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Simon MV, Rutkove SB, Ngo L, Fehnel CR, Das AS, Sarge T, Bose S, Selim M, Kumar S. Understanding the variability of the electrophysiologic laryngeal adductor reflex. Clin Neurophysiol 2024; 162:141-150. [PMID: 38631074 DOI: 10.1016/j.clinph.2024.03.019] [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: 12/02/2023] [Revised: 03/11/2024] [Accepted: 03/16/2024] [Indexed: 04/19/2024]
Abstract
OBJECTIVE The laryngeal adductor reflex (LAR) is vital for airway protection and can be electrophysiologically obtained under intravenous general anesthesia (IGA). This makes the electrophysiologic LAR (eLAR) an important tool for monitoring of the vagus nerves and relevant brainstem circuitry during high-risk surgeries. We investigated the intra-class variability of normal and expected abnormal eLAR. METHODS Repeated measures of contralateral R1 (cR1) were performed under IGA in 58 patients. Data on presence/absence of cR2 and potential confounders were also collected. Review of neuroimaging, pathology and clinical exam, allowed classification into normal and expected abnormal eLAR groups. Using univariate and multivariate analysis we studied the variability of cR1 parameters and their differences between the two groups. RESULTS In both groups, cR1 latencies had coefficients of variation of <2%. In the abnormal group, cR1 had longer latencies, required higher activation currents and was more frequently desynchronized and unsustained; cR2 was more frequently absent. CONCLUSIONS cR1 latencies show high analytical precision for measurements. Delayed onset, difficult to elicit, desynchronized and unsustained cR1, and absence of cR2 signal an abnormal eLAR. SIGNIFICANCE Understanding the variability and behavior of normal and abnormal eLAR under IGA can aid in the interpretation of its changes during monitoring.
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Affiliation(s)
- Mirela V Simon
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA.
| | - Seward B Rutkove
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Long Ngo
- Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Corey R Fehnel
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Alvin S Das
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Todd Sarge
- Department of Anesthesia, Beth Israel Deaconess Medical Center, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Somnath Bose
- Department of Anesthesia, Beth Israel Deaconess Medical Center, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Magdy Selim
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Sandeep Kumar
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
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Kofler M, Hallett M, Iannetti GD, Versace V, Ellrich J, Téllez MJ, Valls-Solé J. The blink reflex and its modulation - Part 1: Physiological mechanisms. Clin Neurophysiol 2024; 160:130-152. [PMID: 38102022 PMCID: PMC10978309 DOI: 10.1016/j.clinph.2023.11.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 11/11/2023] [Accepted: 11/22/2023] [Indexed: 12/17/2023]
Abstract
The blink reflex (BR) is a protective eye-closure reflex mediated by brainstem circuits. The BR is usually evoked by electrical supraorbital nerve stimulation but can be elicited by a variety of sensory modalities. It has a long history in clinical neurophysiology practice. Less is known, however, about the many ways to modulate the BR. Various neurophysiological techniques can be applied to examine different aspects of afferent and efferent BR modulation. In this line, classical conditioning, prepulse and paired-pulse stimulation, and BR elicitation by self-stimulation may serve to investigate various aspects of brainstem connectivity. The BR may be used as a tool to quantify top-down modulation based on implicit assessment of the value of blinking in a given situation, e.g., depending on changes in stimulus location and probability of occurrence. Understanding the role of non-nociceptive and nociceptive fibers in eliciting a BR is important to get insight into the underlying neural circuitry. Finally, the use of BRs and other brainstem reflexes under general anesthesia may help to advance our knowledge of the brainstem in areas not amenable in awake intact humans. This review summarizes talks held by the Brainstem Special Interest Group of the International Federation of Clinical Neurophysiology at the International Congress of Clinical Neurophysiology 2022 in Geneva, Switzerland, and provides a state-of-the-art overview of the physiology of BR modulation. Understanding the principles of BR modulation is fundamental for a valid and thoughtful clinical application (reviewed in part 2) (Gunduz et al., submitted).
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Affiliation(s)
- Markus Kofler
- Department of Neurology, Hochzirl Hospital, Zirl, Austria.
| | - Mark Hallett
- National Institute of Neurological Disorders and Stroke, NIH, USA.
| | - Gian Domenico Iannetti
- University College London, United Kingdom; Italian Institute of Technology (IIT), Rome, Italy.
| | - Viviana Versace
- Department of Neurorehabilitation, Hospital of Vipiteno (SABES-ASDAA), Teaching Hospital of the Paracelsus Medical Private University (PMU), Vipiteno-Sterzing, Italy.
| | - Jens Ellrich
- Friedrich-Alexander-University Erlangen-Nuremberg, Germany.
| | | | - Josep Valls-Solé
- IDIBAPS (Institut d'Investigació August Pi i Sunyer), University of Barcelona, Spain.
