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CompletedNCT04043403Updated Oct 7, 2026Results posted

Bilateral Closed Loop Deep Brain Stimulation for Freezing of Gait Using Neural and Kinematic Feedback

An interventional study of Open Loop DBS and Adaptive (Closed Loop) DBS in Parkinson Disease, sponsored by Stanford University. Completed at 1 site in United States. Open to participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-10-07.

Sponsored by Stanford University · Not applicable, Interventional, and Treatment

Updated Oct 7, 2026Results postedPrimary outcomes revisedGo to Updates ↓
Phase
Not applicable
Study type
Interventional
Enrollment
12
Allocation
Non-randomized
Ages
18 Years to 80 Years
Sex
All
01

Study summary

Deep Brain Stimulation of the subthalamic nucleus (STN) has become a standard of care, FDA-approved treatment for Parkinson's disease, with stimulation delivered at a constant amplitude and voltage, operating in an open-loop fashion that does not respond to a patient's current state. Although gait deficits and freezing of gait may initially respond to continuous open-loop deep brain stimulation (olDBS) and medication, the symptoms often recur over time.

The episodic and predictable nature of FOG makes it well suited for adaptive DBS (aDBS) and a device that overcomes the limitations of traditional high frequency olDBS and is capable of adapting therapy either in the frequency or intensity domain transiently to treat FOG while also treating other PD signs such as tremor and bradykinesia.

The purpose of this study is to determine the feasibility of an adaptive DBS system, that responds to patient-specific neural and kinematic variables with customized DBS parameters.

02

Conditions studied

  • Parkinson Disease

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03

In context

Parkinson Disease

4,484 studies on the registry are indexed under Parkinson Disease; 1,081 are open to participants now.

This study's enrollment of 12 is below the median of 40 across 3,293 interventional studies indexed under Parkinson Disease.

Browse Parkinson Disease studies →

Lead sponsor

Stanford University is the lead sponsor of 2,117 studies on the registry; 425 are open to participants now.

Of its 259 completed or terminated interventional studies of FDA-regulated products, 197 (76%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 80 Years
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  • Clinically-established PD
  • Meets criteria for STN DBS eligibility as part of patient's standard medical care or already implanted in the STN with Percept(TM) PC
  • The presence of complications of medication such as wearing off signs, fluctuating responses and/or dyskinesias, and/or medication refractory tremor, and/or impairment in the quality of life on or off medication due to these factors.
  • Ability and willingness to return for study visits, at the initial programming and after three, six and twelve months of DBS.
  • Age > 18
  • Freezing of gait questionnaire (FOG-Q) score ≥ 1 and/or gait sub-score (Item 3.10) of MDS- UPDRS III ≥ 1
  • Greater than or equal to 1.2 microVp between 8-35 Hz on either the LSTN or RSTN (Percept (TM) PC cohort only)

Exclusion criteria

Exclusion Criteria:

  • Dementia
  • Untreated psychiatric disease
  • Hoehn and Yahr stage 5 on or off medication (non-ambulatory)
  • Age > 80
  • Major surgical morbidities such as severe hypertension, coagulopathy and certain metabolic conditions that might increase the risk of hemorrhage or other surgical complications
  • Presence of a cardiac pacemaker/defibrillator
  • Inability to understand/sign consent
  • Requires rTMS, ECT, MRI (Summit(R) RC+S cohort only), or diathermy
  • Are pregnant or lactating
  • Has a cranial metallic implant
  • History of seizures or epilepsy
05

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Non-randomized
Intervention model
Parallel assignment
Masking
Double (Participant, Outcomes assessor)
Enrollment
12 participants (actual)

Study arms

  • Experimental
    Device: Summit RC+S

    1. Open Loop DBS: Standard DBS therapy at a constant frequency and voltage 2. Adaptive (Closed Loop) DBS: DBS that responds to neural or kinematic features of patient's current state 3. Intermittent Open Loop DBS: Control for aDBS - DBS intensity or frequency changes in a manner that mimics aDBS but is pre-determined and open loop rather than being responsive to neural or kinematic signals.

    Device: Open Loop DBS · Device: Adaptive (Closed Loop) DBS · Device: Intermittent Open Loop DBS

  • Experimental
    Device: Percept PC

    1. Open Loop DBS: Standard DBS therapy at a constant frequency and voltage 2. Adaptive (Closed Loop) DBS: DBS that responds to neural features of patient's current state

    Device: Open Loop DBS · Device: Adaptive (Closed Loop) DBS

Interventions

  • DeviceOpen Loop DBS

    Standard DBS therapy at a constant frequency and voltage

  • DeviceAdaptive (Closed Loop) DBS

    DBS that responds to neural (Percept PC and Summit RC+S) or kinematic (Summit RC+S) features of patient's current state

  • DeviceIntermittent Open Loop DBS

    Control for aDBS - DBS intensity or frequency changes in a manner that mimics aDBS but is pre-determined and open loop rather than being responsive to neural or kinematic signals.

06

What researchers measure

Primary outcomes

  1. Incidence of Treatment-Emergent Adverse Events [Safety and Tolerability] Related to Stimulation Condition

    A Customized Adverse Events and Tolerability Questionnaire will measure the absence/presence and frequency of paresthesias, and muscle twitching relative to each stimulation condition occurring during the respective study visit

    Time frame: Each task/condition was assessed during one day at a planned research visit (occurring from first research visit at month 3, through up to 3 years)

  2. The Movement Disorder Society - Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Parts I, II, and IV

    The Movement Disorder Society - Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Parts I, II, and IV will: (I) Evaluate mentation, behavior, and mood (II) Evaluate a patient's activities of daily life (IV) Measure the presence/severity of dyskinesias and other complications of therapy over time Summed score ranges from 0 to 128 with higher numbers indicating worse impairment.

