Number Of Swallows Research Articles

Acid infusion into the esophagus increases the number of meal-induced transient lower esophageal sphincter relaxations (TLESRs) in healthy volunteers.

Transient lower esophageal sphincter relaxation (TLESR) is the major mechanism of gastroesophageal reflux (GER) but the regulation of TLESR by stimuli in the esophagus is incompletely understood. If stimuli in the esophagus can influence TLESR, then such regulation may perpetuate or limit GER. We addressed the hypothesis that acid in the esophagus enhances TLESRs. We evaluated the effect of acid infusion into the distal esophagus on TLESRs evoked by a standard meal in a paired randomized study in healthy subjects. TLESRs were evaluated by using high resolution manometry (HRM). We found that acid in the esophagus enhanced meal-induced TLESRs. Compared to control infusion the number of TLESRs (median [interquartile range]) was increased during 2h following the acid infusion (11 [9-14] vs 17 [12.5-20], p<0.01). The average duration of individual TLESRs was not affected. The time-course analysis revealed that a robust increase in TLESRs occurred already in the first hour when the number of TLESRs nearly doubled (6 [5.5-7.5] vs 11 [7.5-12.5], p<0.05). In contrast to the enhancement of TLESRs, the number of swallows was not changed. The acid infusion into the esophagus increases the number of meal-induced TLESRs in healthy subjects. Our results provide evidence for the concept that the stimuli in the esophagus can influence TLESRs. The regulation of TLESR by stimuli in the esophagus may contribute to pathogenesis of GER in some patients.

The Relationship Between Limit of Dysphagia and Average Volume Per Swallow in Patients with Parkinson’s Disease

The goal of this study was to obtain the limit of dysphagia and the average volume per swallow in patients with mild to moderate Parkinson's disease (PD) but without swallowing complaints and in normal subjects, and to investigate the relationship between them. We hypothesize there is a direct relationship between these two measurements. The study included 10 patients with idiopathic PD and 10 age-matched normal controls. Surface electromyography was recorded over the suprahyoid muscle group. The limit of dysphagia was obtained by offering increasing volumes of water until piecemeal deglutition occurred. The average volume per swallow was calculated by dividing the time taken by the number of swallows used to drink 100ml of water. The PD group showed a significantly lower dysphagia limit and lower average volume per swallow. There was a significantly moderate direct correlation and association between the two measurements. About half of the PD patients had an abnormally low dysphagia limit and average volume per swallow, although none had spontaneously related swallowing problems. Both measurements may be used as a quick objective screening test for the early identification of swallowing alterations that may lead to dysphagia in PD patients, but the determination of the average volume per swallow is much quicker and simpler.

Electromyographic texture characterization of hydrocolloid gels as model foods with varying mastication and swallowing difficulties

Eating difficulty of solid foods was analyzed using electromyography (EMG) of five hydrocolloid gels with varying textures. Eleven subjects ate gel samples under normal conditions and EMG activities of both sides of masseter (jaw-closing) and suprahyoid (jaw-opening) muscles were recorded during eating. Differences in EMG variables among samples were analyzed separately before and after the first swallow using repeated-measure statistics. The time before the first swallow was related to chewing effort and was estimated according to numbers of chewing actions, masseter muscle activities per chew and the sum of masseter muscle activities during chewing. EMG variables were also correlated with resistance to fracture, which was extracted as the first principal component from sensory evaluations of gel texture, but did not directly relate to any single parameter from mechanical tests or sensory evaluations. The time after the first swallow to the end of eating corresponded with the number of swallows, the EMG amplitude of suprahyoid muscles during chewing, the sum of masseter activity and suprahyoid muscle activity during the period after the first swallow. These EMG variables corresponded with sensory evaluations of adhesiveness but not with other single mechanical and sensory parameters or principal components. The present data suggest that at least two independent factors affect eating difficulty. Although differences among the five gels were predominantly reflected by chewing difficulty, these remained significant after the first swallow.

