Multiple swallow behaviour during high resolution pharyngeal manometry: prevalence and sub-typing in healthy adults

Profiling Number of Swallows per Bolus and Residue in Individuals With Amyotrophic Lateral Sclerosis

PURPOSE

Swallowing efficiency impairments are the most prevalent and earliest manifestation of dysphagia in people with amyotrophic lateral sclerosis (pALS). We aimed to profile number of swallows elicited in pALS across thin liquid, moderately thick liquid, extremely thick liquid, and crackers compared to expected healthy reference data and to determine relationships between degree of pharyngeal residue, number of elicited swallows, and swallowing safety.

METHOD

pALS underwent standardized videofluoroscopic swallowing studies of 10 bolus trials. Trained raters performed duplicate, independent, and blinded ratings to derive Dynamic Imaging Grade of Swallowing Toxicity (DIGEST) efficiency and safety grades and Analysis of Swallowing Physiology: Events, Kinematics, and Timing (ASPEKT) percent total pharyngeal residue. Number of swallows per bolus was quantified (1 = typical, 2 = atypically high, 3 = extremely high). Kruskal-Wallis, Pearson chi-square, and odds ratio analyses were performed at bolus and participant levels.

KEY RESULTS

At the bolus level (N = 2,523), number of swallows per bolus was observed to be, in rank order, as follows: atypically high (49.1%), extremely high (28.5%), and typical (22.4%). Mean number of swallows significantly differed by International Dysphagia Diet Standardisation Initiative level (p < .0001), with a higher number of swallows elicited in pALS for moderately thick versus thin liquids, extremely thick liquids, and crackers, p < .0001. Number of swallows per bolus increased with increasing DIGEST efficiency grades (p < .0001). Positive correlations were observed between ASPEKT percent residue and number of swallows for thin (r = .24) and moderately thick (r = .16) liquids, p < .05. DIGEST efficiency and safety grades were not significantly associated (p > .05).

CONCLUSION AND INFERENCES

pALS demonstrated a higher number of swallows per bolus compared to healthy reference data that may represent a compensation for reductions in swallowing efficiency to clear pharyngeal residue.

The sensitivity and specificity of the modified volume-viscosity swallow test for dysphagia screening among neurological patients

Oropharyngeal dysphagia (OD) is a highly prevalent condition after stroke and other neurological diseases. The volume-viscosity swallow test (V-VST) is a screening tool for OD. Considering that the recommendations of volume and thickeners in the original V-VST limited the popularization and application of the test in the Chinese population, we provide the modified V-VST to detect OD among neurological patients. In addition, the accuracy of the modified V-VST to screen OD needs to be verified. We included 101 patients with neurological diseases. OD was evaluated by a modified V-VST and a videofluoroscopy swallowing study (VFSS) using 3 volumes (i.e., 3, 5, and 10 ml) and 4 viscosities (i.e., water, mildly thick, moderately thick, and extremely thick). In this study, to compare with the original V-VST results, a volume of 20 ml was also included. The discriminating ability of modified V-VST in detecting OD was assessed by the sensitivity and specificity values of clinical signs of impaired efficiency (impaired labial seal, piecemeal deglutition, and residue) and impaired safety of swallowing (cough, voice changes, and oxygen desaturation ≥3%) in comparison to the results of VFSS. The modified V-VST showed 96.6% sensitivity and 83.3% specificity for OD, 85.2% sensitivity and 70% specificity for impaired safety, and 90.9% sensitivity and 76.9% specificity for impaired efficacy. Our study suggests that the modified V-VST offers a high discriminating ability in detecting OD among neurological patients.

Transient hypopharyngeal intrabolus pressurization patterns: Clinically relevant or normal variant?

INTRODUCTION

In oropharyngeal dysphagia, impaired pharyngoesophageal junction (PEJ) opening is reflected by an elevated hypopharyngeal intrabolus pressure (IBP), quantifiable using pharyngeal high-resolution manometry with impedance (P-HRM-I). Transient intrabolus pressurization (TP) phenomena are not sustained and last for only a brief period. We hypothesized that TP patterns reflect impaired coordination between timing of hypopharyngeal bolus arrival and PEJ relaxation.

METHODS

A retrospective audit was conducted of P-HRM-I datasets; 93 asymptomatic Controls and 214 Patients with differing etiological/clinical backgrounds were included. TP patterns were examined during 10ml liquid swallows. TP was defined by a simultaneous, non-sustained, pressurization wave spanning from the velo-/meso-pharynx to PEJ. The coordination between deglutitive pharyngeal bolus distension and PEJ relaxation timing was assessed using timing variables; (i) Distention-Contraction Latency (DCL, s) and (ii) PEJ Relaxation Time (RT, s). Resultant flow resistance was quantified (IBP, mmHg).

RESULTS

TP swallows were observed in 87 (28%) cases. DCL was not significantly different in relation to TP, while PEJ relaxation time was shorter, and IBP was higher during TP swallows. In Patients RT-DCL time difference correlated with IBP (r -0.368, p < 0.01).

CONCLUSION

Bolus distension and PEJ relaxation were miss-timed during TP swallows, impeding bolus flow and leading to a brief period of pressurization of the pharyngeal chamber by muscular propulsive forces. While TP swallows were identified in both Controls and Patients, increased IBPs were most apparent for Patient swallows indicating that the extent of IBP increase may differentiate pathological TP swallows.