    Time frame: The questionnaire was assessed on the first day of a planned research visit (occurring from first research visit at month 3, through up to 3 years)

  3. MDS-UPDRS III Speech Item Score

    The MDS-UPDRS III speech item subscale will measure changes in speech related to each stimulation condition to establish safety and tolerability for speech. Subitem score is scores on ordinal scale between 0 and 4 where higher numbers indicate worse impairment.

    Time frame: Each task/condition was assessed during one day a planned research visit (occurring from second research visit at month 6, through up to 3 years)

  4. Freezing of Gait Questionnaire (FOG-Q) Score

    The Freezing of Gait Questionnaire (FOG-Q) will be used to record changes in gait over time as a measure of safety and tolerability. Scores range from 0 to 28 with higher scores indicating worse impairment.

    Time frame: The questionnaire was assessed on the first day of a planned research visit (occurring from first research visit at month 3, through up to 3 years)

Secondary outcomes

  1. Gait Parameters: Arrhythmicity

    Variability in the stride time during a gait task. Stride time is the total time required to complete one full gait cycle as measured as the time between initial ground contact of one foot and the subsequent ground contact of the same foot. The variability is then measured by taking the cofficient of variation which is the standard deviation divided by the mean. Higher variability is indicative of worse (more arrhthmic) gait.

    Time frame: Each task/condition was assessed during one day at a planned research visit (occurring from first research visit at month 3, through up to 3 years)

  2. Gait Parameters: Mean Shank Angular Velocity

    Median of the average score per participant of the peak shank angular velocities of every stride during the gait task. Lower peak shank angular velocity is indicative of worse gait,

    Time frame: Each task/condition was assessed during one day at a planned research visit (occurring from first research visit at month 3, through up to 3 years)

  3. Gait Parameters: Mean Gait Cycle Time

    Median of the average length of time of each stride during a gait task. Higher values are indicative of slower gait.

    Time frame: Each task/condition was assessed during one day at a planned research visit (occurring from first research visit at month 3, through up to 3 years)

  4. Percent Time Freezing

    The percentage of the gait task was a participant frozen. Ranges from 0 to 100 where higher scores indicate worse gait.

    Time frame: Each task/condition was assessed during one day at a planned research visit (occurring from first research visit at month 3, through up to 3 years)

  5. The Movement Disorder Society - Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part III

    Portion of the scale assesses the motor signs of PD. Each item is scored on a scale from 0 (normal) to 4 (severe), with the total possible score ranging from 0 to 132 where higher score indicate worse impairment.

    Time frame: Each task/condition was assessed during one day at a planned research visit (occurring from first research visit at month 3, through up to 3 years)

07

Results

Posted Oct 7, 2026

Participant flow

Participants with Parkinson's disease attend 6 research visits (each lasting up to 10 days) and perform various tasks at high frequency, low frequency, and kinematic levels of intervention under different conditions (OFF deep brain stimulation, open loop deep brain stimulation, adaptive deep brain stimulation, and intermittent open loop deep brain stimulation).

Participant flow — Overall Study
MilestoneDevice: Summit RC+SDevice: Percept PC
Started93
Completed93
Not completed00

Outcome measures

PrimaryIncidence of Treatment-Emergent Adverse Events [Safety and Tolerability] Related to Stimulation Condition

A Customized Adverse Events and Tolerability Questionnaire will measure the absence/presence and frequency of paresthesias, and muscle twitching relative to each stimulation condition occurring during the respective study visit

Time frame:
Each task/condition was assessed during one day at a planned research visit (occurring from first research visit at month 3, through up to 3 years)
Reported as:
Number · Events
Incidence of Treatment-Emergent Adverse Events [Safety and Tolerability] Related to Stimulation Condition
EventsDevice: Summit RC+SDevice: Percept PC
High Frequency Stepping In Place Visit OFF Deep Brain Stimulation00
High Frequency Stepping In Place Visit Open Loop Deep Brain Stimulation01
High Frequency Stepping In Place Visit Adaptive Deep Brain Stimulation00
High Frequency Stepping In Place Visit Intermittent Open Loop Deep Brain Stimulation0—
High Frequency Turning and Barrier Course Visit OFF Deep Brain Stimulation00
High Frequency Turning and Barrier Course Visit Open Loop Deep Brain Stimulation10
High Frequency Turning and Barrier Course Visit Adaptive Deep Brain Stimulation10
High Frequency Turning and Barrier Course Visit Intermittent Open Loop Deep Brain Stimulation3—
Low Frequency Stepping In Place Visit OFF Deep Brain Stimulation0—
Low Frequency Stepping In Place Visit Open Loop Deep Brain Stimulation0—
Low Frequency Stepping In Place Visit Adaptive Deep Brain Stimulation2—
Low Frequency Stepping In Place Visit Intermittent Open Loop Deep Brain Stimulation2—
Low Frequency Turning and Barrier Course Visit OFF Deep Brain Stimulation0—
Low Frequency Turning and Barrier Course Visit Open Loop Deep Brain Stimulation0—
Low Frequency Turning and Barrier Course Visit Adaptive Deep Brain Stimulation0—
Low Frequency Turning and Barrier Course Visit Intermittent Open Loop Deep Brain Stimulation0—
Kinematic Stepping In Place Visit OFF Deep Brain Stimulation0—
Kinematic Stepping In Place Visit Open Loop Deep Brain Stimulation1—
Kinematic Stepping In Place Visit Adaptive Deep Brain Stimulation0—
Kinematic Stepping In Place Visit Intermittent Open Loop Deep Brain Stimulation0—
Kinematic Turning and Barrier Course OFF Deep Brain Stimulation1—
Kinematic Turning and Barrier Course Visit Open Loop Deep Brain Stimulation0—
Kinematic Turning and Barrier Course Visit Adaptive Deep Brain Stimulation0—
Kinematic Turning and Barrier Course Visit Intermittent Open Loop Deep Brain Stimulation0—
Kinematic Stepping In Place Visit Low Frequency Open Loop Deep Brain Stimulation1—
Kinematic Stepping In Place Visit High Frequency Open Loop Deep Brain Stimulation0—
Kinematic Stepping In Place Visit Adaptive Frequency Deep Brain Stimulation0—
Kinematic Stepping In Place Visit Intermittent Frequency Open Loop Deep Brain Stimulation1—
Kinematic Turning and Barrier Course Visit Low Frequency Open Loop Deep Brain Stimulation0—
Kinematic Turning and Barrier Course Visit High Frequency Open Loop Deep Brain Stimulation0—
Kinematic Turning and Barrier Course Visit Adaptive Frequency Deep Brain Stimulation0—
Kinematic Turning and Barrier Course Visit Intermittent Frequency Open Loop Deep Brain Stimulation0—
PrimaryThe Movement Disorder Society - Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Parts I, II, and IV

