[Objective]　The purpose of this study was to distinguish patients with hysterical swallowing difficulty (HSD) from those with dysphagia due to neuromuscular diseases (NMD) by videofluorography (VF).

[Subjects and Methods]　Sixteen patients who described difficulty in propelling foods from the oral cavity to the pharynx, but had no organic abnormalities on neurologic examination or imaging, were diagnosed with HSD. For comparison, 30 healthy individuals (normal controls, NC), 30 patients with amyotrophic lateral sclerosis (ALS), 30 patients with muscular diseases (MD), and 30 patients with Parkinson's disease (PD) were enrolled. In all individuals, VF was performed while drinking 10 ml of liquid barium (liquid) and while eating 8 g of corned beef hash with barium paste (CB). VF characteristics were compared among the groups (Mann-Whitney U test and correspondence analysis).

[Results]　In the HSD group, the anteroposterior diameter of the pharynx was similar to that in the NC and PD groups, but it was shorter than that in the ALS and MD groups. With liquid, the swallowing reflex was often initiated on the oral side for the HSD and NC groups. Aspiration of liquid was seen in 16.7–20.0% of the NMD patients but in none of the HSD or NC patients. Five patients with HSD showed several interruptions of liquid propulsion from the oral cavity to the pharynx after the start of swallowing. We named this finding “intermittent interruption of food propulsion.” Few individuals in the other groups showed this finding. With CB, three patients with HSD could not swallow the bolus. The number of chews in the HSD group was similar to that in the NC, ALS, and PD groups. The swallowing reflex was often initiated on the oral side for the HSD group; therefore stage II transport was infrequently initiated during chewing. Pharyngeal residue after either eating CB or drinking liquid was rare in the HSD and NC groups.

[Conclusions]　The HSD group resembled the NC group in terms of the position of liquid at the start of the swallowing reflex and the pharyngeal residue after swallowing. Dilatation of the pharynx and liquid aspiration were useful findings to differentiate NMD patients from HSD patients. Intermittent interruption of food propulsion and lack of stage II transport during chewing were characteristic findings for the HSD patients.

As the elderly population grows, dysphagia patients are increasing due to cerebrovascular diseases. These patients often use jelly foods for recovering swallowing function but have a high risk of aspiration. However, there have been few studies on the influence of jelly food aspiration.

The aim of this study was to investigate the functional and histopathologic effects on lung function of different gelling agents for jelly foods (gelatin, carrageenan, and agar) and barium sulfate after pulmonary aspiration in rats. Male SD rats were randomly assigned to one of five groups (n＝5 per group). After anesthesia induction by inhalation of isoflurane, rats were intubated endotracheally with a 16-gauge angiocatheter and test samples (saline solution [0.9%], barium sulfate [contract media], gelatin jelly, carrageenan jelly, and agar jelly) were injected into the lung through the trachea in a dose of 0.1 ml/kg to induce aspiration. After 2 days, the rats were sacrificed and tissue samples from the trachea to the lungs were taken for histological examinations. Blood samples were also taken to measure parameters such as pH, pO₂, and pCO₂. Then, the rheological properties of the jelly samples were measured at 10, 20, 30, and 37℃ using a rheometer.

With the aspiration of barium sulfate, inflammation reaction in the lungs was slight and pulmonary gas change function (blood pH, pO₂, and pCO₂) was not affected. These results suggested that barium sulfate is relatively safe in terms of aspiration at the dose employed in this study.

In the aspiration of various jelly samples, alveolar histiocytes were statistically higher in the agar or carrageenan jelly than in the saline. Lipid-laden alveolar macrophages were significantly higher in the agar or carrageenan jelly than in the saline. The gel stiffness of jelly was decreased as temperature increased, and gelatin jelly melted completely to liquid at near the body temperature of 37℃. Blood pH, pO₂, and pCO₂ remained unchanged after pulmonary aspiration of each jelly. These data suggested that pulmonary aspiration of jelly does not affect lung function at the dose employed in the study.

Based on the results, we concluded that lung tissue damages such as inflammation reaction occurring after pulmonary aspiration of jelly depend on the viscosity of jelly at near body temperature, and hence the choice of suitable training food is important for direct therapy of dysphagia patients.

This study aimed to clarify the relationship between the difference in adhesiveness of biscuits and the function of eating and swallowing.

