1
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Chan PYS, Lee LY, Davenport PW. Neural mechanisms of respiratory interoception. Auton Neurosci 2024; 253:103181. [PMID: 38696917 DOI: 10.1016/j.autneu.2024.103181] [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: 12/29/2023] [Revised: 04/03/2024] [Accepted: 04/22/2024] [Indexed: 05/04/2024]
Abstract
Respiratory interoception is one of the internal bodily systems that is comprised of different types of somatic and visceral sensations elicited by different patterns of afferent input and respiratory motor drive mediating multiple respiratory modalities. Respiratory interoception is a complex system, having multiple afferents grouped into afferent clusters and projecting into both discriminative and affective centers that are directly related to the behavioral assessment of breathing. The multi-afferent system provides a spectrum of input that result in the ability to interpret the different types of respiratory interceptive sensations. This can result in a response, commonly reported as breathlessness or dyspnea. Dyspnea can be differentiated into specific modalities. These respiratory sensory modalities lead to a general sensation of an Urge-to-Breathe, driven by a need to compensate for the modulation of ventilation that has occurred due to factors that have affected breathing. The multiafferent system for respiratory interoception can also lead to interpretation of the sensory signals resulting in respiratory related sensory experiences, including the Urge-to-Cough and Urge-to-Swallow. These behaviors are modalities that can be driven through the differentiation and integration of multiple afferent input into the respiratory neural comparator. Respiratory sensations require neural somatic and visceral interoceptive elements that include gated attention and detection leading to respiratory modality discrimination with subsequent cognitive decision and behavioral compensation. Studies of brain areas mediating cortical and subcortical respiratory sensory pathways are summarized and used to develop a model of an integrated respiratory neural network mediating respiratory interoception.
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Affiliation(s)
- Pei-Ying Sarah Chan
- Department of Occupational Therapy, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Department of Psychiatry, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan.
| | - Lu-Yuan Lee
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Paul W Davenport
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
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2
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Nakajima Y, Tsujimura T, Tsuji K, Magara J, Inoue M. Continuous electrical stimulation of superior laryngeal nerve inhibits initiation of swallowing in anesthetized rats. Neurosci Lett 2024; 825:137672. [PMID: 38360144 DOI: 10.1016/j.neulet.2024.137672] [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: 12/21/2023] [Revised: 02/05/2024] [Accepted: 02/06/2024] [Indexed: 02/17/2024]
Abstract
Pharyngeal electrical stimulation (PES) applies electrical stimulation to pharyngeal mucosa (PhM) and represents a useful approach to improve swallowing function in patients with dysphagia. To determine the optimal PES modality to treat dysphagia, the mechanism underlying the effects of PES on swallowing function must be elucidated. In this study, we evaluated how PES and electrical stimulation of the superior laryngeal nerve (SLN) modulate the initiation of swallowing in anesthetized rats. A swallow was evoked by electrical stimulation of the PhM, SLN, and nucleus of the solitary tract (nTS) and pharyngeal mechanical stimulation using a von Frey filament. A swallow was identified by electromyographic bursts in mylohyoid and thyrohyoid muscles. Bilateral SLN transection abolished the swallows evoked by PhM electrical stimulation. PhM and SLN electrical stimulation decreased swallowing frequency in a similar time-dependent manner. Intravenous administration of the GABAA receptor antagonist bicuculine did not affect the time-dependent change in swallowing frequency during SLN electrical stimulation. Continuous SLN electrical stimulation significantly inhibited pharyngeal mechanically and nTS-electrically evoked swallows compared with before and 5 min after stimulation. The present findings suggest that the SLN plays a primary role in PES-evoked swallows. Additionally, continuous SLN electrical stimulation inhibits the initiation of swallowing, and the modulation of central network associated with swallowing might be partially involved in this inhibition.
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Affiliation(s)
- Yuta Nakajima
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata 951-8514, Japan
| | - Takanori Tsujimura
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata 951-8514, Japan.
