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RecruitingNCT07259577Updated Dec 2, 2025

Effects of Vagus Nerve Stimulation on Motor Function, Respiratory Muscle Strength, and Quality of Life in Stroke Patients

An interventional study of Robotics Assisted Education + taVNS and Robotics Assisted Education + sham in Stroke and Stroke Treatment, sponsored by Istanbul University - Cerrahpasa. Recruiting at 1 site in Turkey (Türkiye). Open to participants aged 18 Years to 70 Years. Per ClinicalTrials.gov, last updated 2025-12-02.

Sponsored by Istanbul University - Cerrahpasa · Not applicable, Interventional, and Treatment

From the registry’s dates

  • Primary completion was expected by May 2026, 4 months ago, but the record still lists the study as recruiting.
  • Started Oct 2025; still recruiting 1 year later.
Phase
Not applicable
Study type
Interventional
Enrollment
30
Allocation
Randomized
Ages
18 Years to 70 Years
Sex
All
01

Study summary

Stroke is one of the leading causes of death and permanent disability worldwide. Loss of upper extremity (UE) function after stroke significantly reduces independence and quality of life. Moreover, weakness in the respiratory muscles negatively affects trunk control and respiratory function, limiting overall functional recovery. In recent years, robot-assisted training (RAT) and non-invasive neuromodulation techniques-particularly transcutaneous auricular vagus nerve stimulation (taVNS)-have emerged as promising approaches to enhance neuroplasticity in stroke rehabilitation.

This study aims to investigate the effects of taVNS combined with robot-assisted training on upper extremity motor function, respiratory muscle strength, and quality of life in individuals with stroke.

This randomized controlled trial will be conducted in collaboration between Istanbul University-Cerrahpaşa and Istanbul Medeniyet University. Thirty individuals aged 18-70 years, with moderate-to-severe upper extremity weakness and a history of stroke of at least six months, will be included. Participants will be randomly assigned to two groups: RAT + taVNS (n=15), RAT + sham taVNS (n=15). Both groups will receive conventional rehabilitation for 45 minutes, three times per week for five weeks. Additionally, each group will undergo 45-minute sessions of RAT twice per week for five weeks, with either active or sham taVNS applied concurrently.

The primary outcome measure will be the Fugl-Meyer Upper Extremity Motor Assessment (FM-UE). Secondary outcomes will include the Stroke Impact Scale (SIS), Maximum Inspiratory Pressure (MIP), Maximum Expiratory Pressure (MEP), and Fatigue Assessment Scale (FAS). Assessments will be conducted at baseline and at the end of the fifth week.

Combining taVNS with robot-assisted upper extremity rehabilitation is expected to result in greater improvements in motor function, respiratory muscle strength, and quality of life compared to robot-assisted rehabilitation alone. This study will provide valuable insights into the synergistic effects of neuromodulation and robotic therapy in stroke rehabilitation and contribute to the growing body of evidence supporting non-invasive, technology-assisted treatment approaches.

02

Conditions studied

  • Stroke
  • Stroke Treatment

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Keywords

  • stroke
  • Upper Extremity Robot-Assisted Training
  • Transcutaneous Auricular Vagus Nerve Stimulation
  • taVNS
  • Respiratory Muscle Strength
03

In context

Stroke

7,286 studies on the registry are indexed under Stroke; 2,007 are open to participants now.

This study's planned enrollment of 30 is below the median of 50 across 5,369 interventional studies indexed under Stroke.

Browse Stroke studies →

Lead sponsor

Istanbul University - Cerrahpasa is the lead sponsor of 680 studies on the registry; 208 are open to participants now.

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

04

Who can participate

Ages eligible
18 Years to 70 Years
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  • Individuals aged 18-70 years diagnosed with ischemic or hemorrhagic stroke lasting longer than 6 months,
  • Moderate to severe upper extremity weakness (20-50 out of 66 on the Fugl-Meyer Upper Extremity Motor Assessment Scale),
  • Ability to communicate and understand (Mini Mental State Examination (MMSE) score ≥ 23),
  • Upper extremity spasticity of 2 or less on the Modified Ashworth Scale.

Exclusion criteria

Exclusion Criteria:

  • Use of any stimulation device, such as a pacemaker or other neurostimulator,
  • Presence of a medical or cognitive condition (personality disorder, anxiety, depression, etc.) that would prevent participants from participating in the study,
  • Receiving a Botox injection into the affected upper extremity at least 4 weeks prior,
  • Severe spasticity in the upper extremity (Modified Ashworth Scale ≥3),
  • Presence of dysphagia or aphasia,
  • Presence of cardiac problems such as atrial fibrillation, atrial flutter, sick sinus syndrome, or atrioventricular block.
05

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
30 participants (estimated)

Study arms

  • Active comparator
    Robotics Assisted Education + taVNS

    Device: Robotics Assisted Education + taVNS

  • Sham comparator
    Robotics Assisted Education + sham

    Other: Robotics Assisted Education + sham

Interventions

  • DeviceRobotics Assisted Education + taVNS

    Conventional rehabilitation will be administered 3 days a week, 45 minutes per day, for 5 weeks. The combination of Upper Extremity Robotic-Assisted Training and Transcutaneous Auricular Vagus Nerve Stimulation will be administered 2 days a week, 45 minutes per day, for 5 weeks.

