Immediate Effects of External Trigeminal Nerve Stimulation on Motor Dysfunction in Parkinson's Disease

June 14, 2026 updated by: Zhengli Di

Parkinson's disease (PD), the most common movement disorder, is characterized by motor symptoms including tremor, rigidity, bradykinesia, and postural instability. These symptoms substantially impair quality of life and increase the risk of falls, disability, and accidental injury, representing a major therapeutic challenge.

External trigeminal nerve stimulation (eTNS), a non-invasive neuromodulation technique, has shown promising potential in PD and other movement disorders. A clinical study published in 2017 suggested that trigeminal nerve stimulation may contribute to the alleviation of motor symptoms in patients with PD. In 2023, the U.S. Food and Drug Administration cleared the Portable Neuromodulation Stimulator (PoNS) as an adjunctive treatment for gait impairment caused by multiple sclerosis; the lingual nerve is a branch of the mandibular division of the trigeminal nerve. In the same year, experimental evidence showed that trigeminal nerve stimulation could activate intracranial dopaminergic neurons and modulate dopamine release in mice. These findings suggest substantial potential for eTNS in modulating motor dysfunction in PD, although high-level clinical evidence remains lacking.

This randomized, within-subject study will evaluate the immediate effects of eTNS at different stimulation frequencies on motor dysfunction in patients with PD. Gait parameters will be quantitatively assessed using the IDEEA gait system, together with the MDS-Unified Parkinson's Disease Rating Scale Part III (MDS-UPDRS Part III), Tinetti Gait Scale, and Hoehn and Yahr Scale.

This within-subject study comprises three 20-min stimulation conditions: 120-Hz eTNS, 40-Hz eTNS, and sham stimulation. Each patient with Parkinson's disease will complete all conditions in a single session in randomized order. Instrumented gait analysis, together with motor and gait rating scales, will be used to quantify immediate post-stimulation changes in gait and motor function relative to baseline.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

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Intervention / Treatment

Intervention / Treatment

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Study Type

Study Type

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Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
30

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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 Contact

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Study Locations

  • China
    • Shaanxi
      • Xi'an, Shaanxi, China, 710000
        • Xi'an Central Hospital, Department of Neurology
        • Contact:

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Patients with idiopathic Parkinson's disease diagnosed by two neurologists, according to the Chinese diagnostic criteria for Parkinson's disease formulated in 2020 by the Chinese Parkinson's Disease and Movement Disorders Society based on the MDS Clinical Diagnostic Criteria for Parkinson's disease.
  2. Hoehn and Yahr stage 1-5 in the medication ON state.
  3. Mini-Mental State Examination (MMSE) score >24.
  4. Stable antiparkinsonian medication for at least 1 month before the trial.
  5. No history of orthopedic or musculoskeletal disorders, and no other conditions that may affect balance or gait, such as ophthalmologic disorders.
  6. No history of epilepsy, intracranial tumors, or other neurological disorders; no severe psychiatric disorders, such as schizophrenia; and no long-term use of antipsychotic medications.
  7. Age between 40 and 80 years.
  8. Ability to cooperate with all assessments and eTNS treatment, and provision of written informed consent.

Exclusion Criteria:

  1. Secondary parkinsonism or atypical parkinsonian syndromes.
  2. Current use of anticholinergic medications.
  3. Contraindications to non-invasive electrical neuromodulation.
  4. Previous eTNS treatment within the past 6 months.
  5. Severe neurological, renal, cardiovascular, hepatic, or other major systemic diseases.
  6. Inability to complete clinical assessments or refusal to provide written informed consent.

