Influence of Acid Swallows on the Dynamics of the Upper Esophageal Sphincter

Differences in velopharyngeal pressures during speech sound production in patients with unilateral cleft lip and palate (UCLP) and healthy individuals

Background

During articulation the velopharynx needs to be opened and closed rapidly and a tight closure is needed. Based on the hypothesis that patients with cleft lip and palate (CLP) produce lower pressures in the velopharynx than healthy individuals, this study compared pressure profiles of the velopharyngeal closure during articulation of different sounds between healthy participants and patients with surgically closed unilateral CLP (UCLP) using high resolution manometry (HRM).

Materials and methods

Ten healthy adult volunteers (group 1: 20-25.5 years) and ten patients with a non-syndromic surgically reconstructed UCLP (group 2: 19.1-26.9 years) were included in this study. Pressure profiles during the articulation of four sounds (/i:/, /s/, /ʃ/ and /n/) were measured by HRM. Maximum, minimum and average pressures, time intervals as well as detection of a previously described 3-phase-model were compared.

Results

Both groups presented with similar pressure curves for each phoneme with regards to the phases described and pressure peaks, but differed in total pressures. An exception was noted for the sound /i:/, where a 3-phase-model could not be seen for most patients with UCLP. Differences in velopharynx pressures of 50% and more were found between the two groups. Maximum and average pressures in the production of the alveolar fricative reached statistical significance.

Conclusions

It can be concluded that velopharyngeal pressures of patients with UCLP are not sufficient to eliminate nasal resonance or turbulence during articulation, especially for more complex sounds. These results support a general understanding of hypernasality during speech implying a (relative) velopharyngeal insufficiency.

Modification of velopharyngeal closure pressures during phonation by neuromuscular electrical stimulation in healthy individuals

Introduction

Rhinophonia aperta may result from velopharyngeal insufficiency. Neuromuscular electrical stimulation (NMES) has been discussed in the context of muscle strengthening. The aim of this study was to evaluate in healthy subjects whether NMES can change the velopharyngeal closure pattern during phonation and increase muscle strength.

Method

Eleven healthy adult volunteers (21-57 years) were included. Pressure profiles were measured by high resolution manometry (HRM): isolated sustained articulation of /a/ over 5 s (protocol 1), isolated NMES applied to soft palate above motor threshold (protocol 2) and combined articulation with NMES (protocol 3). Mean activation pressures (MeanAct), maximum pressures (Max), Area under curve (AUC) and type of velum reactions were compared. A statistical comparison of mean values of protocol 1 versus protocol 3 was carried out using the Wilcoxon signed rank test. Ordinally scaled parameters were analyzed by cross table.

Results

MeanAct values measured: 17.15±20.69 mmHg (protocol 1), 34.59±25.75 mmHg (protocol 3) on average, Max: 37.86±49.17 mmHg (protocol 1), 87.24±59.53 mmHg (protocol 3) and AUC: 17.06±20.70 mmHg.s (protocol 1), 33.76±23.81 mmHg.s (protocol 3). Protocol 2 produced velum reactions on 32 occasions. These presented with MeanAct values of 13.58±12.40 mmHg, Max values of 56.14±53.14 mmHg and AUC values of 13.84±12.78 mmHg.s on average. Statistical analysis comparing protocol 1 and 3 showed more positive ranks for MeanAct, Max and AUC. This difference reached statistical significance (p=0.026) for maximum pressure values.

Conclusions

NMES in combination with articulation results in a change of the velopharyngeal closure pattern with a pressure increase of around 200% in healthy individuals. This might be of therapeutic benefit for patients with velopharyngeal insufficiency.

Phonation-induced Upper Esophageal Sphincter Contraction Caused by Different Phonation Types

INTRODUCTION

The upper esophageal sphincter (UES) has been reported to show activity during phonation. As it is still unknown whether the phonation-induced UES contraction represents a reflex or a simultaneous activation phenomenon, i.e. co-innervation, this study aims to investigate and characterize the phonation-induced contraction of the UES in healthy individuals by analyzing the influence of various phonation tasks on pressure parameters of the UES.

METHODS

Twenty-five healthy volunteers produced the German neutral vowel [ə] in five different phonation tasks (modal voice, whispering, voiceless speech, creaky voice, and whispery voice). Simultaneously, they underwent high resolution manometry and electroglottography for measurement of pressure parameters in the region of the UES and latencies between larynx and UES activation.

RESULTS

During all types of phonation, the maximum pressures of the UES increased significantly (maximum pressure increases of 72%-132%). With regard to mean pressures this was valid for modal voice and whispering (mean pressure increases of 20%-25%). Differences concerning total pressure changes reached statistical significance when comparing whispering and voiceless speech as well as whispery voice. However, differences concerning the total pressure change between modal voices on the one hand and voiceless speech and whispery voice on the other hand turned out to be small. The averaged time delay between larynx and UES activation ranged from approximately -15 ms (whispery voice) to +15 ms (whispering).

CONCLUSION

A phonation induced pressure increase of the UES was confirmed in this study and did exist for different types of phonation. The extent of total pressure changes in the UES increases in relation with laryngeal muscle activity necessary for the phonation type. Next to varying effects of different types of phonation on UES activation, very short latencies indicate that a phonation induced contraction of the UES exists most likely due to co-innervation of UES and laryngeal muscles by the vagus nerve.

Recent Progress of SERS Nanoprobe for pH Detecting and Its Application in Biological Imaging

As pH value almost affects the function of cells and organisms in all aspects, in biology, biochemical and many other research fields, it is necessary to apply simple, intuitive, sensitive, stable detection of pH and base characteristics inside and outside the cell. Therefore, many research groups have explored the design and application of pH probes based on surface enhanced Raman scattering (SERS). In this review article, we discussed the basic theoretical background of explaining the working mechanism of pH SERS sensors, and also briefly described the significance of cell pH measurement, and simply classified and summarized the factors that affected the performance of pH SERS probes. Some applications of pH probes based on surface enhanced Raman scattering in intracellular and extracellular pH imaging and the combination of other analytical detection techniques are described. Finally, the development prospect of this field is presented.