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Téllez MJ, Sinclair CF, Díaz-Baamonde A, Peláez-Cruz R, Ulkatan S. The short-latency R1 response of the electrical laryngeal adductor reflex contributes to airway protection by initiating glottic closure. Clin Neurophysiol 2021; 132:3160-3165. [PMID: 34758416 DOI: 10.1016/j.clinph.2021.09.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 08/18/2021] [Accepted: 09/22/2021] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The fundamental role of the short-latency (R1) laryngeal adductor reflex (LAR) response remains unclear with conflicting reports in the literature. This study's primary aim was to objectively determine whether the bilateral R1 response, which was elicited by electrical stimulation of the supraglottic mucosa, triggered bilateral glottis closure. METHODS Video recording of the LAR in a prospective case series of patients undergoing trans-oral rigid laryngoscopy. The LAR was elicited by electrical stimulation of supraglottic mucosa. The LAR R1 and long-latency (R2) responses in laryngeal adductor musculature were correlated with mechanical vocal fold (VF) adduction in a time-locked manner. A high-speed camera recording 1057 frames per second was used to determine where in the LAR contractile closure the electrical R1 component occurred. RESULTS Five patients were prospectively enrolled. The R1 response was present in all trials for all patients. The R2 response was recorded in four patients (80%). As assessed by the latency of the R1 response, electrical activation of the adductor muscles always preceded the mechanical onset of VF movement. VF adduction began near the middle of the R1 response in all trials for all patients. The R2 response of the LAR began after visible VF adduction for all patients. CONCLUSIONS This study provides the first objective evidence that the bilateral R1 response of the electrically elicited LAR is the electrical event that initiates reflex airway closure. SIGNIFICANCE These results suggest that under total intravenous anesthesia, the larynx preserves its capacity to elicit a LAR, thereby maintaining some protective functions that can prevent airway penetration.
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Affiliation(s)
- Maria J Téllez
- Department of Intraoperative Neurophysiology, Mount Sinai West Hospital, New York, NY, USA.
| | - Catherine F Sinclair
- Department of Otolaryngology Head and Neck Surgery, Mount Sinai West Hospital, New York, NY, USA
| | - Alba Díaz-Baamonde
- Department of Intraoperative Neurophysiology, Mount Sinai West Hospital, New York, NY, USA
| | - Roberto Peláez-Cruz
- Department of Intraoperative Neurophysiology, Mount Sinai West Hospital, New York, NY, USA
| | - Sedat Ulkatan
- Department of Intraoperative Neurophysiology, Mount Sinai West Hospital, New York, NY, USA
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Lever TE, Kloepper AM, Deninger I, Hamad A, Hopewell BL, Ovaitt AK, Szewczyk M, Bunyak F, Zitsch B, Blake B, Vandell C, Dooley L. Advancing Laryngeal Adductor Reflex Testing Beyond Sensory Threshold Detection. Dysphagia 2021; 37:1151-1171. [PMID: 34686917 DOI: 10.1007/s00455-021-10374-5] [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: 11/17/2020] [Accepted: 09/27/2021] [Indexed: 11/25/2022]
Abstract
Flexible endoscopic evaluation of swallowing with sensory testing (FEESST) is a promising clinical tool to assess airway integrity via the laryngeal adductor reflex (LAR). The current clinical protocol relies on sensory threshold detection, as relatively little is known about the motor response of this sensorimotor airway protective reflex. Here, we focused on characterizing normative LAR motion dynamics in 20 healthy young participants using our prototype high-pressure syringe-based air pulse device and analytic software (VFtrack™) that tracks vocal fold (VF) motion in endoscopic videos. Following device bench testing for air pulse stimulus characterization, we evoked and objectively quantified LAR motion dynamics in response to two suprathreshold air pulse stimuli (40 versus 60 mm Hg), delivered to the arytenoid mucosa through a bronchoscope working channel. The higher air pressures generated by our device permitted an approximate 1 cm endoscope working distance for continual visualization of the bilateral VFs throughout the LAR. Post hoc video analysis identified two main findings: (1) there are variant and invariant subcomponents of the LAR motor response, and (2) only a fraction of suprathreshold stimuli evoked complete glottic closure during the LAR. While the clinical relevance of these findings remains to be determined, we have nonetheless demonstrated untapped potential in the current FEESST protocol. Our ongoing efforts may reveal LAR biomarkers to quantify the severity of laryngeal pathology and change over time with natural disease progression, spontaneous recovery, or in response to intervention. The ultimate goal is to facilitate predictive modeling of patients at high risk for dysphagia-related aspiration pneumonia.
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Affiliation(s)
- Teresa E Lever
- Department of Otolaryngology - Head and Neck Surgery, University of Missouri School of Medicine, One Hospital Dr. MA314, Columbia, MO, 65212, USA.
