, Brief Assessment of Capacity to Consent (UBACC). If concerns are raised from the UBACC test, the individual will be further tested using the MacArthur Competency Assessment Tool.
- Pregnant people.
- Post-operative complications or adverse effects (e.g. ON stimulation dystonia) that affect patient safety or confound the experiment.
Where
- Minneapolis, Minnesota
Collaborators
National Institute of Neurological Disorders and Stroke (NINDS)
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Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Mar 3, 2026 · Source of record for eligibility and locations