Pharyngeal Stimulation in Head and Neck Cancer Patients with Dysphagia: Functional Outcomes and Transcranial Magnetic Stimulation Motor Evoked Potentials

Purpose: Head and neck cancer patients often experience swallowing disorders, impacting health and quality of life. This study examined effects of electrical stimulation to the pharynx on swallowing outcomes in post-surgical head and neck cancer patients. Methods: Swallowing was assessed using video fluoroscopy before, and 30 minutes after, a ten-minute application of electrical stimulation to the pharynx in five patients experiencing moderate-severe dysphagia. Corticopharyngeal motor projections were measured before and after stimulation of the pharynx using transcranial magnetic stimulation of motor cortex and measurements of motor evoked potentials (MEPs) in the striated muscle of the posterior pharyngeal wall. Results: Short-term changes in swallowing function were observed post-stimulation in: pharyngeal transit time, cricopharyngeal opening duration, total number of swallows, penetration/aspiration score, and duration of contact between the base of tongue and posterior pharyngeal wall. MEPs could not be measured in two participants. In the remaining participants, the MEP measures were not strongly associated with changes in observed swallowing function as has been found for neurogenic dysphagia. Conclusions: These findings indicated that somatosensory input, generated by electrical stimulation of the pharynx, changes swallowing function in head and neck cancer patients. These changes are not strongly correlated with alterations of corticopharyngeal excitability as previously observed in acutely dysphagic stroke patients.

Salt and fat contents influence the microstructure of model cheeses, chewing/swallowing and in vivo aroma release

ABSTRACTThe effects of the lipid/protein ratio (20/28, 24/24, 28/20) and salt content of model cheeses were investigated simultaneously with respect to chewing behaviour, swallowing events and in vivo aroma release. Chewing parameters were measured by electromyography. Swallowing events were recorded manually. In vivo aroma release was investigated using nose‐space on‐line atmospheric pressure chemical ionisation–mass spectrometry. The values for chewing activity and time before swallowing were higher with lower lipid/protein ratios and lower salt contents, due to the greater mechanical resistance of the model cheeses. The corresponding microstructure was made up of smaller and more circular fat droplets in a stronger protein network. Furthermore, the maximum intensity and in‐mouth release rate of aroma decreased as the lipid/protein ratio fell. This could be explained by a retention effect of the proteins, which was stronger than the chewing effect. A rise in salt content triggered more rapid aroma release from the protein phase of the model cheese to the oral cavity, and thence to the nasal cavity. The larger fat droplet size in salt‐supplemented model cheeses slowed down the transfer of aroma release and the levels of aroma release after swallowing were higher. A more rapid swallowing was observed for model cheeses containing added salt and with a higher L/P ratio. It is suggested that this was due to greater salivation and lubrication. Moreover, the number of swallows was positively correlated to the total amount of aroma release. Copyright © 2013 John Wiley &amp; Sons, Ltd.

Clinical evaluations for the masticatory efficiency of heat cure resin and flexible types of denture base materials

The aim of this study was for estimation and comparism of masticatory efficiency in patient wearing heat cured acrylic and flexible base partial denture, finding out the role of peanuts and carrots on the measurement of chewing efficiency, and to find out whether the types of P.D. (being single or two opposing each other) has any effect on the masticatory performance. Materials and methods: Twenty partially edentulous patients were selected. Five of these patients were selected having Kennedy class I with no modification against natural dentition, other 5patients having Cl.I against Cl.I. The other 5 patients having Cl.III against natural dentition and the last 5 patients were with Cl.III against Cl.III. several ways were used for measuring masticatory efficiency including: number of chewing strokes, number of swallows, the mastication time, and measure the masticatory performance by sieving method. Differences between the means of the four groups were analyzed with t-test. Results: The differences between the two denture base types in total number of strokes was significant at (p<0.001) in study group (2,3,4), the study group (4)have the highest mean value of the total number of strokes for acrylic denture during chewing carrots food types(47.6)strokes. The highest mean value of the total chewing time is for the fourth group with the acrylic denture during chewing carrots (35.2 sec.), and the highest masticatory performance index was for the flexible denture in all study groups during chewing the two tested food. Conclusion: The flexible partial denture provide better chewing efficiency than heat cure acrylic partial denture, the masticatory performance was higher for flexible partial denture than heat cure acrylic partial denture, there was significant differences between carrots and peanuts in both flexible and heat cure acrylic partial denture, and patient with single denture show better chewing efficiency than patient with paired denture.

