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Zou N, Zhou Q, Zhang Y, Xin C, Wang Y, Claire-Marie R, Rong P, Gao G, Li S. Transcutaneous auricular vagus nerve stimulation as a novel therapy connecting the central and peripheral systems: a review. Int J Surg 2024; 110:4993-5006. [PMID: 38729100 PMCID: PMC11326027 DOI: 10.1097/js9.0000000000001592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 04/26/2024] [Indexed: 05/12/2024]
Abstract
Currently, clinical practice and scientific research mostly revolve around a single disease or system, but the single disease-oriented diagnostic and therapeutic paradigm needs to be revised. This review describes how transcutaneous auricular vagus nerve stimulation (taVNS), a novel non-invasive neuromodulation approach, connects the central and peripheral systems of the body. Through stimulation of the widely distributed vagus nerve from the head to the abdominal cavity, this therapy can improve and treat central system disorders, peripheral system disorders, and central-peripheral comorbidities caused by autonomic dysfunction. In the past, research on taVNS has focused on the treatment of central system disorders by modulating this brain nerve. As the vagus nerve innervates the heart, lungs, liver, pancreas, gastrointestinal tract, spleen and other peripheral organs, taVNS could have an overall modulatory effect on the region of the body where the vagus nerve is widespread. Based on this physiological basis, the authors summarize the existing evidence of the taVNS ability to regulate cardiac function, adiposity, glucose levels, gastrointestinal function, and immune function, among others, to treat peripheral system diseases, and complex diseases with central and peripheral comorbidities. This review shows the successful examples and research progress of taVNS using peripheral neuromodulation mechanisms from more perspectives, demonstrating the expanded scope and value of taVNS to provide new ideas and approaches for holistic therapy from both central and peripheral perspectives.
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Affiliation(s)
- Ningyi Zou
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences
| | - Qing Zhou
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences
| | - Yuzhengheng Zhang
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences
| | - Chen Xin
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences
| | - Yifei Wang
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences
| | | | - Peijing Rong
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences
| | - Guojian Gao
- Graduate School, China Academy of Chinese Medical Sciences, Beijing, China
| | - Shaoyuan Li
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences
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Kang D, Choi Y, Lee J, Park E, Kim IY. Analysis of taVNS effects on autonomic and central nervous systems in healthy young adults based on HRV, EEG parameters. J Neural Eng 2024; 21:046012. [PMID: 38941990 DOI: 10.1088/1741-2552/ad5d16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 06/28/2024] [Indexed: 06/30/2024]
Abstract
Objective.Transcutaneous auricular vagus nerve stimulation (taVNS), a non-invasive method of stimulating the vagus nerve, simultaneously affects the autonomic nervous system (ANS) and central nervous system (CNS) through efferent and afferent pathways. The purpose of this study is to analyze the effect of taVNS on the ANS and CNS through heart rate variability (HRV) and electroencephalography (EEG) parameters of identified responders.Approach.Two sets of data were collected from each of 10 healthy adult male subjects in their 20 s, and five HRV parameters from the time domain (RMSSD, pNN50, pNN30, pNN20, ppNNx) and two EEG parameters (power of alpha band, power of delta band) were extracted.Main results.Based on pNN50, responders to taVNS were identified; among them, pNN50 (p= 0.0041) and ppNNx (p= 0.0037) showed significant differences before and after taVNS. At the same time, for alpha power and delta power of EEG, significant difference (p< 0.05) was observed in most channels after taVNS compared to before stimulation.Significance.This study demonstrated the validity of identifying responders using pNN50 and the influence of taVNS on both the ANS and CNS. We conclude that taVNS can be used to treat a variety of diseases and as a tool to help control the ANS and CNS.
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Affiliation(s)
- Donghun Kang
- Department of Biomedical Engineering, Hanyang University, Seoul, Republic of Korea
| | - Youngseok Choi
- Department of Electronic Engineering, Hanyang University, Seoul, Republic of Korea
| | - Jongshill Lee
- Department of Biomedical Engineering, Hanyang University, Seoul, Republic of Korea
| | - Eunkyoung Park
- Department of Biomedical Engineering, Soonchunhyang University, Asan, Republic of Korea
| | - In Young Kim
- Department of Biomedical Engineering, Hanyang University, Seoul, Republic of Korea
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Wu Q, Wang J, Han D, Qian L, Hu H, Gao H. Current status of transcutaneous auricular vagus nerve stimulation for tinnitus: a narrative review of modern research. Front Neurosci 2024; 18:1405310. [PMID: 39027324 PMCID: PMC11254635 DOI: 10.3389/fnins.2024.1405310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Accepted: 06/25/2024] [Indexed: 07/20/2024] Open
Abstract
Tinnitus, characterized by phantom sound perception, is a highly disruptive disorder lacking definitive and effective treatments. Its intricate neural mechanisms are not fully understood. Transcutaneous auricular vagus nerve stimulation (taVNS) has demonstrated potential as a substitute or supplementary treatment by activating central vagal pathways. However, standardized therapeutic protocols and objective tests to assess efficacy are lacking. Therefore, taVNS shows promise as a therapy for tinnitus, and treatment protocols should be optimized in future clinical trials.
