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

NCT07259577 | Recruiting

• 1 other identifier: 1439695
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief 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.

Conditions

Stroke; Stroke Treatment

Keywords

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

Outcome Measures

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.

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

Secondary Outcomes (4)

• Stroke Impact Scale (SIS)

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

• Maximum Inspiratory Pressure (MIP)

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

• Maximum Expiratory Pressure (MEP)

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

• Fatigue Assessment Scale(FAS)

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

Study Arms (2)

Robotics Assisted Education + taVNS

ACTIVE COMPARATOR

Device: Robotics Assisted Education + taVNS

Robotics Assisted Education + sham

SHAM COMPARATOR

Other: Robotics Assisted Education + sham

Interventions

Robotics Assisted Education + taVNS DEVICE

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.

Robotics Assisted Education + taVNS

Robotics Assisted Education + sham OTHER

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.

Robotics Assisted Education + sham

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• Istanbul University - Cerrahpasa: lead

Study Sites (1)

İstanbul Üniversitesi-Cerrahpaşa Sağlık Bilimleri Fakültesi Büyükçekmece Yerleşkesi

Istanbul, Istanbul, Turkey (Türkiye)

RECRUITING

MeSH Terms

Conditions

Stroke

Interventions

salicylhydroxamic acid

Condition Hierarchy (Ancestors)

Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases

Study Officials

• Yusuf Açıkgöz

  Istanbul University - Cerrahpasa

  PRINCIPAL INVESTIGATOR

• Rüstem Mustafaoğlu

  Istanbul University-Cerrahpasa Faculty of Health Sciences, Department of Physiotherapy and Rehabilitation

  STUDY DIRECTOR

Central Study Contacts

Yusuf Açıkgöz

CONTACT

+905396335531; fztysfackgz@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: November 14, 2025
• First Posted: December 2, 2025
• Study Start: October 6, 2025
• Primary Completion (Estimated): May 15, 2026
• Study Completion (Estimated): June 1, 2026
• Last Updated: December 2, 2025

Record last verified: 2025-11

Locations

TU (1)