1034 The Dual Action of the KAMPO MEDICINE Rikkunshito Offers a Promising New Approach for the Treatment of Ghrelin Resistance in Cancer Anorexia-Cachexia

G A A b st ra ct s using HRM. Methods: Studies were performed in 12 healthy volunteers (5 males, median age 23 years). Nausea was induced by a motion video of a rotating and tilted view of a landscape and rated on a VAS scale ranging from 1-4 (no/mild/moderate/severe nausea) every minute until complete recovery. GEP and anatomical changes were assessed with HRM. FP was measured from the five pressure channels positioned below the LES. Reflux was assessed by impedance-pH (MII-pH). After intubation, a baseline (BL) recording of 15min was obtained. This was followed by the motion video (until the volunteer perceived nausea VAS≥3 (at least 10min, max 20min)) followed by 30min recovery recording. Results correspond to measurements at peak nausea, early recovery (first 5 min after the end of the motion video) and late recovery (last 5min of the 30min recovery period). Results: 10/12 subjects showed a drop in FP during peak nausea compared to BL (-4.0±0.8mmHg; p= 0.005) with 8/10 subjects showing a partial or complete FP return during late recovery. 8/ 10 subjects who showed FP drop also showed a drop of LES pressure during peak nausea (-8.8±2.5mmHg; p=0.04) with 9/10 subjects showing a partial or complete return of LES pressure during late recovery. Peak nausea preceded peak fundus and LES relaxation. 8/10 subjects showed increase in length of the oesophageal body during peak nausea and early recovery (+0.8±0.2cm and +0.7±0.1cm; p,0.05) whereas a shortening of the oesophagus was observed during late recovery (-0.6±0.2cm; p,0.05). There was a significant decrease in LES thickness during peak nausea (-0.8±0.3cm; p,0.05). The number of swallows was comparable during BL/nausea/recovery. MII-pH showed normal acid exposure and 0-2 reflux episodes during total recording times. The number of TLESRs was significantly greater during the recovery period compared to the nausea period (p=0.01). Conclusion: Fundus and GEJ changes during nausea are different from those observed during meals, TLESRs and vomiting. Peak nausea is followed by a drop in fundus and LES pressure, oesophageal lengthening and a decrease in LES thickness. LES relaxation during nausea is incomplete and not accompanied by reflux. Whether anatomical changes provoke the sensation of nausea or vice versa is unknown, however the time sequence in our experiment suggests the latter.

1035 Subpopulation Analysis Based on Background Responds to Rabeprazole Dose in Patients With Functional Dyspepsia in a Multicenter, Double-Blind, Randomized, Placebo-Controlled Clinical Trial; the Samurai Study