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Affiliation(s)
- Qiqi Wu
- Department of Acupuncture, Moxibustion and Massage, Wenzhou Central Hospital, Wenzhou, China
| | - Jiawei Wang
- The Third Clinical College of Zhejiang Chinese Medical University, Hangzhou, China
| | - Dexiong Han
- Department of Acupuncture and Moxibustion, The Third Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, China
| | - Lala Qian
- Department of Acupuncture, Moxibustion and Massage, Wenzhou Central Hospital, Wenzhou, China
| | - Hantong Hu
- Department of Acupuncture and Moxibustion, The Third Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, China
| | - Hong Gao
- Department of Acupuncture and Moxibustion, The Third Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, China
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Gerges ANH, Graetz L, Hillier S, Uy J, Hamilton T, Opie G, Vallence AM, Braithwaite FA, Chamberlain S, Hordacre B. Transcutaneous auricular vagus nerve stimulation modifies cortical excitability in middle-aged and older adults. Psychophysiology 2024:e14584. [PMID: 38602055 DOI: 10.1111/psyp.14584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 03/23/2024] [Accepted: 03/26/2024] [Indexed: 04/12/2024]
Abstract
There is a growing interest in the clinical application of transcutaneous auricular vagus nerve stimulation (taVNS). However, its effect on cortical excitability, and whether this is modulated by stimulation duration, remains unclear. We evaluated whether taVNS can modify excitability in the primary motor cortex (M1) in middle-aged and older adults and whether the stimulation duration moderates this effect. In addition, we evaluated the blinding efficacy of a commonly reported sham method. In a double-blinded randomized cross-over sham-controlled study, 23 healthy adults (mean age 59.91 ± 6.87 years) received three conditions: active taVNS for 30 and 60 min and sham for 30 min. Single and paired-pulse transcranial magnetic stimulation was delivered over the right M1 to evaluate motor-evoked potentials. Adverse events, heart rate and blood pressure measures were evaluated. Participant blinding effectiveness was assessed via guesses about group allocation. There was an increase in short-interval intracortical inhibition (F = 7.006, p = .002) and a decrease in short-interval intracortical facilitation (F = 4.602, p = .014) after 60 min of taVNS, but not 30 min, compared to sham. taVNS was tolerable and safe. Heart rate and blood pressure were not modified by taVNS (p > .05). Overall, 96% of participants detected active stimulation and 22% detected sham stimulation. taVNS modifies cortical excitability in M1 and its effect depends on stimulation duration in middle-aged and older adults. taVNS increased GABAAergic inhibition and decreased glutamatergic activity. Sham taVNS protocol is credible but there is an imbalance in beliefs about group allocation.
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Affiliation(s)
- Ashraf N H Gerges
- Innovation, Implementation and Clinical Translation (IIMPACT) in Health, Allied Health and Human Performance, University of South Australia, Adelaide, South Australia, Australia
| | - Lynton Graetz
- College of Education, Psychology and Social Work, Flinders University, Adelaide, South Australia, Australia
| | - Susan Hillier
- Innovation, Implementation and Clinical Translation (IIMPACT) in Health, Allied Health and Human Performance, University of South Australia, Adelaide, South Australia, Australia
| | - Jeric Uy
- Innovation, Implementation and Clinical Translation (IIMPACT) in Health, Allied Health and Human Performance, University of South Australia, Adelaide, South Australia, Australia
| | - Taya Hamilton
- Perron Institute for Neurological and Translational Science, Perth, Western Australia, Australia
- Centre for Neuromuscular and Neurological Disorders, University of Western Australia, Perth, Western Australia, Australia
| | - George Opie
- Discipline of Physiology, School of Biomedicine, The University of Adelaide, Adelaide, South Australia, Australia
| | - Ann-Maree Vallence
- School of Psychology, College of Health and Education, Murdoch University, Perth, Western Australia, Australia
- Centre for Healthy Ageing, Health Futures Institute, Murdoch University, Perth, Western Australia, Australia
| | - Felicity A Braithwaite
- Innovation, Implementation and Clinical Translation (IIMPACT) in Health, Allied Health and Human Performance, University of South Australia, Adelaide, South Australia, Australia
| | - Saran Chamberlain
- Innovation, Implementation and Clinical Translation (IIMPACT) in Health, Allied Health and Human Performance, University of South Australia, Adelaide, South Australia, Australia
| | - Brenton Hordacre
- Innovation, Implementation and Clinical Translation (IIMPACT) in Health, Allied Health and Human Performance, University of South Australia, Adelaide, South Australia, Australia
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Gerges ANH, Williams EER, Hillier S, Uy J, Hamilton T, Chamberlain S, Hordacre B. Clinical application of transcutaneous auricular vagus nerve stimulation: a scoping review. Disabil Rehabil 2024:1-31. [PMID: 38362860 DOI: 10.1080/09638288.2024.2313123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 01/27/2024] [Indexed: 02/17/2024]
Abstract
PURPOSE Transcutaneous auricular vagus nerve stimulation (taVNS) is an emerging non-invasive neuromodulation therapy. This study aimed to explore the therapeutic use of taVNS, optimal stimulation parameters, effective sham protocols, and safety. METHODS A scoping review was conducted. Five databases and grey literature were searched. The data extracted included stimulation parameters, adverse events (AEs), and therapeutic effects on clinical outcomes. RESULTS 109 studies were included. taVNS was used across 21 different clinical populations, most commonly in psychiatric, cardiac, and neurological disorders. Overall, 2,214 adults received active taVNS and 1,017 received sham taVNS. Reporting of stimulation parameters was limited and inconsistent. taVNS appeared to have a favourable therapeutic effect across a wide range of clinical populations with varied parameters. Three sham protocols were reported but their effectiveness was documented in only two of the 54 sham-controlled studies. Most reported adverse events were localised to stimulation site. CONCLUSION There is growing evidence for taVNS therapeutic effect. taVNS appears safe and tolerable. Sham protocols need evaluation. Standardised and comprehensive reporting of both stimulation parameters and adverse events is required. Two different questionnaires have been proposed to evaluate adverse events and the effectiveness of sham methods in blinding participants.
