Pharyngeal Pressure Variability During Volitional Swallowing Maneuvers

Purpose: Within-individual pharyngeal swallowing pressure variability differs among pharyngeal regions in healthy individuals and increases with age. It remains unknown if pharyngeal pressure variability is impacted by volitional swallowing tasks. We hypothesized that pressure variability would increase during volitional swallowing maneuvers and differ among pharyngeal regions depending on the type of swallowing task being performed. Method: Pharyngeal high-resolution manometry was used to record swallowing pressure data from 156 healthy participants during liquid (5 cc) or saliva swallows, and during volitional swallowing tasks including effortful swallow, Mendelsohn maneuver, Masako maneuver, or during postural adjustments. The coefficient of variation was used to determine pressure variability of velopharynx, tongue base, hypopharynx, and upper esophageal sphincter regions. Repeated-measures analysis of variance was used on log-transformed data to examine effects of pharyngeal region and swallowing tasks on swallow-to-swallow variability. Results: There was a significant main effect of task with greater pressure variability for the effortful swallow ( p = .002), Mendelsohn maneuver ( p < .001), Masako maneuver ( p = .002), and the head turn ( p = .006) compared with normal effort swallowing. There was also a significant main effect of region ( p < .01). In general, swallowing pressure variability was lower for the tongue base and upper esophageal sphincter regions than the hypopharynx. There was no significant interaction of task and region (effortful, p = .182; Mendelsohn, p = .365; Masako, p = .885; chin tuck, p = .840; head turn, p = .059; and inverted, p = .773). Conclusions: Pharyngeal swallowing pressure variability increases in healthy individuals during volitional swallowing tasks. Less stable swallow patterns may result when tasks are less automatic and greater in complexity. These findings may have relevance to swallowing motor control integrity in healthy aging and individuals with neurogenic dysphagia.

Age-Related Functional Reserve Decline Is Not Seen in Pharyngeal Swallowing Pressures

Purpose Functional reserve represents the difference between an individual's ability to produce a maximum output function and the ability to perform a functional task. Several studies have documented an age-related decrease in functional reserve with oral tongue pressure generation. Whether this pattern is seen in pharyngeal swallowing pressures is unknown. The aim of this study was to investigate pharyngeal functional reserve using high-resolution manometry during normal-effort and effortful swallows. Method Pharyngeal high-resolution manometry was performed on 38 younger healthy individuals (≤ 40 years) and 18 older healthy individuals (≥ 60 years) during normal-effort and effortful water swallows. Pressure metrics included maximum pressure in the velopharynx, tongue base, and hypopharynx, as well as pharyngeal contractile integral and minimum pressure in the upper esophageal sphincter (UES). Repeated-measures analysis of variance was used to determine the effects of swallow task, age, and pharyngeal region on pressure generation. Results Maximum pharyngeal pressures and pharyngeal contractile integral were significantly increased during the effortful swallows compared to normal-effort swallows ( p < .001), but there were no interactions between task and age in pharyngeal pressures. In the UES, minimum pressures were significantly elevated in older individuals during effortful swallows compared to normal-effort swallows ( p = .007) but did not follow a pattern consistent with reduced functional reserve. Conclusions Healthy individuals increase pharyngeal driving pressures during effortful swallows, without an age-related reduction in the magnitude of pressure increase. Thus, this study did not find evidence for an age-related reduction in pharyngeal functional reserve. The preserved ability to increase pharyngeal pressures during effortful swallowing in aging may support the use of behavioral swallowing interventions in older individuals without neuromuscular conditions. Supplemental Material https://doi.org/10.23641/asha.16606709

Effects of remifentanil on pharyngeal swallowing and esophageal motility - no impact of different bolus volumes, and partial antagonism by methylnaltrexone

Background Remifentanil impairs swallowing, and disturbed accommodation to bolus volume may be one of the underlying causes. It is not fully understood whether remifentanil-induced swallowing dysfunction is mediated by peripheral or central mechanisms. Aims To investigate if remifentanil-induced swallowing dysfunction is dependent on the bolus volume and whether the effect of remifentanil could be counteracted by methylnaltrexone, a peripherally acting opioid antagonist. Methods Nineteen healthy volunteers were included in this double-blinded, randomized, placebo-controlled, crossover study. Study participants received target-controlled remifentanil infusions and placebo infusions in a randomized order. Methylnaltrexone was administered by intravenous injection of doses of 0.3 mg/kg. Recordings of pressure and impedance data were acquired using a combined manometry and impedance solid state catheter. Data was analyzed from three series of bolus swallows, baseline, during remifentanil exposure, and 15 min after methylnaltrexone. Results Remifentanil induced significant effects on multiple pharyngeal and esophageal function parameters. No significant differences in remifentanil-induced swallowing dysfunction related to different bolus volumes were found. Pharyngeal effects of remifentanil were not significantly counteracted by methylnaltrexone, whereas on the distal esophageal level, effects on distension pressures were counteracted. Conclusions Changes in pharyngeal and esophageal pressure flow variables were consistent with previous results on remifentanil-induced swallowing dysfunction, and uniform across all bolus volumes. The effects of remifentanil on the pharyngeal level and on the proximal esophagus appear to be predominantly centrally mediated, whereas the effects of remifentanil on the distal esophagus may be mediated by both central and peripheral mechanisms.