| | - Ashley M Kloepper
- Department of Otolaryngology - Head and Neck Surgery, University of Missouri School of Medicine, One Hospital Dr. MA314, Columbia, MO, 65212, USA
| | - Ian Deninger
- Department of Otolaryngology - Head and Neck Surgery, University of Missouri School of Medicine, One Hospital Dr. MA314, Columbia, MO, 65212, USA
| | - Ali Hamad
- Electrical Engineering and Computer Science, University of Missouri, Columbia, MO, USA
| | - Bridget L Hopewell
- Department of Otolaryngology - Head and Neck Surgery, University of Missouri School of Medicine, One Hospital Dr. MA314, Columbia, MO, 65212, USA
| | - Alyssa K Ovaitt
- Department of Otolaryngology - Head and Neck Surgery, University of Missouri School of Medicine, One Hospital Dr. MA314, Columbia, MO, 65212, USA
| | - Marlena Szewczyk
- Department of Otolaryngology - Head and Neck Surgery, University of Missouri School of Medicine, One Hospital Dr. MA314, Columbia, MO, 65212, USA
| | - Filiz Bunyak
- Electrical Engineering and Computer Science, University of Missouri, Columbia, MO, USA
| | - Bradford Zitsch
- Department of Otolaryngology - Head and Neck Surgery, University of Missouri School of Medicine, One Hospital Dr. MA314, Columbia, MO, 65212, USA
| | - Brett Blake
- Department of Otolaryngology - Head and Neck Surgery, University of Missouri School of Medicine, One Hospital Dr. MA314, Columbia, MO, 65212, USA
| | - Caitlin Vandell
- Department of Otolaryngology - Head and Neck Surgery, University of Missouri School of Medicine, One Hospital Dr. MA314, Columbia, MO, 65212, USA
| | - Laura Dooley
- Department of Otolaryngology - Head and Neck Surgery, University of Missouri School of Medicine, One Hospital Dr. MA314, Columbia, MO, 65212, USA
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5
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Strohl MP, Chang JL, Dwyer CD, Young VN, Rosen CA, Cheung SW. Laryngeal Adductor Reflex Movement Latency Following Tactile Stimulation. Otolaryngol Head Neck Surg 2021; 166:720-726. [PMID: 34253075 DOI: 10.1177/01945998211025517] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To measure the latency of laryngeal adductor reflex (LAR) motion onset at 2 laryngopharyngeal subsites using calibrated aesthesiometers. STUDY DESIGN Cross-sectional. SETTING Academic institution. METHODS Twenty-one asymptomatic, healthy subjects (11 male, 10 female) underwent laryngopharyngeal sensory testing with tactile stimuli delivered to the aryepiglottic fold and medial pyriform sinus using 30-mm Cheung-Bearelly monofilaments (4-0 and 5-0 nylon sutures) via channeled flexible laryngoscope. The LAR onset latency, defined as the first visual detection of ipsilateral vocal fold adduction following tactile stimulation, was measured with frame-by-frame analysis of video recordings. RESULTS The overall mean LAR latency across both subsites and stimulation forces was 176.6 (95% CI, 170.3-183.0) ms, without significant difference between subsites or forces. The critical value for LAR response latency prolongation at the .01 significance level was 244 ms. At 30 frames/s video capture resolution, LAR response latency ≥8 frame intervals would indicate abnormal prolongation. CONCLUSION Aesthesiometer-triggered LAR latency appears to be invariant over an 8.7-dB force range and between the aryepiglottic fold and medial pyriform sinus subsites in controls. Laryngeal adductor reflex latency incongruences between stimulation forces or laryngopharyngeal subsites may serve as pathophysiological features to dissect mechanisms of upper aerodigestive tract disorders. LEVEL OF EVIDENCE Level 3B.
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Affiliation(s)
- Madeleine P Strohl
- Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, San Francisco, California, USA
| | - Jolie L Chang
- Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, San Francisco, California, USA
| | - Christopher D Dwyer
- Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, San Francisco, California, USA
| | - VyVy N Young
- Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, San Francisco, California, USA
| | - Clark A Rosen
- Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, San Francisco, California, USA
| | - Steven W Cheung
- Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, San Francisco, California, USA
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Foote AG, Thibeault SL. Sensory Innervation of the Larynx and the Search for Mucosal Mechanoreceptors. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2021; 64:371-391. [PMID: 33465318 PMCID: PMC8632506 DOI: 10.1044/2020_jslhr-20-00350] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 09/19/2020] [Accepted: 10/28/2020] [Indexed: 05/03/2023]
Abstract
Purpose The larynx is a uniquely situated organ, juxtaposed between the gastrointestinal and respiratory tracts, and endures considerable immunological challenges while providing reflexogenic responses via putative mucosal mechanoreceptor afferents. Laryngeal afferents mediate precise monitoring of sensory events by relay to the internal branch of the superior laryngeal nerve (iSLN). Exposure to a variety of stimuli (e.g., mechanical, chemical, thermal) at the mucosa-airway interface has likely evolved a diverse array of specialized sensory afferents for rapid laryngeal control. Accordingly, mucosal mechanoreceptors in demarcated laryngeal territories have been hypothesized as primary sources of sensory input. The purpose of this article is to provide a tutorial on current evidence for laryngeal afferent receptors in mucosa, the role of mechano-gated ion channels within airway epithelia and mechanisms for mechanoreceptors implicated in laryngeal health and disease. Method An overview was conducted on the distribution and identity of iSLN-mediated afferent receptors in the larynx, with specific focus on mechanoreceptors and their functional roles in airway mucosa. Results/Conclusions Laryngeal somatosensation at the cell and molecular level is still largely unexplored. This tutorial consolidates various animal and human researches, with translational emphasis provided for the importance of mucosal mechanoreceptors to normal and abnormal laryngeal function. Information presented in this tutorial has relevance to both clinical and research arenas. Improved understanding of iSLN innervation and corresponding mechanotransduction events will help shed light upon a variety of pathological reflex responses, including persistent cough, dysphonia, and laryngospasm.