| | - Kojun Tsuji
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata 951-8514, Japan
| | - Jin Magara
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata 951-8514, Japan
| | - Makoto Inoue
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata 951-8514, Japan
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Mélotte E, Maudoux A, Panda R, Kaux JF, Lagier A, Herr R, Belorgeot M, Laureys S, Gosseries O. Links Between Swallowing and Consciousness: A Narrative Review. Dysphagia 2023; 38:42-64. [PMID: 35773497 DOI: 10.1007/s00455-022-10452-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 12/06/2021] [Indexed: 01/27/2023]
Abstract
This literature review explores a wide range of themes addressing the links between swallowing and consciousness. Signs of consciousness are historically based on the principle of differentiating reflexive from volitional behaviors. We show that the sequencing of the components of swallowing falls on a continuum of voluntary to reflex behaviors and we describe several types of volitional and non-volitional swallowing tasks. The frequency, speed of initiation of the swallowing reflex, efficacy of the pharyngeal phase of swallowing and coordination between respiration and swallowing are influenced by the level of consciousness during non-pathological modifications of consciousness such as sleep and general anesthesia. In patients with severe brain injury, the level of consciousness is associated with several components related to swallowing, such as the possibility of extubation, risk of pneumonia, type of feeding or components directly related to swallowing such as oral or pharyngeal abnormalities. Based on our theoretical and empirical analysis, the efficacy of the oral phase and the ability to receive exclusive oral feeding seem to be the most robust signs of consciousness related to swallowing in patients with disorders of consciousness. Components of the pharyngeal phase (in terms of abilities of saliva management) and evoked cough may be influenced by consciousness, but further studies are necessary to determine if they constitute signs of consciousness as such or only cortically mediated behaviors. This review also highlights the critical lack of tools and techniques to assess and treat dysphagia in patients with disorders of consciousness.
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Affiliation(s)
- Evelyne Mélotte
- Coma Science Group, GIGA-Consciousness, University of Liège, Liège, Belgium.
- Physical and Rehabilitation Medicine Department, University and University Hospital of Liège, Avenue de l'Hopital 1, 4000, Liège, Belgium.
- Centre du Cerveau², University Hospital of Liège, Liège, Belgium.
| | - Audrey Maudoux
- Sensation and Perception Research Group, GIGA, University and University Hospital of Liège, Liège, Belgium
- Otorhinolaryngology Head and Neck Surgery Department, Robert Debré University Hospital, APHP, Paris, France
| | - Rajanikant Panda
- Coma Science Group, GIGA-Consciousness, University of Liège, Liège, Belgium
| | - Jean-François Kaux
- Physical and Rehabilitation Medicine Department, University and University Hospital of Liège, Avenue de l'Hopital 1, 4000, Liège, Belgium
| | - Aude Lagier
- Otorhinolaryngology Head and Neck Surgery Department, University Hospital of Liège, Liège, Belgium
| | - Roxanne Herr
- Department of Speech and Language Pathology, Faculty of Medicine, University of Strasbourg, Strasbourg, France
| | - Marion Belorgeot
- Physical and Rehabilitation Medicine Department, University Hospital of Nîmes, Nîmes, France
| | - Steven Laureys
- Coma Science Group, GIGA-Consciousness, University of Liège, Liège, Belgium
- Centre du Cerveau², University Hospital of Liège, Liège, Belgium
| | - Olivia Gosseries
- Coma Science Group, GIGA-Consciousness, University of Liège, Liège, Belgium
- Centre du Cerveau², University Hospital of Liège, Liège, Belgium
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4
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Braun T, Doerr JM, Peters L, Viard M, Reuter I, Prosiegel M, Weber S, Yeniguen M, Tschernatsch M, Gerriets T, Juenemann M, Huttner HB, Hamzic S. Age-related changes in oral sensitivity, taste and smell. Sci Rep 2022; 12:1533. [PMID: 35087097 PMCID: PMC8795375 DOI: 10.1038/s41598-022-05201-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 01/06/2022] [Indexed: 11/11/2022] Open
Abstract
Oropharyngeal sensitivity plays a vital role in the initiation of the swallowing reflex and is thought to decline as part of the aging-process. Taste and smell functions appear to decline with age as well. The aim of our study was to generate data of oral sensitivity in healthy participants for future studies and to analyse age-related changes and their interdependence by measuring oral sensitivity, taste, and smell function. The experiment involved 30 participants younger than and 30 participants older than 60. Sensitivity threshold as a surrogate of oral sensitivity was measured at the anterior faucial pillar by electrical stimulation using commercially available pudendal electrode mounted on a gloved finger. Smell and taste were evaluated using commercially available test kits. Mean sensitivity was lower in young participants compared to older participants (1.9 ± 0.59 mA vs. 2.42 ± 1.03 mA; p = 0.021). Young participants also performed better in smell (Score 11.13 ± 0.86 vs 9.3 ± 1.93; p < 0.001) and taste examinations (Score 11.83 ± 1.86 vs 8.53 ± 3.18; p < 0.001). ANCOVA revealed a statistical association between sensitivity and smell (p = 0.08) that was moderated by age (p = 0.044). Electrical threshold testing at the anterior faucial pillar is a simple, safe, and accurate diagnostic measure of oral sensitivity. We detected a decline of oral sensitivity, taste, and smell in older adults.Trial registration: Clinicaltrials.gov, NCT03240965. Registered 7th August 2017- https://clinicaltrials.gov/ct2/show/NCT03240965 .