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: Treatment
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: 40Hz-eTNS
40-Hz eTNS: frequency,40Hz; pulse width, 250 μs; duty cycle, 30 s on/30 s off; total stimulation duration, 20 min.
Device: external Trigeminal Nerve Stimulation, eTNS
The experiment will be conducted in the MED-ON state, consistently 1-2 h after administration of antiparkinsonian medication. Baseline gait and motor function assessments will first be performed, followed by three randomized eTNS stimulation sessions. Gait will be assessed after each stimulation session, and motor function scales will be reassessed after completion of all experimental conditions.
Other Names:
  • Anti-parkinson's disease drugs
Active Comparator: 120Hz-eTNS
120-Hz eTNS: frequency,120Hz; pulse width, 250 μs; duty cycle, 30 s on/30 s off; total stimulation duration, 20 min.
Device: external Trigeminal Nerve Stimulation, eTNS
The experiment will be conducted in the MED-ON state, consistently 1-2 h after administration of antiparkinsonian medication. Baseline gait and motor function assessments will first be performed, followed by three randomized eTNS stimulation sessions. Gait will be assessed after each stimulation session, and motor function scales will be reassessed after completion of all experimental conditions.
Other Names:
  • Anti-parkinson's disease drugs
Sham Comparator: sham-eTNS
Sham eTNS used a double-ramp paradigm with the same parameters as the 120-Hz condition(frequency,120Hz; pulse width, 250 μs; total stimulation duration, 20 min.), but current was delivered only at stimulation onset (0-15 s) and midway through the session (15 s at 10 min).
Device: external Trigeminal Nerve Stimulation, eTNS
The experiment will be conducted in the MED-ON state, consistently 1-2 h after administration of antiparkinsonian medication. Baseline gait and motor function assessments will first be performed, followed by three randomized eTNS stimulation sessions. Gait will be assessed after each stimulation session, and motor function scales will be reassessed after completion of all experimental conditions.
Other Names:
  • Anti-parkinson's disease drugs

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Dual-Task Cost (DTC)
Time Frame: DTC will be assessed at baseline and after each randomized eTNS condition during walking tasks, using the IDEEA inertial sensor based gait analysis system.
This is a within-subject study. Instrumented gait parameters and clinical rating scales will be assessed at baseline, followed by eTNS stimulation in randomized order under the 120-Hz, 40-Hz, and sham conditions. After each eTNS condition, instrumented gait parameters will be collected during walking tasks. Clinical rating scales will be additionally assessed after the final stimulation condition.Dual-task cost will be calculated as: [(single-task gait speed - dual-task gait speed) / single-task gait speed] × 100%.DTC reflects the reduction in walking performance under dual-task conditions relative to single-task conditions. A decrease in DTC after eTNS indicates reduced dual-task interference during walking, suggesting that eTNS may reduce dual-task gait cost in patients with PD.
DTC will be assessed at baseline and after each randomized eTNS condition during walking tasks, using the IDEEA inertial sensor based gait analysis system.
Mean Gait Speed（m/s）
Time Frame: Mean gait speed will be assessed at baseline and after each randomized eTNS condition during walking tasks, using the IDEEA inertial sensor-based gait analysis system.

This is a within-subject study. Instrumented gait parameters and clinical rating scales will be assessed at baseline, followed by eTNS stimulation in randomized order under the 120-Hz, 40-Hz, and sham conditions. After each eTNS condition, instrumented gait parameters will be collected during walking tasks. Clinical rating scales will be additionally assessed after the final stimulation condition.

Mean gait speed will be directly obtained from the IDEEA system, which uses inertial sensors to quantitatively monitor gait during walking tasks in patients with PD.
Mean gait speed will be assessed at baseline and after each randomized eTNS condition during walking tasks, using the IDEEA inertial sensor-based gait analysis system.
Mean Stride Length (m)
Time Frame: Mean stride length will be assessed at baseline and after each randomized eTNS condition during walking tasks, using the IDEEA inertial sensor-based gait analysis system.
This is a within-subject study. Instrumented gait parameters and clinical rating scales will be assessed at baseline, followed by eTNS stimulation in randomized order under the 120-Hz, 40-Hz, and sham conditions. After each eTNS condition, instrumented gait parameters will be collected during walking tasks. Clinical rating scales will be additionally assessed after the final stimulation condition. Mean stride length will be directly obtained from the IDEEA system, which uses inertial sensors to quantitatively monitor gait during walking tasks in patients with PD.
Mean stride length will be assessed at baseline and after each randomized eTNS condition during walking tasks, using the IDEEA inertial sensor-based gait analysis system.