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Affiliation(s)
- Alexander G. Foote
- Division of Otolaryngology–Head and Neck Surgery, University of Wisconsin–Madison
| | - Susan L. Thibeault
- Division of Otolaryngology–Head and Neck Surgery, University of Wisconsin–Madison
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Fast JF, Westermann KA, Laves MH, Jungheim M, Ptok M, Ortmaier T, Kahrs LA. Droplet applicator module for reproducible and controlled endoscopic laryngeal adductor reflex stimulation. BIOMICROFLUIDICS 2020; 14:044112. [PMID: 32831985 PMCID: PMC7414942 DOI: 10.1063/5.0004351] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 07/28/2020] [Indexed: 06/11/2023]
Abstract
This work presents a droplet applicator module to generate stable droplets with different muzzle energies for the reproducible endoscopic stimulation of the laryngeal adductor reflex (LAR). The LAR is a protective reflex of the human larynx; an abnormal LAR performance may cause aspiration pneumonia. A pathological LAR can be detected by evaluating its onset latency. The reflex can be triggered by shooting a droplet onto the laryngeal mucosa, which is referred to as Microdroplet Impulse Testing of the LAR (MIT-LAR). Stimulation intensity variation is desired as the reflex threshold may vary inter-individually. The kinetic energy of a droplet after detachment from the nozzle, i.e., its muzzle energy, is considered an appropriate metric for the LAR stimulation intensity. In this work, a suitable nozzle channel geometry is identified based on the experimental evaluation of droplet formation using three different nozzle channel geometries. Two nontoxic additives are evaluated regarding their effect on fluid properties and droplet formation. The range of achievable droplet muzzle energies is determined by high-speed cinematography in association with a physically motivated model of the macroscopic droplet motion. The experimental results show that sodium chloride is a suitable additive to enhance droplet stability in the studied parameter range with the proposed system. Droplet muzzle energy variation from 0.02 μ J to 1.37 μ J was achieved while preserving the formation of a single stimulation droplet. These results are an important prerequisite for a safe and reproducible LAR stimulation by MIT-LAR, which could also help to further elucidate the physiological mechanisms underlying this laryngeal reflex.
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Affiliation(s)
- J. F. Fast
- Author to whom correspondence should be addressed:
| | - K. A. Westermann
- Institute of Mechatronic Systems, Leibniz Universität Hannover, 30823 Garbsen, Germany
| | - M.-H. Laves
- Institute of Mechatronic Systems, Leibniz Universität Hannover, 30823 Garbsen, Germany
| | - M. Jungheim
- Department of Phoniatrics and Pediatric Audiology, Hannover Medical School, 30625 Hannover, Germany
| | - M. Ptok
- Department of Phoniatrics and Pediatric Audiology, Hannover Medical School, 30625 Hannover, Germany
| | - T. Ortmaier
- Institute of Mechatronic Systems, Leibniz Universität Hannover, 30823 Garbsen, Germany
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Téllez MJ, Ulkatan S, Blitzer A, Sinclair CF. Unearthing a consistent bilateral R1 component of the laryngeal adductor reflex in awake humans. Laryngoscope 2018; 128:2581-2587. [PMID: 30194734 DOI: 10.1002/lary.27249] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Maria J. Téllez
- Department of Intraoperative Neurophysiology; New York New York U.S.A
| | - Sedat Ulkatan
- Department of Intraoperative Neurophysiology; New York New York U.S.A
| | - Andrew Blitzer
- New York Center for Voice and Swallowing Disorders; New York New York U.S.A
| | - Catherine F. Sinclair
- Department of Otolaryngology Head and Neck Surgery; Mount Sinai West Hospital; New York New York U.S.A
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Sinclair CF, Téllez MJ, Tapia OR, Ulkatan S. Contralateral R1 and R2 components of the laryngeal adductor reflex in humans under general anesthesia. Laryngoscope 2017; 127:E443-E448. [PMID: 28776686 DOI: 10.1002/lary.26744] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 05/22/2017] [Indexed: 11/10/2022]
Affiliation(s)
- Catherine F. Sinclair
- Department of Otolaryngology Head and Neck Surgery; Mount Sinai West Hospital; New York New York U.S.A
| | - Maria J. Téllez
- Department of Intraoperative Neurophysiology; Mount Sinai West Hospital; New York New York U.S.A
| | - Oscar R. Tapia
- Department of Intraoperative Neurophysiology; Mount Sinai West Hospital; New York New York U.S.A
| | - Sedat Ulkatan
- Department of Otolaryngology Head and Neck Surgery; Mount Sinai West Hospital; New York New York U.S.A
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10
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Mor N, Simonyan K, Blitzer A. Central voice production and pathophysiology of spasmodic dysphonia. Laryngoscope 2017; 128:177-183. [PMID: 28543038 DOI: 10.1002/lary.26655] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 01/27/2017] [Accepted: 04/03/2017] [Indexed: 01/12/2023]
Abstract
OBJECTIVE Our ability to speak is complex, and the role of the central nervous system in controlling speech production is often overlooked in the field of otolaryngology. In this brief review, we present an integrated overview of speech production with a focus on the role of central nervous system. The role of central control of voice production is then further discussed in relation to the potential pathophysiology of spasmodic dysphonia (SD). DATA SOURCES Peer-review articles on central laryngeal control and SD were identified from PUBMED search. Selected articles were augmented with designated relevant publications. REVIEW METHODS Publications that discussed central and peripheral nervous system control of voice production and the central pathophysiology of laryngeal dystonia were chosen. RESULTS Our ability to speak is regulated by specialized complex mechanisms coordinated by high-level cortical signaling, brainstem reflexes, peripheral nerves, muscles, and mucosal actions. Recent studies suggest that SD results from a primary central disturbance associated with dysfunction at our highest levels of central voice control. The efficacy of botulinum toxin in treating SD may not be limited solely to its local effect on laryngeal muscles and also may modulate the disorder at the level of the central nervous system. CONCLUSION Future therapeutic options that target the central nervous system may help modulate the underlying disorder in SD and allow clinicians to better understand the principal pathophysiology. LEVEL OF EVIDENCE NA.Laryngoscope, 128:177-183, 2018.
