Normal Oropharyngeal Swallowing Research Articles

Noninvasive Evaluation of the Biomechanical Accommodations to Bolus Volume during Human Swallowing.

Bolus volume is very important in the biomechanics of swallowing. By noninvasively characterizing swallow responses to volume challenges, we can gain more knowledge on swallowing and evaluate swallowing behavior easily. This study aimed to evaluate the impact of bolus volume on the biomechanical characteristics of oropharyngeal swallowing events with a noninvasive sensing system. Fifteen healthy male subjects were recruited and instructed to swallow 5, 10, and 15 ml of water. The sensing system consisted of a tongue pressure sensor sheet, bend sensor, surface electrodes, and a microphone. They were used to monitor tongue pressure, hyoid activity, surface EMG of swallowing-related muscles, and swallowing sound, respectively. In addition to the onset, the peak time and offset of the above four structures, certain characteristics, such as the duration, peak value, and interval of the structure motions, were measured during the different drinking tasks. The coordination between the hyoid movement and tongue pressure was also assessed. Although no sequence of the structural events changed with volume, most of the timings of the structural events were significantly delayed, except for certain hyoid activities. The swallowing volume did not affect the active durations of the monitored structures, the peak values, or intervals of tongue pressure and supra- and infrahyoid muscle activity, but certain hyoid kinetic phases were prolonged when a larger volume was swallowed. Additionally, sequential coordination between hyoid movement and tongue pressure was confirmed among the three volumes. These findings suggest that oropharyngeal structural movements change in response to bolus volume to facilitate safe swallowing. The noninvasive and quantitative measurements taken with the sensing system provide essential information for understanding normal oropharyngeal swallowing.

Functional and patient-reported changes in swallowing and voice after combined chemotherapy and radiotherapy for limited-stage small-cell lung cancer.

The purpose of this study was to describe the nature and impact of dysphagia and dysphonia in patients with limited-stage small-cell lung cancer (SCLC) before and after chemoradiation. A prospective cohort study was conducted on patients receiving chemoradiotherapy for limited-stage SCLC. Patients received either 40, 45 or 50Gy, commencing the second cycle of chemotherapy. Outcomes included: videofluoroscopy (VFSS) to investigate aspiration, swallowing function and oesophageal motility; oral intake limitations; patient-reported dysphagia; and patient-reported dysphonia. Data were collected before treatment and one, three and six months post-treatment. Twelve patients were enrolled. Oropharyngeal swallowing was safe and functional at all times. Three patients exhibited oesophageal motility disorders before treatment, and a further three post-treatment. Oral intake was most compromised one month post-treatment with five patients either tube dependent or eating very limited diets. At all other times patients were eating normal or near-normal diets. Despite normal oropharyngeal swallowing on VFSS, three patients reported moderate or severe dysphagia one month post-treatment. Three additional patients reported moderate or severe difficulties three and six months post-treatment. Patients who reported dysphagia one month post-treatment all received a mean and maximum oesophageal dose of ≥15.7Gy and ≥42Gy, respectively. Dose-response relationships were not apparent three and six months post-treatment. Voice problems varied, with worst scores reported one month post-treatment. This study identified discordance between observed swallowing function and patient-reported problems, which has clinical implications for patient management, and highlights future research needs. Ongoing efforts to reduce mucosal toxicity in patients with lung cancer are essential.

Critical Factors in the Oral Control Needed for Chewing and Swallowing.

Normal oropharyngeal swallowing is a complex set of neuromotor behaviors containing three phases: 1) Oral preparation to break food down to a swallowable consistency; 2) Oral phase which propels food from the mouth; 3) Pharyngeal phase creates pressure to push food into the esophagus, and includes valve functions which prevent food from entering the nose or airway and allow food into the esophagus. Systematic changes in normal oropharyngeal swallow are based on volume, viscosity, and taste of the food swallowed as well as age. Patients with oropharyngeal swallowing difficulties (dysphagia) react differently to these systematic variables in food characteristics. This review manuscript presents the results of a series of studies that examine the role of each of the stages of the nonoral orpharyngeal swallow. The importance of the definition of food viscosity in the care of dysphagic patients and the role of food production companies in this effort are emphasized.