Two types of cream sand biscuits: normal biscuits, biscuits with normal nutrient contents; less adhesive biscuits, less adhesive and more easily triturated biscuits during mastication than the normal biscuits were used in this study. Thirty healthy adults (mean age: 32.7±7.3 years), twenty elderly people without trouble to eating biscuits (mean age: 72.5±4.4 years), and eleven stroke patients undergoing rehabilitation without trouble to eating biscuits (mean age: 63.2±11.4 years) participated in the study after giving informed consent. We measured the amount of food residues in the oral cavity and the number of the chewing strokes, the chewing time, the number of times of swallowing, and the swallowing duration. A sensory assessment was conducted for each participant. The results were compared within each group and among the three different groups.

There was no difference in the amount of food residues between the normal biscuits and the less adhesive biscuits in the healthy adults. On the other hand, the amount of food residues of the less adhesive biscuits was significantly less than that of the normal biscuits in the elderly people and the stroke patients (p＜0.01–0.05). The amount of food residues of the normal biscuits eaten by the elderly people and the stroke patients was larger than that of the healthy adults (p＜0.01–0.10).

The number of chewing strokes while masticating the less adhesive biscuits by the healthy adults and the elderly people was less than that of the normal biscuits (p＜0.01). The chewing time while masticating the less adhesive biscuits in all the three groups was shorter than that of the normal biscuits(p＜0.01-0.05). The elderly people and the stroke patients needed more chewing strokes and longer chewing time to eat either type of biscuit than the healthy adults (p＜0.01–0.05).

The number of times of swallowing for the less adhesive biscuits was smaller than that for swallowing the normal biscuits in the healthy adults and the elderly people (p＜0.01–0.05).The swallowing time of the less adhesive biscuits was shorter than that of the normal biscuits in the healthy adults（p＜0.05）.

The healthy adults and the elderly people gave higher scores for the less adhesive biscuits than the normal biscuits in the sensory assessment of adhesiveness and disintegration.

Our findings suggest that less adhesive biscuits would be more suitable for elderly people and patients with dysphagia. Regarding oral hygiene, it might be important to provide those people with foods that leave less residues in the oral cavity after swallowing.

[Objective] Pharyngeal swallows consist of consecutive pharyngeal swallows (CPS) and isolated pharyngeal swallows (IPS). CPS is a swallow with consecutive oral and pharyngeal stages, while IPS is a swallow without oral bolus transport by the tongue. The objective of this study is to compare the trajectory of the hyoid bone between CPS and IPS.

[Subjects and Methods] Fifty-three healthy subjects who gave informed consent were enrolled in this study. A videofluoroscopic examination of swallowing (VF) was performed in lateral projection in an upright posture. A mixture of semi-solid food and liquid was administered two times to each subject. The first and second swallows were divided into CPS and IPS upon agreement of one physiatrist and two dentists. The trajectory of the hyoid bone during swallowing was measured. The maximum distance of the horizontal and vertical axes, and the distance and time from onset to the end of the motion of the hyoid bone to antero-superior direction between CPS and IPS were compared.

[Results] Among 106 trials in 53 subjects, IPS occurred 26 times and CPS 80 times in the first swallows. All second swallows were CPS. In comparison of the trajectory of the hyoid bone between 18 subjects (26 trials) who had IPS and 20 subjects (30 trials) who had CPS in the first swallows, the maximum distance of horizontal and vertical axes, and the distance and time from onset to the end of the motion of the hyoid bone to antero-superior direction were found to be significantly smaller in IPS than CPS.

[Conclusion] IPS was a small and quick movement compared to CPS and seemed to occur for airway protection purposes.

he Line Spread Test（LST）is known as a simple method for measuring the rheological properties of thickened liquid foods. However, the applicability of these methods has not been thoroughly examined. Therefore, we assessed various thickened liquid foods prepared with instant food thickeners by a modified LST method by which the measured value is more precise than the original ring method. We then measured the rheological properties of thickened liquid foods and analyzed the relationships between the various properties with the LST values. First, we measured the properties of three thickened liquid foods, water, milk, and orange juice, in which three xanthan gum-based thickeners, commercially available, were dissolved. The correlations between the LST values and other physical properties such as viscosity, hardness, and adhesive energy, were analyzed. The LST values were correlated linearly with the viscosities and with the hardness, but logarithmically with the adhesive energy. The range of viscosities practically measurable by LST was from 1,000 to 7,000 mPa・s. In addition, we measured the properties of thickened milk in which xanthan gum, starch, or guar gum-based thickeners were dissolved and evaluated by the simple linear regression analysis between the LST value and each of other physical properties. We found that the lower the rotor rotating speed for the viscosity measurements, the higher the contribution ratio between the LST values and the viscosity. We then performed multiple linear regression analysis with the LST value as an objective variable, and with the other physical properties as explanatory variables. The LST values without the starch-based thickeners match a good multiple linear regression model which comprises three factors including viscosity, hardness, and adhesive energy. In conclusion, the LST value reflects multiple physical properties, and it is important to set up appropriate measuring conditions and evaluation indices for practical application.