Videofluoroscopic Swallow Study Findings and Correlations in Infancy of Children with Cerebral Palsy

Objectives: Cerebral palsy (CP) in infants can affect global motor function and lead to swallowing difficulties. This study aims to characterize oral and pharyngeal swallowing dynamics in infancy of patients later diagnosed with CP and to determine if swallow study performance in early infancy is associated with later CP severity and characteristics. Methods: This is a retrospective chart review of infants who underwent videofluoroscopic swallow studies (VFSS) between 6/2008 and 10/2018 at a tertiary children’s hospital, and were later diagnosed with CP. Demographic data, CP characteristics and metrics, and VFSS findings were collected and analyzed. Results: There were 66 patients included in this study. The average age at the time of VFSS was 4 months (range: 0.3-12 months), 42% of patients were female, and 50% of patients were born premature. In our sample, 86% of patients presented with oral dysphagia, and 76% with pharyngeal dysphagia. Laryngeal penetration in isolation was seen in 39% of patients, and tracheal aspiration was seen in 38% of patients. Of these tracheal aspiration events, 64% were silent. At the time of VFSS, 58% of patients had a nasogastric tube, 12% had a gastrostomy tube, and 3% had a prior hospitalization for pneumonia. Rates of penetration and aspiration in early infancy did not consistently correlate with prematurity, type of CP (spastic, non-spastic, or mixed), degree of paralysis (quadriplegic, hemiplegic, or diplegic), or severity of Gross Motor Function Classification System (GMFCS) score. Conclusion: While there was not a consistent correlation of swallowing dynamics in infancy with later gross motor categorizations of CP, the results of this retrospective review highlight the essential role of early clinical and videofluoroscopic swallowing evaluations to identify oral and pharyngeal swallowing dysfunction in this patient population.

Modulation of pharyngeal swallowing by bolus volume and viscosity

The neuromodulation of the healthy oropharyngeal swallow response was described in relation to bolus volume and viscosity challenges, using intraluminal pressure and impedance topography methods. Among a wide range of physiological measures, those indicative of distension pressure, luminal opening, and flow timing were most significantly altered by bolus condition and therefore considered potential markers of swallow neuromodulation. The study methods and associated findings inform a diagnostic framework for swallow assessment in patients with oropharyngeal dysphagia.

Effects of texture properties of semi-solid food on the sensory test for pharyngeal swallowing effort in the older adults

Background Increasing viscosity can reduce the risk of aspiration into the airway, but excessively thickened food may require more force and effort. We assumed that semi-solid foods with similar viscosities will behave differently in the oropharynx and there might exist the possibility that properties other than viscosity may have clinical relevance. This study aimed to find out the texture of semi-solid foods that affects the effort of pharyngeal swallow in the older adults. Methods Nine kinds of semi-solid foods not requiring mastication were selected for texture profile analysis (TPA), and included whipped cream, mayonnaise, soft tofu, mango pudding, boiled mashed pumpkin, boiled mashed potatoes, boiled mashed sweet potatoes, red bean paste, and peanut butter. Hardness, adhesiveness and cohesiveness of each food were measured three times by using the rheometer. A blinded sensory test using a 9-point hedonic scale was also conducted in eighteen older adults people to investigate how much effort was required to swallow food, and how much of the food remained in the pharynx after swallowing. The correlation between texture and sensory outcome was statistically analyzed. Results Foods that belonged to the same viscosity category showed different texture values, and the participants also rated different scores respectively. Only adhesiveness among three properties was significantly correlated with the sensory test. (r = 0.882, p = 0.002 for difficult to swallow, r = 0.879, p = 0.002 for sense of residue). Conclusions Adhesiveness was the most important property of the semi-solid foods, requiring most efforts in pharyngeal swallow in the older adults. If we select and provide food having low adhesiveness value in the same viscosity category, there might be the possibility to make it easier to swallow in older adults.

Effects of texture properties of semi-solid food on the sensory test for pharyngeal swallowing effort in the older adults

Background: Increasing viscosity can reduce the risk of aspiration into the airway, but excessively thickened food may require more force and effort. We assumed that semi-solid foods with similar viscosities will behave differently in the oropharynx and there might exist the possibility that properties other than viscosity may have clinical relevance. This study aimed to find out the texture of semi-solid foods that affects the effort of pharyngeal swallow in the older adults. Methods: Nine kinds of semi-solid foods not requiring mastication were selected for texture profile analysis (TPA), and included whipped cream, mayonnaise, soft tofu, mango pudding, boiled mashed pumpkin, boiled mashed potatoes, boiled mashed sweet potatoes, red bean paste, and peanut butter. Hardness, adhesiveness and cohesiveness of each food were measured three times by using the rheometer. A blinded sensory test using a 9-point hedonic scale was also conducted in eighteen older adults people to investigate how much effort was required to swallow food, and how much of the food remained in the pharynx after swallowing. The correlation between texture and sensory outcome was statistically analyzed.Results: Foods that belonged to the same viscosity category showed different texture values, and the participants also rated different scores respectively. Only adhesiveness among three properties was significantly correlated with the sensory test. (r= 0.882, p=0.002 for difficult to swallow, r=0.879, p=0.002 for sense of residue).Conclusions: Adhesiveness was the most important property of the semi-solid foods, requiring most efforts in pharyngeal swallow in the older adults. If we select and provide food having low adhesiveness value in the same viscosity category, there might be the possibility to make it easier to swallow in older adults.