The Relationship Between Chronic Cough and Laryngopharyngeal Reflux

Glottic Insufficiency in the Vertical Plane in Patients With Unknown-Source Unilateral Vocal Fold Hypomobility

OBJECTIVE

To observe the laryngeal CT and strobe laryngoscopy signs of unilateral vocal fold hypomobility (UVFHM) in patients with well-closed glottises in the horizontal plane.

METHODS

A retrospective analysis was performed on 18 subjects with well-closed glottises in the horizontal plane using strobe laryngoscopy, 9 patients diagnosed with unilateral vocal fold hypomobility with an unknown etiology were enrolled in the UVFHM group, and 9 healthy matched subjects with symmetrical bilateral vocal fold movement were enrolled in the control group. Vertical plane distances of bilateral vocal folds and three-dimensional structural parameters of vocal folds were measured through laryngeal CT. Glottic insufficiency in the vertical plane and reflux findings scores (RFS) were assessed under laryngeal CT and strobe laryngoscopy. Reflux symptom index (RSI) were collected. SPSS25.0 software was used for statistical analysis.

RESULTS

The height differences in vertical plane and thicknesses of bilateral vocal folds in the UVFHM group were larger than those in the control (P < 0.05), while the length, width and subglottic convergence angle of the vocal folds were not statistically significant between the two groups (P > 0.05). In the UVFHM group, laryngeal CT showed that 77.78% of patients (7/9) had glottic insufficiency in the vertical plane, with height differences ranging from 0.3 to 1.9 mm and a mean of 0.76mm. However, strobe laryngoscopy showed that 33.33% (3/9) had glottic insufficiency in the vertical plane. The proportion of patients with glottic insufficiency in vertical plane in the UVFHM group was significantly higher than that in the control group (P < 0.05). RSI and RFS scores of the UVFHM group were higher than those of the control group (P < 0.05).

CONCLUSION

Glottic insufficiency in the vertical plane often occurred in patients with UVFHM with an unknown cause of hoarseness, so the presence of glottic insufficiency in the vertical plane should be considered when hoarseness is detected by clinicians. Laryngeal dynamic CT can enhance the diagnostic rate compared to strobe laryngoscopy. Unexplained UVFHM patients have higher RSI and RFS compared to control subjects, warranting further research about the relationship between UVFHM and laryngopharyngeal reflux.

The Effects of Hard Voice Onset on Objective Voice Function in Patients With Laryngopharyngeal Reflux

OBJECTIVE

Laryngopharyngeal reflux (LPR) causes laryngopharyngeal hypersensitivity and laryngeal muscle hyperfunction, which may result in hard voice onset in patients with LPR. The purpose of this study is to examine the incidence of hard voice onset in patients with LPR and the effects of hard voice onset on objective voice function in patients with LPR.

METHODS

Forty patients with confirmed LPR were enrolled in the LPR group, and 40 healthy subjects were enrolled in the non-LPR group. Subjects underwent laryngeal high-speed videoendoscopy, and the presence or absence of hard voice onset in each subject was determined by two experienced laryngologists based on whether glottal closure was complete or incomplete before vocal fold vibration. Based on the results, the subjects with LPR were divided into a hard voice onset group and a non-hard voice onset group. The voice onset time (VOT) was measured and compared between the hard and non-hard voice onset groups within the LPR group. Laryngeal aerodynamic assessment was also carried out on the LPR group, and subglottal pressure, phonation threshold pressure (PTP), glottal resistance, and mean flow rate were measured. The voice acoustic signals of subjects were additionally analyzed in the LPR group, and the fundamental frequency, jitter, shimmer, and noise-harmony ratio were determined. The kappa statistic, chi-square test and independent-samples t test in SPSS were used for statistical analysis.

RESULTS

The two laryngologists had substantial inter-rater consistency on the evaluation of hard voice onset and non-hard voice onset, with a kappa statistic of 0.71. In the LPR group, 42.5% of patients had hard voice onset (17/40), significantly more than in the non-LPR group (8/40, 20%) (P < 0.05). The VOT in the LPR group was significantly longer than in the non-LPR group (P < 0.05). Within the LPR group, the VOT, PTP and shimmer were significantly greater in the hard voice onset group than in the non-hard voice onset group (all P < 0.05). The other laryngeal aerodynamic parameters and acoustic parameters were not significantly different between the hard voice onset group and the non-hard voice onset group (P > 0.05).

CONCLUSION

Changes in vocal production may occur in LPR patients, causing them to be more susceptible to hard voice onset. The patients with hard voice onset require longer VOT and greater PTP to initiate phonation.

Manometric Abnormalities in Patients With and Without Chronic Cough

PURPOSE

This study examines the relationship between chronic cough and vagal hypersensitivity by measuring baseline esophageal motility, with interest in the upper esophageal sphincter (UES).

MATERIALS AND METHODS

Patients undergoing workup for dysphagia were assigned to a chronic cough or control group based on self-reported symptoms. Differences in demographics, medical comorbidities, and high resolution esophageal manometry findings were obtained retrospectively.

