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

Examining the Influence of Chemosensation on Laryngeal Health and Disorders

Inhaled airborne stimuli are associated with laryngeal disorders affecting respiration. Clinically, several themes emerged from the literature that point to specific gaps in the understanding and management of these disorders. There is wide variation in the types of airborne stimuli that trigger symptoms, lack of standardization in provocation challenge testing using airborne stimuli, and vague reporting of laryngeal symptoms. Scientifically, evidence exists outside the field of voice science that could prove useful to implement among patients with impaired laryngeal-respiration. To expand this area of expertise, here we provide a thematic overview of relevant evidence and methodological tools from the discipline of chemosensory sciences. This review provides distinctions across the three chemosensory systems of olfaction, trigeminal chemesthesis, and gustation, guidance on selecting and delivering common chemosensory stimuli for clinical testing, and methods of quantifying sensory experiences using principles of human psychophysics. Investigating the science of chemosensation reveals that laryngeal responses to inhaled airborne stimuli have explanations involving physiological mechanisms as well as higher cognitive processing. Fortunately, these findings are consistent with current pharmacological and nonpharmacological interventions for impaired laryngeal-respiration. Based on the close relationships among inhaled airborne stimuli, respiration, and laryngeal function, we propose that new perspectives from chemosensory sciences offer opportunities to improve patient care and target areas of future research.

A systematic review and meta-analysis of neuromodulators to treat chronic airway hypersensitivity

OBJECTIVES

Chronic laryngitis can present with numerous symptoms, including chronic cough. Patients who do not respond to standard treatment are sometimes diagnosed with chronic airway hypersensitivity (CAH). In many centers, neuromodulators are prescribed off-label despite limited evidence of efficacy. A previous meta-analysis suggested neuromodulator therapy improved cough-related quality-of-life (QoL). This current updated and expanded meta-analysis examined whether neuromodulators reduced cough frequency, reduced cough severity, and/or improved QoL in CAH patients.

DATA SOURCES

PubMed, Embase, Medline, Cochrane Review, and publication bibliographies were searched from 01/01/2000 to 07/31/2021 using MESH terms.

REVIEW METHODS

PRISMA guidelines were followed. 999 abstracts were identified/screened, 28 studies were fully reviewed, and 3 met inclusion criteria. Only randomized controlled trials (RCT) investigating CAH patients with comparable cough-related outcomes were included. Three authors reviewed potentially eligible papers. Fixed-effect models and calculated pooled estimates using the Inverse-Variance method were used.

RESULTS

The estimated difference in change in log coughs per hour (from baseline to intervention end) between treatment and control groups was -0.46, 95%CI [-0.97; 0.05]. Estimated change-from-baseline in VAS scores was -12.24, 95 % CI [-17.84; -6.65] lower for patients who received treatment vs placebo. Estimated change-from-baseline for LCQ scores was 2.15, 95 % CI [1.49-2.80] higher for patients who receive treatment vs placebo. Only change in LCQ score was clinically significant.

CONCLUSIONS

This study tentatively suggests that neuromodulators have the potential to reduce cough symptoms associated with CAH. However, high-quality evidence is lacking. This could be due to limited treatment effect or significant limitations in the design and comparability of existing trials. A well-designed and properly powered RCT is needed to authoritatively test the efficacy of neuromodulators for the treatment of CAH.

LEVEL OF EVIDENCE

Level I, evidence from a systematic review or meta-analysis of all relevant RCTs (randomized controlled trial) or evidence-based clinical practice guidelines based on systematic reviews of RCTs or three or more RCTs of good quality that have similar results.

Curbing the Cough: Multimodal Treatments for Neurogenic Cough: A Systematic Review and Meta-Analysis

OBJECTIVES/HYPOTHESIS

Neurogenic cough affects 11% of Americans and causes significant detriment to quality of life. With the advent of novel therapies, the objective of this review is to determine how procedural therapies (e.g., superior laryngeal nerve block) compare to other established pharmacologic and non-pharmacologic treatments for neurogenic cough.

METHODS

With the assistance of a medical librarian, a systematic review was performed using PICOS (patients, interventions, comparator, outcome, study design) format: adults with neurogenic cough receiving any pharmacologic or non-pharmacologic treatment for neurogenic cough compared to adults with neurogenic cough receiving any other relevant interventions, or treated as single cohorts, assessed with cough-specific quality of life outcomes, in all study designs and case series with ≥ 10 cases. Case reports, review articles, non-human studies, non-English language articles, and unavailable full-text articles were excluded.

RESULTS

There were 2408 patients with neurogenic cough in this review, treated with medical therapy (77%), speech therapy (19%), both medical and speech therapy (1%), and procedural therapy (3%). The included studies ranged from low to intermediate quality. Overall, most interventions demonstrated successful improvement in cough. However, the heterogeneity of included study designs precluded direct comparisons between intervention types.

CONCLUSION

This meta-analysis compared various treatments for neurogenic cough. Procedural therapy should be considered in the armamentarium of neurogenic cough treatments, particularly in patients refractory to, or intolerant of, the side effects of medical therapy. Lastly, this review illuminates key areas for improving neurogenic cough diagnosis, such as strict adherence to diagnostic and treatment guidelines, sophisticated reflux testing, and standardized, consistent outcome reporting. Laryngoscope, 132:107-123, 2022.

