Effect of Transcutaneous Auricular Vagus Nerve Stimulation Application on Respiratory Functions in Stroke Patients

NCT06793800 | Recruiting

• 1 other identifier: 80.2024fbu
• Study Type: interventional
• Target: 50
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of this study is to evaluate the effectiveness of Transcutaneous Auricular Vagus Nerve Stimulation (TAVSS) in improving respiratory muscle strength and function in chronic stroke patients. It aims to explore TAVSS as a potential complementary approach in enhancing rehabilitation outcomes for this population.

Conditions

Respiratory Function Loss; Hemiplegia

Keywords

hemiplegia; Vagus Nerve Stimulation; Respiration

Outcome Measures

Primary Outcomes (5)

• Inspiratory muscle strength

  Inspiratory muscle strength will be measured using the Minispir 2 spirometer by Medical International Research. This spirometer, classified as a Class II medical device (medium risk) by Health Canada, is a non-invasive tool for assessing respiratory function. It evaluates lung ventilation by measuring the air volume during inspiration and expiration. The device records inspiratory effort and lung capacity, helping determine respiratory muscle performance.

  From enrollment to the end of treatment at 4 weeks

• Expiratory muscle strength

  Expiratory muscle strength will be measured using the Minispir 2 spirometer by Medical International Research. This spirometer, classified as a Class II medical device (medium risk) by Health Canada, is a non-invasive tool for assessing respiratory function. It evaluates lung ventilation by measuring air volume during expiration, helping assess expiratory muscle performance and overall pulmonary function.

  From enrollment to the end of treatment at 4 weeks

• Forced Expiratory Volume in 1 Second (FEV₁)

  Forced Expiratory Volume in 1 Second (FEV₁) will be measured using the Minispir 2 spirometer by Medical International Research. This spirometer, classified as a Class II medical device (medium risk) by Health Canada, is a non-invasive tool for assessing respiratory function. It evaluates lung ventilation by measuring the air volume exhaled in the first second of a forced expiration, providing critical data on airway obstruction and pulmonary function.

  From enrollment to the end of treatment at 4 weeks

• Forced Vital Capacity (FVC)

  Forced Vital Capacity (FVC) will be measured using the Minispir 2 spirometer by Medical International Research. This spirometer, classified as a Class II medical device (medium risk) by Health Canada, is a non-invasive tool for assessing respiratory function. It evaluates lung ventilation by measuring the maximum air volume forcefully exhaled after a deep inhalation, providing essential data on pulmonary function and lung capacity.

  From enrollment to the end of treatment at 4 weeks

• Forced Expiratory Volume in 1 Second (FEV₁) to Forced Vital Capacity (FVC)

  Forced Expiratory Volume in 1 Second (FEV₁) to Forced Vital Capacity (FVC) ratio will be measured using the Minispir 2 spirometer by Medical International Research. This spirometer, classified as a Class II medical device (medium risk) by Health Canada, is a non-invasive tool for assessing respiratory function. It evaluates lung ventilation by determining the proportion of air exhaled in the first second relative to total forced vital capacity, providing key insights into airway obstruction and pulmonary function.

  From enrollment to the end of treatment at 4 weeks

Secondary Outcomes (1)

• Chest Circumference Measurement

  From enrollment to the end of treatment at 4 weeks

Study Arms (2)

experimental (TAVSS + conventional physiotherapy)

EXPERIMENTAL

TAVSS and conventional physiotherapy will be applied for a total of 10 sessions, three times a week. TAVSS application electrodes will be placed on the tragus and the inner and posterior surfaces of the concha in both the right and left outer ear. The stimulation will be delivered continuously for 20 minutes with a biphasic asymmetric waveform, a pulse duration of 300 microseconds, and a frequency of 25 hertz. Electrical stimulation will be increased in 0.1 mA increments until the perception threshold is reached. Individualized conventional physiotherapy protocols tailored to the specific needs of the patients in the experimental group will be administered by a physiotherapist for a total of 10 sessions, three times a week. The conventional physiotherapy interventions will generally include strengthening exercises, stretching exercises, proprioceptive neuromuscular facilitation, electrotherapy, balance exercises, fine motor exercises, active range of motion exercises (45 minutes).