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Affiliation(s)
- Tobias Braun
- Department of Neurology, University Hospital Giessen and Marburg, Justus Liebig University, Klinikstrasse 33, 35392, Giessen, Germany.
| | - Johanna M Doerr
- Department of Neurology, University Hospital Giessen and Marburg, Justus Liebig University, Klinikstrasse 33, 35392, Giessen, Germany
| | - Laura Peters
- Justus-Liebig-University Giessen, Faculty of Medicine, Klinikstrasse 29, 35392, Giessen, Germany
| | - Maxime Viard
- Department of Neurology, University Hospital Giessen and Marburg, Justus Liebig University, Klinikstrasse 33, 35392, Giessen, Germany
| | - Iris Reuter
- Department of Neurology, University Hospital Giessen and Marburg, Justus Liebig University, Klinikstrasse 33, 35392, Giessen, Germany
| | - Mario Prosiegel
- Faculty of Languages and Literatures, Department I, Ludwig-Maximilians-University (LMU), Munich, Germany
| | - Susanne Weber
- Stroke Unit, Buergerhospital Friedberg, Ockstaedter Str. 3-5, 61169, Friedberg, Germany
| | - Mesut Yeniguen
- Department of Neurology, University Hospital Giessen and Marburg, Justus Liebig University, Klinikstrasse 33, 35392, Giessen, Germany
| | - Marlene Tschernatsch
- Department of Neurology, University Hospital Giessen and Marburg, Justus Liebig University, Klinikstrasse 33, 35392, Giessen, Germany
- Department of Neurology, Gesundheitszentrum Wetterau, Chaumontplatz 1, 61231, Bad Nauheim, Germany
| | - Tibo Gerriets
- Department of Neurology, University Hospital Giessen and Marburg, Justus Liebig University, Klinikstrasse 33, 35392, Giessen, Germany
- Stroke Unit, Buergerhospital Friedberg, Ockstaedter Str. 3-5, 61169, Friedberg, Germany
- Department of Neurology, Gesundheitszentrum Wetterau, Chaumontplatz 1, 61231, Bad Nauheim, Germany
| | - Martin Juenemann
- Department of Neurology, University Hospital Giessen and Marburg, Justus Liebig University, Klinikstrasse 33, 35392, Giessen, Germany
| | - Hagen B Huttner
- Department of Neurology, University Hospital Giessen and Marburg, Justus Liebig University, Klinikstrasse 33, 35392, Giessen, Germany
| | - Samra Hamzic
- Department of Neurology, University Hospital Giessen and Marburg, Justus Liebig University, Klinikstrasse 33, 35392, Giessen, Germany
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Facilitation of oral sensitivity by electrical stimulation of the faucial pillars. Sci Rep 2021; 11:10762. [PMID: 34031508 PMCID: PMC8144216 DOI: 10.1038/s41598-021-90262-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 05/10/2021] [Indexed: 11/13/2022] Open
Abstract
Dysphagia is common in neurological disease. However, our understanding of swallowing and its central nervous control is limited. Sensory information plays a vital role in the initiation of the swallowing reflex and is often reduced in stroke patients. We hypothesized that the sensitivity threshold of the anterior faucial pillar could be facilitated by either electrical stimulation (ES) or taste and smell information. The sensitivity threshold was measured by ES in the anterior faucial pillar region. The measurement was repeated 5 min after baseline. Thirty minutes after baseline, the participants underwent a test for taste and smell. Immediately after the test, the ES was repeated. Thirty healthy volunteers with a mean age of 27 ± 5.1 participated in the trial. Mean sensitivity threshold at baseline was 1.9 ± 0.59 mA. The values 5 min after baseline (1.74 ± 0.56 mA, p = 0.027) and 30 min after baseline (1.67 ± 0.58 mA, p = 0.011) were significantly lower compared to the baseline, but there was no difference between the latter (p = 0.321). After 5 min, a potentially facilitating effect was found on oral sensitivity by ES of the faucial pillar area. Thirty minutes later, this effect was still present. Trial registration Clinicaltrials.gov, NCT03240965. Registered 7th August 2017—https://clinicaltrials.gov/ct2/show/NCT03240965.