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
stride frequency（steps/min）
Time Frame: It will be assessed at baseline and after each randomized eTNS condition during walking tasks, using the IDEEA inertial sensor-based gait analysis system.
This is a within-subject study. Instrumented gait parameters and clinical rating scales will be assessed at baseline, followed by eTNS stimulation in randomized order under the 120-Hz, 40-Hz, and sham conditions. After each eTNS condition, instrumented gait parameters will be collected during walking tasks. Clinical rating scales will be additionally assessed after the final stimulation condition.Stride frequency will be recorded as directly generated by the IDEEA system.Improvement in stride frequency after eTNS suggests potential improvement in walking rhythm and gait control in patients with PD.
It will be assessed at baseline and after each randomized eTNS condition during walking tasks, using the IDEEA inertial sensor-based gait analysis system.
Double-support phase percentage（%）
Time Frame: It will be assessed at baseline and after each randomized eTNS condition during walking tasks, using the IDEEA inertial sensor-based gait analysis system.

This is a within-subject study. Instrumented gait parameters and clinical rating scales will be assessed at baseline, followed by eTNS stimulation in randomized order under the 120-Hz, 40-Hz, and sham conditions. After each eTNS condition, instrumented gait parameters will be collected during walking tasks. Clinical rating scales will be additionally assessed after the final stimulation condition.Double-support phase percentage will be calculated as: (double-support time / gait cycle time) × 100%.

A higher Double-support phase percentage value generally indicates greater reliance on double-limb support to maintain stability, suggesting more cautious gait, impaired dynamic balance, and increased fall risk. A decrease in double-support phase percentage after eTNS suggests reduced dependence on double-limb support and potential improvement in gait stability and dynamic balance in patients with PD.
It will be assessed at baseline and after each randomized eTNS condition during walking tasks, using the IDEEA inertial sensor-based gait analysis system.
gait symmetry index（%）
Time Frame: It will be assessed at baseline and after each randomized eTNS condition during walking tasks, using the IDEEA inertial sensor-based gait analysis system.
This is a within-subject study. Instrumented gait parameters and clinical rating scales will be assessed at baseline, followed by eTNS stimulation in randomized order under the 120-Hz, 40-Hz, and sham conditions. After each eTNS condition, instrumented gait parameters will be collected during walking tasks. Clinical rating scales will be additionally assessed after the final stimulation condition.The symmetry index will be calculated as: |left-side gait parameter - right-side gait parameter| / [0.5 × (left-side gait parameter + right-side gait parameter)] × 100%.The symmetry index reflects the degree of difference between left- and right-side gait parameters and is used to evaluate bilateral gait symmetry. A higher value indicates greater asymmetry, whereas a lower value indicates better gait symmetry. A decrease in the symmetry index after eTNS suggests improved bilateral gait symmetry in patients with PD.
It will be assessed at baseline and after each randomized eTNS condition during walking tasks, using the IDEEA inertial sensor-based gait analysis system.

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Hoehn and Yahr Scale
Time Frame: The scale will be administered twice: once at baseline before the experiment and once after completion of all eTNS stimulation conditions and walking tasks, namely at the end of the experiment.

This is a within-subject study. Instrumented gait parameters and clinical rating scales will be assessed at baseline, followed by eTNS stimulation in randomized order under the 120-Hz, 40-Hz, and sham conditions. After each eTNS condition, instrumented gait parameters will be collected during walking tasks. Clinical rating scales will be additionally assessed after the final stimulation condition.The Hoehn and Yahr scale ranges from 1 to 5 in this study. Higher stages indicate more advanced disease and greater motor disability.