The Movement Disorder Society - Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Parts I, II, and IV will: (I) Evaluate mentation, behavior, and mood (II) Evaluate a patient's activities of daily life (IV) Measure the presence/severity of dyskinesias and other complications of therapy over time Summed score ranges from 0 to 128 with higher numbers indicating worse impairment.

Time frame:
The questionnaire was assessed on the first day of a planned research visit (occurring from first research visit at month 3, through up to 3 years)
Reported as:
Median · score on a scale
The Movement Disorder Society - Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Parts I, II, and IV
score on a scaleDevice: Summit RC+SDevice: Percept PC
High Frequency Stepping In Place Visit19 (16 to 27.5)18 (17 to 20)
High Frequency Turning and Barrier Course Visit21.5 (14.75 to 33.5)13 (11.5 to 14.5)
Low Frequency Stepping In Place Visit21.5 (15.75 to 22)—
Low Frequency Turning and Barrier Course Visit14 (14 to 20)—
Kinematic Stepping In Place Visit20.5 (17 to 21.5)—
Kinematic Turning and Barrier Course19 (17 to 25.5)—
PrimaryMDS-UPDRS III Speech Item Score

The MDS-UPDRS III speech item subscale will measure changes in speech related to each stimulation condition to establish safety and tolerability for speech. Subitem score is scores on ordinal scale between 0 and 4 where higher numbers indicate worse impairment.

Time frame:
Each task/condition was assessed during one day a planned research visit (occurring from second research visit at month 6, through up to 3 years)
Reported as:
Median · score on a scale
MDS-UPDRS III Speech Item Score
score on a scaleDevice: Summit RC+SDevice: Percept PC
High Frequency Stepping In Place Visit OFF Deep Brain Stimulation1 (1 to 1.75)1.5 (1.25 to 1.75)
High Frequency Stepping In Place Visit Open Loop Deep Brain Stimulation1 (1 to 1)1 (1 to 1.5)
High Frequency Stepping In Place Visit Adaptive Deep Brain Stimulation1 (1 to 1)1 (1 to 1.5)
High Frequency Stepping In Place Visit Intermittent Open Loop Deep Brain Stimulation1 (1 to 1)—
High Frequency Turning and Barrier Course Visit OFF Deep Brain Stimulation1 (1 to 1)1 (1 to 1)
High Frequency Turning and Barrier Course Visit Open Loop Deep Brain Stimulation1 (1 to 2)1 (1 to 1.75)
High Frequency Turning and Barrier Course Visit Adaptive Deep Brain Stimulation1 (1 to 2)1 (0 to 2)
High Frequency Turning and Barrier Course Visit Intermittent Open Loop Deep Brain Stimulation1 (1 to 1)—
Low Frequency Stepping In Place Visit OFF Deep Brain Stimulation1 (1 to 1)—
Low Frequency Stepping In Place Visit Open Loop Deep Brain Stimulation1 (1 to 1)—
Low Frequency Stepping In Place Visit Adaptive Deep Brain Stimulation1 (1 to 1)—
Low Frequency Stepping In Place Visit Intermittent Open Loop Deep Brain Stimulation1 (1 to 1)—
Low Frequency Turning and Barrier Course Visit OFF Deep Brain Stimulation1 (1 to 1.25)—
Low Frequency Turning and Barrier Course Visit Open Loop Deep Brain Stimulation1 (0.75 to 1.25)—
Low Frequency Turning and Barrier Course Visit Adaptive Deep Brain Stimulation1 (1 to 1)—
Low Frequency Turning and Barrier Course Visit Intermittent Open Loop Deep Brain Stimulation1 (0.75 to 1.25)—
PrimaryFreezing of Gait Questionnaire (FOG-Q) Score

The Freezing of Gait Questionnaire (FOG-Q) will be used to record changes in gait over time as a measure of safety and tolerability. Scores range from 0 to 28 with higher scores indicating worse impairment.

