The Application of Superior Laryngeal Nerve Block for Non-Cough Laryngeal Hypersensitivity.

OBJECTIVE(S): To investigate the effect of superior laryngeal nerve (SLN) block in patients with non-cough complaints relating to laryngeal who have failed conventional medical therapy. METHODS: Retrospective chart review of 46 patients who underwent SLN block for non-cough indications between July 2019 and March 2022 was performed. Demographics, comorbidities, and patient-reported outcomes were collected. The primary diagnoses for this group included: odynophagia, throat pain, cervicalgia, muscle tension dysphonia, globus sensation, hyoid bone syndrome, and Eagle syndrome. RESULTS: The cohort underwent an average of 1.24 bilateral injections (range 0-7) and 0.87 unilateral injections (range 0-4). About 35 of 46 patients reported an average of 51.0% improvement in their symptoms, with the treatment effect lasting 7.60 weeks on average. On subgroup analysis, the patients with spasmodic dysphonia, odynophagia, and hyoid bone syndrome had the best percent improvement on average (75%-77.5%). Patients with globus sensation had the lowest percent improvement on average in response to this therapy, reporting only about 25%. Five patients experienced a mild adverse reaction immediately following injection which resolved spontaneously. CONCLUSION: The use of in-office SLN block for non-cough disorders involving the larynx requires further study with larger sample sizes to better delineate the efficacy of these applications. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:1765-1768, 2024.

Superior Laryngeal Nerve Block Response Rates in 54 Neurogenic Cough Patients.

OBJECTIVE: Neurogenic cough related to hypersensitivity of the internal branch of the superior laryngeal nerve (SLN) is often treated with neuromodulating medications, which can cause considerable side effects. An alternative therapy is steroid and local anesthetic injection of the SLN ("SLN block"), initially proposed to benefit those with lateralizing symptoms (tenderness over the thyrohyoid membrane or unilateral cough source). Our objectives are to determine if SLN block produces subjective symptomatic improvements and if repeat injections further improve symptoms, and evaluate clinical factors potentially predictive of response. METHODS: Retrospective chart review of 54 patients receiving SLN blocks at a tertiary medical academic center from January 2010 to June 2020. Medical history and anticipated predictors of positive response, including stigmata of laryngeal hypersensitivity, were recorded. Outcomes included symptomatic response, number of injections required, and side effects. Response was defined subjectively by asking patients whether the injection was beneficial and objectively by using CSI scores. RESULTS: Fifty-four patients met the inclusion criteria. Thirty-eight patients (70.4%) endorsed improvement. No variables were identified as positive predictors of response. Thirty-two of the 38 (84.2%) endorsed improvement after one injection. Six of 15 (40%) patients who failed the first injection had positive response to the second. No significant side effects were reported. CONCLUSION: No localizing symptoms, specific cough features, or aspects of the medical history helped predict response, suggesting that a broader range of patients may be offered the intervention. The majority of patients reported symptomatic improvement and repeat injections may benefit patients with initial nonresponse. LEVEL OF EVIDENCE: 4 Laryngoscope, 133:2647-2653, 2023.

Clinical Findings among Patients with Respiratory Symptoms Related to Moisture Damage Exposure at the Workplace-The SAMDAW Study.

BACKGROUND: Respiratory tract symptoms are associated with workplace moisture damage (MD). The focus of this observational clinical study was patients with workplace MD-associated symptoms, to evaluate the usefulness of different clinical tests in diagnostics in secondary healthcare with a special interest in improving the differential diagnostics between asthma and laryngeal dysfunction. METHODS: In patients referred because of workplace MD-associated respiratory tract symptoms, we sought to systematically assess a wide variety of clinical findings. RESULTS: New-onset asthma was diagnosed in 30% of the study patients. Laryngeal dysfunction was found in 28% and organic laryngeal changes in 22% of the patients, and these were common among patients both with and without asthma. Most of the patients (85%) reported a runny or stuffy nose, and 11% of them had chronic rhinosinusitis. Atopy was equally as common as in the general population. CONCLUSIONS: As laryngeal changes were rather common, we recommend proper differential diagnostics with lung function testing and investigations of the larynx and its functioning, when necessary, in cases of prolonged workplace MD-associated symptoms. Chronic rhinosinusitis among these patients was not uncommon. Based on this study, allergy testing should not play a major role in the examination of these patients.