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Effect of Aging, Gender and Sensory Stimulation of TRPV1 Receptors with Capsaicin on Spontaneous Swallowing Frequency in Patients with Oropharyngeal Dysphagia: A Proof-of-Concept Study. Diagnostics (Basel) 2021; 11:diagnostics11030461. [PMID: 33799960 PMCID: PMC7999082 DOI: 10.3390/diagnostics11030461] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/26/2021] [Accepted: 03/03/2021] [Indexed: 11/16/2022] Open
Abstract
Spontaneous swallowing contributes to airway protection and depends on the activation of brainstem reflex circuits in the central pattern generator (CPG). We studied the effect of age and gender on spontaneous swallowing frequency (SSF) in healthy volunteers and assessed basal SSF and TRPV1 stimulation effect on SSF in patients with post-stroke oropharyngeal dysphagia (OD). The effect of age and gender on SSF was examined on 141 healthy adult volunteers (HV) divided into three groups: GI-18-39 yr, GII-40-59 yr, and GIII->60 yr. OD was assessed by the Volume-Viscosity Swallowing Test (VVST). The effect of sensory stimulation with capsaicin 10-5 M (TRPV1 agonist) was evaluated in 17 patients with post-stroke OD, using the SSF. SSF was recorded in all participants during 10 min using surface electromyography (sEMG) of the suprahyoid muscles and an omnidirectional accelerometer placed over the cricothyroid cartilage. SSF was significantly reduced in GII (0.73 ± 0.50 swallows/min; p = 0.0385) and GIII (0.50 ± 0.31 swallows/min; p < 0.0001) compared to GI (1.03 ± 0.62 swallows/min), and there was a moderate significant correlation between age and SFF (r = -0.3810; p < 0.0001). No effect of gender on SSF was observed. Capsaicin caused a strong and significant increase in SSF after the TRPV1 stimulation when comparing to basal condition (pre-capsaicin: 0.41 ± 0.32 swallows/min vs post-capsaicin: 0.81 ± 0.51 swallow/min; p = 0.0003). OD in patients with post-stroke OD and acute stimulation with TRPV1 agonists caused a significant increase in SSF, further suggesting the potential role of pharmacological stimulation of sensory pathways as a therapeutic strategy for CPG activation in patients with OD.
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Hossain MZ, Ando H, Unno S, Kitagawa J. Targeting Chemosensory Ion Channels in Peripheral Swallowing-Related Regions for the Management of Oropharyngeal Dysphagia. Int J Mol Sci 2020; 21:E6214. [PMID: 32867366 PMCID: PMC7503421 DOI: 10.3390/ijms21176214] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 08/24/2020] [Accepted: 08/26/2020] [Indexed: 12/22/2022] Open
Abstract
Oropharyngeal dysphagia, or difficulty in swallowing, is a major health problem that can lead to serious complications, such as pulmonary aspiration, malnutrition, dehydration, and pneumonia. The current clinical management of oropharyngeal dysphagia mainly focuses on compensatory strategies and swallowing exercises/maneuvers; however, studies have suggested their limited effectiveness for recovering swallowing physiology and for promoting neuroplasticity in swallowing-related neuronal networks. Several new and innovative strategies based on neurostimulation in peripheral and cortical swallowing-related regions have been investigated, and appear promising for the management of oropharyngeal dysphagia. The peripheral chemical neurostimulation strategy is one of the innovative strategies, and targets chemosensory ion channels expressed in peripheral swallowing-related regions. A considerable number of animal and human studies, including randomized clinical trials in patients with oropharyngeal dysphagia, have reported improvements in the efficacy, safety, and physiology of swallowing using this strategy. There is also evidence that neuroplasticity is promoted in swallowing-related neuronal networks with this strategy. The targeting of chemosensory ion channels in peripheral swallowing-related regions may therefore be a promising pharmacological treatment strategy for the management of oropharyngeal dysphagia. In this review, we focus on this strategy, including its possible neurophysiological and molecular mechanisms.
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Affiliation(s)
- Mohammad Zakir Hossain
- Department of Oral Physiology, School of Dentistry, Matsumoto Dental University, 1780 Gobara Hirooka, Shiojiri, Nagano 399-0781, Japan;
| | - Hiroshi Ando
- Department of Biology, School of Dentistry, Matsumoto Dental University, 1780 Gobara, Hirooka, Shiojiri, Nagano 399-0781, Japan;
| | - Shumpei Unno
- Department of Oral Physiology, School of Dentistry, Matsumoto Dental University, 1780 Gobara Hirooka, Shiojiri, Nagano 399-0781, Japan;
| | - Junichi Kitagawa
- Department of Oral Physiology, School of Dentistry, Matsumoto Dental University, 1780 Gobara Hirooka, Shiojiri, Nagano 399-0781, Japan;
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Kamarunas E, Wong SM, Ludlow CL. Laryngeal Vibration Increases Spontaneous Swallowing Rates in Chronic Oropharyngeal Dysphagia: A Proof-of-Principle Pilot Study. Dysphagia 2018; 34:640-653. [PMID: 30488335 DOI: 10.1007/s00455-018-9962-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 11/14/2018] [Indexed: 11/30/2022]
Abstract
Previously, vibratory stimulation increased spontaneous swallowing rates in healthy volunteers indicating that sensory stimulation excited the neural control of swallowing. Here, we studied patients with severe chronic dysphagia following brain injury or radiation for head and neck cancer to determine if sensory stimulation could excite an impaired swallowing system. We examined (1) if laryngeal vibratory stimulation increased spontaneous swallowing rates over sham (no stimulation); (2) the optimal rate of vibration, device contact pressure, and vibratory mode for increasing swallowing rates; and (3) if vibration altered participants' urge to swallow, neck comfort, and swallow initiation latency. Vibration was applied to the skin overlying the thyroid lamina bilaterally in thirteen participants to compare vibratory rates 30, 70, 110, 150, or 70 + 110 Hz, different devices to neck pressures (2, 4, or 6 kilopascals), and pulsed versus continuous vibration. Swallows were confirmed from recordings of laryngeal accelerometry and respiratory apneas and viewing neck movement. Participants' swallowing rates, urge to swallow, discomfort levels, and swallow initiation latencies were measured. Vibration at 70 Hz and at 110 Hz significantly increased swallowing rates over sham. All vibratory frequencies except 70 + 100 Hz increased participants' urge to swallow, while no pressures or modes were optimal for increasing urge to swallow. No conditions increased discomfort. Vibration did not reduce measures of swallow initiation latency using accelerometry. In conclusion, as non-invasive neck vibration overlying the larynx increased swallowing rates and the urge to swallow without discomfort in patients with chronic dysphagia, the potential for vibratory stimulation facilitating swallowing during dysphagia rehabilitation should be investigated.