Time frame:
The questionnaire was assessed on the first day of a planned research visit (occurring from first research visit at month 3, through up to 3 years)
Reported as:
Median · score on a scale
Freezing of Gait Questionnaire (FOG-Q) Score
score on a scaleDevice: Summit RC+SDevice: Percept PC
High Frequency Stepping In Place Visit19 (0 to 20.5)0 (0 to 3)
High Frequency Turning and Barrier Course Visit15.5 (2.75 to 20.75)0 (0 to 0)
Low Frequency Stepping In Place Visit11.5 (5 to 19.5)—
Low Frequency Turning and Barrier Course Visit9 (8 to 11)—
Kinematic Stepping In Place Visit16.5 (9 to 18.75)—
Kinematic Turning and Barrier Course Visit13 (3 to 18)—
SecondaryGait Parameters: Arrhythmicity

Variability in the stride time during a gait task. Stride time is the total time required to complete one full gait cycle as measured as the time between initial ground contact of one foot and the subsequent ground contact of the same foot. The variability is then measured by taking the cofficient of variation which is the standard deviation divided by the mean. Higher variability is indicative of worse (more arrhthmic) gait.

Time frame:
Each task/condition was assessed during one day at a planned research visit (occurring from first research visit at month 3, through up to 3 years)
Reported as:
Median · Percentage of CV (100*SD/mean)
Gait Parameters: Arrhythmicity
Percentage of CV (100*SD/mean)Device: Summit RC+SDevice: Percept PC
High Frequency Stepping In Place Visit OFF Deep Brain Stimulation19.1 (10.5 to 104.8)9.49 (8.4 to 10.6)
High Frequency Stepping In Place Visit Open Loop Deep Brain Stimulation6.5 (5.2 to 69.9)5.1 (4.9 to 5.2)
High Frequency Stepping In Place Visit Adaptive Deep Brain Stimulation13.6 (5.4 to 82.8)4.4 (4.3 to 6.8)
High Frequency Stepping In Place Visit Intermittent Open Loop Deep Brain Stimulation7.6 (5.0 to 89.1)—
High Frequency Turning and Barrier Course Visit OFF Deep Brain Stimulation16.0 (7.0 to 27.0)12.1 (10.9 to 13.2)
High Frequency Turning and Barrier Course Visit Open Loop Deep Brain Stimulation8.5 (6.9 to 16.5)7.6 (7.2 to 8.4)
High Frequency Turning and Barrier Course Visit Adaptive Deep Brain Stimulation7.8 (7.4 to 11.7)8.3 (7.2 to 8.7)
High Frequency Turning and Barrier Course Visit Intermittent Open Loop Deep Brain Stimulation15.1 (6.6 to 21.6)—
Low Frequency Stepping In Place Visit OFF Deep Brain Stimulation18.8 (8.1 to 30.4)—
Low Frequency Stepping In Place Visit Open Loop Deep Brain Stimulation7.3 (6.0 to 44.3)—
Low Frequency Stepping In Place Visit Adaptive Deep Brain Stimulation8.3 (7.5 to 67.0)—
Low Frequency Stepping In Place Visit Intermittent Open Loop Deep Brain Stimulation12.5 (8.8 to 75.4)—
Low Frequency Turning and Barrier Course Visit OFF Deep Brain Stimulation9.9 (8.0 to 16.2)—
Low Frequency Turning and Barrier Course Visit Open Loop Deep Brain Stimulation8.4 (7.9 to 12)—
Low Frequency Turning and Barrier Course Visit Adaptive Deep Brain Stimulation9.7 (8.6 to 12.9)—
Low Frequency Turning and Barrier Course Visit Intermittent Open Loop Deep Brain Stimulation9.2 (8.2 to 11.1)—
Kinematic Stepping In Place Visit OFF Deep Brain Stimulation127.6 (18.9 to 219.3)—
Kinematic Stepping In Place Visit Open Loop Deep Brain Stimulation8.6 (5.5 to 59.8)—
Kinematic Stepping In Place Visit Adaptive Deep Brain Stimulation14.3 (6.5 to 47.9)—
Kinematic Stepping In Place Visit Intermittent Open Loop Deep Brain Stimulation11.0 (6.8 to 62.6)—
Kinematic Turning and Barrier Course OFF Deep Brain Stimulation14.2 (7.4 to 16.5)—
Kinematic Turning and Barrier Course Visit Open Loop Deep Brain Stimulation10.6 (7.3 to 16.9)—
Kinematic Turning and Barrier Course Visit Adaptive Deep Brain Stimulation10.8 (7.7 to 20.8)—
Kinematic Turning and Barrier Course Visit Intermittent Open Loop Deep Brain Stimulation10.1 (7.5 to 23.6)—
Kinematic Stepping In Place Visit Low Frequency Open Loop Deep Brain Stimulation7.4 (5.1 to 44.0)—
Kinematic Stepping In Place Visit High Frequency Open Loop Deep Brain Stimulation17.1 (7.0 to 37.0)—
Kinematic Stepping In Place Visit Adaptive Frequency Deep Brain Stimulation22.9 (0.8 to 35.0)—
Kinematic Stepping In Place Visit Intermittent Frequency Open Loop Deep Brain Stimulation25.2 (12.2 to 49.0)—
Kinematic Turning and Barrier Course Visit Low Frequency Open Loop Deep Brain Stimulation11.6 (6.3 to 18.5)—
Kinematic Turning and Barrier Course Visit High Frequency Open Loop Deep Brain Stimulation12.2 (6.7 to 21.5)—
Kinematic Turning and Barrier Course Visit Adaptive Frequency Deep Brain Stimulation12.0 (7.5 to 19.3)—
Kinematic Turning and Barrier Course Visit Intermittent Frequency Open Loop Deep Brain Stimulation11.2 (7.7 to 18.3)—
SecondaryGait Parameters: Mean Shank Angular Velocity

Median of the average score per participant of the peak shank angular velocities of every stride during the gait task. Lower peak shank angular velocity is indicative of worse gait,