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Affiliation(s)
- Ashraf N H Gerges
- Innovation, Implementation and Clinical Translation (IIMPACT) in Health, Allied Health and Human Performance, University of South Australia, Adelaide, Australia
| | - Ellen E R Williams
- School of Biomedicine, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, Australia
- Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, Australia
| | - Susan Hillier
- Innovation, Implementation and Clinical Translation (IIMPACT) in Health, Allied Health and Human Performance, University of South Australia, Adelaide, Australia
| | - Jeric Uy
- Innovation, Implementation and Clinical Translation (IIMPACT) in Health, Allied Health and Human Performance, University of South Australia, Adelaide, Australia
| | - Taya Hamilton
- Perron Institute for Neurological and Translational Science, Perth, Australia
- Fourier Intelligence International Pte Ltd., Global Headquarters, Singapore, Singapore
| | - Saran Chamberlain
- Innovation, Implementation and Clinical Translation (IIMPACT) in Health, Allied Health and Human Performance, University of South Australia, Adelaide, Australia
| | - Brenton Hordacre
- Innovation, Implementation and Clinical Translation (IIMPACT) in Health, Allied Health and Human Performance, University of South Australia, Adelaide, Australia
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Prott LS, Spitznagel FA, Hugger A, Langner R, Gierthmühlen PC, Gierthmühlen M. Transcutaneous auricular vagus nerve stimulation for the treatment of myoarthropatic symptoms in patients with craniomandibular dysfunction - a protocol for a randomized and controlled pilot trial. Pilot Feasibility Stud 2024; 10:27. [PMID: 38331976 PMCID: PMC10851508 DOI: 10.1186/s40814-024-01447-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 01/12/2024] [Indexed: 02/10/2024] Open
Abstract
BACKGROUND Temporomandibular disorders (TMD) are a collective term for pain and dysfunction of the masticatory muscles and the temporomandibular joints. The most common types of TMD are pain-related, which may impact the psychological behavior and quality of life. Currently, the most popular methods for the treatment of TMD patients are occlusal splint therapy, often in combination with physical- and/or pharmacotherapy. However, due to the complexity of etiology, the treatment of chronic TMD remains a challenge. Recently, CE-certified systems for non-invasive VNS (transcutaneous auricular vagus nerve stimulation, taVNS) have become available and show positive effects in the treatment of chronic pain conditions, like migraine or fibromyalgia, with which TMD shares similarities. Therefore, it is the main purpose of the study to evaluate the feasibility of daily taVNS against chronic TMD and to assess whether there is an improvement in pain severity, quality of life, and kinetic parameters. METHODS This study is designed as a single-blinded, double-arm randomized controlled trial (RCT) in a 1:1 allocation ratio. Twenty adult patients with chronical TMD symptoms will be enrolled and randomized to stimulation or sham group. In the stimulation group, taVNS is performed on the left tragus (25 Hz, pulse width 250 µs, 28 s on/32 s off, 4 h/day). The sham group will receive no stimulation via a non-functional identical-looking electrode. Validated questionnaire data and clinical parameters will be collected at the beginning of the study and after 4 and 8 weeks. The compliance of a daily taVNS of patients with chronical TMD will be evaluated via a smartphone app recording daily stimulation time and average intensity. Additionally, the treatment impact on pain severity and quality of life will be assessed with different questionnaires, and the effect on the mandibular mobility and muscle activity will be analyzed. DISCUSSION This is the first clinical trial to assess the feasibility of taVNS in patients with chronic TMD symptoms. If taVNS improves the symptoms of TMD, it will be a significant gain in quality of life for these chronic pain patients. The results of this pilot study will help to determine the feasibility of a large-scale RCT. TRIAL REGISTRATION This study has been registered in the DRKS database (DRKS00029724).