G A A b st ra ct s using HRM. Methods: Studies were performed in 12 healthy volunteers (5 males, median age 23 years). Nausea was induced by a motion video of a rotating and tilted view of a landscape and rated on a VAS scale ranging from 1-4 (no/mild/moderate/severe nausea) every minute until complete recovery. GEP and anatomical changes were assessed with HRM. FP was measured from the five pressure channels positioned below the LES. Reflux was assessed by impedance-pH (MII-pH). After intubation, a baseline (BL) recording of 15min was obtained. This was followed by the motion video (until the volunteer perceived nausea VAS≥3 (at least 10min, max 20min)) followed by 30min recovery recording. Results correspond to measurements at peak nausea, early recovery (first 5 min after the end of the motion video) and late recovery (last 5min of the 30min recovery period). Results: 10/12 subjects showed a drop in FP during peak nausea compared to BL (-4.0±0.8mmHg; p= 0.005) with 8/10 subjects showing a partial or complete FP return during late recovery. 8/ 10 subjects who showed FP drop also showed a drop of LES pressure during peak nausea (-8.8±2.5mmHg; p=0.04) with 9/10 subjects showing a partial or complete return of LES pressure during late recovery. Peak nausea preceded peak fundus and LES relaxation. 8/10 subjects showed increase in length of the oesophageal body during peak nausea and early recovery (+0.8±0.2cm and +0.7±0.1cm; p,0.05) whereas a shortening of the oesophagus was observed during late recovery (-0.6±0.2cm; p,0.05). There was a significant decrease in LES thickness during peak nausea (-0.8±0.3cm; p,0.05). The number of swallows was comparable during BL/nausea/recovery. MII-pH showed normal acid exposure and 0-2 reflux episodes during total recording times. The number of TLESRs was significantly greater during the recovery period compared to the nausea period (p=0.01). Conclusion: Fundus and GEJ changes during nausea are different from those observed during meals, TLESRs and vomiting. Peak nausea is followed by a drop in fundus and LES pressure, oesophageal lengthening and a decrease in LES thickness. LES relaxation during nausea is incomplete and not accompanied by reflux. Whether anatomical changes provoke the sensation of nausea or vice versa is unknown, however the time sequence in our experiment suggests the latter.

Water-Swallowing Test: Screening for Aspiration in Stroke Patients

Background and Purpose: The water-swallowing test (WST) is frequently used in clinical practice as a functional assessment to detect aspiration and prevent pneumonia. It is a standardized test used all over the world, but the amount of water given varies depending on the examiner. Furthermore, there are very few reports on the simultaneous performance of the WST and videofluorography (VF). This study compared the amount of swallowed water to investigate the reliability of WST to exclude aspiration following acute stroke. Methods: We assessed 111 stroke patients (65 men and 46 women) with suspected dysphagia/difficulty in swallowing and performed VF upon obtaining consent from the patients and their families. Patients were aged between 20 and 98 years (65.6 ± 13.4 years); 64 had cerebral infarction, 26 cerebral hemorrhage, 13 subarachnoid hemorrhage, and 8 had other cerebrovascular disease. The time from stroke onset to VF was 16.6 ± 10.3 days (range, 2-55). WSTs using 5, 10, 30, and 60 ml and the modified WST (MWST) were performed during VF. Results: We found that the number of instances of choking, cough, wet voice, and aspiration increased with higher amounts of water. The sensitivity and specificity of WST for aspiration ranged from 34.8 to 55.7% and from 78.9 to 93.2%, respectively. The MWST, which used only 3 ml of water, yielded a sensitivity of 55.3% and a specificity of 80.8% for aspiration. There was a positive correlation between the time for one swallow and age, but there was no difference between genders. There was also no connection between clinical findings during WST or the presence of aspiration with the number of swallows, swallowing speed, or time for one swallow. Conclusions: WSTs are not as powerful as VF as a screening instrument in acute stroke. WSTs with more water detected aspiration with greater sensitivity, but there is no justification for overconfidence when investigating aspiration. We recommend using WST as well as VF to investigate swallowing in stroke patients.