Time frame:
Each task/condition was assessed during one day at a planned research visit (occurring from first research visit at month 3, through up to 3 years)
Reported as:
Median · degrees per second
Gait Parameters: Mean Shank Angular Velocity
degrees per secondDevice: Summit RC+SDevice: Percept PC
High Frequency Stepping In Place Visit OFF Deep Brain Stimulation29.1 (13.8 to 30.8)41.7 (33.6 to 49.8)
High Frequency Stepping In Place Visit Open Loop Deep Brain Stimulation34.2 (30.7 to 69.2)59.1 (49.4 to 62.9)
High Frequency Stepping In Place Visit Adaptive Deep Brain Stimulation38.4 (29.8 to 61.0)66.0 (52.3 to 68.4)
High Frequency Stepping In Place Visit Intermittent Open Loop Deep Brain Stimulation32.7 (29.6 to 87.0)—
High Frequency Turning and Barrier Course Visit OFF Deep Brain Stimulation166.7 (142.1 to 175.9)226.8 (209.3 to 244.3)
High Frequency Turning and Barrier Course Visit Open Loop Deep Brain Stimulation210.2 (174.4 to 256.7)262.1 (221.8 to 266.3)
High Frequency Turning and Barrier Course Visit Adaptive Deep Brain Stimulation202.2 (171.9 to 217.1)255.0 (224.6 to 262.0)
High Frequency Turning and Barrier Course Visit Intermittent Open Loop Deep Brain Stimulation206.0 (184.1 to 218.5)—
Low Frequency Stepping In Place Visit OFF Deep Brain Stimulation28.5 (20.8 to 40.5)—
Low Frequency Stepping In Place Visit Open Loop Deep Brain Stimulation38.8 (19.8 to 70.8)—
Low Frequency Stepping In Place Visit Adaptive Deep Brain Stimulation38.4 (21.9 to 67.4)—
Low Frequency Stepping In Place Visit Intermittent Open Loop Deep Brain Stimulation39.3 (20.8 to 61.8)—
Low Frequency Turning and Barrier Course Visit OFF Deep Brain Stimulation209.8 (152.9 to 263.4)—
Low Frequency Turning and Barrier Course Visit Open Loop Deep Brain Stimulation225.5 (175.7 to 285.0)—
Low Frequency Turning and Barrier Course Visit Adaptive Deep Brain Stimulation214.9 (162.8 to 274.4)—
Low Frequency Turning and Barrier Course Visit Intermittent Open Loop Deep Brain Stimulation224.9 (175.2 to 273.9)—
Kinematic Stepping In Place Visit OFF Deep Brain Stimulation29.2 (16.3 to 34.7)—
Kinematic Stepping In Place Visit Open Loop Deep Brain Stimulation39.2 (27.4 to 55.5)—
Kinematic Stepping In Place Visit Adaptive Deep Brain Stimulation41.3 (30.7 to 47.6)—
Kinematic Stepping In Place Visit Intermittent Open Loop Deep Brain Stimulation36.1 (29.1 to 57.9)—
Kinematic Turning and Barrier Course Visit OFF Deep Brain Stimulation174.2 (65.1 to 187.5)—
Kinematic Turning and Barrier Course Visit Open Loop Deep Brain Stimulation187.7 (183.5 to 197.7)—
Kinematic Turning and Barrier Course Visit Adaptive Deep Brain Stimulation195.5 (184.9 to 208.6)—
Kinematic Turning and Barrier Course Visit Intermittent Open Loop Deep Brain Stimulation189.4 (175.4 to 205.7)—
Kinematic Stepping In Place Visit Low Frequency Open Loop Deep Brain Stimulation38.5 (25.8 to 66.1)—
Kinematic Stepping In Place Visit High Frequency Open Loop Deep Brain Stimulation39.6 (29.9 to 62.2)—
Kinematic Stepping In Place Visit Adaptive Frequency Deep Brain Stimulation39.6 (26.6 to 55.0)—
Kinematic Stepping In Place Visit Intermittent Frequency Open Loop Deep Brain Stimulation33.2 (28.4 to 56.2)—
Kinematic Turning and Barrier Course Visit Low Frequency Open Loop Deep Brain Stimulation195.0 (184.7 to 245.7)—
Kinematic Turning and Barrier Course Visit High Frequency Open Loop Deep Brain Stimulation213.6 (189.5 to 245.7)—
Kinematic Turning and Barrier Course Visit Adaptive Frequency Deep Brain Stimulation224.0 (190.3 to 259.9)—
Kinematic Turning and Barrier Course Visit Intermittent Frequency Open Loop Deep Brain Stimulation221.3 (193.6 to 252.5)—
SecondaryGait Parameters: Mean Gait Cycle Time

Median of the average length of time of each stride during a gait task. Higher values are indicative of slower gait.