Evidence of Possible Irritable Larynx Syndrome in Obstructive Sleep Apnea: An Epidemiologic Approach.

OBJECTIVE: "Irritable larynx syndrome" (ILS) often refers to a constellation of laryngeal-based symptoms including chronic cough (CC), diurnal dyspnea, and dysphonia. In patients with OSA, we examined: (1) the frequency, severity, comorbidity, risks and triggers of each problem, (2) whether these symptoms were compatible with stereotypic ILS and (3) the role of CPAP in their expression. STUDY DESIGN: Cross-sectional, descriptive epidemiology study. SETTING: Sleep-Wake Center at University of Utah Health Care, Salt Lake City, UT. SUBJECTS AND METHODS: Ninety-four individuals with OSA (53 men, 41 women; mean age 54.7 ± 12.8 yrs.) underwent an extensive telephone interview that addressed study objectives. RESULTS: Long-term CC, daytime breathing and voice problems were common, especially among women despite less severe OSA. Women, more than men, reported all three chronic conditions alone or in combination: CC (44% vs 11.3%), diurnal dyspnea (41.5% vs 13.2%) and voice disorders (41.5% vs 13.2%). Symptoms were not associated with age, BMI or Apnea Hypopnea Index after adjusting for sex. Although evidence supporting stereotypic ILS symptomatology was inconsistent, those participants with a voice disorder were 3.3 (95% CI = 1.8-6.0) times more likely to report CC and 2.4 (95% CI = 1.3-4.4) times more likely to experience diurnal dyspnea. Esophageal reflux, post-nasal drip, and frequent sinus infections were significantly associated with all three conditions. Triggers that provoked or made symptoms worse varied by condition and sex. Nightly, humidified CPAP use was associated with fewer symptoms overall and improved quality of life. CONCLUSIONS: Symptoms suggestive of possible ILS are common in OSA, especially among women, and lessened by nightly CPAP use.

Work-Related Upper-Airway Disorders.

Work-related rhinitis and laryngeal disorders are common and can significantly contribute to work absences and presenteeism. Each can cause respiratory symptoms that may be misdiagnosed as asthma symptoms, and each may occur as an isolated disorder or may also accompany asthma. Suspicion of these disorders and correct management require a careful medical and occupational history. Investigations for work-related rhinitis include examination of the nose, allergy skin tests, and in some cases, monitoring of peak inspiratory nasal flows at work and off work, or specific challenge tests. Work-related laryngeal disorders require assistance from an otolaryngologist and speech language pathologist.

Cough related to swallowing in asthma patients.

BACKGROUND: Occurrence of cough during swallowing is common among asthma patients, but has not been investigated in detail. OBJECTIVE: We conducted an observational study to determine the prevalence of swallowing-related cough (SRC) and its characteristics in asthma patients. METHODS: Asthma patients attending our outpatient department between May 2005 and April 2007 were interviewed to investigate if they had ever experienced SRC, as well as postnasal drip or heartburn and cough related to these conditions. RESULTS: Among 417 patients who completed the questionnaire, 121 patients (29.0%) had experienced SRC. Spicy and sour foods were the most frequent tussigenic foods, causing cough in 76.0% and 53.7% of the 121 patients, respectively. In patients without SRC, the prevalence rates of postnasal drip and postnasal drip-induced cough were 35.8% (106 of 296) and 7.8% (23 of 296), respectively. The corresponding prevalence rates in patients with SRC were 50.4% (61 of 121) and 37.2% (45 of 121), which were both significantly higher than in patients without cough (p = 0.006 and p < 0.001 respectively). In patients without SRC, the prevalence rates of heartburn and heartburn-induced cough were 22.2% (66 of 296) and 2.4% (7 of 296), respectively. The corresponding prevalence rates in patients with SRC were 45.5% (55 of 121) and 16.5% (20 of 121), with both being significantly higher than in patients without cough (p = 0.002 and p < 0.001, respectively). CONCLUSION: SRC was frequent in asthma patients, and was closely related to postnasal drip and heartburn. Irritable larynx is one of the possible underlying mechanisms of SRC. This study was registered with the University Hospital Medical Information Network clinical trials registry (registration number: UMIN000017426).