Assessment of mastication in healthy children and children with cerebral palsy: a validity and consistency study

The aim of this study was to develop the Mastication Observation and Evaluation instrument for observing and assessing the chewing ability of children eating solid and lumpy foods. This study describes the process of item definition and item selection and reports the content validity, reproducibility and consistency of the instrument. In the developmental phase, 15 experienced speech therapists assessed item relevance and descriptions over three Delphi rounds. Potential items were selected based on the results from a literature review. At the initial Delphi round, 17 potential items were included. After three Delphi rounds, 14 items that regarded as providing distinctive value in assessment of mastication (consensus >75%) were included in the Mastication Observation and Evaluation instrument. To test item reproducibility and consistency, two experts and five students evaluated video recordings of 20 children (10 children with cerebral palsy aged 29-65 months and 10 healthy children aged 11-42 months) eating bread and a biscuit. Reproducibility was estimated by means of the intraclass correlation coefficient (ICC). With the exception of one item concerning chewing duration, all items showed good to excellent intra-observer agreement (ICC students: 0.73-1.0). With the exception of chewing duration and number of swallows, inter-observer agreement was fair to excellent for all items (ICC experts: 0.68-1.0 and ICC students: 0.42-1.0). Results indicate that this tool is a feasible instrument and could be used in clinical practice after further research is completed on the reliability of the tool.

Oral processing characteristics of solid savoury meal components, and relationship with food composition, sensory attributes and expected satiation

Background: The modern food supply is often dominated by a large variety of energy dense, softly textured foods that can be eaten quickly. Previous studies suggest that particular oral processing characteristics such as large bite size and lack of chewing activity contribute to the low satiating efficiency of these foods. To better design meals that promote greater feelings of satiation, we need an accurate picture of the oral processing characteristics of a range of solid food items that could be used to replace softer textures during a normal hot meal. Aim: The primary aim of this study was to establish an accurate picture of the oral processing characteristics of a set of solid savoury meal components. The secondary aim was to determine the associations between oral processing characteristics, food composition, sensory properties, and expected satiation. Methods: In a within subjects design, 15 subjects consumed 50g of 35 different savoury food items over 5 sessions. The 35 foods represented various staples, vegetables and protein rich foods such a meat and fish. Subjects were video-recorded during consumption and measures included observed number of bites, number of chews, number of swallows and derived measures such as chewing rate, eating rate, bite size, and oral exposure time. Subjects rated expected satiation for a standard 200g portion of each food using a 100mm and the sensory differences between foods were quantified using descriptive analysis with a trained sensory panel. Statistical analysis focussed on the oral processing characteristics and associations between nutritional, sensory and expected satiation parameters of each food. Results: Average number of chews for 50g of food varied from 27 for mashed potatoes to 488 for tortilla chips. Oral exposure time was highly correlated with the total number of chews, and varied from 27s for canned tomatoes to 350s for tortilla chips. Chewing rate was relatively constant with an overall average chewing rate of approximately 1chew/s. Differences in oral processing were not correlated with any macronutrients specifically. Expected satiation was positively related to protein and the sensory attributes chewiness and saltiness. Foods that consumed in smaller bites, were chewed more and for longer and expected to impart a higher satiation. Discussion: This study shows a large and reliable variation in oral exposure time, number of required chews before swallowing and expected satiation across a wide variety of foods. We conclude that bite size and oral-sensory exposure time could contribute to higher satiation within a meal for equal calories.

Reliability and Validity of Swallows as a Measure of Breast Milk Intake in the First Days of Life

Breastfeeding assessment in the hospital to determine adequacy of feeds remains controversial. Swallow evaluation is integral to current assessment tools, but the literature is not clear about whether the number of swallows is an accurate indicator of breast milk intake in early postpartum. To determine the reliability and validity of swallows as a measure of breast milk intake in the first days of a newborn's life. Thirty mother-baby dyads were observed at one breastfeeding; pre- and postfeed weights were done, bedside audible swallows were counted, and feeds were videotaped for independent rating. Milk intake was determined from weight change, adjusted for insensible water loss. Number of swallows was significantly and positively correlated with breast milk intake (r = .71). Number of swallows alone, however, accounted for only 50.8% (R (2) = .508) of the variation in milk intake. Infant age was the best predictor of milk intake (β(age) = .56 vs β(No. swallows) = .36), accounting for 68% of the variation in milk intake when combined with swallows. The majority of infants took in 10 g or less of breast milk (77%); length of feeds was variable. In-room (at bedside) lactation consultant (LC) and video rater LC swallow counts were significantly and positively correlated (r = .93; P < .01). However, the 2 lactation consultant swallow numbers include clinically important discrepancies in a Bland-Altman analysis. Number of swallows was not supported as a reliable or valid indicator of milk intake and adequacy of a feed in the first few days of life.