Time frame:
Each task/condition was assessed during one day at a planned research visit (occurring from first research visit at month 3, through up to 3 years)
Reported as:
Median · Seconds
Gait Parameters: Mean Gait Cycle Time
SecondsDevice: Summit RC+SDevice: Percept PC
High Frequency Stepping In Place Visit OFF Deep Brain Stimulation1.57 (1.22 to 1.82)1.41 (1.36 to 1.45)
High Frequency Stepping In Place Visit Open Loop Deep Brain Stimulation1.18 (1.05 to 1.31)1.27 (1.22 to 1.27)
High Frequency Stepping In Place Visit Adaptive Deep Brain Stimulation1.24 (1.16 to 1.57)1.25 (1.23 to 1.26)
High Frequency Stepping In Place Visit Intermittent Open Loop Deep Brain Stimulation1.03 (1.00 to 1.16)—
High Frequency Turning and Barrier Course Visit OFF Deep Brain Stimulation1.01 (0.91 to 1.11)1.13 (1.13 to 1.14)
High Frequency Turning and Barrier Course Visit Open Loop Deep Brain Stimulation1.02 (1.00 to 1.03)1.17 (1.14 to 1.22)
High Frequency Turning and Barrier Course Visit Adaptive Deep Brain Stimulation1.00 (0.98 to 1.10)1.20 (1.15 to 1.25)
High Frequency Turning and Barrier Course Visit Intermittent Open Loop Deep Brain Stimulation1.00 (0.98 to 1.13)—
Low Frequency Stepping In Place Visit OFF Deep Brain Stimulation1.57 (1.00 to 1.64)—
Low Frequency Stepping In Place Visit Open Loop Deep Brain Stimulation1.32 (1.03 to 2.02)—
Low Frequency Stepping In Place Visit Adaptive Deep Brain Stimulation1.39 (1.03 to 2.90)—
Low Frequency Stepping In Place Visit Intermittent Open Loop Deep Brain Stimulation1.40 (1.00 to 1.92)—
Low Frequency Turning and Barrier Course Visit OFF Deep Brain Stimulation1.13 (1.04 to 1.23)—
Low Frequency Turning and Barrier Course Visit Open Loop Deep Brain Stimulation1.11 (1.06 to 1.21)—
Low Frequency Turning and Barrier Course Visit Adaptive Deep Brain Stimulation1.14 (1.09 to 1.16)—
Low Frequency Turning and Barrier Course Visit Intermittent Open Loop Deep Brain Stimulation1.17 (1.06 to 1.19)—
Kinematic Stepping In Place Visit OFF Deep Brain Stimulation1.44 (1.29 to 2.36)—
Kinematic Stepping In Place Visit Open Loop Deep Brain Stimulation1.18 (1.01 to 1.30)—
Kinematic Stepping In Place Visit Adaptive Deep Brain Stimulation1.12 (0.99 to 1.32)—
Kinematic Stepping In Place Visit Intermittent Open Loop Deep Brain Stimulation1.19 (1.00 to 1.42)—
Kinematic Turning and Barrier Course Visit OFF Deep Brain Stimulation1.18 (0.95 to 1.22)—
Kinematic Turning and Barrier Course Visit Open Loop Deep Brain Stimulation1.01 (0.99 to 1.12)—
Kinematic Turning and Barrier Course Visit Adaptive Deep Brain Stimulation1.02 (0.96 to 1.14)—
Kinematic Turning and Barrier Course Visit Intermittent Open Loop Deep Brain Stimulation0.98 (0.94 to 1.09)—
Kinematic Stepping In Place Visit Low Frequency Open Loop Deep Brain Stimulation1.17 (0.98 to 1.36)—
Kinematic Stepping In Place Visit High Frequency Open Loop Deep Brain Stimulation1.11 (0.89 to 1.20)—
Kinematic Stepping In Place Visit Adaptive Frequency Deep Brain Stimulation1.02 (0.86 to 1.20)—
Kinematic Stepping In Place Visit Intermittent Frequency Open Loop Deep Brain Stimulation1.09 (0.91 to 1.27)—
Kinematic Turning and Barrier Course Visit Low Frequency Open Loop Deep Brain Stimulation1.06 (0.93 to 1.16)—
Kinematic Turning and Barrier Course Visit High Frequency Open Loop Deep Brain Stimulation0.96 (0.94 to 1.02)—
Kinematic Turning and Barrier Course Visit Adaptive Frequency Deep Brain Stimulation1.00 (0.97 to 1.07)—
Kinematic Turning and Barrier Course Visit Intermittent Frequency Open Loop Deep Brain Stimulation0.99 (0.94 to 1.06)—
SecondaryPercent Time Freezing

The percentage of the gait task was a participant frozen. Ranges from 0 to 100 where higher scores indicate worse gait.