RESULTS

62.5% of our cohort had chronic cough (30/48). There were no significant differences between the two groups with respect to sex, age, and race/ethnicity. Laryngopharyngeal reflux (LPR) was the only statistically significant predictor of CC (OR 74.04, p = 0.010). Cough patients had upper esophageal sphincter relaxation duration (734 ms) significantly longer than the non-cough patients (582 ms; p = 0.03), though both groups had similar upper esophageal mean basal pressure, mean residual pressure, relaxation time-to-nadir, and recovery time. No significant difference was found in the median intrabolus pressure and UES motility mean peak pressure between groups.

CONCLUSION

Subtle differences in high-resolution manometry between patients with and without cough suggest, in line with previous studies, baseline alterations of upper esophageal function may manifest in patients with chronic cough through an undetermined mechanism that may include underlying vagal hypersensitivity. These findings encourage further manometric study examining the relationship between UES dysfunction and chronic cough.

Narrative review of relationship between chronic cough and laryngopharyngeal reflux

Gastroesophageal reflux disease (GERD) as a possible cause of chronic cough is known for decades. However, more than 75% of patients with extraoesophageal symptoms do not suffer from typical symptoms of GERD like pyrosis and regurgitations and have negative upper gastrointestinal endoscopy. For such a condition term laryngopharyngeal reflux (LPR) was introduced and is used for more than two decades. Since the comprehensive information on relationship between chronic cough and LPR is missing the aim of this paper is to summarize current knowledge based on review of published information during last 13 years. Laryngopharyngeal reflux is found in 20% of patients with chronic cough. The main and recognized diagnostic method for LPR is 24-h multichannel intraluminal impedance-pH (MII-pH) monitoring, revealing reflux episodes irritating the upper and lower respiratory tract mucosa. The treatment of LPR should be initiated with dietary and lifestyle measures, followed by proton pump inhibitor (PPI) therapy and other measures. Despite progress, more research is needed for accurate diagnosis and targeted therapies. Key areas for exploration include biomarkers for diagnosis, the impact of non-acid reflux on symptom development, and the efficacy of new drugs. Further studies with a focused population, excluding other causes like asthma, and using new diagnostic criteria for LPR are essential. It's crucial to consider LPR as a potential cause of unexplained chronic cough and to approach diagnosis and treatment with a multidisciplinary perspective.

Voice Hoarseness with Reflux as a Suspected Etiology: Incidence, Evaluation, Treatment, and Symptom Outcomes

PURPOSE

To describe the clinical evaluation course, treatments, and outcomes of patients with a primary complaint of hoarseness due to suspected laryngopharyngeal reflux (LPR).

METHODS

A retrospective chart review was conducted of patients with a primary complaint of hoarseness with acid reflux as the suspected cause at a single institution between October 2011 and March 2020 who underwent clinical evaluation, treatment, and follow-up. Data collected included diagnostic procedures and treatments received, subjective symptom outcomes, and final diagnosis as determined by the treating physician.

RESULTS

A total of 134 patients met the inclusion criteria. Videostroboscopy was the most performed procedure (n = 59, 44%) followed by endoscopy (n = 38, 28%) and pH monitoring (n = 28, 21%). Three patients were removed for statistical analysis of treatment differences and outcomes due to variant treatment plans. Most patients received sole medical management (n = 86, 66%), 7 patients received only voice therapy (5%), and 10 patients underwent surgical management (8%). Several patients received combined medical management and voice therapy (n = 21, 16%). Final diagnoses included gastroesophageal reflux disease (GERD) (25%), followed by multifactorial causes (17%) and dysphonia with unclear etiology (13%). Among all patients, 82 (61%) reported symptom improvement. Twenty-eight patients were diagnosed with LPR or LPR with GERD (21%), and 22 reported symptom improvement (79%). There was a statistically significant relationship between a final diagnosis with a reflux component and symptom improvement (p = .038). There was no statistically significant difference between treatment types and symptom outcomes both within the total patient population (p = .051) and patients diagnosed with a reflux condition (p = .572).

CONCLUSION

LPR remains a difficult diagnosis to establish and represents a minority of patients with voice complaints. Despite varying evaluation and treatment modalities, most patients with LPR improved during their treatment and evaluation period without a clear association with any specific type of treatment. Further studies should explore diagnostic criteria for LPR, the necessary and efficient clinical evaluation to establish a diagnosis, and possible beneficial treatments.

Ear, nose and throat (ENT) manifestations and complications of reflux

Laryngopharyngeal reflux disease describes the backflow of acidic stomach content towards the larynx and is associated with symptoms such as cough, throat clearing and globus. It is a common presentation in primary care and the sequelae of symptoms that arise from the disease often present in ear, nose and throat clinics. Assessment and examination of patients presenting with reflux symptoms includes questionnaires, as well as direct visualisation of the pharynx and larynx, and takes a multidisciplinary team approach. Treatment options include lifestyle modification, medical therapy and in some specialist centres, surgical management to address the multitude of symptoms associated with the disease.