Observational cross-sectional study on Symptoms Associated to Moisture DAmage at Workplace: the SAMDAW study protocol.

INTRODUCTION: Moisture damage (MD) exposure at work has been shown to increase the risk of new onset asthma and exacerbation of asthma. However, most of the studies in this field have been questionnaire studies. A small proportion of MD-exposed workers are diagnosed with asthma. Many patients with MD exposure at work referred to secondary healthcare report intermittent hoarseness, loss of voice or difficulty to inhale, referring to functional or organic problems of the larynx. For accurate treatment, proper differential diagnostics is paramount. We present an ongoing observational study in which we describe the prevalence of respiratory, voice and other symptoms related to MD at work in patients referred to secondary healthcare. Case-control setting will be used to evaluate the frequencies of the background factors, bronchial hyperreactivity and laryngeal findings. METHODS AND ANALYSIS: The study sample consists of patients with workplace MD exposure and associated respiratory tract and/or voice symptoms referred to Tampere University Hospital. The clinical tests conducted to the study patients included comprehensive lung function tests, laboratory and skin prick tests, imaging and clinical evaluation by specialists of respiratory medicine, oto-rhino-laryngology and phoniatrics. The exposure assessment was performed by an occupational physician. The study patients filled out a questionnaire on previous illnesses and other background factors, which for comparison was also sent to 1500 Finnish-speaking people in the same hospital district randomly selected by the Finnish Population Information System. To explore how common laryngeal disorders and voice symptoms are in general, a part of the tests will be conducted to 50 asymptomatic volunteers. ETHICS AND DISSEMINATION: The regional ethics committee of Tampere University Hospital approved the study. All study subjects gave their written informed consent, which is required also from the controls. The results will be communicated locally and internationally as conference papers and journal articles.

Cough related to swallowing in asthma patients

BACKGROUND: Occurrence of cough during swallowing is common among asthma patients, but has not been investigated in detail. OBJECTIVE: We conducted an observational study to determine the prevalence of swallowing-related cough (SRC) and its characteristics in asthma patients. METHODS: Asthma patients attending our outpatient department between May 2005 and April 2007 were interviewed to investigate if they had ever experienced SRC, as well as postnasal drip or heartburn and cough related to these conditions. RESULTS: Among 417 patients who completed the questionnaire, 121 patients (29.0%) had experienced SRC. Spicy and sour foods were the most frequent tussigenic foods, causing cough in 76.0% and 53.7% of the 121 patients, respectively. In patients without SRC, the prevalence rates of postnasal drip and postnasal drip-induced cough were 35.8% (106 of 296) and 7.8% (23 of 296), respectively. The corresponding prevalence rates in patients with SRC were 50.4% (61 of 121) and 37.2% (45 of 121), which were both significantly higher than in patients without cough (p = 0.006 and p < 0.001 respectively). In patients without SRC, the prevalence rates of heartburn and heartburn-induced cough were 22.2% (66 of 296) and 2.4% (7 of 296), respectively. The corresponding prevalence rates in patients with SRC were 45.5% (55 of 121) and 16.5% (20 of 121), with both being significantly higher than in patients without cough (p = 0.002 and p < 0.001, respectively). CONCLUSION: SRC was frequent in asthma patients, and was closely related to postnasal drip and heartburn. Irritable larynx is one of the possible underlying mechanisms of SRC. This study was registered with the University Hospital Medical Information Network clinical trials registry (registration number: UMIN000017426).

Episodic Laryngeal Breathing Disorders: Literature Review and Proposal of Preliminary Theoretical Framework.

