Auricular Vagus Nerve Stimulation Combined With Rehabilitation in Parkinson's Disease

Investigation of the Effects of Auricular Vagus Nerve Stimulation Combined With Neurological Physiotherapy and Rehabilitation on Balance, Gait, and Clinical Symptoms in People With Parkinson's Disease

Parkinson's disease (PD) is a progressive, neurodegenerative movement disorder characterized by a combination of motor and non-motor symptoms. Auricular vagus nerve stimulation (aVNS), one of the physiotherapy methods used in PD, has been shown in studies to have a positive effect on symptoms such as motor symptoms, gait disturbance, freezing, and cognitive impairment, and is considered a safe and feasible method. The aim of this study is to investigate the effects of neurological physiotherapy and rehabilitation, in combination with aVNS application, on balance, gait, and clinical symptoms in individuals with PD.

Study Overview

• Status: Enrolling by invitation
• Conditions: PARKINSON DISEASE (Disorder)
• Intervention / Treatment: Other: Neurological Physiotherapy and Rehabilitation Combined with Active Vagus Nerve Stimua; Other: Neurological Physiotherapy and Rehabilitation Combined with Sham Vagus Nerve Stimua

Detailed Description

Parkinson's disease (PD) is a progressive, neurodegenerative movement disorder characterized by a combination of motor symptoms such as bradykinesia, rigidity, tremor, and postural instability, and non-motor symptoms such as depression, anxiety, and cognitive impairment. Neurological physiotherapy and rehabilitation are among the most important components of PD in the literature to prevent progression, alleviate symptoms, and slow neurodegeneration. Auricular vagus nerve stimulation (aVNS), one of the physiotherapy methods used in PD, has been shown in studies to have a positive effect on symptoms such as motor symptoms, gait disturbance, freezing, and cognitive impairment, and is considered a safe and feasible method. Looking at PD studies in the literature, it is seen that participants applied aVNS at home on their own, in an isolated study design, and individuals were not included in any rehabilitation program. The aim of this study is to investigate the effects of neurological physiotherapy and rehabilitation, in combination with aVNS application, on balance, gait, and clinical symptoms in individuals with PD. The study will include individuals diagnosed with Parkinson's disease. Individuals will be divided into two groups: a control group and a study group. In this blinded study, individuals in both groups will be included in a physiotherapy and rehabilitation program at the Neurological Physiotherapy and Rehabilitation Unit. Individuals in the control group will receive sham aVNS, while individuals in the active treatment group will receive active aNVS. Individuals will be evaluated twice, before and after their three-week, five-day-a-week program. Balance, gait, and clinical symptoms will be assessed using tests and scales.

• Study Type: Interventional
• Enrollment (Estimated): 20
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Please Select
    • Ankara, Please Select, Turkey (Türkiye), 06490
      • Gazi University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Diagnosis of Parkinson's disease confirmed by a neurologist according to the United Kingdom Brain Bank criteria
• Age 40 years or older
• Hoehn and Yahr stage between 1 and 3 according to the Modified Hoehn and Yahr Staging Scale
• Stable pharmacological treatment regimen
• Ability to turn 180 degrees and walk 30 meters independently without assistance

Exclusion Criteria:

• Score below 21 on the Montreal Cognitive Assessment (MoCA)
• Presence of uncorrected visual or hearing impairments
• Presence of additional neurological (e.g., migraine), orthopedic (e.g., osteoarthritis), or cardiovascular conditions (e.g., myocardial infarction, uncontrolled hypertension, arrhythmias)
• Presence of a cardiac pacemaker
• Presence of metallic implants in the head or neck region
• History of deep brain stimulation surgery