Time frame:
Each task/condition was assessed during one day at a planned research visit (occurring from first research visit at month 3, through up to 3 years)
Reported as:
Median · Percentage of time
Percent Time Freezing
Percentage of timeDevice: Summit RC+SDevice: Percept PC
High Frequency Stepping In Place Visit OFF Deep Brain Stimulation68.8 (0.6 to 100)0 (0 to 0)
High Frequency Stepping In Place Visit Open Loop Deep Brain Stimulation0 (0 to 31.1)0 (0 to 0)
High Frequency Stepping In Place Visit Adaptive Deep Brain Stimulation0 (0 to 20.4)0 (0 to 0)
High Frequency Stepping In Place Visit Intermittent Open Loop Deep Brain Stimulation0 (0 to 27.8)—
High Frequency Turning and Barrier Course Visit OFF Deep Brain Stimulation41.9 (0 to 53.6)2.0 (1.4 to 2.7)
High Frequency Turning and Barrier Course Visit Open Loop Deep Brain Stimulation0 (0 to 7.9)0 (0 to 0)
High Frequency Turning and Barrier Course Visit Adaptive Deep Brain Stimulation0 (0 to 9.1)0 (0 to 0)
High Frequency Turning and Barrier Course Visit Intermittent Open Loop Deep Brain Stimulation4.5 (0 to 11.2)—
Low Frequency Stepping In Place Visit OFF Deep Brain Stimulation1.8 (0 to 18.5)—
Low Frequency Stepping In Place Visit Open Loop Deep Brain Stimulation0 (0 to 13.9)—
Low Frequency Stepping In Place Visit Adaptive Deep Brain Stimulation1.34 (0 to 39.2)—
Low Frequency Stepping In Place Visit Intermittent Open Loop Deep Brain Stimulation0 (0 to 40.1)—
Low Frequency Turning and Barrier Course Visit OFF Deep Brain Stimulation0 (0 to 13.7)—
Low Frequency Turning and Barrier Course Visit Open Loop Deep Brain Stimulation0 (0 to 4.8)—
Low Frequency Turning and Barrier Course Visit Adaptive Deep Brain Stimulation0 (0 to 8.9)—
Low Frequency Turning and Barrier Course Visit Intermittent Open Loop Deep Brain Stimulation0 (0 to 3.2)—
Kinematic Stepping In Place Visit OFF Deep Brain Stimulation67.3 (0 to 82.1)—
Kinematic Stepping In Place Visit Open Loop Deep Brain Stimulation0 (0 to 17.6)—
Kinematic Stepping In Place Visit Adaptive Deep Brain Stimulation0 (0 to 19.3)—
Kinematic Stepping In Place Visit Intermittent Open Loop Deep Brain Stimulation0 (0 to 22.7)—
Kinematic Turning and Barrier Course Visit OFF Deep Brain Stimulation13.3 (0 to 84.6)—
Kinematic Turning and Barrier Course Visit Open Loop Deep Brain Stimulation0 (0 to 16.9)—
Kinematic Turning and Barrier Course Visit Adaptive Deep Brain Stimulation0 (0 to 14.3)—
Kinematic Turning and Barrier Course Visit Intermittent Open Loop Deep Brain Stimulation0 (0 to 19.3)—
Kinematic Stepping In Place Visit Low Frequency Open Loop Deep Brain Stimulation1.0 (0 to 9.3)—
Kinematic Stepping In Place Visit High Frequency Open Loop Deep Brain Stimulation3.7 (0 to 8.0)—
Kinematic Stepping In Place Visit Adaptive Frequency Deep Brain Stimulation6.8 (0.3 to 16.4)—
Kinematic Stepping In Place Visit Intermittent Frequency Open Loop Deep Brain Stimulation19.1 (2.3 to 19.1)—
Kinematic Turning and Barrier Course Visit Low Frequency Open Loop Deep Brain Stimulation5.2 (0 to 17.9)—
Kinematic Turning and Barrier Course Visit High Frequency Open Loop Deep Brain Stimulation2.1 (0 to 15.0)—
Kinematic Turning and Barrier Course Visit Adaptive Frequency Deep Brain Stimulation0.6 (0 to 12.5)—
Kinematic Turning and Barrier Course Visit Intermittent Frequency Open Loop Deep Brain Stimulation3.1 (0 to 15.2)—
SecondaryThe Movement Disorder Society - Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part III

Portion of the scale assesses the motor signs of PD. Each item is scored on a scale from 0 (normal) to 4 (severe), with the total possible score ranging from 0 to 132 where higher score indicate worse impairment.

Time frame:
Each task/condition was assessed during one day at a planned research visit (occurring from first research visit at month 3, through up to 3 years)
Reported as:
Median · score on a scale
The Movement Disorder Society - Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part III
score on a scaleDevice: Summit RC+SDevice: Percept PC
High Frequency Stepping In Place Visit OFF Deep Brain Stimulation46 (43.5 to 53.75)39 (35 to 43)
High Frequency Stepping In Place Visit Open Loop Deep Brain Stimulation19 (11.5 to 22)36 (27.5 to 38)
High Frequency Stepping In Place Visit Adaptive Deep Brain Stimulation16 (11.5 to 21)23 (21 to 30)
High Frequency Stepping In Place Visit Intermittent Open Loop Deep Brain Stimulation19 (11.5 to 22)—
High Frequency Turning and Barrier Course Visit OFF Deep Brain Stimulation45 (44 to 50)33.5 (27.25 to 39.75)
High Frequency Turning and Barrier Course Visit Open Loop Deep Brain Stimulation18 (16.75 to 21)27.5 (18 to 29.5)
High Frequency Turning and Barrier Course Visit Adaptive Deep Brain Stimulation17.5 (16 to 28.25)22 (13 to 34)
High Frequency Turning and Barrier Course Visit Intermittent Open Loop Deep Brain Stimulation21.5 (18.5 to 22.5)—
Low Frequency Stepping In Place Visit OFF Deep Brain Stimulation37 (26 to 46.5)—
Low Frequency Stepping In Place Visit Open Loop Deep Brain Stimulation33 (25 to 35)—
Low Frequency Stepping In Place Visit Adaptive Deep Brain Stimulation38 (30 to 38)—
Low Frequency Stepping In Place Visit Intermittent Open Loop Deep Brain Stimulation32 (30 to 34)—
Low Frequency Turning and Barrier Course Visit OFF Deep Brain Stimulation38 (28.25 to 45.75)—
Low Frequency Turning and Barrier Course Visit Open Loop Deep Brain Stimulation21 (16.75 to 30.75)—
Low Frequency Turning and Barrier Course Visit Adaptive Deep Brain Stimulation23.5 (18 to 34.75)—
Low Frequency Turning and Barrier Course Visit Intermittent Open Loop Deep Brain Stimulation22 (17.5 to 35)—