Cricopharyngeal Muscle Electromyography Findings in Patients with Gastroesophageal Reflux Disease

To analyze the grade of reflux and the behavior of the cricopharyngeal muscle (CPM) in patients with gastroesophageal reflux (GER) by means of electromyographic (EMG) analysis of CPM. Prospective clinical study. Istanbul Training and Research Hospital. Motor unit potential (MUP) recordings and kinesiological recordings of CPM were performed using a concentric needle electrode during dry material swallowing and 3-, 5-, and 10-mL water swallowing. Twenty-four patients with GER were compared with 21 healthy volunteers. GER was mild in 15 patients and moderate-to-severe in 9 patients. MUP recordings were normal in both groups during the preswallowing/postswallowing periods. Kinesiological investigations revealed that the number of patients who did not show a preswallow EMG burst had a positive correlation with the severity of reflux and the amount of liquid swallowed. Rebound bursts were observed in the patient and the control groups. Duration of preswallow and rebound bursts was similar in all groups. Duration of swallowing was shorter in mild GER patients compared with healthy volunteers and moderate-to-severe GER patients. Piecemeal deglutition during 10-mL liquid swallowing was higher in moderate-to-severe GER patients. We also found a positive correlation between the number of swallows and the severity of reflux. Needle EMG of the upper esophageal sphincter was normal in GER patients. Kinesiological evaluations showed increased piecemeal deglutition and number of swallows that correlated positively with the severity of GER.

Individual-dependent effects of pharyngeal electrical stimulation on swallowing in healthy humans

The present study tested whether electrical stimulation increases the number of voluntary repetitive swallows in humans. In addition, the potential of initiating both voluntary and involuntary swallows was compared using electrical stimulation. Fourteen normal male adults were instructed to perform repetitive voluntary swallowing as quickly as possible over 30s, and the number of swallows was counted with and without repetitive electrical stimulation (80% of maximal tolerated intensity; 0.1ms in pulse duration; 30Hz) of the nasal cavity, nasopharynx, oropharynx, or laryngopharynx. Although the number of swallows was significantly increased during electrical stimulation of the laryngopharynx, oropharynx, and nasopharynx, there was a wide variation in the number among subjects. The number of reflexively evoked swallows (i.e., involuntary swallows) by pharyngeal stimulation also varied greatly, and there was a significant linear correlation in the number of swallows between voluntary and involuntary swallows. The present study demonstrated the facilitatory effects of pharyngeal electrical stimulation on voluntary swallowing in humans. Furthermore, the potentials of initiation of voluntary swallows are identical to those of involuntary swallows, which suggests that the swallowing central pattern generator is a common component of both neuronal networks and therefore is responsible for inter-individual variations.

Possible interaction of gender and age on human swallowing behavior

The swallowing behavior is affected by age and possibly by gender. However, the interaction of the effects of age and gender on swallowing is not completely known. To evaluate the possibility of interaction of gender and age on human swallowing behavior. Swallowing was evaluated in 89 healthy subjects by the water swallowing test, 43 men and 46 women aged 20-40 years (younger, n = 38), 41-60 years (middle-aged, n = 31) and 61-80 years (older, n = 20). Each subject ingested in triplicate 50 mL of water while precisely timed and the number of swallows needed to ingest all the volume was counted. The interval between swallows was shorter and the volume in each swallow was smaller in women compared to men. In older subjects the time to ingest the 50 mL of water was longer, the interval between swallows was longer, and swallowing flow and volume in each swallow were smaller than in younger and middle-aged subjects. The swallowing flow was lower in women compared to men in younger subjects. The volume of each swallow was smaller in women than in men in younger and middle-aged subjects. There was no difference in swallowing flow and volume between older men and older women. Age and gender influence swallowing behavior, with the effect of gender being more evident in younger subjects and the effect of age being more evident in men.