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Affiliation(s)
- Niv Mor
- Maimonides Medical Center, Voice and Swallowing Disorders, Division of Otolaryngology-Head and Neck Surgery, Brooklyn
| | - Kristina Simonyan
- Department of Neurology, The Icahn School of Medicine at Mount Sinai, New York, New York, U.S.A.,Department of Otolaryngology-Head and Neck Surgery, The Icahn School of Medicine at Mount Sinai, New York, New York, U.S.A
| | - Andrew Blitzer
- Department of Neurology, The Icahn School of Medicine at Mount Sinai, New York, New York, U.S.A.,New York Center for Voice and Swallowing Disorders, New York, New York, U.S.A
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Cunningham JJ, Halum SL, Butler SG, Postma GN. Intraobserver and Interobserver Reliability in Laryngopharyngeal Sensory Discrimination Thresholds: A Pilot Study. Ann Otol Rhinol Laryngol 2016; 116:582-8. [PMID: 17847725 DOI: 10.1177/000348940711600805] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objectives: Laryngopharyngeal sensory discrimination threshold (LPSDT) testing is a method used to detect sensory deficits in patients in whom swallowing disorders are suspected. LPSDTs have been used to stratify patient risk status with regard to aspiration and to guide dietary management. The aim of this pilot study was to evaluate the intraobserver and interobserver reliability of LPSDT testing among a group of examiners with differing levels of testing experience. Methods: Twenty-seven healthy volunteers were enrolled in the study to elicit LPSDTs for intraobserver and interobserver reliability measurements. The examiners represented 3 levels of testing experience: An attending laryngologist, a laryngology fellow, and an otolaryngology resident. With the examiners blinded to test results, each subject was examined twice by one examiner and once by a different examiner in an alternating fashion. Results: Six subjects were unable to tolerate the examinations because of coughing and gagging. Spearman rank correlations revealed strong intraobserver reliability for the experienced endoscopists (ie, attending and fellow) but poor reliability for the novice endoscopist (ie, resident). Poor interobserver reliability regardless of endoscopy experience was found. Eighteen percent of the participants demonstrated LPSDTs of more than 4.0 mm Hg (above normal). Conclusions: 1) Intraobserver reliability was good for experienced endoscopists. 2) Interobserver LPSDT agreement between endoscopists was poor. 3) Eighteen percent of the subjects demonstrated elevated LPSDT thresholds of more than 4 mm Hg.
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Affiliation(s)
- Jeffrey J Cunningham
- Center for Voice and Swallowing Disorders, Department of Otolaryngology, Wake Forest University Baptist Medical Center, Winston-Salem, North Carolina, USA
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12
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Abstract
This review examines the current level of knowledge and techniques available for the study of laryngeal reflexes. Overall, the larynx is under constant control of several systems (including respiration, swallowing and cough) as well as sensory motor reflex responses involving glossopharyngeal, pharyngeal, laryngeal, and tracheobronchial sensory receptors. Techniques for the clinical assessment of these reflexes are emerging and need to be examined for sensitivity and specificity in identifying laryngeal sensory disorders. Quantitative assessment methods for the diagnosis of sensory reductions and sensory hypersensitivity may account for laryngeal disorders, such as chronic cough, paradoxical vocal fold disorder, and muscular tension dysphonia. The development of accurate assessment techniques could improve our understanding of the mechanisms involved in these disorders.
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Sun QJ, Chum JM, Bautista TG, Pilowsky PM, Berkowitz RG. Neuronal mechanisms underlying the laryngeal adductor reflex. Ann Otol Rhinol Laryngol 2012; 120:755-60. [PMID: 22224318 DOI: 10.1177/000348941112001110] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVES Electromyographic studies of the laryngeal adductor reflex, glottal closure occurring in response to laryngeal stimulation, have demonstrated an early ipsilateral response (R1) and a late bilateral response (R2). To better define the physiologic properties of these responses, we recorded responses from expiratory laryngeal motoneurons (ELMs) in rats during stimulation of the superior laryngeal nerve (SLN). METHODS Single unit extracellular recordings were obtained from 5 ELMs, identified by their antidromic responses to recurrent laryngeal nerve stimulation and postinspiratory firing pattern, in 4 Sprague-Dawley rats. RESULTS Unilateral stimulation of the SLN (at 20 Hz) stopped both phrenic nerve inspiratory activity and ELM postinspiratory activity. However, the ELMs displayed robust tonic firing, consisting of non-respiratory burst activity and single action potentials. The single action potentials were identified as short-latency ones (5 to 10 ms) activated by ipsilateral SLN stimulation, with an occurrence rate of 90%, and long-latency ones (20 to 50 ms) activated by bilateral SLN stimulation, with occurrence rates of 47% on the ipsilateral side and 58% on the contralateral side. CONCLUSIONS The R1 response appears to be the result of the short-latency action potentials, orthodromically activated by ipsilateral stimulation of the SLN. The R2 response is likely to be a result of the long-latency action potentials that can be recorded from ELMs on both sides.