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Affiliation(s)
- Erin Kamarunas
- Department of Communication Sciences and Disorders, James Madison University, 235 MLK Jr. Way, MSC 4304, Harrisonburg, VA, 22087, USA.
| | - Seng Mun Wong
- Department of Communication Sciences and Disorders, James Madison University, 235 MLK Jr. Way, MSC 4304, Harrisonburg, VA, 22087, USA
| | - Christy L Ludlow
- Department of Communication Sciences and Disorders, James Madison University, 235 MLK Jr. Way, MSC 4304, Harrisonburg, VA, 22087, USA
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Yamamura K, Kurose M, Okamoto K. Guide to Enhancing Swallowing Initiation: Insights from Findings in Healthy Subjects and Dysphagic Patients. CURRENT PHYSICAL MEDICINE AND REHABILITATION REPORTS 2018; 6:178-185. [PMID: 30147997 PMCID: PMC6096907 DOI: 10.1007/s40141-018-0192-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE OF REVIEW Difficulty in initiating swallowing is one of the main symptoms of oropharyngeal dysphagia. Therefore, enhancing swallowing initiation is an important approach for the treatment of oropharyngeal dysphagia. This review aims to introduce recent approaches to enhancing swallowing and to discuss their therapeutic potential. RECENT FINDINGS Both central interventions such as non-invasive brain stimulation and peripheral interventions such as electrical stimulation to peripheral tissues are conducted to enhance swallowing. Recent studies have paid more attention to generating neuroplasticity to produce long-lasting facilitative effect on swallowing. SUMMARY Transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), pharyngeal electrical stimulation (PES), transcutaneous electrical stimulation, and somatic and chemical stimulation were introduced. Considerable evidence supports the therapeutic potential of TMS and PES. Other approaches need further studies to verify their efficacy (e.g., duration of the effect and a limit of effectiveness) and/or possible risk of adverse effects.
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Affiliation(s)
- Kensuke Yamamura
- Division of Oral Physiology, Department of Oral Biological Sciences, Niigata University Graduate School of Medical and Dental Sciences, 2-5274 Gakkocho-dori, Chuo-ku, Niigata, 951-8514 Japan
| | - Masayuki Kurose
- Division of Oral Physiology, Department of Oral Biological Sciences, Niigata University Graduate School of Medical and Dental Sciences, 2-5274 Gakkocho-dori, Chuo-ku, Niigata, 951-8514 Japan
| | - Keiichiro Okamoto
- Division of Oral Physiology, Department of Oral Biological Sciences, Niigata University Graduate School of Medical and Dental Sciences, 2-5274 Gakkocho-dori, Chuo-ku, Niigata, 951-8514 Japan
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10
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Direct and Indirect Therapy: Neurostimulation for the Treatment of Dysphagia After Stroke. Dysphagia 2018. [DOI: 10.1007/174_2017_147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Mulheren RW, Ludlow CL. Vibration over the larynx increases swallowing and cortical activation for swallowing. J Neurophysiol 2017; 118:1698-1708. [PMID: 28679839 DOI: 10.1152/jn.00244.2017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 06/16/2017] [Accepted: 06/23/2017] [Indexed: 11/22/2022] Open
Abstract
Sensory input can alter swallowing control in both the cortex and brainstem. Electrical stimulation of superior laryngeal nerve afferents increases reflexive swallowing in animals, with different frequencies optimally effective across species. Here we determined 1) if neck vibration overlying the larynx affected the fundamental frequency of the voice demonstrating penetration of vibration into the laryngeal tissues, and 2) if vibration, in comparison with sham, increased spontaneous swallowing and enhanced cortical hemodynamic responses to swallows in the swallowing network. A device with two motors, one over each thyroid lamina, delivered intermittent 10-s epochs of vibration. We recorded swallows and event-related changes in blood oxygenation level to swallows over the motor and sensory swallowing cortexes bilaterally using functional near infrared spectroscopy. Ten healthy participants completed eight 20-min conditions in counterbalanced order with either epochs of continuous vibration at 30, 70, 110, 150, and 70 + 110 Hz combined, 4-Hz pulsed vibration at 70 + 110 Hz, or two sham conditions without stimulation. Stimulation epochs were separated by interstimulus intervals varying between 30 and 45 s in duration. Vibration significantly reduced the fundamental frequency of the voice compared with no stimulation demonstrating that vibration penetrated laryngeal tissues. Vibration at 70 and at 150 Hz increased spontaneous swallowing compared with sham. Hemodynamic responses to swallows in the motor cortex were enhanced during conditions containing stimulation compared with sham. As vibratory stimulation on the neck increased spontaneous swallowing and enhanced cortical activation for swallows in healthy participants, it may be useful for enhancing swallowing in patients with dysphagia.NEW & NOTEWORTHY Vibratory stimulation at 70 and 150 Hz on the neck overlying the larynx increased the frequency of spontaneous swallowing. Simultaneously vibration also enhanced hemodynamic responses in the motor cortex to swallows when recorded with functional near-infrared spectroscopy (fNIRS). As vibrotactile stimulation on the neck enhanced cortical activation for swallowing in healthy participants, it may be useful for enhancing swallowing in patients with dysphagia.
