Evaluating the tongue-hold maneuver using high-resolution manometry and electromyography.

The tongue-hold maneuver is a widely used clinical technique designed to increase posterior pharyngeal wall movement in individuals with dysphagia. It is hypothesized that the tongue-hold maneuver results in increased contraction of the superior pharyngeal constrictor. However, an electromyographic study of the pharynx and tongue during the tongue-hold is still needed to understand whether and how swallow muscle activity and pressure may change with this maneuver. We tested eight healthy young participants using simultaneous intramuscular electromyography with high-resolution manometry during three task conditions including (a) saliva swallow without maneuver, (b) saliva swallow with the tongue tip at the lip, and (c) saliva swallow during the tongue-hold maneuver. We tested the hypothesis that tongue and pharyngeal muscle activity would increase during the experimental tasks, but that pharyngeal pressure would remain relatively unchanged. We found that the pre-swallow magnitude of tongue, pharyngeal constrictor, and cricopharyngeus muscle activity increased. During the swallow, the magnitude and duration of tongue and pharyngeal constrictor muscle activity each increased. However, manometric pressures and durations remained unchanged. These results suggest that increased superior pharyngeal constrictor activity may serve to maintain relatively stable pharyngeal pressures in the absence of posterior tongue movement. Thus, the tongue-hold maneuver may be a relatively simple but robust example of how the medullary swallow center is equipped to dynamically coordinate actions between tongue and pharynx. Our findings emphasize the need for combined modality swallow assessment to include high-resolution manometry and intramuscular electromyography to evaluate the potential benefit of the tongue-hold maneuver for clinical populations.

Detection of chronic laryngitis due to laryngopharyngeal reflux using color and texture analysis of laryngoscopic images.

OBJECTIVE: To determine if pattern recognition of hue and textural parameters can be used to identify laryngopharyngeal reflux (LPR). METHODS: Laryngoscopic images from 20 subjects with LPR and 42 control subjects without LPR were obtained. LPR status was determined using the reflux finding score. Color and texture features were quantified using hue calculation and two-dimensional Gabor filtering. Five regions were analyzed: true vocal folds, false vocal folds, epiglottis, interarytenoid space, and arytenoid mucosae. A multilayer perceptron artificial neural network with varying numbers of hidden nodes was used to classify images according to pattern recognition. Receiver operating characteristic (ROC) analysis was used to evaluate diagnostic utility, and intraclass correlation coefficient analysis was performed to determine interrater reliability. RESULTS: Classification accuracy when including all parameters was 80.5% ± 1.2% with an area under the ROC curve of 0.887. Classification accuracy decreased when including only hue (73.1% ± 3.5%; area under the curve = 0.834) or texture (74.9% ± 3.6%; area under the curve = 0.852) parameters. Interrater reliability was 0.97 ± 0.03 for hue parameters and 0.85 ± 0.11 for texture parameters. CONCLUSIONS: This preliminary study suggests that a combination of hue and texture features can be used to detect chronic laryngitis due to LPR. A simple, minimally invasive assessment would be a valuable addition to the currently invasive and somewhat unreliable methods currently used for diagnosis. Including more data will likely improve classification accuracy. Additional investigations will be performed to determine if results are in accordance with those provided by pH probe monitoring.

Artificial neural network classification of pharyngeal high-resolution manometry with impedance data.

OBJECTIVES/HYPOTHESIS: To use classification algorithms to classify swallows as safe, penetration, or aspiration based on measurements obtained from pharyngeal high-resolution manometry (HRM) with impedance. STUDY DESIGN: Case series evaluating new method of data analysis. METHODS: Multilayer perceptron, an artificial neural network (ANN), was evaluated for its ability to classify swallows as safe, penetration, or aspiration. Data were collected from 25 disordered subjects swallowing 5- or 10-mL boluses. Following extraction of relevant parameters, a subset of the data was used to train the models, and the remaining swallows were then independently classified by the ANN. RESULTS: A classification accuracy of 89.4 ± 2.4% was achieved when including all parameters. Including only manometry-related parameters yielded a classification accuracy of 85.0 ± 6.0%, whereas including only impedance-related parameters yielded a classification accuracy of 76.0 ± 4.9%. Receiver operating characteristic analysis yielded areas under the curve of 0.8912 for safe, 0.8187 for aspiration, and 0.8014 for penetration. CONCLUSIONS: Classification models show high accuracy in classifying swallows from dysphagic patients as safe or unsafe. HRM-impedance with ANN represents one method that could be used clinically to screen for patients at risk for penetration or aspiration.

Application of classification models to pharyngeal high-resolution manometry.