  • OtherRobotics Assisted Education + sham

    Conventional rehabilitation will be administered 3 days a week, 45 minutes per day, for 5 weeks. The combination of Upper Extremity Robotic-Assisted Training and Sham Transcutaneous Auricular Vagus Nerve Stimulation will be administered 2 days a week, 45 minutes per day, for 5 weeks.

06

What researchers measure

Primary outcomes

  1. Fugl Meyer Upper Extremity Evaluation (FM-UE)

    We will use the Fugl-Meyer Upper Motor Assessment score, which is the most sensitive for treatment outcomes in stroke patients presenting with unilateral paresis in the post-stroke period. It measures upper extremity use and impairment, measuring shoulder, elbow, forearm, wrist, finger, and reflex movements from proximal to distal, synergistic to extrinsic. The score ranges from 0 to 66 and consists of 33 items. 0-28 indicates severe motor impairment; 29-42 indicates moderate motor impairment; and 43-66 indicates mild motor impairment. Higher scores indicate better performance. The FM-UE consists of one component, each rated on a 3-point ordinal scale (0=not achieved, 1=partially contributed, 2=completely contributed). The minimum clinically meaningful change on the FM-UE for chronic stroke has been determined to be 4.25 to 7.25. Consistent with the literature, we define an improvement of at least 6 points or more as significant.

    Time frame: Outcome measures will be assessed and recorded at baseline (assessment session) and after intervention (week 5).

Secondary outcomes

  1. Stroke Impact Scale (SIS)

    The SIS 3.0 assesses function and quality of life based on subjective report in eight clinically important domains. It consists of two parts. The first part is the main scale of the IAS, which assesses multidimensional health-related quality of life (QOL) including strength, hand function, ADL/instrumental ADL, mobility, communication, emotion, memory/thinking, and social participation. It consists of 59 items, and each item is subjectively rated by stroke patients on a 5-point Likert-type scale according to their perceived difficulty with the item in the past week. The score for each domain is converted to a score out of 100, and the average scores for all domains are used to represent stroke patients' multidimensional health-related quality of life. The formula Domain Score = \[(Average Item Score -1) / (5 -1) x 100\] is used to convert each domain score. SIS 3.0 also includes assessment of post-stroke recovery using a 0-100 visual analog scale (0: no recovery, 100: complete recovery)

    Time frame: Outcome measures will be assessed and recorded at baseline (assessment session) and after intervention (week 5).

  2. Maximum Inspiratory Pressure (MIP)

    This is the pressure measured when the patient tries to breathe as forcefully as possible into their lungs (inspiration). It assesses the strength of the diaphragm and accessory respiratory muscles-in other words, the inspiratory capacity of the respiratory muscles. The measurement is taken through the mouth. A nose clip is applied. After maximum exhalation near the residual volume (RV), the patient tries to breathe in as forcefully as possible for 1-2 seconds. Three repetitions are performed, and the average is calculated. (The higher the pressure value, the greater the muscle strength.)

    Time frame: Outcome measures will be assessed and recorded at baseline (assessment session) and after intervention (week 5).

  3. Maximum Expiratory Pressure (MEP)

    This is the pressure measured during the patient's strongest possible exhalation (expiration). This indicates the strength of the respiratory muscles that assist exhalation, such as the abdominal muscles and internal/external intercostal muscles. The measurement is taken orally. A nose clip is applied. After taking a maximum inspiration (close to TLC), the patient attempts to exhale as forcefully as possible for 1-2 seconds. Three repetitions are performed, and the average is calculated. (The higher the pressure value, the greater the muscle strength.)

    Time frame: Outcome measures will be assessed and recorded at baseline (assessment session) and after intervention (week 5).

  4. Fatigue Assessment Scale(FAS)

    It is a brief and practical self-report instrument developed to measure the severity of fatigue experienced by individuals. It consists of 10 items, and each item is rated subjectively on a 5-point Likert-type scale used to assess overall fatigue level over the past week. The lowest score is 10, and the highest is 50. (≤ 21 points: None/low fatigue, 22-34 points: Moderate fatigue, ≥ 35 points: High fatigue)

    Time frame: Outcome measures will be assessed and recorded at baseline (assessment session) and after intervention (week 5).

07

Study locations

1 of 1 sites recruiting
  • İstanbul Üniversitesi-Cerrahpaşa Sağlık Bilimleri Fakültesi Büyükçekmece Yerleşkesi
    Istanbul, Istanbul, Turkey (Türkiye)
    Recruiting
08

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Dec 2, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
09

Registry details

Key details

Study ID
NCT07259577
Lead sponsor
Istanbul University - Cerrahpasa
Responsible party
Yusuf AÇIKGÖZ (Principal Investigator, Istanbul University - Cerrahpasa) — Principal investigator
First posted
Dec 2, 2025
Start date
Oct 6, 2025
Primary completion
May 15, 2026 (estimated)
Completion
Jun 1, 2026 (estimated)
Last update
Dec 2, 2025

Study contacts

Yusuf Açıkgöz
Contact
fztysfackgz@gmail.com
+905396335531
Yusuf Açıkgöz
principal investigator · Istanbul University - Cerrahpasa
Rüstem Mustafaoğlu
study director · Istanbul University-Cerrahpasa Faculty of Health Sciences, Department of Physiotherapy and Rehabilitation

Oversight

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

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