It is a clinical staging system used to assess the overall severity of Parkinson's disease based on the distribution of motor symptoms, postural instability, walking ability, and functional disability. A higher stage indicates more severe disease. A decrease in Hoehn and Yahr scale after eTNS would suggest improvement in overall motor function and disease severity.
The scale will be administered twice: once at baseline before the experiment and once after completion of all eTNS stimulation conditions and walking tasks, namely at the end of the experiment.
Incidence of eTNS-Related Adverse Reactions [Safety and Tolerability]
Time Frame: Throughout the experimental session, approximately 2.5-3 hours
Adverse reactions related to eTNS will be recorded throughout the experimental session, including local skin numbness, tingling, itching, redness at the electrode site, headache, dizziness, or any other discomfort reported by the participant or observed by the investigator. The number and percentage of participants experiencing eTNS-related adverse reactions will be reported.
Throughout the experimental session, approximately 2.5-3 hours
Movement Disorder Society-Unified Parkinson's Disease Rating Scale Part III
Time Frame: The scale will be administered twice: once at baseline before the experiment and once after completion of all eTNS stimulation conditions and walking tasks, namely at the end of the experiment.

This is a within-subject study. Instrumented gait parameters and clinical rating scales will be assessed at baseline, followed by eTNS stimulation in randomized order under the 120-Hz, 40-Hz, and sham conditions. After each eTNS condition, instrumented gait parameters will be collected during walking tasks. Clinical rating scales will be additionally assessed after the final stimulation condition.

Movement Disorder Society-Unified Parkinson's Disease Rating Scale Part III(MDS-UPDRS III) is a clinician-rated motor examination scale used to assess the severity of motor signs in Parkinson's disease, including rigidity, bradykinesia, tremor, gait, posture, and postural stability. The score ranges from 0 to 132, with each item rated from 0 to 4. Higher scores indicate more severe motor impairment.A decrease in the MDS-UPDRS Part III score after eTNS indicates improvement in motor function.
The scale will be administered twice: once at baseline before the experiment and once after completion of all eTNS stimulation conditions and walking tasks, namely at the end of the experiment.
Tinetti Gait Assessment
Time Frame: The scale will be administered twice: once at baseline before the experiment and once after completion of all eTNS stimulation conditions and walking tasks, namely at the end of the experiment.
This is a within-subject study. Instrumented gait parameters and clinical rating scales will be assessed at baseline, followed by eTNS stimulation in randomized order under the 120-Hz, 40-Hz, and sham conditions. After each eTNS condition, instrumented gait parameters will be collected during walking tasks. Clinical rating scales will be additionally assessed after the final stimulation condition.The Tinetti Gait Assessment score ranges from 0 to 12. Higher scores indicate better gait performance and stability.The Tinetti Gait Assessment evaluates gait performance during walking, including gait initiation, step length and height, step symmetry, step continuity, walking path, trunk stability, and walking stance. A lower score indicates poorer gait function and greater gait instability, whereas a higher score indicates better gait function. An increase in the Tinetti Gait Assessment score after eTNS suggests improvement in gait function in patients with PD.
The scale will be administered twice: once at baseline before the experiment and once after completion of all eTNS stimulation conditions and walking tasks, namely at the end of the experiment.

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Zhengli Di

Study record dates

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Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
June 15, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 15, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 15, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 8, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 14, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 18, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 18, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 14, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
June 1, 2026

More Information

Terms related to this study

Keywords

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Other Study ID Numbers

Other Study ID Numbers

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  • LSS-K-2026-012-01

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be shared because the informed consent documents and ethics approval do not specifically include permission for public or external sharing of individual-level participant data. Aggregate study results may be shared through publications or presentations.

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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