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Affiliation(s)
- Lea S Prott
- Department of Prosthodontics, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Moorenstraße 5, Düsseldorf, 40225, Germany.
| | - Frank A Spitznagel
- Department of Prosthodontics, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Moorenstraße 5, Düsseldorf, 40225, Germany
| | - Alfons Hugger
- Department of Prosthodontics, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Moorenstraße 5, Düsseldorf, 40225, Germany
| | - Robert Langner
- Institute of Systems Neuroscience, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, Moorenstraße 5, Düsseldorf, 40225, Germany
- Institute of Neuroscience and Medicine (INM-7: Brain and Behaviour), Research Centre Jülich, Jülich, 52425, Germany
| | - Petra C Gierthmühlen
- Department of Prosthodontics, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Moorenstraße 5, Düsseldorf, 40225, Germany
| | - Mortimer Gierthmühlen
- Department of Neurosurgery, University Medical Center Knappschaftskrankenhaus Bochum, In Der Schornau 23-25, Bochum, 44892, Germany
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Cesario E, Larionova N, Scalo J, Tepe V, Esquivel C, Spear SA. Battlefield Acupuncture as a Treatment Option for Chronic Tinnitus: A Pilot Study. Mil Med 2023; 188:3295-3301. [PMID: 37522358 DOI: 10.1093/milmed/usad265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 06/23/2023] [Accepted: 07/20/2023] [Indexed: 08/01/2023] Open
Abstract
INTRODUCTION There is no cure for tinnitus, which is a highly prevalent condition in service members and veterans. Battlefield acupuncture (BFA) can be used to manage pain and stress-related symptoms. We investigated BFA as a safe, low-cost treatment for tinnitus perception and coping in eight chronic tinnitus patients who were followed for 6 months after two BFA treatments to identify changes in tinnitus severity or impact. MATERIALS AND METHODS Patients completed case history, Tinnitus Screener, Tinnitus Functional Index (TFI), Tinnitus Reaction Questionnaire (TRQ), and Hospital Anxiety and Depression Scale (HADS) questionnaires at baseline, at two BFA treatment sessions (2 weeks apart), and at four follow-up sessions (at 1, 2, 4 and 6 months after treatment). Questionnaire score changes were evaluated over time by using restricted maximum likelihood hierarchical regression modeling from baseline to 1-, 2-, 4-, and 6-month post-treatment follow-ups. RESULTS TFI and TRQ group means were both significantly reduced at 1 month after treatment, and these reductions persisted through the 2- and 4-month follow-ups. The TRQ group mean remained significantly reduced after 6 months. CONCLUSIONS Findings from eight chronic tinnitus sufferers who received two BFA treatment sessions are reported here, suggesting at least short-term treatment benefits observed as reductions in tinnitus-related psychological distress and impact. Although these findings are constrained by the study's small sample size and limited treatment period, its findings underscore the need for further research to determine the potential benefits of BFA for individuals who suffer from chronic tinnitus. Future research should consider the possibility of more lasting benefits through extended BFA treatment, with a comparison of BFA treatment against other treatment methods.
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Affiliation(s)
- Erin Cesario
- zCore Business Solutions, Inc., Round Rock, TX 78681, USA
- Department of Defense Hearing Center of Excellence, DHA/R&E/HCE, JBSA-Lackland, TX 78236, USA
| | - Nicole Larionova
- zCore Business Solutions, Inc., Round Rock, TX 78681, USA
- Department of Defense Hearing Center of Excellence, DHA/R&E/HCE, JBSA-Lackland, TX 78236, USA
| | - Julieta Scalo
- zCore Business Solutions, Inc., Round Rock, TX 78681, USA
- Department of Defense Hearing Center of Excellence, DHA/R&E/HCE, JBSA-Lackland, TX 78236, USA
| | - Victoria Tepe
- Department of Defense Hearing Center of Excellence, DHA/R&E/HCE, JBSA-Lackland, TX 78236, USA
- The Geneva Foundation, Tacoma, WA 98402, USA
| | - Carlos Esquivel
- Department of Defense Hearing Center of Excellence, DHA/R&E/HCE, JBSA-Lackland, TX 78236, USA
| | - Samuel A Spear
- Department of Defense Hearing Center of Excellence, DHA/R&E/HCE, JBSA-Lackland, TX 78236, USA
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Rudolph M, Schaaf H. [Stress and suffering from tinnitus-a psychosomatic approach]. HNO 2023; 71:632-639. [PMID: 37580418 DOI: 10.1007/s00106-023-01340-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/21/2023] [Indexed: 08/16/2023]
Abstract
The development and processing of tinnitus is often associated with stress. There are many publications on this subject that have investigated possible connections between stress perception and tinnitus symptoms using different concepts and different test inventories. In this review, we present the development of Selye's concept of stress using the transactional stress model of Lazarus and its transfer to patients suffering from tinnitus. The literature evaluating the influence of stress on tinnitus symptoms with partly very different concepts is critically reviewed. For example, it is suggested that psychosocial stress has the same likelihood of contributing to tinnitus as noise in the workplace. However, what is striking in previous studies is that "stress" as an influencing variable could not be clearly verified with suitable psychometric test procedures or that no significant differences-to very different comparison groups-could be shown. Finally, a possible therapeutic approach to stress management is outlined.
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Affiliation(s)
- Matthias Rudolph
- Abteilung für Psychosomatik, Mittelrhein-Klinik Bad Salzig, Salzbornstraße 14, 56154, Boppard - Bad Salzig, Deutschland.