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Affiliation(s)
- Qi-Jian Sun
- Australian School of Advanced Medicine, Macquarie University, Sydney, Australia
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14
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Ludlow CL. Central nervous system control of interactions between vocalization and respiration in mammals. Head Neck 2011; 33 Suppl 1:S21-5. [DOI: 10.1002/hed.21904] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/05/2011] [Indexed: 11/07/2022] Open
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Chapin WJ, Hoffman MR, Rieves AL, Jiang JJ. Comparison of labial and mechanical interruption for measurement of aerodynamic parameters. J Voice 2010; 25:337-41. [PMID: 20189755 DOI: 10.1016/j.jvoice.2010.01.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Accepted: 01/06/2010] [Indexed: 11/24/2022]
Abstract
OBJECTIVES/HYPOTHESIS To directly compare the mechanical and labial interruption techniques of measuring subglottal pressure (P(s)), mean flow rate (MFR), and laryngeal resistance (R(L)). METHODS Thirty-four subjects performed 10 trials with both mechanical and labial interruption. P(s) and MFR were recorded, whereas R(L) was calculated by dividing P(s) by MFR. Coefficients of variation were calculated to compare intrasubject precision. A subset of 10 subjects performed the tasks twice with 30 minutes between sessions. Bland-Altman plots were used to determine intrasubject repeatability for each of the methods. RESULTS Mechanical interruption produced coefficients of variation for P(s), MFR, and R(L) of 0.0995, 0.127, and 0.129, respectively. Labial interruption produced coefficients of variation of 0.102, 0.147, and 0.169, respectively. P values were 0.824 for P(s), 0.159 for MFR, and 0.043 for R(L). The Bland-Altman plots revealed comparable repeatability between the two methods. The 95% confidence intervals of the Bland-Altman plots for mechanical interruption were (-0.050, 0.072), (-0.543, 1.832), and (-2.498, 10.528) for MFR, P(s), and R(L). Confidence intervals for labial interruption were (-0.018, 0.031), (0.057, 2.442), and (-3.267, 10.595) for MFR, P(s,) and R(L). CONCLUSIONS Mechanical interruption produced higher precision when measuring R(L) because of more reliable airflow measurements. Mechanical and labial interruption showed comparable repeatability. Further research into using mechanical interruption clinically is warranted.
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Affiliation(s)
- William J Chapin
- Division of Otolaryngology-Head and Neck Surgery, Department of Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
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Rieves AL, Regner MF, Jiang JJ. Phonation threshold pressure estimation using electroglottography in an airflow redirection system. Laryngoscope 2010; 119:2378-83. [PMID: 19688842 DOI: 10.1002/lary.20611] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVES/HYPOTHESIS The present study proposed to estimate phonation threshold pressure (PTP) noninvasively using airflow redirection into a pneumatic capacitance system. STUDY DESIGN Prospective study. METHODS Subjects phonated into the device, which interrupts airflow mechanically and redirects the flow into a pneumatic capacitor. Five interruptions were effected per trial. PTP was estimated as the difference between subglottal pressure (SGP) and transglottal pressure at phonation offset. The novel method was tested for consistency in 20 normal human subjects at low (75 dB) and high (85 dB) sound pressure levels. The device was tested for validity on a tracheotomy patient. RESULTS Mean SGP was 9.02 +/- 3.27 cm H(2)O, and mean PTP was 3.68 +/- 1.41 cm H(2)O. Intrasubject coefficient of variation, a measure of intrasubject consistency, was 0.33 +/- 0.23. Statistically significant differences existed between the means of SGP but not PTP at 75 dB and 85 dB. The correlation coefficient between accepted and experimental SGP in a tracheotomy patient was 0.947 (P < .001). CONCLUSIONS Measurements corresponded well to previously reported values, and intrasubject variability was low, indicating the device was consistent. Testing on a tracheotomy patient demonstrated validity. More research is needed to determine the sensitivity and specificity of the device in differentiating between normal and pathological voices. This device may have clinical application as a noninvasive and reliable method of estimating PTP and indicating that laryngeal health is likely abnormal.
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Affiliation(s)
- Adam L Rieves
- Department of Surgery, Division of Otolaryngology-Head and Neck Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin 53706, USA
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17
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Rieves AL, Hoffman MR, Jiang JJ. Indirect estimation of laryngeal resistance via airflow redirection. Ann Otol Rhinol Laryngol 2009; 118:124-30. [PMID: 19326763 DOI: 10.1177/000348940911800208] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVES Our aim was to estimate aerodynamic parameters of laryngeal resistance (RL) and aerodynamic power indirectly from a subglottal pressure (Ps) data trace obtained with the airflow redirection system. METHODS During airflow interruption, the airflow redirection tank fills capacitively with pressure until it reaches the subject's Ps. Therefore, a time constant, tau, can be extracted from the data trace and used to calculate RL. The validity of applying this method to the estimation of RL was demonstrated with a computer model. Estimations were made for values of 10, 20, 30, 40, and 50 cm H2O per liter per second (L/s). Twenty subjects performed 10 trials on the experimental system designed to measure Ps. The values of RL and aerodynamic power were then calculated. RESULTS The computer model simulation yielded a maximum measurement error of 3.00% and a mean error of 1.78%. In human subject testing, the mean +/- SD laryngeal resistance was 22.61 +/- 8.65 cm H2O per L/s, the mean Ps was 6.91 +/- 1.94 cm H2O, and the mean aerodynamic power was 0.247 +/- 0.170 kPa x (L/s). CONCLUSIONS The proposed method of data analysis enables a clinician to estimate RL and aerodynamic power from a single experimental trial designed to measure Ps. This technique provides the clinician with an aerodynamic function report that can be used to analyze patient health and treatment efficacy.