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Affiliation(s)
- Rachel W Mulheren
- Department of Communication Sciences and Disorders, James Madison University, Harrisonburg, Virginia
| | - Christy L Ludlow
- Department of Communication Sciences and Disorders, James Madison University, Harrisonburg, Virginia
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12
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Troche MS, Brandimore AE, Godoy J, Hegland KW. A framework for understanding shared substrates of airway protection. J Appl Oral Sci 2014; 22:251-60. [PMID: 25141195 PMCID: PMC4126819 DOI: 10.1590/1678-775720140132] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 05/06/2014] [Indexed: 02/01/2023] Open
Abstract
Deficits of airway protection can have deleterious effects to health and quality of
life. Effective airway protection requires a continuum of behaviors including
swallowing and cough. Swallowing prevents material from entering the airway and
coughing ejects endogenous material from the airway. There is significant overlap
between the control mechanisms for swallowing and cough. In this review we will
present the existing literature to support a novel framework for understanding shared
substrates of airway protection. This framework was originally adapted from Eccles'
model of cough28 (2009) by Hegland,
et al.42 (2012). It will serve to
provide a basis from which to develop future studies and test specific hypotheses
that advance our field and ultimately improve outcomes for people with airway
protective deficits.
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Affiliation(s)
- Michelle Shevon Troche
- Department of Speech, Language, and Hearing Sciences, University of Florida, Gainesville, FL, USA
| | | | - Juliana Godoy
- Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil
| | - Karen Wheeler Hegland
- Department of Speech, Language, and Hearing Sciences, University of Florida, Gainesville, FL, USA
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Suntrup S, Teismann I, Wollbrink A, Winkels M, Warnecke T, Pantev C, Dziewas R. Pharyngeal electrical stimulation can modulate swallowing in cortical processing and behavior - magnetoencephalographic evidence. Neuroimage 2014; 104:117-24. [PMID: 25451471 DOI: 10.1016/j.neuroimage.2014.10.016] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2014] [Revised: 09/15/2014] [Accepted: 10/06/2014] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND The act of swallowing is a complex neuromuscular function that is processed in a distributed network involving cortical, subcortical and brainstem structures. Difficulty in swallowing arises from a variety of neurologic diseases for which therapeutic options are currently limited. Pharyngeal electrical stimulation (PES) is a novel intervention designed to promote plastic changes in the pharyngeal motor cortex to aid dysphagia rehabilitation. In the present study we evaluate the effect of PES on cortical swallowing network activity and associated changes in swallowing performance. METHODS In a randomized, crossover study design 10min of real (0.2-ms pulses, 5Hz, 280V, stimulation intensity at 75% of maximum tolerated threshold) or sham PES were delivered to 14 healthy volunteers in two separate sessions. Stimulation was delivered via a pair of bipolar ring electrodes mounted on an intraluminal catheter positioned in the pharynx. Before and after each intervention swallowing capacity (ml/s) was tested using a 150ml-water swallowing stress test. Event-related desynchronization (ERD) of cortical oscillatory activity during volitional swallowing was recorded applying whole-head magnetoencephalography before, immediately after and 45min past the intervention. RESULTS A prominent reduction of ERD in sensorimotor brain areas occurred in the alpha and beta frequency ranges immediately after real PES but not after sham stimulation (p<0.05) and had faded after 45min. Volume per swallow and swallowing capacity significantly increased following real stimulation only. CONCLUSION Attenuation of ERD following PES reflects stimulation-induced increased swallowing processing efficiency, which is associated with subtle changes in swallowing function in healthy subjects. Our data contribute evidence that swallowing network organization and behavior can effectively be modulated by PES.