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Graham AS, Ben-Azu B, Tremblay MÈ, Torre P, Senekal M, Laughton B, van der Kouwe A, Jankiewicz M, Kaba M, Holmes MJ. A review of the auditory-gut-brain axis. Front Neurosci 2023; 17:1183694. [PMID: 37600010 PMCID: PMC10435389 DOI: 10.3389/fnins.2023.1183694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 07/17/2023] [Indexed: 08/22/2023] Open
Abstract
Hearing loss places a substantial burden on medical resources across the world and impacts quality of life for those affected. Further, it can occur peripherally and/or centrally. With many possible causes of hearing loss, there is scope for investigating the underlying mechanisms involved. Various signaling pathways connecting gut microbes and the brain (the gut-brain axis) have been identified and well established in a variety of diseases and disorders. However, the role of these pathways in providing links to other parts of the body has not been explored in much depth. Therefore, the aim of this review is to explore potential underlying mechanisms that connect the auditory system to the gut-brain axis. Using select keywords in PubMed, and additional hand-searching in google scholar, relevant studies were identified. In this review we summarize the key players in the auditory-gut-brain axis under four subheadings: anatomical, extracellular, immune and dietary. Firstly, we identify important anatomical structures in the auditory-gut-brain axis, particularly highlighting a direct connection provided by the vagus nerve. Leading on from this we discuss several extracellular signaling pathways which might connect the ear, gut and brain. A link is established between inflammatory responses in the ear and gut microbiome-altering interventions, highlighting a contribution of the immune system. Finally, we discuss the contribution of diet to the auditory-gut-brain axis. Based on the reviewed literature, we propose numerous possible key players connecting the auditory system to the gut-brain axis. In the future, a more thorough investigation of these key players in animal models and human research may provide insight and assist in developing effective interventions for treating hearing loss.
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Affiliation(s)
- Amy S. Graham
- Imaging Sciences, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
- Department of Human Biology, Division of Biomedical Engineering, University of Cape Town, Cape Town, South Africa
| | - Benneth Ben-Azu
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Department of Pharmacology, Faculty of Basic Medical Sciences, College of Health Sciences, Delta State University, Abraka, Delta State, Nigeria
| | - Marie-Ève Tremblay
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Département de Médecine Moléculaire, Université Laval, Québec City, QC, Canada
- Axe Neurosciences, Centre de Recherche du CHU de Québec, Université Laval, Quebec City, QC, Canada
- Neurology and Neurosurgery Department, McGill University, Montreal, QC, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
- Centre for Advanced Materials and Related Technology (CAMTEC), University of Victoria, Victoria, BC, Canada
- Institute for Aging and Lifelong Health, University of Victoria, Victoria, BC, Canada
| | - Peter Torre
- School of Speech, Language, and Hearing Sciences, San Diego State University, San Diego, CA, United States
| | - Marjanne Senekal
- Department of Human Biology, Division of Physiological Sciences, University of Cape Town, Cape Town, South Africa
| | - Barbara Laughton
- Family Clinical Research Unit, Department of Pediatrics and Child Health, Stellenbosch University, Cape Town, South Africa
| | - Andre van der Kouwe
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, United States
- Department of Radiology, Harvard Medical School, Boston, MA, United States
| | - Marcin Jankiewicz
- Imaging Sciences, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
- Department of Human Biology, Division of Biomedical Engineering, University of Cape Town, Cape Town, South Africa
| | - Mamadou Kaba
- Department of Pathology, Division of Medical Microbiology, University of Cape Town, Cape Town, South Africa
| | - Martha J. Holmes
- Imaging Sciences, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
- Department of Human Biology, Division of Biomedical Engineering, University of Cape Town, Cape Town, South Africa
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
- ImageTech, Simon Fraser University, Surrey, BC, Canada
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Fernández-Hernando D, Fernández-de-Las-Peñas C, Machado-Martín A, Angulo-Díaz-Parreño S, García-Esteo FJ, Mesa-Jiménez JA. Effects of Non-Invasive Neuromodulation of the Vagus Nerve for Management of Tinnitus: A Systematic Review with Meta-Analysis. J Clin Med 2023; 12:jcm12113673. [PMID: 37297867 DOI: 10.3390/jcm12113673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 05/16/2023] [Accepted: 05/23/2023] [Indexed: 06/12/2023] Open
Abstract
BACKGROUND Tinnitus is the perception of sound in the absence of actual external stimuli. Other associated symptoms include frustration, annoyance, anxiety, depression, stress, cognitive dysfunction, insomnia, or emotional exhaustion. OBJECTIVE In this study, we aimed to conduct a systematic review and meta-analysis on the effectiveness of the non-invasive neuromodulation of the vagus nerve in patients with tinnitus. METHODS Six databases were searched from their date of inception to 15 June 2022 to identify clinical trials in which at least one group received any form of non-invasive neuromodulation of the vagus nerve for tinnitus management, with outcomes based on annoyance and related disability. Data on participants, interventions, blinding strategies, assessment outcomes, and results were extracted by two reviewers. RESULTS The search identified 183 articles with five clinical trials eligible for inclusion in the review and four for the meta-analysis. The methodological quality scores ranged from 6 to 8 (mean: 7.3, SD: 0.8) points. The meta-analysis identified a significant positive effect on THI post-treatment for unilateral auricular stimulation (hg = 0.69, 95% CI 0.06, 1.32) or transcutaneous nerve stimulation (hg = 0.51, 95% CI 0.1, 0.9) compared with a comparative group. No effect on loudness intensity was observed. CONCLUSION The results of the meta-analysis suggest that the application of the non-invasive neuromodulation of the vagus nerve has a positive effect post-treatment in terms of related disability in patients with tinnitus, although its clinical relevance is low. No firm conclusions about the effect of the non-invasive neuromodulation of the vagus nerve on tinnitus are available based on the current literature.
