PHARYNGEAL, UPPER ESOPHAGEAL SPHINCTERIC AND ESOPHAGEAL PRESSURES RESPONSES RELATED TO VOCAL TASKS AT THE LIGHT OF HIGH RESOLUTION MANOMETRY

Stress Effects on Pharyngeal Air Pressure and Upper Esophageal Sphincter Pressure During Phonation: The Influence of Vocal Tract Semi-Occlusion

OBJECTIVES/HYPOTHESIS

The objective of this study was to determine whether vocal tract semi-occlusion (SOVT) influenced stress effects on pharyngeal air pressure and upper esophageal sphincter (UES) pressure during phonation. Relationships between dysphonia and stress are well recognized but poorly understood. Stress effects act globally on the body, and may be observed beyond intrinsic laryngeal muscles to include pharyngeal muscles and the UES, which contribute to voice modulation. Phonation with SOVT may provide resistance to stress effects on the vocal tract. We hypothesized that stress effects on pharyngeal air pressure and UES pressure would be measurable with a high-resolution, 360° pressure catheter, and that stress effects would be impacted differently by occlusal and non-occlusal phonatory tasks.

METHODS

Ten healthy adults performed sustained vowel tasks (comfortable /a/, and loud /a/), and SOVT tasks (bilabial fricative and straw phonation). Each task was performed during a baseline condition, and during stress induced through a cold pressor task. Pharyngeal air pressure and UES pressure were measured via high-resolution manometry. Changes in pressure between baseline and stress were compared among phonatory tasks.

RESULTS

Stress-induced changes to UES pressure differed by phonatory task (P < 0.01). Stress increased UES pressures during vowels, but had no effect during bilabial fricative, and decreased UES pressures during straw phonation. Change in UES pressure with stress was greater for comfortable /a/ and loud /a/ than straw phonation (P = 0.048 and P = 0.019, respectively), and was not significantly different between comfortable /a/ or loud /a/ and bilabial fricative. Stress-induced changes in pharyngeal air pressure were not significantly different among tasks.

CONCLUSIONS

These findings help identify possible mechanisms underlying the relationship between stress and voice, and point to the utility of SOVT tasks for training vocal tract resistance to stress. This methodology provides a foundation for measuring changes to extra-laryngeal components of the vocal tract during phonation.

The upper esophageal sphincter in the high-resolution manometry era

BACKGROUND

The evaluation of the upper esophageal sphincter (UES) has been neglected during routine manometric tests for decades, mostly due to the limitations of the conventional manometry which were eventually overcome by high-resolution manometry (HRM).

METHODS

This study reviewed the current knowledge of the manometric evaluation of the UES in health and disease in the HRM era.

RESULTS

We found that HRM allowed more precise measurements, in addition to the parameters as compared to conventional manometry, but most of them still need confirmation of the clinical significance. The parameters used to evaluate the UES were extension, basal pressure, residual pressure, relaxation duration, relaxation time to nadir, recovery time, intrabolus pressure, and deglutitive sphincter resistance. UES may be affected by different diseases: achalasia (UES is hypertonic with impaired relaxation), gastroesophageal reflux disease (UES is short and hypotonic), globus (UES ranges from normal to impaired relaxation to hypertonic), neurologic diseases (stroke and Parkinson - UES is hypotonic in early-stage to impaired relaxation in end-stage disease), and Zenker's diverticulum (UES has impaired relaxation).

CONCLUSION

This review shows that UES dysfunction is part of several disease processes and that the study of the UES is possible and valuable with the aid of HRM.