Adverse events

Collected over Up to three years (Timeline per study plan was 6 total research visits, each separated by 3 months).. Non-serious events are listed at a 0% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
Device: Summit RC+S0/9 (0%)1/9 (11.1%)9/9 (100%)
Device: Percept PC0/3 (0%)3/3 (100%)3/3 (100%)
Most frequent serious events
Most frequent serious events
EventDevice: Summit RC+SDevice: Percept PC
FractureMusculoskeletal and connective tissue disorders0/91/3
Small Lymphocytic LymphomaNeoplasms benign, malignant and unspecified (incl cysts and polyps)0/91/3
LabyrinthitisEar and labyrinth disorders0/91/3
Worsening of Parkinson's disease symptomsNervous system disorders1/90/3
Most frequent other events
Showing 10 of 13
Most frequent other events
EventDevice: Summit RC+SDevice: Percept PC
FallNervous system disorders7/93/3
TremorNervous system disorders3/91/3
Worsening of Parkinson's disease symptomsNervous system disorders3/90/3
Incision site pain/burningGeneral disorders0/91/3
Muscle TwitchingNervous system disorders2/90/3
Implant site hematomaInjury, poisoning and procedural complications1/90/3
WeaknessNervous system disorders1/90/3
Skin lesionSkin and subcutaneous tissue disorders1/90/3
DizzinessNervous system disorders1/90/3
Herpes zosterInfections and infestations1/90/3

Baseline characteristics

Age, Continuous
Age, Continuous(Years)Device: Summit RC+SDevice: Percept PCTotal
Mean64.4 ± 4.765.2 ± 10.464.6 ± 6.0
Sex: Female, Male
Sex: Female, Male(Participants)Device: Summit RC+SDevice: Percept PCTotal
Female314
Male628
Ethnicity (NIH/OMB)
Ethnicity (NIH/OMB)(Participants)Device: Summit RC+SDevice: Percept PCTotal
Hispanic or Latino000
Not Hispanic or Latino9312
Unknown or Not Reported000
Race (NIH/OMB)
Race (NIH/OMB)(Participants)Device: Summit RC+SDevice: Percept PCTotal
American Indian or Alaska Native000
Asian000
Native Hawaiian or Other Pacific Islander000
Black or African American000
White9312
More than one race000
Unknown or Not Reported000
Region of Enrollment
Region of Enrollment(Participants)Device: Summit RC+SDevice: Percept PCTotal
United States9312
Disease Duration (From Parkinson's Diagnosis)
Disease Duration (From Parkinson's Diagnosis)(Years)Device: Summit RC+SDevice: Percept PCTotal
Mean12.6 ± 3.915.2 ± 1.713.3 ± 3.6
08

Study locations

1 site
  • Stanford University
    Stanford, California 94305, United States
09

References and documents

Publications

  • Negi AS, Cui C, Wilkins KB, Lambert EF, Melbourne JA, Petrucci MN, Hoffman SL, Aditham S, Diep C, Dorris HJ, Akella P, Parisi L, Gala AS, Herron JA, Bronte-Stewart HM. Low-Frequency Adaptive Deep Brain Stimulation for Parkinson's Disease. medRxiv [Preprint]. 2025 Dec 27:2025.12.17.25342333. doi: 10.64898/2025.12.17.25342333. PubMed 41480041 ↗
  • Wilkins KB, Petrucci MN, Lambert EF, Melbourne JA, Gala AS, Akella P, Parisi L, Cui C, Kehnemouyi YM, Hoffman SL, Aditham S, Diep C, Dorris HJ, Parker JE, Herron JA, Bronte-Stewart HM. Beta burst-driven adaptive deep brain stimulation for gait impairment and freezing of gait in Parkinson's disease. Brain Commun. 2025 Jul 9;7(4):fcaf266. doi: 10.1093/braincomms/fcaf266. eCollection 2025. PubMed 40677701 ↗
  • Karjagi S, Kehnemouyi YM, Petrucci MN, Parisi L, Lambert EF, Melbourne JA, Akella P, Wilkins KB, O'Day J, Dorris HJ, Diep C, Gala AS, Cui C, Hoffman SL, Acharyya P, Herron JA, Bronte-Stewart HM. Real-Time Kinematic Adaptive Deep Brain Stimulation Safely Reduces Gait Impairment and Freezing of Gait in Parkinson's Disease. medRxiv [Preprint]. 2026 Mar 2:2026.02.23.26346487. doi: 10.64898/2026.02.23.26346487. PubMed 41867218 ↗

Study documents

  • Study protocol · Jul 18, 2019
  • Study protocol · Feb 20, 2025
  • Statistical analysis plan · Dec 11, 2024
  • Informed consent form · Jun 11, 2025
  • Informed consent form · Jun 28, 2020

Documents are hosted by the registry — open the source record to download them.

Individual participant data

Plan to share: Yes — De-identified participant data, including neural and kinematic data will be shared on the Data Archive for the Brain Initiative (DABI).

Supporting information: Csr

10

Updates

1 registry update since Sep 25, 2026
Results
Results posted
posted Oct 7, 2026
Also revised
primary outcomes
Show all 1 update
  1. Oct 7, 2026
    Results posted
    Primary outcomes Revised (8 changes)
    + 8 other changes: index terms, identifiers, verification date, responsible party, secondary outcomes, references, data sharing statement and documents

From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗

11

Registry details

Key details

Study ID
NCT04043403
Lead sponsor
Stanford University
Collaborators
National Institute of Neurological Disorders and Stroke (NINDS)
Responsible party
Helen M. Bronte-Stewart (Principal Investigator, Stanford University) — Principal investigator
First posted
Aug 2, 2019
Start date
Oct 28, 2019
Primary completion
Aug 8, 2025
Completion
Aug 8, 2025
Results posted
Oct 7, 2026
Last update
Oct 7, 2026

Study contacts

Helen M. Bronte-Stewart, MD,MSE
principal investigator · Stanford University

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
Yes
View the source record on ClinicalTrials.gov ↗

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This study is completed, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.

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