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Active Auricular Vagus Nerve Stimulation Group	Other: Neurological Physiotherapy and Rehabilitation Combined with Active Vagus Nerve Stimua; Individuals will be enrolled in an intensive and individualized physiotherapy and rehabilitation program for three weeks, consisting of 15 sessions in total, five days a week. This program is primarily structured to include exercises and functional task activities recommended in PD guidelines for patients' exercise routines, and previously demonstrated in neurological rehabilitation clinics to improve balance and gait. The goals of the program are to increase strength and flexibility of large muscle groups, improve large and coordinated movement skills, postural accuracy, aerobic capacity, balance, and gait. The intensive and individualized physiotherapy and rehabilitation program will last approximately 90-120 minutes. The current form of the aVSS application received by the participants is a monophasic square wave. The current transit time is 250 milliseconds, the frequency is 25 Hertz, and the intensity is submaximal sensory perception.
Sham Comparator: Sham Auricular Vagus Nerve Stimulation Group	Other: Neurological Physiotherapy and Rehabilitation Combined with Sham Vagus Nerve Stimua; Individuals will be enrolled in an intensive and individualized physiotherapy and rehabilitation program for three weeks, consisting of 15 sessions in total, five days a week. This program is primarily structured to include exercises and functional task activities recommended in PD guidelines for patients' exercise routines, and previously demonstrated in neurological rehabilitation clinics to improve balance and gait. The goals of the program are to increase strength and flexibility of large muscle groups, improve large and coordinated movement skills, postural accuracy, aerobic capacity, balance, and gait. The intensive and individualized physiotherapy and rehabilitation program will last approximately 90-120 minutes. The vagus nerve stimulation device will not turn on.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Movement Disorders Society-Unified Parkinson's Disease Rating Scale	The Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) was used to assess motor and non-motor symptom severity in individuals with Parkinson's disease. The MDS-UPDRS is a validated, comprehensive clinical rating scale consisting of four parts: non-motor experiences of daily living (Part I), motor experiences of daily living (Part II), motor examination (Part III), and motor complications (Part IV). Higher scores indicate greater symptom severity. The scale has demonstrated excellent reliability, validity, and sensitivity to change in clinical trials and is widely recommended as a primary outcome measure in Parkinson's disease research.	twice: once on the initial assessment day and once after the 3-week program.
Postural Stability	The force platform, considered the gold standard for the quantitative assessment of postural stability, is a valid and reliable method that enables objective evaluation of balance. In this study, postural stability during quiet standing will be assessed using a force platform. Participants will stand on the platform in a standardized foot position, with their arms at their sides and their gaze fixed forward. Measurements will be performed under eyes-open and eyes-closed conditions. For each condition, trials of fixed duration will be recorded, and center of pressure (CoP) parameter will be calculated. Higher CoP value will indicate reduced postural stability. Measurements will be repeated according to a standardized protocol, and the average values will be used for analysis.	twice: once on the initial assessment day and once after the 3-week program.
Spatiotemporal Gait Parameters	Spatiotemporal gait characteristics will be evaluated using a gait analysis system. Participants will walk across the walkway six times at their self-selected comfortable speed. Temporal and spatial parameters (step length, stride length, step time, stride time, double support time) of gait, as well as variability measures, will be calculated.	twice: once on the initial assessment day and once after the 3-week program.
Functional Walking Capacity	Functional walking capacity will be assessed using the 6-Minute Walk Test (6MWT). Participants will be instructed to walk as far as possible within six minutes along a standardized walkway. The total distance covered will be recorded in meters. In individuals with Parkinson's disease, the minimal clinically important difference has been reported as 82 meters.	twice: once on the initial assessment day and once after the 3-week program.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Berg Balance Sclae	Functional balance will be assessed using the Berg Balance Scale (BBS), a widely used and validated clinical scale for the evaluation of balance performance in individuals with neurological conditions. The BBS consists of 14 functional tasks, including sitting, standing, transfers, reaching, turning, and single-leg stance. Each item is scored on a 5-point ordinal scale ranging from 0 to 4, with a maximum total score of 56 points. Higher scores indicate better balance performance. The BBS has demonstrated high reliability, validity, and sensitivity to change in individuals with Parkinson's disease and other neurological populations.	twice: once on the initial assessment day and once after the 3-week program.
Activities-specific Balance Confidence Scale	Balance confidence will be assessed using the Activities-specific Balance Confidence Scale (ABC). The ABC is a self-reported questionnaire designed to evaluate an individual's confidence in maintaining balance during various daily activities. It consists of 16 items, each scored from 0% (no confidence) to 100% (complete confidence). The overall score is calculated as the average of all item scores, with higher values indicating greater balance confidence. The ABC has demonstrated good reliability, validity, and responsiveness in individuals with Parkinson's disease and other neurological populations.	twice: once on the initial assessment day and once after the 3-week program.
Functional Mobility	Functional mobility will be assessed using the Timed Up and Go Test (TUG). In this test, participants are instructed to stand up from a chair on the command "go," walk 3 meters, turn around, walk back, and sit down again. The test is performed on a flat, unobstructed 3-meter walkway. Timing begins at the command "go" and stops when the participant sits back in the chair. A chair with armrests will be used (seat height: 50 cm, seat depth: 47 cm, seat width: 50 cm, armrest height: 65 cm). One practice trial will be performed, followed by two recorded trials, and the final measurement will be used for analysis.	twice: once on the initial assessment day and once after the 3-week program.
Trail Making Test	The Trail Making Test (TMT) is used to assess executive functions, task-switching ability, attention, visual scanning speed, visuomotor processing, planning, organization, abstract thinking, and response inhibition. The test consists of two parts: Part A (TMT-A) and Part B (TMT-B). In Part A, participants are asked to connect numbered circles in sequential order from 1 to 25, and the completion time is recorded. In Part B, participants are required to alternate between numbers and letters in sequence (e.g., 1-A-2-B-3-C), and the completion time is recorded.	twice: once on the initial assessment day and once after the 3-week program.
Stroop Test	The Stroop Test is a cognitive assessment that evaluates executive functions, particularly selective attention, cognitive flexibility, and the ability to inhibit automatic responses under interference conditions. In this study, the Stroop Test-Basic Sciences Research Group Form (ST-BSRG) will be used. This form is a combined version of the original Stroop Test and the Victoria version. The test is administered in five sections using four different cards. Each card contains six rows, with each row consisting of four items arranged in sequence. The completion time and errors are recorded for analysis.	twice: once on the initial assessment day and once after the 3-week program.
Quality of Life Assessment	Quality of life will be evaluated using the Parkinson's Disease Questionnaire-8 (PDQ-8). The PDQ-8 is a short-form, disease-specific questionnaire that assesses the impact of Parkinson's disease on quality of life. The items evaluate the individual's experiences over the previous month and are scored on a scale from 0 (never) to 4 (always). The total score is converted to a 0-100 scale, with higher scores indicating poorer quality of life. The Turkish version of the PDQ-8 has been shown to be valid and reliable, with excellent test-retest reliability (ICC = 0.97) as reported by Kahraman and colleagues.	twice: once on the initial assessment day and once after the 3-week program.
Fatigue Assessment	Subjective fatigue will be evaluated using the Parkinson Fatigue Scale (PFS). The PFS consists of 16 items and is rated on a five-point Likert scale. It was specifically developed to assess fatigue related to Parkinson's disease. Each item is scored from "strongly disagree" to "strongly agree," with higher scores indicating greater fatigue severity. The Turkish version of the scale has been shown to be valid and reliable.	twice: once on the initial assessment day and once after the 3-week program.