Device: Transcutaneous Auricular Vagus Nerve Stimulation

control (sham TAVSS + conventional physiotherapy)

SHAM COMPARATOR

shamTAVSS and conventional physiotherapy will be applied for a total of 10 sessions, three times a week. TAVSS application electrodes will be placed on the tragus and the inner and posterior surfaces of the concha in both the right and left outer ear without any current. Individualized conventional physiotherapy protocols tailored to the specific needs of the patients in this group will be administered by a physiotherapist for a total of 10 sessions, three times a week. The conventional physiotherapy interventions will generally include strengthening exercises, stretching exercises, proprioceptive neuromuscular facilitation, electrotherapy, balance exercises, fine motor exercises, active range of motion exercises (45 minutes).

Device: Transcutaneous Auricular Vagus Nerve Stimulation

Interventions

Transcutaneous Auricular Vagus Nerve Stimulation DEVICE

TAVSS is an application system that uses an electrical transcutaneous stimulation device placed on the concha or tragus of the ear. Functional Magnetic Resonance Imaging studies have shown that stimulation of these areas activates the ipsilateral nucleus tractus solitarius (NTS) via vagal projections to the brainstem and forebrain. Unlike cervical vagus nerve stimulation, TAVSS utilizes a physiological pathway to activate the NTS and the dorsal motor nucleus, which subsequently sends impulses bilaterally to the heart surface via efferent cervical vagus nerves. Therefore, this technique eliminates the possibility of directly and asymmetrically stimulating cardiac motor efferent fibers, which could lead to adverse cardiac events. TAVSS combines advantageous qualities such as being non-invasive, cost-effective, convenient, and efficient.

control (sham TAVSS + conventional physiotherapy); experimental (TAVSS + conventional physiotherapy)

Eligibility Criteria

• Age: 40 Years - 80 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Being a chronic stroke patient with an ischemic or hemorrhagic stroke diagnosis made 1-3 years ago
• Having been diagnosed with stroke for the first time
• Ability to understand and follow simple verbal instructions
• Being between the ages of 40 and 80
• No conditions affecting perioral muscles, such as facial paralysis or swallowing disorders
• No visual, auditory, or communication problems
• No cardiopulmonary disorders
• No additional neurological, cardiovascular, orthopedic, or similar conditions causing balance problems
• Mini Mental State Examination (MMSE) score ≥24
• No surgical operations or Botox applications in the last 6 months
• Scoring 2 or below on the Modified Ashworth Scale

You may not qualify if:

• Presence of infection, ulcer, or scar on the auricle
• Metallic implants in the skull, hypersensitivity, injury, or inflammation inside the ear
• Chronic pulmonary and/or cardiac diseases
• Resting heart rate below 60 beats per minute
• Devices such as pacemakers or cochlear implants
• Uncontrolled hypertension
• Chronic obstructive pulmonary disease (COPD) or asthma unrelated to stroke
• History of surgical operation or Botox application within the last 6 months
• Presence of aphasia, apraxia, or neglect syndrome
• History of 2 or more strokes (SVO)
• Comorbid conditions affecting respiratory functions (e.g., Multiple Sclerosis, Parkinson's, spinal cord injury, contractures, deformities after fractures, active upper or lower respiratory infections, etc.)
• Lack of cooperation

Sponsors & Collaborators

• Fenerbahce University: lead

Study Sites (1)

Mediworld Medical Center Physical Therapy and Rehabilitation Department

Istanbul, 34040, Turkey (Türkiye)

RECRUITING

MeSH Terms

Conditions

Hemiplegia; Respiratory Aspiration

Condition Hierarchy (Ancestors)

Paralysis; Neurologic Manifestations; Nervous System Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Respiration Disorders; Respiratory Tract Diseases; Pathologic Processes

Study Officials

• Burcu AKKURT

  Fenerbahce University

  STUDY DIRECTOR

Central Study Contacts

Burcu AKKURT, Ph.D.

CONTACT

+9005536046713; burcu.akkurt@fbu.edu.tr

Mustafa AKKURT, Ph.D.

CONTACT

+9005055762579; ferit.akkurt@fbu.edu.tr

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: The participants will not be aware of which group they are assigned to. The treatment protocols, evaluations, and statistical calculations will be carried out by three separate investigators.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Model Details: Two groups with experimental group (TAVSS + conventional physiotherapy) and sham TAVSS + (conventional physiotherapy)

Study Record Dates

• First Submitted: January 21, 2025
• First Posted: January 27, 2025
• Study Start: August 5, 2025
• Primary Completion: August 26, 2025
• Study Completion (Estimated): July 30, 2027
• Last Updated: April 1, 2026

Record last verified: 2026-03

Locations

TU (1)