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Affiliation(s)
- David Fernández-Hernando
- Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, 28660 Boadilla del Monte, Spain
| | - Cesar Fernández-de-Las-Peñas
- Department of Physical Therapy, Occupational Therapy, Physical Medicine and Rehabilitation, Universidad Rey Juan Carlos, 28922 Alcorcón, Spain
| | - Ana Machado-Martín
- Servicio de Otorrino-Laringología, Hospital Universitario Quiron Salud Pozuelo, Universidad Europea de Madrid, 28670 Madrid, Spain
| | | | - Francisco J García-Esteo
- Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, 28660 Boadilla del Monte, Spain
- Facultad de Medicina, Universidad San Pablo CEU, 28660 Madrid, Spain
| | - Juan A Mesa-Jiménez
- Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, 28660 Boadilla del Monte, Spain
- Facultad de Medicina, Universidad San Pablo CEU, 28660 Madrid, Spain
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11
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Mortimer G, Nadine H, Nina T, Kirsten S, Anke RS. Effect of transcutaneous auricular vagal nerve stimulation on the fatigue syndrome in patients with gastrointestinal cancers - FATIVA: a randomized, placebo-controlled pilot study protocol. Pilot Feasibility Stud 2023; 9:66. [PMID: 37087481 PMCID: PMC10121416 DOI: 10.1186/s40814-023-01289-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 03/30/2023] [Indexed: 04/24/2023] Open
Abstract
BACKGROUND Cancer-related fatigue (CRF) is defined as a "distressing, persistent, subjective sense of physical, emotional, and/or cognitive tiredness or exhaustion related to cancer or cancer treatment that is not proportional to recent activity and interferes with usual functioning." CRF is frequently observed in cancer patients even before the initiation of tumor therapy. Its cause is not clear, but in addition to primary effects of therapy, a tumor-induced elevated level of inflammatory cytokines may play a role. Transcutaneous auricular vagal nerve stimulation (taVNS) is a noninvasive way to activate central nervous pathways and modulate pain perception and the immune system. It has positive effects on autoimmune conditions and can also improve fatigue associated with Sjogren's syndrome. It is the main purpose of this feasibility study to investigate the feasibility of daily taVNS against CRF. Therefore, the stimulation protocol of the newly introduced smartphone app of the manufacturer is evaluated. Additionally, the effect taVNS on CRF and quality of life (QoL) shall be evaluated. METHODS Thirty adult patients with gastrointestinal tumors during or after treatment, relevant CRF (Hornheide questionnaire) and life expectancy > 1 year, are enrolled. Patients are randomized to treatment or sham arm and be informed that they will either feel the stimulation or not. Treatment group will receive left-sided tragus above-threshold stimulation with 25 Hz, 250 µs pulse width, and 28-s/32-s on/off paradigm for 4 h throughout the day for 4 weeks. Sham group will receive no stimulation via a nonfunctional electrode. A daily stimulation protocol with time and average intensity is automatically created by a smartphone app connected to the stimulator via Bluetooth®. Multidimensional Fatigue Inventory-20, Short-Form 36 and Beck Depression Inventory questionnaires will be filled out before and after 4 weeks of stimulation. DISCUSSION Primarily, the patients' daily stimulation time and intensity will be evaluated through the electronic protocol after 4 weeks. Secondarily, the effect of taVNS on cancer-related fatigue and QoL will be measured through the questionnaires. As taVNS seems to modulate inflammatory cytokines, this noninvasive method may - if accepted by the patients - be a promising adjunct in the treatment of cancer-related fatigue. TRIAL REGISTRATION The study was approved by local ethics committee (21-7395) and registered at the DRKS database (DRKS00027481).
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Affiliation(s)
- Gierthmuehlen Mortimer
- Department of Neurosurgery, University Medical Center Knappschaftskrankenhaus Bochum, In Der Schornau 23-25, 44892, Bochum, Germany.