Collaborators and Investigators

• Sponsor: Gazi University

Publications and helpful links

General Publications

• Eissazade N, Eghdami S, Rohani M, Ajdari A, Fereshtehnejad SM, Fasano A, Khoeini T. Noninvasive Vagus Nerve Stimulation in Parkinson's Disease: A Systematic Review. Neuromodulation. 2025 Jun;28(4):641-651. doi: 10.1016/j.neurom.2025.01.012. Epub 2025 Mar 6.
• Sigurdsson HP, Raw R, Hunter H, Baker MR, Taylor JP, Rochester L, Yarnall AJ. Noninvasive vagus nerve stimulation in Parkinson's disease: current status and future prospects. Expert Rev Med Devices. 2021 Oct;18(10):971-984. doi: 10.1080/17434440.2021.1969913. Epub 2021 Sep 8.

Study record dates

Study Major Dates

• Study Start (Actual): March 3, 2026
• Primary Completion (Estimated): March 23, 2027
• Study Completion (Estimated): April 23, 2027

Study Registration Dates

• First Submitted: February 16, 2026
• First Submitted That Met QC Criteria: February 23, 2026
• First Posted (Actual): February 27, 2026

Study Record Updates

• Last Update Posted (Actual): March 5, 2026
• Last Update Submitted That Met QC Criteria: March 3, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: gait; rehabilitation; Parkinson's disease; balance; vagus nerve stimulation
• Additional Relevant MeSH Terms: Synucleinopathies; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Neurodegenerative Diseases; Movement Disorders; Parkinsonian Disorders; Basal Ganglia Diseases; Parkinson Disease; Therapeutics; Rehabilitation; Physical Therapy Modalities
• Other Study ID Numbers: 2025 - 1202

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No