| Unique ID issued by UMIN | UMIN000063327 |
|---|---|
| Receipt number | R000071745 |
| Scientific Title | Investigation of Anatomical Factors Determining Responsiveness to Transcutaneous Auricular Vagus Nerve Stimulation and Development of Individualized Stimulation Methods |
| Date of disclosure of the study information | 2026/10/31 |
| Last modified on | 2026/10/18 01:22:50 |
Study of Ear Anatomical Features Related to the Response to Vagus Nerve Stimulation of the Ear
Study of Ear Anatomy and Response to Vagus Nerve Stimulation
Investigation of Anatomical Factors Determining Responsiveness to Transcutaneous Auricular Vagus Nerve Stimulation and Development of Individualized Stimulation Methods
Anatomical Factors in taVNS
| Japan |
ear disease
| Oto-rhino-laryngology |
Others
NO
Using temporal bone CT images, we will evaluate anatomical features related to the course of the auricular branch of the vagus nerve (Arnold's nerve), including the tympanomastoid fissure and external auditory canal morphology, and analyze their associations with changes in pupil diameter induced by transcutaneous auricular vagus nerve stimulation (taVNS) as the primary outcome. Furthermore, we will investigate the associations of these anatomical features with the sensory and pain thresholds for taVNS, the presence or absence of the Arnold reflex (cough reflex), and changes in subjective symptoms such as tinnitus, dizziness, and aural fullness. Through these analyses, we aim to identify anatomical factors that determine responsiveness to taVNS and establish imaging-based markers that may contribute to the development of individualized neuromodulation therapy.
Others
To explore the associations between physiological responses and stimulation thresholds to transcutaneous auricular vagus nerve stimulation (taVNS) and anatomical features, and to identify imaging-based markers that may contribute to the development of individualized stimulation methods.
Exploratory
Change in pupil diameter before and after transcutaneous auricular vagus nerve stimulation (taVNS)
1.Sensory and pain thresholds for transcutaneous auricular vagus nerve stimulation (taVNS)
2.Presence or absence of the Arnold reflex (cough reflex) induced by taVNS
3.Changes in subjective symptoms, including tinnitus, dizziness, and aural fullness, before and after taVNS
4.Associations between anatomical features related to the course of Arnold's nerve, including the tympanomastoid fissure and external auditory canal morphology, assessed using temporal bone CT, and changes in pupil diameter induced by taVNS
5.Associations between anatomical features and sensory and pain thresholds for taVNS and the presence or absence of the Arnold reflex
Interventional
Single arm
Non-randomized
Open -no one is blinded
Uncontrolled
NO
NO
Institution is not considered as adjustment factor.
NO
No need to know
1
Treatment
| Device,equipment |
Transcutaneous auricular vagus nerve stimulation (taVNS) will be applied to the left auricle, targeting the tragus or cymba conchae. Constant-current stimulation will be delivered at a frequency of 20-25 Hz with a pulse width of 200-500 us. The stimulation intensity will be set below the participant's pain threshold and at a comfortable level without discomfort. Stimulation will be performed for 5-30 minutes, and pupil diameter will be measured before and after stimulation. Stimulation intensity, sensory and pain thresholds, the Arnold reflex (cough reflex), and changes in subjective symptoms will also be assessed.
| 18 | years-old | <= |
| 70 | years-old | >= |
Male and Female
Individuals aged 18 to 70 years
Individuals who have received sufficient explanation of the study and have provided written informed consent
Individuals with available temporal bone CT images
Healthy individuals or patients with tinnitus, dizziness, or aural fullness
Individuals with a cardiac pacemaker or implantable cardioverter-defibrillator
Individuals who are pregnant or may be pregnant
Individuals with active ear disease in the left ear, such as otitis externa or otitis media
Individuals with wounds or skin disorders of the left auricle
Individuals with a history of epilepsy
Individuals with severe cardiovascular disease
Individuals with severe psychiatric disorders
Individuals currently taking medications that significantly affect autonomic nervous system function
Individuals deemed unsuitable for participation by the principal investigator
40
| 1st name | Noriko |
| Middle name | |
| Last name | Nagase |
Gifu University Graduate School of Medicine
Department of Otolaryngology-Head and Neck Surgery
501-1193
1-1, Yanagido, Gifu City, Gifu, 501-1193, Japan
058-230-6000
nagase.noriko.n3@f.gifu-u.ac.jp
| 1st name | Noriko |
| Middle name | |
| Last name | Nagase |
Gifu University Graduate School of Medicine
Department of Otolaryngology-Head and Neck Surgery
501-1193
1-1, Yanagido, Gifu City, Gifu, 501-1193, Japan
058-230-6000
nagase.noriko.n3@f.gifu-u.ac.jp
Gifu University
Gifu University
Self funding
Japan
The ethics committee of Gifu University Graduate School of Medicine
1-1, Yanagido, Gifu City, Gifu, 501-1193, Japan
058-230-6059
rinri@t.gifu-u.ac.jp
NO
岐阜大学医学部附属病院(岐阜県)
| 2026 | Year | 10 | Month | 31 | Day |
Unpublished
Preinitiation
| 2026 | Year | 08 | Month | 20 | Day |
| 2026 | Year | 11 | Month | 01 | Day |
| 2029 | Year | 03 | Month | 31 | Day |
| 2026 | Year | 10 | Month | 18 | Day |
| 2026 | Year | 10 | Month | 18 | Day |
Value
https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000071745