Laryngopharyngeal Reflux: A State-of-the-Art Algorithm Management for Primary Care Physicians

Laryngopharyngeal reflux (LPR) is a common disease in the general population with acute or chronic symptoms. LPR is often misdiagnosed in primary care because of the lack of typical gastroesophageal reflux disease (GERD) symptoms and findings on endoscopy. Depending on the physician's specialty and experience, LPR may be over- or under-diagnosed. Management of LPR is potentially entirely feasible in primary care as long as General Practitioners (GPs) are aware of certain "red flags" that will prompt referral to a Gastroenterologist or an Otolaryngologist. The use of patient-reported outcome questionnaires and the consideration of some easy ways to diagnose LPR without special instrumentation oropharyngeal findings may help the GP to diagnose and often manage LPR. In this review, we provide a practical algorithm for LPR management for GPs and other specialists that cannot perform fiberoptic examination. In this algorithm, physicians have to exclude some confounding conditions such as allergy or other causes of pharyngolaryngitis and "red flags". They may prescribe an empirical treatment based on diet and behavioral changes with or without medication, depending on the symptom severity. Proton pump inhibitors and alginates remain a popular choice in order to protect the upper aerodigestive tract mucosa from acid, weakly acid and alkaline pharyngeal reflux events.

Is empirical treatment a reasonable strategy for laryngopharyngeal reflux? A contemporary review

BACKGROUND

Diagnosis and treatment of presumed laryngopharyngeal reflux (LPR) remain controversial. Empiric medication trials remain widespread for suspected LPR despite emerging evidence against proton pump inhibitor (PPI) safety and for pepsin as a mediator of LPR symptoms. Ongoing concerns exist related to inaccurate diagnosis, the cost and morbidity of potentially unnecessary PPI prescriptions, and availability and interpretation of objective reflux testing.

OBJECTIVES

To review contemporary evidence that does and does not support empiric medication trials for presumed LPR.

METHODS

PubMed, Scopus and Cochrane Library were searched for literature about benefits, limitations and alternatives to empiric medication trial for LPR, in order to present both sides of this debate and identify best practices.

RESULTS

The majority of physicians perform prolonged empiric medication trial with PPIs for patients with suspected LPR. Because symptoms and signs of LPR are non-specific, empiric medication trials require exclusion of other conditions that can mimic LPR. Following a PPI empiric medication trial, over one-third of patients remain non-responders. The use of hypopharyngeal-oesophageal multichannel intraluminal impedance-pH monitoring (HEMII-pH) has benefits and limitations in objective diagnosis of LPR.

CONCLUSIONS

Use of PPIs for single-agent empiric medication trial does not account for possible non-responders with non-acid or mixed LPR. If LPR diagnosis remains uncertain, alginates can be added to PPI trials. HEMII-pH testing upfront is ideal for patients with suspected LPR, but not always practical; it is indicated when PPI and alginate empiric medication trials have failed or when comorbidities confuse the diagnosis. A more comprehensive, combination therapy empiric medication trial regimen may be needed.

Viral laryngitis: a mimic and a monster - range, presentation, management

PURPOSE OF REVIEW

The purpose of this review is to highlight recent literature relating to the diagnosis and treatment of some less common forms of viral laryngitis. The main conditions addressed in this review are chronic cough or postviral vagal neuropathy, varicella zoster infection of the larynx, and a condition increasingly suspected as being virally induced, idiopathic ulcerative laryngitis.

RECENT FINDINGS

Diagnosis of these conditions requires a thorough history and physical exam, and in certain cases referral to other subspecialties such as gastroenterology and pulmonology. Chronic cough due to postviral vagal neuropathy is a diagnosis of exclusion; however, recent literature does suggest that certain studies such as laryngeal electromyography can be of use in reaching a diagnosis. Treatment of this neuropathy has focused on use of neuromodulators. Treatment of laryngeal shingles and idiopathic ulcerative laryngitis has not been well defined because of the rarity of these conditions.

SUMMARY

Recent studies regarding these conditions and potential future treatment options will be discussed.

Should the Reflex Be Reflux? Throat Symptoms and Alternative Explanations

Although laryngopharyngeal reflux, also known as extraesophageal reflux (EER), was codified more than 25 years ago, it has not been characterized fully. There is no sensitive and specific diagnostic test, and its symptoms often are nonspecific and overlap with those of other conditions commonly seen in primary care and specialist practices. Otolaryngologists have an important role in the evaluation and management of these patients--they must investigate persistent reflux-attributed symptoms by direct visualization of the upper airway and larynx, and, in some circumstances, the esophagus. It is of utmost importance to rule out the possibility of malignancy, which often presents with symptoms similar to those of EER. Once cancer is excluded, many benign upper airway conditions also can masquerade as, and often incorrectly are attributed to, EER. Although reflux is a potential etiologic factor for upper-airway symptoms, it is important not to reflexively blame reflux. We discuss other etiologies that should be considered carefully for persistent symptoms.

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.