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Affiliation(s)
- Adam L Rieves
- Department of Surgery, Division of Otolaryngology-Head and Neck Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
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18
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Ludlow CL, Adler CH, Berke GS, Bielamowicz SA, Blitzer A, Bressman SB, Hallett M, Jinnah HA, Juergens U, Martin SB, Perlmutter JS, Sapienza C, Singleton A, Tanner CM, Woodson GE. Research priorities in spasmodic dysphonia. Otolaryngol Head Neck Surg 2008; 139:495-505. [PMID: 18922334 DOI: 10.1016/j.otohns.2008.05.624] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2007] [Revised: 05/02/2008] [Accepted: 05/28/2008] [Indexed: 10/21/2022]
Abstract
OBJECTIVE To identify research priorities to increase understanding of the pathogenesis, diagnosis, and improved treatment of spasmodic dysphonia. STUDY DESIGN AND SETTING A multidisciplinary working group was formed that included both scientists and clinicians from multiple disciplines (otolaryngology, neurology, speech pathology, genetics, and neuroscience) to review currently available information on spasmodic dysphonia and to identify research priorities. RESULTS Operational definitions for spasmodic dysphonia at different levels of certainty were recommended for diagnosis and recommendations made for a multicenter multidisciplinary validation study. CONCLUSIONS The highest priority is to characterize the disorder and identify risk factors that may contribute to its onset. Future research should compare and contrast spasmodic dysphonia with other forms of focal dystonia. Development of animal models is recommended to explore hypotheses related to pathogenesis. Improved understanding of the pathophysiology of spasmodic dysphonia should provide the basis for developing new treatment options and exploratory clinical trials. SIGNIFICANCE This document should foster future research to improve the care of patients with this chronic debilitating voice and speech disorder by otolaryngology, neurology, and speech pathology.
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Affiliation(s)
- Christy L Ludlow
- Laryngeal and Speech Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 10 Center Drive, Bethesda, MD 20892, USA
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19
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Hoffman MR, Baggott CD, Jiang J. Reliable time to estimate subglottal pressure. J Voice 2008; 23:169-74. [PMID: 18207358 DOI: 10.1016/j.jvoice.2007.09.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2007] [Accepted: 09/13/2007] [Indexed: 11/27/2022]
Abstract
Measuring subglottal pressure (P(s)) with complete interruption can be problematic due to unsteady plateaus in supraglottal pressure data traces during balloon valve interruption. Subjectively determining when the graph plateaus neglect the effects of laryngeal, auditory, and other physical reflexes may alter patient effort and glottal configuration. If the P(s) estimation was made at a consistent time before the onset of reflexes, the recorded pressure would not be dependent on subjective analysis by a clinician, and intrasubject data would be more precise. Previously collected data using the airflow interruption system have shown consistency at approximately 150 milliseconds after balloon valve inflation. To evaluate the validity of estimating P(s) at this point, a theoretical and a physical model were applied. A theoretical ideal gas model of capacitance calculated the time necessary for supraglottal pressure to equilibrate with P(s). Using a mechanical pseudolung which served as a constant pressure source, known subresistor pressures were compared to the pressure measured by the interruption device. Both models confirmed the validity of measuring P(s) consistently at 150 milliseconds into the 500-millisecond interruption. In human trials testing 25 subjects, mean intrasubject standard deviation using this optimal time constant was 0.66+/-0.37cm H(2)O, and 1.11+/-0.48cm H(2)O when performing plateau analysis (P<0.0005). This novel modification to the clinically feasible interruption model for P(s) estimation demonstrates a marked improvement in the reliability of balloon valve interruption while maintaining the validity demonstrated in previous studies.
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Affiliation(s)
- Matthew R Hoffman
- Department of Surgery, Division of Otolaryngology-Head and Neck Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53706, USA
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20
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Vertigan AE, Gibson PG, Theodoros DG, Winkworth AL. The role of sensory dysfunction in the development of voice disorders, chronic cough and paradoxical vocal fold movement. INTERNATIONAL JOURNAL OF SPEECH-LANGUAGE PATHOLOGY 2008; 10:231-244. [PMID: 20840039 DOI: 10.1080/17549500801932089] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Sensory function may be important in the pathogenesis of Chronic Cough (CC) and Paradoxical Vocal Fold Movement (PVFM). This paper aims to explore sensory issues related to the pathogenesis, classification, assessment and management of these conditions. Sensory disruption of the vagus nerve can occur through neural plasticity whereby a change occurs in the way a central neuron reacts to an incoming stimulus. Such disruption can be demonstrated through assessment of cough reflex sensitivity and extrathoracic airway hyperresponsiveness both of which may be increased in CC and PVFM. In addition, sensory function may be determined by measuring the laryngeal adductor reflex, however this phenomenon is yet to be explored in CC and PVFM. The similarity in sensory dysfunction between CC and PVFM provides support for a link between the two conditions. There are also similarities in underlying medical conditions and symptom profiles between CC/PVFM and voice disorders such as muscle tension dysphonia. Although coughing and throat clearing may be contributing factors in the development and maintenance of voice disorders, they may occur in response to extrathoracic airway hyperresponsiveness. Dysphonia can occur in CC/PVFM and may improve following behavioural treatment of CC.