| | - Höffken Nadine
- Department of Hematology, Oncology and Palliative Medicine, University Medical Center St. Josef-Hospital Bochum, Gudrunstrasse 56, 44791, Bochum, Germany
| | - Timmesfeld Nina
- Department of Medical Informatics, Biometry and Epidemiology, Ruhr-University Bochum, Universitaetsstrasse 150, 44801, Bochum, Germany
| | - Schmieder Kirsten
- Department of Neurosurgery, University Medical Center Knappschaftskrankenhaus Bochum, In Der Schornau 23-25, 44892, Bochum, Germany
| | - Reinacher-Schick Anke
- Department of Hematology, Oncology and Palliative Medicine, University Medical Center St. Josef-Hospital Bochum, Gudrunstrasse 56, 44791, Bochum, Germany
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12
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Chen S, Du M, Wang Y, Li Y, Tong B, Qiu J, Wu F, Liu Y. State of the art: non-invasive electrical stimulation for the treatment of chronic tinnitus. Ther Adv Chronic Dis 2023; 14:20406223221148061. [PMID: 36860934 PMCID: PMC9969452 DOI: 10.1177/20406223221148061] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 12/13/2022] [Indexed: 01/19/2023] Open
Abstract
Subjective tinnitus is the perception of sound in the absence of external stimulation. Neuromodulation is a novel method with promising properties for application in tinnitus management. This study sought to review the types of non-invasive electrical stimulation in tinnitus to provide the foothold for further research. PubMed, EMBASE, and Cochrane databases were searched for studies on the modulation of tinnitus by non-invasive electrical stimulation. Among the four forms of non-invasive electrical modulation, transcranial direct current stimulation, transcranial random noise stimulation, and transauricular vagus nerve stimulation yielded promising results, whereas the effect of transcranial alternating current stimulation in the treatment of tinnitus has not been confirmed. Non-invasive electrical stimulation can effectively suppress tinnitus perception in some patients. However, the heterogeneity in parameter settings leads to scattered and poorly replicated findings. Further high-quality studies are needed to identify optimal parameters to develop more acceptable protocols for tinnitus modulation.
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Affiliation(s)
- Shanwen Chen
- Department of Otorhinolaryngology–Head and Neck Surgery, The First Affiliated Hospital of Anhui Medical University, Hefei, P.R. China
| | - Maoshan Du
- Department of Otorhinolaryngology–Head and Neck Surgery, The First Affiliated Hospital of Anhui Medical University, Hefei, P.R. China
| | - Yang Wang
- Department of Otorhinolaryngology–Head and Neck Surgery, The First Affiliated Hospital of Anhui Medical University, Hefei, P.R. China
| | - Yifan Li
- Department of Otorhinolaryngology–Head and Neck Surgery, The First Affiliated Hospital of Anhui Medical University, Hefei, P.R. China
| | - Busheng Tong
- Department of Otorhinolaryngology–Head and Neck Surgery, The First Affiliated Hospital of Anhui Medical University, Hefei, P.R. China
| | - Jianxin Qiu
- Department of Otorhinolaryngology–Head and Neck Surgery, The First Affiliated Hospital of Anhui Medical University, Hefei, P.R. China
| | - Feihu Wu
- Department of Otorhinolaryngology–Head and Neck Surgery, The First Affiliated Hospital of Anhui University of Chinese Medicine, 117 Meishan Road, Hefei 230031, Anhui, P.R. China
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13
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Mazurek B, Hesse G, Sattel H, Kratzsch V, Lahmann C, Dobel C. S3 Guideline: Chronic Tinnitus : German Society for Otorhinolaryngology, Head and Neck Surgery e. V. (DGHNO-KHC). HNO 2022; 70:795-827. [PMID: 36227338 PMCID: PMC9581878 DOI: 10.1007/s00106-022-01207-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/20/2022] [Indexed: 11/16/2022]
Affiliation(s)
- Birgit Mazurek
- Tinnituszentrum, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany.
| | - Gerhard Hesse
- Tinnitus-Klinik, KH Bad Arolsen, Große Allee 50, 34454, Bad Arolsen, Germany.
- Universität Witten/Herdecke, Witten, Germany.
| | - Heribert Sattel
- Klinikum rechts der Isar, Klinik und Poliklinik für Psychosomatische Medizin und Psychotherapie, Technical University of Munich, Langerstr. 3, 81675, Munich, Germany
| | - Volker Kratzsch
- Abt. Hörbehinderung, Tinnitus und Schwindelerkrankungen, VAMED Rehaklinik Bad Grönenbach, Sebastian-Kneipp-Allee 3-5, 87730, Bad Grönenbach, Germany
| | - Claas Lahmann
- Klinik für Psychosomatische Medizin und Psychotherapie, Universitätsklinikum Freiburg, Hauptstr. 8, 79104, Freiburg, Germany
| | - Christian Dobel
- Klinik für Hals-, Nasen- und Ohrenheilkunde, Universitätsklinikum Jena, Am Klinikum 1, 07747, Jena, Germany
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14
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Wagner JL. The vagus nerve: current concepts in anaesthesia and ICU management. SOUTHERN AFRICAN JOURNAL OF ANAESTHESIA AND ANALGESIA 2022. [DOI: 10.36303/sajaa.2022.28.5.2811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- JL Wagner
- Department of Anaesthesiology, University of the Witwatersrand,
South Africa
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15
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Ylikoski J, Lehtimäki J, Pääkkönen R, Mäkitie A. Prevention and Treatment of Life-Threatening COVID-19 May Be Possible with Oxygen Treatment. Life (Basel) 2022; 12:754. [PMID: 35629421 PMCID: PMC9142938 DOI: 10.3390/life12050754] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 04/22/2022] [Accepted: 05/12/2022] [Indexed: 01/08/2023] Open
Abstract
Most SARS CoV-2 infections probably occur unnoticed or cause only cause a mild common cold that does not require medical intervention. A significant proportion of more severe cases is characterized by early neurological symptoms such as headache, fatigue, and impaired consciousness, including respiratory distress. These symptoms suggest hypoxia, specifically affecting the brain. The condition is best explained by primary replication of the virus in the nasal respiratory and/or the olfactory epithelia, followed by an invasion of the virus into the central nervous system, including the respiratory centers, either along a transneural route, through disruption of the blood-brain barrier, or both. In patients, presenting with early dyspnea, the primary goal of therapy should be the reversal of brain hypoxia as efficiently as possible. The first approach should be intermittent treatment with 100% oxygen using a tight oronasal mask or a hood. If this does not help within a few hours, an enclosure is needed to increase the ambient pressure. This management approach is well established in the hypoxia-related diseases in diving and aerospace medicine and preserves the patient's spontaneous breathing. Preliminary research evidence indicates that even a small elevation of the ambient pressure might be lifesaving. Other neurological symptoms, presenting particularly in long COVID-19, suggest imbalance of the autonomous nervous system, i.e., dysautonomia. These patients could benefit from vagal nerve stimulation.