Normal Values for Esophageal Motility and Function During Multiple Swallows of Low vs. High Viscosity Liquid

Introduction High resolution manometry (HRM) with spatiotemporal presentation of pressure data provides a detailed representation of oesophageal anatomy, motility and function. In the pharynx, raised Intrabolus pressure (IBP) with a steep intrabolus pressure gradient on HRM identifies clinically significant resistance to flow in the region of the upper oesophageal sphincter. The same principle can be applied to identify pathology that obstructs bolus passage also in the oesophagus and lower oesophageal sphincter (LOS); however larger volumes are required due to the greater capacity of the distal oesophagus. The sensitivity of this test to detect pathology may be increased by ingestion of high viscosity fluids compared to water; however normal values for these tests have not been established. The aim of this study was to compare oesophageal function with 200 ml high viscosity versus low viscosity liquid swallows in the physiologic, upright seated, position. Methods 9 healthy subjects (Male:Female 5:4, age 20–44) underwent HRM using a 36 channel solid state assembly (Manoscan 360, Sierra Scientific Instruments). After standard 10×5 ml water swallows, 200 ml of water (viscosity 1 cPois) and 200 ml of a thick lactose-free fruit-smoothie (100 kcal, ∼100 cPois) were ingested in consecutive order. Volunteers were asked to drink the liquid through a straw without stopping. Spatiotemporal plots of 5 ml water and large volume multiple swallows were assessed. Results are presented as Median (IQR). χ 2 test was used for qualitative analysis and Wilcoxon test was used to for non-parametric quantitative group comparisons. Results A similar number of swallows were required to drink the high and low viscosity liquid (19.9 vs 17.9; p=0.4); however the duration required to ingest the smoothie was greater (35 s (33–49 s) vs 25 s (22–30 s; p=0.018). Complete suppression of oesophageal contractility was achieved for all water and 7/9 fruit-smoothie swallows. IBP was somewhat higher for 5 ml water swallows (8.9 mm Hg (6.7–13.8 mm Hg)) compared to 200 ml water (3.6 mm Hg (2.5–4.6)) and 200 ml smoothie (3.0 mm Hg (0.0–4.4 mm Hg)), although this difference was non-significant (p=0.109 and 0.139 respectively). A powerful postcontraction was observed in most patients after drinking the smoothie and water (8 vs 5/9 patients; p=0.294) followed by an increase in LOS postcontraction pressure (12.7 vs 7.1 mm Hg; p=0.144) respectively. Conclusion This study compares the function of the healthy oesophagus to free drinking of low versus high viscosity fluids. Furthermore it provides reference values for future clinical studies to assess the clinical utility of including high viscosity fluids in HRM investigation of patients with oesophageal symptoms.

Evaluation of liquid ingestion after bariatric surgery

Bariatric surgery is an effective treatment for obesity; however, after surgery the patient may have difficulty in swallowing liquid and solid foods. To evaluate liquid ingestion in patients who had undergone bariatric surgery. We studied 43 volunteers with normal body mass index (BMI) (BMI: 18.5-24.9 kg/m²), 55 subjects with class III obesity (BMI: >40.0 kg/m²), and 48 subjects with bariatric surgery for treatment of class III obesity. The method chosen for evaluation was the water swallowing test. The subjects drank in triplicate 50 mL of water while being precisely timed and the number of swallows were counted. There was no difference between subjects with normal BMI and subjects with class III obesity. During the first 2 months after bariatric surgery the patients showed an increase in the time needed to drink the entire volume, in the number of swallows, and in the inter-swallow interval, and a decrease in the volume swallowing capacity (volume/swallowing) and swallowing flow rate (volume swallowed/second). After 2 months, the results of the swallowing measurements moved in the direction of normal values. Bariatric surgery may cause more intense alterations of liquid bolus swallowing within 2 months after the procedure, which moved to normal values after this time.