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Affiliation(s)
- Sonja Suntrup
- Department of Neurology, University of Muenster, Albert-Schweitzer-Campus 1, Gebäude A1, 48149 Münster, Germany; Institute for Biomagnetism and Biosignalanalysis, University of Muenster, Malmedyweg 15, 48149 Muenster, Germany.
| | - Inga Teismann
- Department of Neurology, University of Muenster, Albert-Schweitzer-Campus 1, Gebäude A1, 48149 Münster, Germany
| | - Andreas Wollbrink
- Institute for Biomagnetism and Biosignalanalysis, University of Muenster, Malmedyweg 15, 48149 Muenster, Germany
| | - Martin Winkels
- Institute for Biomagnetism and Biosignalanalysis, University of Muenster, Malmedyweg 15, 48149 Muenster, Germany
| | - Tobias Warnecke
- Department of Neurology, University of Muenster, Albert-Schweitzer-Campus 1, Gebäude A1, 48149 Münster, Germany
| | - Christo Pantev
- Institute for Biomagnetism and Biosignalanalysis, University of Muenster, Malmedyweg 15, 48149 Muenster, Germany
| | - Rainer Dziewas
- Department of Neurology, University of Muenster, Albert-Schweitzer-Campus 1, Gebäude A1, 48149 Münster, Germany
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Abe K, Weisz SEM, Dunn RL, DiGioacchino MC, Nyentap JA, Stanbouly S, Theurer JA, Bureau Y, Affoo RH, Martin RE. Occurrences of yawn and swallow are temporally related. Dysphagia 2014; 30:57-66. [PMID: 25240300 DOI: 10.1007/s00455-014-9573-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Accepted: 09/10/2014] [Indexed: 12/19/2022]
Abstract
Yawning is a stereotyped motor behavior characterized by deep inhalation and associated dilation of the respiratory tract, pronounced jaw opening, and facial grimacing. The frequency of spontaneous yawning varies over the diurnal cycle, peaking after waking and before sleep. Yawning can also be elicited by seeing or hearing another yawn, or by thinking about yawning, a phenomenon known as "contagious yawning". Yawning is mediated by a distributed network of brainstem and supratentorial brain regions, the components of which are shared with other airway behaviors including respiration, swallowing, and mastication. Nevertheless, the possibility of behavioral coordination between yawning and other brainstem-mediated functions has not been examined. Here we show, with a double-blind methodology, a greater-than-fivefold increase in rest (saliva) swallowing rate during the 10-s period immediately following contagious yawning elicited in 14 adult humans through the viewing of videotaped yawn stimuli. Sixty-five percent of yawns were followed by a swallow within 10 s and swallows accounted for 26 % of all behaviors produced during this post-yawn period. This novel finding of a tight temporal coupling between yawning and swallowing provides preliminary evidence that yawning and swallowing are physiologically related, thus extending current models of upper airway physiology and neurophysiology. Moreover, our finding suggests the possibility that yawning plays a role in eliciting rest swallowing, a view not considered in previous theories of yawning. As such, the present demonstration of a temporal association between yawning and swallowing motivates a re-examination of the longstanding question, "Why do we yawn?".
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Affiliation(s)
- Kimiko Abe
- School of Communication Sciences and Disorders, Faculty of Health Sciences, Western University, London, ON, N6A 5B9, Canada,
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15
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Crary MA, Carnaby GD, Sia I, Khanna A, Waters MF. Spontaneous swallowing frequency has potential to identify dysphagia in acute stroke. Stroke 2013; 44:3452-7. [PMID: 24149008 DOI: 10.1161/strokeaha.113.003048] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Spontaneous swallowing frequency has been described as an index of dysphagia in various health conditions. This study evaluated the potential of spontaneous swallow frequency analysis as a screening protocol for dysphagia in acute stroke. METHODS In a cohort of 63 acute stroke cases, swallow frequency rates (swallows per minute [SPM]) were compared with stroke and swallow severity indices, age, time from stroke to assessment, and consciousness level. Mean differences in SPM were compared between patients with versus without clinically significant dysphagia. Receiver operating characteristic curve analysis was used to identify the optimal threshold in SPM, which was compared with a validated clinical dysphagia examination for identification of dysphagia cases. Time series analysis was used to identify the minimally adequate time period to complete spontaneous swallow frequency analysis. RESULTS SPM correlated significantly with stroke and swallow severity indices but not with age, time from stroke onset, or consciousness level. Patients with dysphagia demonstrated significantly lower SPM rates. SPM differed by dysphagia severity. Receiver operating characteristic curve analysis yielded a threshold of SPM≤0.40 that identified dysphagia (per the criterion referent) with 0.96 sensitivity, 0.68 specificity, and 0.96 negative predictive value. Time series analysis indicated that a 5- to 10-minute sampling window was sufficient to calculate spontaneous swallow frequency to identify dysphagia cases in acute stroke. CONCLUSIONS Spontaneous swallowing frequency presents high potential to screen for dysphagia in acute stroke without the need for trained, available personnel.