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Affiliation(s)
- Jukka Ylikoski
- Department of Otorhinolaryngology—Head and Neck Surgery, University of Helsinki and Helsinki University Hospital, 00029 Helsinki, Finland; (J.Y.); (R.P.)
- Helsinki Ear Institute, 00420 Helsinki, Finland;
- Salustim Group Inc., 90440 Kempele, Finland
| | - Jarmo Lehtimäki
- Helsinki Ear Institute, 00420 Helsinki, Finland;
- Salustim Group Inc., 90440 Kempele, Finland
| | - Rauno Pääkkönen
- Department of Otorhinolaryngology—Head and Neck Surgery, University of Helsinki and Helsinki University Hospital, 00029 Helsinki, Finland; (J.Y.); (R.P.)
| | - Antti Mäkitie
- Department of Otorhinolaryngology—Head and Neck Surgery, University of Helsinki and Helsinki University Hospital, 00029 Helsinki, Finland; (J.Y.); (R.P.)
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16
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Transcutaneous vagus nerve stimulation in patients with attention-deficit/hyperactivity disorder: A viable option? PROGRESS IN BRAIN RESEARCH 2021; 264:171-190. [PMID: 34167655 DOI: 10.1016/bs.pbr.2021.03.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Individuals with attention-deficit/hyperactivity disorder (ADHD) suffer from a range of cognitive and behavioral problems that severely impair their educational and occupational attainment. ADHD symptoms have been linked to structural and functional changes within and between different brain regions, particularly the prefrontal cortex. At the system level, reduced availability of the neurotransmitters dopamine (DA) and norepinephrine (NE) but also γ-aminobutyric acid (GABA) have been repeatedly demonstrated. Recently, non-invasive brain stimulation (NIBS) techniques have been explored as treatment alternatives to alter dysfunctional activation patterns in specified brain areas or networks. In the current paper, we introduce transcutaneous vagus nerve stimulation (tVNS) as a systemic approach to directly affect NE and GABA neurotransmission. TVNS is a non-drug intervention with low risk and proven efficacy in improving cognitive particularly executive functions. It is easy to apply and therefore well-suited to provide home-based or mobile treatment options allowing a significant increase in treatment intensity and providing easier access to medical care for individuals who are unable to regularly visit a clinician. We describe in detail the underlying mechanisms of tVNS and current fields of application and discuss its potential as an adjuvant treatment for ADHD.
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Yakunina N, Nam EC. Direct and Transcutaneous Vagus Nerve Stimulation for Treatment of Tinnitus: A Scoping Review. Front Neurosci 2021; 15:680590. [PMID: 34122002 PMCID: PMC8193498 DOI: 10.3389/fnins.2021.680590] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 05/05/2021] [Indexed: 12/27/2022] Open
Abstract
Recent animal research has shown that vagus nerve stimulation (VNS) paired with sound stimuli can induce neural plasticity in the auditory cortex in a controlled manner. VNS paired with tones excluding the tinnitus frequency eliminated physiological and behavioral characteristics of tinnitus in noise-exposed rats. Several clinical trials followed and explored the effectiveness of VNS paired with sound stimuli for alleviating tinnitus in human subjects. Transcutaneous VNS (tVNS) has received increasing attention as a non-invasive alternative approach to tinnitus treatment. Several studies have also explored tVNS alone (not paired with sound stimuli) as a potential therapy for tinnitus. In this review, we discuss existing knowledge about direct and tVNS in terms of applicability, safety, and effectiveness in diminishing tinnitus symptoms in human subjects. This review includes all existing clinical and neuroimaging studies of tVNS alone or paired with acoustic stimulation in tinnitus patients and outlines the present limitations that must be overcome to maximize the potential of (t)VNS as a therapy for tinnitus.
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Affiliation(s)
- Natalia Yakunina
- Institute of Medical Science, School of Medicine, Kangwon National University, Chuncheon, South Korea
| | - Eui-Cheol Nam
- Department of Otolaryngology, School of Medicine, Kangwon National University, Chuncheon, South Korea
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