Dysfunction of bulbar central pattern generator in ALS patients with dysphagia during sequential deglutition

Objective The aim of this study is to investigate a probable dysfunction of the central pattern generator (CPG) in dysphagic patients with ALS. Methods We investigated 58 patients with ALS, 23 patients with PD, and 33 normal subjects. The laryngeal movements and EMG of the submental muscles were recorded during sequential water swallowing (SWS) of 100 ml of water. The coordination of SWS and respiration was also studied in some normal cases and ALS patients. Results Normal subjects could complete the SWS optimally within 10 s using 7 swallows, while in dysphagic ALS patients, the total duration and the number of swallows were significantly increased. The novel finding was that the regularity and rhythmicity of the swallowing pattern during SWS was disorganized to irregular and arhythmic pattern in 43% of the ALS patients. The duration and speed of swallowing were the most sensitive parameters for the disturbed oropharyngeal motility during SWS. Conclusions The corticobulbar control of swallowing is insufficient in ALS, and the swallowing CPG cannot work very well to produce segmental muscle activation and sequential swallowing. CPG dysfunction can result in irregular and arhythmical sequential swallowing in ALS patients with bulbar plus pseudobulbar types. Significance The arhythmical SWS pattern can be considered as a kind of dysfunction of CPG in human ALS cases with dysphagia.

Deglutition and respiratory patterns during sleep in younger adults

Conclusion: Deglutition was infrequent and displayed unique patterns during sleep in healthy younger adults. Objectives: The deglutition, electroencephalographic arousal, and respiratory phase patterns during sleep in younger adults were investigated. Methods: Ten younger adults were examined via time-matched recordings of polysomnography and surface electromyography. Results: During sleep, swallowing was infrequent and absent for long periods. The mean number of swallows per hour during the total sleep time was 2.4 ± 1.0. The mean longest deglutition-free period was 68.8 ± 24.8 min. Most deglutition occurred in association with spontaneous electroencephalographic arousal. Deglutition was related to the sleep stage. The mean number of swallows per hour was 11.2 ± 8.1 during stage 1 sleep, 1.9 ± 1.0 during stage 2 sleep, 0.5 ± 1.5 during stage 3 sleep, and 0.2 ± 0.5 during stage 4 sleep. The deeper the sleep stage, the lower the mean deglutition frequency. The mean number of swallows per hour was 1.9 ± 1.7 during rapid eye movement sleep. The deeper the sleep stage, the lower the mean arousal frequency and the lower the mean ratio of arousal with deglutition to arousal. Approximately 60% of swallows were followed by arrested breathing and approximately 25% by expiration.

Impact of tracheostomy on swallowing performance in Duchenne muscular dystrophy

Mechanical ventilation has improved survival in patients with Duchenne muscular dystrophy (DMD). Over time, these patients experience upper airway dysfunction, swallowing impairments, and dependency on the ventilator that may require invasive mechanical ventilation via a tracheostomy. Tracheostomy is traditionally believed to further impair swallowing. We assessed swallowing performance and breathing-swallowing interactions before and after tracheostomy in 7 consecutive wheelchair-bound DMD patients, aged 25 ± 4 years, over a 4-year period. Chin electromyography, laryngeal motion, and inductive respiratory plethysmography recordings were obtained during swallowing of three water-bolus sizes in random order. Piecemeal deglutition occurred in all patients over several breathing cycles. Half the swallows were followed by inspiration before tracheostomy. Total bolus swallowing time was significantly shorter ( P = 0.009), and the number of swallows per bolus significantly smaller ( P = 0.01), after than before tracheostomy. Invasive ventilation via a tracheostomy may improve swallowing.