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Affiliation(s)
- Michael A Crary
- From the Swallowing Research Laboratory (M.A.C., G.D.C., I.S.), Departments of Speech, Language, and Hearing Science (M.A.C.), Behavioral Science and Community Health (G.D.C.), and Neurology (A.K., M.W.), University of Florida Health Science Center, Gainesville
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16
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Neurostimulation as an Approach to Dysphagia Rehabilitation: Current Evidence. CURRENT PHYSICAL MEDICINE AND REHABILITATION REPORTS 2013. [DOI: 10.1007/s40141-013-0034-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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17
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Proof-of-Principle Pilot Study of Oropharyngeal Air-Pulse Application in Individuals With Dysphagia After Hemispheric Stroke. Arch Phys Med Rehabil 2013; 94:1088-94. [DOI: 10.1016/j.apmr.2012.11.033] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 10/27/2012] [Accepted: 11/11/2012] [Indexed: 11/21/2022]
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18
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Crary MA, Sura L, Carnaby G. Validation and demonstration of an isolated acoustic recording technique to estimate spontaneous swallow frequency. Dysphagia 2012; 28:86-94. [PMID: 22707084 DOI: 10.1007/s00455-012-9416-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Accepted: 05/30/2012] [Indexed: 11/25/2022]
Abstract
Spontaneous swallowing is considered a reflexive, pharyngeal clearance mechanism. Reductions in spontaneous swallow frequency may be a sensitive index for dysphagia and related morbidities. This study evaluated an acoustic recording technique as a measure to estimate spontaneous swallow frequency. Initially, a multichannel physiologic (surface electromyography, swallow apnea, cervical auscultation) recording technique was validated and subsequently compared to an isolated acoustic (microphone) recording technique on a sample of younger (25 ± 2.8 years) and older (68 ± 5.3 years) healthy adult participants. Sensitivity (94 %), specificity (99 %), and classification accuracy (98 %) were high for swallow identification from the multichannel physiologic recording technique. Interjudge reliability was high (k = 0.94, 95 % CI = 0.92-0.96). No significant differences in spontaneous swallow frequency were observed between the multichannel physiologic recordings and the acoustic recordings (0.85 vs. 0.81 swallows per minute). Furthermore, these two techniques were highly correlated (r = 0.95). Interjudge reliability for swallow identification via acoustic recordings was high (k = 0.96, 95 % CI = 0.94-0.99). Preliminary evaluation of the temporal stability of spontaneous swallow frequency measured from acoustic recordings indicated that time samples as short as 5 min produce viable results. Age differences were identified in spontaneous swallow frequency rates, with older participants swallowing less frequently than younger participants (0.47 vs. 1.02 swallows per minute). Collectively, these results indicate that an isolated acoustic recording technique is a valid approach to estimate spontaneous swallow frequency.
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Affiliation(s)
- Michael A Crary
- Swallowing Research Laboratory, University of Florida Health Science Center (UFHSC), Box 100174, Gainesville, FL 32610-0174, USA.
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19
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Mistry S, Michou E, Vasant DH, Hamdy S. Direct and Indirect Therapy: Neurostimulation for the Treatment of Dysphagia After Stroke. Dysphagia 2011. [DOI: 10.1007/174_2011_416] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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20
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Steele CM, Miller AJ. Sensory input pathways and mechanisms in swallowing: a review. Dysphagia 2010; 25:323-33. [PMID: 20814803 PMCID: PMC2992653 DOI: 10.1007/s00455-010-9301-5] [Citation(s) in RCA: 178] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2009] [Accepted: 08/14/2010] [Indexed: 01/21/2023]
Abstract
Over the past 20 years, research on the physiology of swallowing has confirmed that the oropharyngeal swallowing process can be modulated, both volitionally and in response to different sensory stimuli. In this review we identify what is known regarding the sensory pathways and mechanisms that are now thought to influence swallowing motor control and evoke its response. By synthesizing the current state of research evidence and knowledge, we identify continuing gaps in our knowledge of these mechanisms and pose questions for future research.
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Affiliation(s)
- Catriona M Steele
- Toronto Rehabilitation Institute, 550 University Avenue, #12030, Toronto, ON, M5G 2A2, Canada.
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