[Objective] We investigated the history of asphyxiation and the status of food intake and swallowing in schizophrenia patients in order to establish a screening method to determine the asphyxiation risk for schizophrenia patients.

[Subjects and Methods] We created a questionnaire to evaluate the status of food intake and swallowing in schizophrenia patients. Nurses assessed 98 schizophrenia patients undergoing inpatient treatment using the questionnaire. We surveyed the subjects’ history of asphyxiation from their medical records. Subjects were divided into two groups according to the presence or absence of a history of asphyxiation, and their answers compared. We used discriminant analysis to identify questions that contributed to the determination of a history of asphyxiation in schizophrenia patients, and produced a screening method to determine asphyxiation risk.

[Results] Four patients had a history of asphyxiation. Answers that were significantly more common in these patients were “possess false teeth,” “swallow food almost whole,” “have previously engaged in stealthy or secret eating,” and “swallowing improved.” The answer that was significantly less common in patients with a history of asphyxia was “delayed swallow response.” In discriminant analysis, when we allocated a score of ＋1 point for “swallow food almost whole,” of ＋1 point for “have previously engaged in stealthy or secret eating,” and of ＋2 points for “swallowing improved,” a total of ≥ 2 points indicated elevated risk of asphyxiation. The method had a discrimination rate of 92.9%, sensitivity of 100%, and specificity of 92.6%.

[Conclusion] Asphyxiation in schizophrenia was related to behavioral abnormalities concerning food intake behavior and meals, and there was a tendency for it to occur more easily in patients in whom swallowing had improved. The screening method proposed in this study may be of use in the risk management of patients with schizophrenia.

[Objective] Aspiration observed during a videofluoroscopic swallowing study (VF) may occur subsequent to an involuntary spillage of food boluses into the pharynx. To prevent such aspiration, attempts are often made to adjust the patient's posture and modify the physical properties of food. Iida developed a videofluoroscopic swallowing simulation system using a full-scale model of the oropharyngeal cavity as the subject and examined the kinetics of a test material. In this study, we simulated an involuntary spillage of food boluses into the pharynx through postural procedures and the physical properties of food boluses using VF simulation.

[Materials and Methods] Three full-scale models of the oropharyngeal cavity were created based on conebeam CT image data of the human head. The oropharyngeal cavity in the upright, chin-down, and head rotation to the left positions was reproduced in each cylindrical plaster model. Barium contrast medium, thickened barium contrast medium, and test materials such as pudding and cream were prepared as the test materials. Physical properties of the test materials were evaluated in terms of food texture including the hardness, adherability and aggregability using a texture analyzing system. Each sample was applied onto the center, right side and left side of the tongue of the model. VF images of the bolus sliding over the base of the tongue were acquired, and the speed of the bolus and the sliding route were measured.

[Results] The sliding speed of the 90% liquid barium contrast medium was decreased by approximately 90% by adding a more than 5 W/V% thickening agent, regardless of the patient's posture. The chin-down position model provided a slower sliding speed for the liquid barium contrast medium than the other positions tested. The gel-like test materials slid more slowly than the liquid barium contrast medium but faster than the thickened liquid barium contrast medium. The upright position model and chin-down position model allowed the barium contrast medium to slide along the midline regardless of where the barium contrast medium was applied, while the left neck rotation position model caused the barium contrast medium to slide over the left side.

[Discussion] The chin-down position may be effective for controlling the sliding speed of food boluses. Rotating the neck during active swallowing may guide the food bolus toward the opposite side to which the neck is rotated. However, in case of involuntary spillage, a food bolus may slide along an unintended route.

Tracheostomy is considered to negatively affect the evaluation of deglutition, and early extubation is desirable. Evaluation at an appropriate timing and the initiation of oral ingestion based on the evaluation are important. In this study, we investigated deglutition evaluation methods for tracheostomized patients.