OBJECTIVE: The purposes of this literature review were (1) to identify and assess frameworks for clinical characterization of episodic laryngeal breathing disorders (ELBD) and their subtypes, (2) to integrate concepts from these frameworks into a novel theoretical paradigm, and (3) to provide a preliminary algorithm to classify clinical features of ELBD for future study of its clinical manifestations and underlying pathophysiological mechanisms. STUDY DESIGN: This is a literature review. METHODS: Peer-reviewed literature from 1983 to 2015 pertaining to models for ELBD was searched using Pubmed, Ovid, Proquest, Cochrane Database of Systematic Reviews, and Google Scholar. Theoretical models for ELBD were identified, evaluated, and integrated into a novel comprehensive framework. Consensus across three salient models provided a working definition and inclusionary criteria for ELBD within the new framework. Inconsistencies and discrepancies within the models provided an analytic platform for future research. RESULTS: Comparison among three conceptual models-(1) Irritable larynx syndrome, (2) Dichotomous triggers, and (3) Periodic occurrence of laryngeal obstruction-showed that the models uniformly consider ELBD to involve episodic laryngeal obstruction causing dyspnea. The models differed in their description of source of dyspnea, in their inclusion of corollary behaviors, in their inclusion of other laryngeal-based behaviors (eg, cough), and types of triggers. CONCLUSION: The proposed integrated theoretical framework for ELBD provides a preliminary systematic platform for the identification of key clinical feature patterns indicative of ELBD and associated clinical subgroups. This algorithmic paradigm should evolve with better understanding of this spectrum of disorders and its underlying pathophysiological mechanisms.

Muscle Tension Dysphagia: Symptomology and Theoretical Framework.

OBJECTIVE: To identify symptoms, common diagnostic findings, pattern of treatments and referrals offered, and their efficacy in a group of patients with idiopathic functional dysphagia in an otolaryngology setting with multiple providers. STUDY DESIGN: Case series with chart review. SETTING: Tertiary academic center. SUBJECTS AND METHODS: Following Mayo Clinic Institutional Review Board approval, a retrospective chart review was conducted of patients with dysphagia who had a videofluoroscopic swallow study between January 1, 2013, and April 30, 2015. Each patient's dysphagia symptomology, videofluoroscopic swallow study, flexible laryngoscopy, and medical chart were reviewed to identify the treatment paradigms that were utilized. RESULTS: Sixty-seven adult patients met the inclusion criteria. Abnormal laryngeal muscle tension was present in 97% of patients. Eighty-two percent of patients also demonstrated signs of laryngeal hyperresponsiveness. Nonspecific laryngeal inflammation was evident in 52% of patients. Twenty-seven patients were referred to speech-language pathology for evaluation. Thirteen patients completed a course of voice therapy directed toward unloading muscle tension. All 13 patients self-reported resolution of dysphagia symptoms. CONCLUSION: The study results suggest that laryngeal muscle tension may be a factor in the underlying etiology in patients with idiopathic functional dysphagia. We propose the diagnostic term muscle tension dysphagia to describe a subset of patients with functional dysphagia. Further prospective studies are needed to better evaluate potential gastroesophageal confounders in this group of patients and to identify an effective paradigm for treatment. In our limited series, speech-language pathology intervention directed toward unloading muscle tension appears effective.

Irritable Larynx Syndrome with Dyspnea

An irritable larynx syndrome is characterized by a sudden episodic dyspnea and dysphonia that is difficult to diagnose, and patients are often treated unnecessarily and/or too much. A correct diagnosis can be made by monitoring the larynx closing in the reversed direction during inhalation and posterior chink with videolaryngoscopy and by measuring a decrease in air flow volume during inhalation with a lung function test. Patients can be effectively treated with thorough differential diagnosis. Medications targeting precipitating factors, physical therapy sessions to improve abnormal larynx movement, counseling to reduce patients'anxiety rising from dyspnea, and etc. can effectively alleviate symptoms.

Postviral Vagal Neuropathy: What Is the Role of Laryngeal Electromyography in Improving Diagnostic Accuracy?