PURPOSE: The authors present 3 methods of performing pattern recognition on spatiotemporal plots produced by pharyngeal high-resolution manometry (HRM). METHOD: Classification models, including the artificial neural networks (ANNs) multilayer perceptron (MLP) and learning vector quantization (LVQ), as well as support vector machines (SVM), were evaluated for their ability to identify disordered swallowing. Data were collected from 12 control subjects and 13 subjects with swallowing disorders; for this experiment, these subjects swallowed 5-ml water boluses. Following extraction of relevant parameters, a subset of the data was used to train the models, and the remaining swallows were then independently classified by the networks. RESULTS: All methods produced high average classification accuracies, with MLP, SVM, and LVQ achieving accuracies of 96.44%, 91.03%, and 85.39%, respectively. When evaluating the individual contributions of each parameter and groups of parameters to the classification accuracy, parameters pertaining to the upper esophageal sphincter were most valuable. CONCLUSION: Classification models show high accuracy in segregating HRM data sets and represent 1 method of facilitating application of HRM to the clinical setting by eliminating the time required for some aspects of data extraction and interpretation.

High-resolution manometry of pharyngeal swallow pressure events associated with effortful swallow and the Mendelsohn maneuver.

Effortful swallow and the Mendelsohn maneuver are two common strategies to improve disordered swallowing. We used high-resolution manometry (HRM) to quantify the effects of these maneuvers on pressure and timing characteristics. Fourteen normal subjects swallowed multiple, 5-ml water boluses using three techniques: normal swallow, effortful swallow, and the Mendelsohn maneuver. Maximum pressure, rate, duration, area integral, and line integral were determined for the velopharynx and tongue base. Minimum pressure, duration of pressure-related change, duration of nadir pressure, maximum preopening and postclosure pressure, area integral, and line integral were recorded for the upper esophageal sphincter (UES). Area and line integrals of the velopharyngeal pressure curve significantly increased with the Mendelsohn maneuver; the line integral increased with the effortful swallow. Preopening UES pressure decreased significantly for the Mendelsohn, while postclosure pressure tended to increase insignificantly for both maneuvers. UES area and line integrals as well as nadir UES pressure duration increased with both maneuvers. Maneuver-dependent changes were observed primarily at the velopharynx and UES. These regions are critical to safe swallowing, as the velopharynx provides positive pressure at the bolus tail while the UES allows a bolus to enter the esophagus without risk of regurgitation. Integrals were more responsive than maximum pressure or duration and should be investigated further.

Automated analysis of pharyngeal pressure data obtained with high-resolution manometry.

We present an algorithm developed in MATLAB that can be applied to both normal and disordered swallowing to automatically extract a wide array of measurements from the spatiotemporal plots produced by high-resolution manometry (HRM) of the pharyngeal swallow. The algorithm was developed from data from 12 normal and 3 disordered subjects swallowing 5-ml water boluses. Automated extraction was compared to manual extraction for a subset of seven normal and the three disordered subjects to evaluate algorithm accuracy. Area and line integrals, pressure wave velocity, and pressure gradients during upper esophageal sphincter opening were also measured. Automated extraction showed strong correlations with manual extraction, producing high correlation coefficients in both normal and disordered subjects for maximum velopharyngeal pressure and maximum tongue base pressure. Timing data were also strongly correlated for all variables, including velopharyngeal pressure duration, tongue base pressure duration, and total swallow duration. Preliminary descriptive data on area and line integrals are presented. Our results indicate that the algorithm can effectively extract data automatically from HRM spatiotemporal plots. The efficiency of the algorithm makes it a valuable tool to supplement clinical and research use of HRM.

Pharyngeal swallow adaptations to bolus volume measured with high-resolution manometry.

OBJECTIVE: : To determine the effect of bolus volume on pharyngeal swallowing using high-resolution manometry (HRM). STUDY DESIGN: : Repeated measures with subjects serving as own controls. METHODS: : Twelve subjects swallowed four bolus volumes in the neutral head position: saliva; 5 mL water; 10 mL water; and 20 mL water. Pressure measurements were taken along the length of the pharynx using a high-resolution manometer, with emphasis placed on the velopharynx, tongue base, and upper esophageal sphincter (UES). Variables were analyzed across bolus volumes using three-way repeated measures analysis of covariance (ANCOVA) investigating the effect of sex, bolus volume, and pharynx length. Pearson's product moment tests were performed to evaluate how pharyngeal pressure and timing events changed across bolus volume. RESULTS: : Velopharyngeal duration, maximum tongue base pressure, tongue base pressure rise rate, UES opening duration, and total swallow duration varied significantly across bolus volume. Sex did not have an effect, whereas pharynx length appeared to affect tongue base pressure duration. Maximum velopharyngeal pressure and minimum UES pressure had a direct relationship with bolus volume, whereas maximum tongue base pressure had an inverse relationship. Velopharyngeal pressure duration, UES opening duration, and total swallow duration increased as bolus volume increased. CONCLUSIONS: : Differences in pharyngeal pressures and timing of key pressure events were detected across varying bolus volumes. Knowing the relationships between bolus volume and pharyngeal pressure activity can be valuable when diagnosing and treating dysphagic patients.