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Affiliation(s)
- Anne E Vertigan
- Speech Pathology Department, John Hunter Hospital, Newcastle, Australia
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21
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Henriquez VM, Schulz GM, Bielamowicz S, Ludlow CL. Laryngeal reflex responses are not modulated during human voice and respiratory tasks. J Physiol 2007; 585:779-89. [PMID: 17962327 DOI: 10.1113/jphysiol.2007.143438] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The laryngeal adductor response (LAR) is a protective reflex that prevents aspiration and can be elicited either by electrical stimulation of afferents in the superior laryngeal nerve (SLN) or by deflection of mechanoreceptors in the laryngeal mucosa. We hypothesized that because this reflex is life-sustaining, laryngeal muscle responses to sensory stimuli would not be suppressed during volitional laryngeal tasks when compared to quiet respiration. Unilateral electrical superior laryngeal nerve stimulation was used to elicit early (R1) and late (R2) responses in the ipsilateral thyroarytenoid muscle in 10 healthy subjects. The baseline levels of muscle activity before stimulation, R1 and R2 response occurrence and the integrals of responses were measured during each task: quiet inspiration, prolonged vowels, humming, forced inhalation and effort closure. We tested whether R1 response integrals during tasks were equal to either: (1) baseline muscle activity during the task added to the response integral at rest; (2) the response integral at rest minus the baseline muscle activity during the task; or (3) the response integral at rest. R1 response occurrence was not altered by task from rest while fewer R2 responses occurred only during effort closure and humming compared to rest. Because the R1 response integrals did not change from rest, task increases in motor neuron firing did not alter the LAR. These findings demonstrate that laryngeal motor neuron responses to sensory inputs are not gated during volitional tasks confirming the robust life-sustaining protective mechanisms provided by this airway reflex.
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Affiliation(s)
- Victor M Henriquez
- Laryngeal and Speech Section, National Institute of Neurological Disorders and Stroke/NIH, 10 Center Drive MSC 1416, Bethesda, MD 20892-1416, USA
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Baggott CD, Yuen AK, Hoffman MR, Zhou L, Jiang JJ. Estimating subglottal pressure via airflow redirection. Laryngoscope 2007; 117:1491-5. [PMID: 17762273 DOI: 10.1097/mlg.0b013e318063e89e] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Subglottal pressure (SGP) is a valuable parameter in the research and clinical assessment of laryngeal function. The lungs serve as a constant pressure source during sustained phonation, and that pressure, SGP, can be used to determine the efficiency with which the larynx converts aerodynamic power to acoustic power. As the larynx serves as an aerodynamic transducer, the vocal efficiency (Ve) coefficient, defined as acoustic power (dB) divided by aerodynamic power (SGP x glottal airflow) has been shown to reliably reflect vocal health. However, current SGP measurement techniques are hesitantly used because of either an invasive nature or the requirement of intensive patient training. This study tests a novel device that has been designed to noninvasively estimate SGP through mechanical airflow redirection, producing a numeric output on completion of the trial, which lasts only a few seconds. The novelty of this design lies in the ease of use for both the patient and the clinician. Multiple mechanical airflow redirections occlude the airway for only 135 ms, which is predicted to limit the effect of confounding laryngeal reflexes that may occur during the trials. Additionally, the airflow redirection into a retention device allows for the pneumatic in-trial comparison of the estimated SGP with the pressure achieved by the patient, providing a numeric output to the clinician on completion.
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Affiliation(s)
- Christopher D Baggott
- Department of Surgery, Division of Otolaryngology-Head and Neck Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53792-7375, USA
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Ludlow CL. Central nervous system control of the laryngeal muscles in humans. Respir Physiol Neurobiol 2005; 147:205-22. [PMID: 15927543 PMCID: PMC1351146 DOI: 10.1016/j.resp.2005.04.015] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2004] [Revised: 04/01/2005] [Accepted: 04/01/2005] [Indexed: 11/15/2022]
Abstract
Laryngeal muscle control may vary for different functions such as: voice for speech communication, emotional expression during laughter and cry, breathing, swallowing, and cough. This review discusses the control of the human laryngeal muscles for some of these different functions. Sensori-motor aspects of laryngeal control have been studied by eliciting various laryngeal reflexes. The role of audition in learning and monitoring ongoing voice production for speech is well known; while the role of somatosensory feedback is less well understood. Reflexive control systems involving central pattern generators may contribute to swallowing, breathing and cough with greater cortical control during volitional tasks such as voice production for speech. Volitional control is much less well understood for each of these functions and likely involves the integration of cortical and subcortical circuits. The new frontier is the study of the central control of the laryngeal musculature for voice, swallowing and breathing and how volitional and reflexive control systems may interact in humans.
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Affiliation(s)
- Christy L Ludlow
- Laryngeal and Speech Section, Medical Neurology Branch, National Institute of Neurological Disorders and Stroke/NIH, Building 10, Room 5D 38, 10 Center Drive MSC 1416, Bethesda, MD 20892, USA.
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