OBJECTIVES: To investigate the convenience of laryngeal electromyography (EMG) findings in patients with chronic cough thought to be postviral vagal neuropathy (PVVN) with the clinical symptoms. STUDY DESIGN: Prospective cohort study. METHODS: We applied PVVN questionnaire and chronic cough quality of life (QoL) questionnaire, which is for determining the effect of chronic cough on the QoL, to 20 chronic cough applicants who has no explanatory cause in differential diagnosis. We also carried out videolaryngostroboscopy (VLS) and laryngeal needle EMG in these patients. RESULTS: The mean duration of persisting cough was 1.875 months (SD ±0.825). The overall mean symptom score of chronic cough questionnaire was 58.80 (SD ±9.89). There was a significant positive correlation between total EMG score and chronic cough score (Spearman r, 0.489, P < 0.05). The correlation between VLS findings and either chronic cough scores or EMG scores did not reach statistical significance. CONCLUSIONS: Cranial nerves might be affected by inflammatory processes as occur in the PVVN, which must be considered in the etiology of chronic cough. We showed that the laryngeal EMG can be used as an appropriate diagnostic tool for these patients.

Management of chronic laryngopharyngeal neuropathy in the United States and Europe.

OBJECTIVE: This study aimed to analyze differences in the evaluation of laryngopharyngeal neuropathy by laryngologists in the United States and Europe. METHODS: Members of the American Laryngological Association (ALA) and the European Laryngological Society (ELS) were surveyed. Questionnaires were emailed to all 179 members of the ALA and all 324 members of the ELS. RESULTS: Of the ALA members surveyed, 40 (23.3%) responded, compared to 72 members (22.2%) of the ELS group. Of the ALA respondents, 79.5% identified laryngology as their primary area of practice, whereas 56.9% of ELS respondents identified devoting more than 50% of their practice to laryngology. Of ELS laryngologists, 81.1% received training in laryngology or associated subspecialties. For diagnosing laryngopharyngeal neuropathy, the average comfort level on the Likert scale was significantly greater for ALA members than ELS members (P<.01). Furthermore, ALA laryngologists were less likely to consider laryngopharyngeal reflux as an overdiagnosed condition compared to ELS laryngologists (P<.05). CONCLUSION: Laryngologists in the United States and Europe vary significantly in their familiarity with laryngopharyngeal neuropathy. This could reflect either differences in awareness concerning this condition or a more critical perspective of European providers regarding the chronic laryngopharyngeal neuropathy (CLPN) diagnosis. As CLPN is still lacking definitive proof, the addition of European researchers could aid in validating CLPN and determining its overall effect on the chronic cough population.

U.S. practice variations in the treatment of chronic laryngopharyngeal neuropathy.

OBJECTIVES/HYPOTHESIS: To evaluate differences in evaluation and workup of laryngopharyngeal neuropathy in a population of general otolaryngologists and fellowship-trained laryngologists. STUDY DESIGN: Survey. METHODS: Members of the American Laryngological Association (ALA) and a general otolaryngologist database from the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) were surveyed. A questionnaire was e-mailed or mailed to 179 members of the ALA and 900 members from the AAO-HNS database. RESULTS: Responses were received from 43 subjects in the ALA group (24.5%) and 96 in the AAO-HNS database group (10.6%). Compared to the general otolaryngologists surveyed, ALA members were found to be more likely to practice in academics (79.6% vs. 6.6%) and to have been fellowship trained (79.5% vs. 16.5%). Among the general otolaryngologists, 44.6% reported being unfamiliar with laryngopharyngeal neuropathy compared to 0% from the ALA group (P < .0001). After accounting for the respondents unfamiliar with the condition, the general otolaryngologists reported being less comfortable in diagnosing laryngopharyngeal neuropathy (P < .0001) and were more concerned about the over-diagnosis of laryngopharyngeal reflux when compared to the ALA (P = .0030). CONCLUSION: General otolaryngologists and fellowship-trained laryngologist have several differences in the knowledge, workup, and treatment of chronic laryngopharyngeal neuropathy. This may translate to unnecessary treatments and tests for effected patients and should be addressed with further education targeting general otolaryngologists. LEVEL OF EVIDENCE: 4.