Of tracheostomized patients referred to our department between April 2007 and March 2008, 38 patients (13 females and 25 males, aged 67 years on average (11–88 years)) underwent the evaluation. The evaluation items were: the age at the time of the first examination, primary disease, reason for necessity of trachea incision, range of motion of the tongue, repetitive saliva swallowing test (RSST), Modified Evan's Blue Dye Test (MEBDT), and the volume of excretions on the tracheotomy cuff that could be aspirated. The relationship between these items and the time of initiating oral ingestion was investigated.

There was no relationship between the primary disease and time of initiating oral ingestion. The age and time of initiating oral ingestion were significantly correlated (p＝0.0054), and the initiation of oral ingestion was delayed in older patients. MEBDT and the volume of excretions on the cuff aspirated were not significantly correlated with the time of initiating oral ingestion (p＜0.0001, p＝0.0003).

It was suggested that the evaluation of deglutition based on tongue mobility and RSST is difficult. MEBDT and the aspiration volume were significantly associated with the time of initiating oral ingestion after the first examination, suggesting their usefulness for screening. Since the aspiration of excretions on the cuff is a routine activity of nurses, it is a very useful technique to evaluate deglutition in routine care. The formulation of an index based on the volume of excretions on the cuff aspirated is necessary.

[Purpose]　To evaluate the effects of professional instructions as part of the swallowing function therapy routinely performed in outpatients with dysphagia in our Regional Rehabilitation Center for Children with Disabilities, the status of the swallowing functions at the first examination was examined and compared with that at the final evaluation in pediatric patients suffering from dysphagia.

[Subjects]　Among 72 affected children who visited our Regional Habilitation Center for Children with Disabilities during the 2 years and 3 months from September 2003 to December 2006, 60 children including 31 boys and 29 girls (mean age: 2.6±1.4 yrs), who received swallowing function therapy for 1 year or more, were selected for this study.

[Methods]　From the patients' medical records as well as the outpatients' medical records concerning dysphagia, the frequency of consultation, outcome, and changes in the swallowing function based on external observation were examined. In addition, possible factors that might have contributed to the improved swallowing functions were also studied.

[Results]　The frequency of consultation was 5.8 times (2–10 times) per patient on average. As for outcome, the professional instructions were still continued in 49 patients (81.7%), completed in 6 patients (10.0%), and discontinued in 2 patients (3.3%). Five examination items on the swallowing function were compared at two occasions, that is, at the first examination and at the final evaluation. As a result, three examination items including “lip closure at biting,”“food-grasping and food-cutting capacities with the anterior teeth,” and “water-drinking ability using a spoon” improved significantly. When possible factors that might have related to the changes in the swallowing functions were examined, it was revealed that “tongue movement during treatment” related significantly to the patient's age at the first examination as well as to the frequency of consultation.

[Discussion]　In our Center where numerous specialists can participate in the treatment of outpatients with dysphagia, it was suggested from the present study that professional instructions have been given successfully, contributing significantly to the improved swallowing functions as seen in this study.

[Purpose]　Many children with dysphagia often have tactile hyperesthesia or sensory defensiveness against the oral area. The aim of this study was to investigate the effect of desensitization therapy in school children with tactile hyperesthesia.

[Subjects and Methods]　The subjects were three disabled school children (Subject A, an 8-year-old boy with Down syndrome; Subject B, an 8-year-old boy with cerebral palsy; and Subject C, an 11-year-old girl with cerebral palsy) who attended a class for disabled children at an elementary school in Tokyo. A dentist specializing in the training of children with dysphagia evaluated their tactile hyperesthesia over the whole body, on the face, and around the oral area. An adverse reaction upon tactile stimulus was judged to be a major factor in determining the reaction to tactile hyperesthesia, and was differentiated from physiological reaction. The guardians of subjects performed desensitization therapy once a day at home. The study period was from February 2007 to February 2008.

[Results]　In Subject A, the degree of tactile hyperesthesia reduced 1 month after the start of therapy. After 1 year, tactile hyperesthesia completely disappeared on part of the face. In Subject B, the region of tactile hyperesthesia was markedly decreased, and the extent of the symptom was alleviated after 1 year. In Subject C, the tactile hyperesthesia remained unchanged.

[Conclusion]　1. Desensitization therapy was effective for tactile hyperesthesia, however, it was not always effective for all the cases in this study.

2. This study suggested that tactile hyperesthesia in feeding therapy should be appropriately defined, and it is very important to establish the most suitable desensitization therapy for individual subjects.