Aging effects on oropharyngeal swallow and the role of dental care in oropharyngeal dysphagia

Difficulty with oropharyngeal swallow requires careful diagnosis and treatment from a team of professionals including the patients' physicians and the speech-language pathologist specializing in dysphagia. The dentist can be a critical team member in prevention, early identification, and management of oropharyngeal dysphagia. This manuscript reviews the physiology of normal oropharyngeal swallow and the effects of normal aging on this physiology. Typical etiologies for oropharyngeal dysphagia are defined as is the most commonly used physiologic diagnostic procedure, the modified barium swallow (MBS). The critical role of the dentist in identifying risk of oropharyngeal dysphagia, making appropriate referrals, and improving oral hygiene to prevent aspiration pneumonia in the elderly is discussed.

Preliminary Temporal Measurement Analysis of Normal Oropharyngeal Swallowing in Infants and Young Children

Temporal measures of normal pediatric oropharyngeal deglutition have not been studied. Knowledge of range and variation of normative temporal measures could define abnormal deglutition and assist in design of appropriate compensatory and rehabilitative treatment techniques. The purpose of this retrospective study was to determine temporal measurements for oral filling, oral transit, onset of laryngeal closure, time of bolus arrival at the valleculae, pharyngeal delay, pharyngeal transit, and UES opening. Videofluoroscopic swallow studies of 15 normally swallowing pediatric subjects were divided into three age groups and method of liquid delivery. Mean, standard deviation, percentages, and extension of the median were utilized to determine relationships of temporal measures. Mean temporal duration increased with age for oral filling, oral transit time, time of laryngeal closure, UES opening, and pharyngeal delay time. However, no significant differences were found between age groups indicating a deglutitive biomechanical adaptation to growth of the oral and pharyngeal cavity. Feeding method for bottle versus cup mean duration increased for oral transit time, laryngeal closure time, UES opening, and pharyngeal delay time. Bolus head location relative to onset of laryngeal vestibule closure changed with increased age and method of feeding. Temporal measures were not significantly different for age groups or feeding methods. Bolus location was at or fully contained in the valleculae at the onset of laryngeal closure and appeared to be a normal finding in functional pediatric swallows and is not indicative of a delay or disorder.

Breathing and Swallowing Dynamics Across the Adult Lifespan

Aberrations in the physiologic components of normal oropharyngeal swallowing have been linked to aspiration events and to predisposition to aspiration pneumonia, a common, deadly disease in elderly persons. Studies have demonstrated a temporal, physiologic link between breathing and the principal physiologic swallowing components involved in airway protection during swallowing. We developed a normative model of integrated breathing and swallowing patterns using concomitant videofluoroscopic images and nasal respiratory airflow recordings. To establish normative temporal and respiratory-phase pattern relationships between breathing and swallowing in adult human beings across the aging continuum; to relate any alterations in these patterns to swallowing abnormality, an aspiration event during swallowing, and predisposition to aspiration pneumonia; and to develop clinically practical evaluation methods for identifying breathing and swallowing discoordination. Fluoroscopy suite in an acute care hospital. Eighty-two healthy adult volunteers gave informed consent. All eligible healthy volunteers were welcome and were screened for age, race, and sex for equal distribution of each. Respiratory-phase patterns and the onset and duration of 11 predetermined swallowing events and associated respiratory activities were studied. All participants' single-liquid barium swallow examinations were studied with simultaneous videofluoroscopy and respiratory recordings. Onset of each of the 11 predetermined breathing and swallowing events was digitally recorded and analyzed. The phases of breathing before and after swallowing were identified. The presence, depth, and response to airway penetration were recorded and related to respiratory pattern. Four respiratory-phase patterns were identified that changed with advanced age. The correlation analyses of the temporal breathing and swallowing events revealed a normal pattern of 4 clearly distinguishable functional units. Differences in apnea duration and apnea offset occurred with advanced age. This research provides evidence for clearly distinguishable patterns and functional groupings of breathing and swallowing events, a necessary first step toward determining whether abnormal breathing and swallowing patterns in patients with dysphagia are associated with health outcome.

Oropharyngeal swallowing and aging: A review

This article provides an overview of normal oropharyngeal swallowing in relation to advanced age, with specific attention to oropharyngeal movement patterns and temporospatial swallowing durations. Swallowing disorders associated with aging are addressed with specific attention to the need for application of normative data to the diagnostic process. Attention is drawn to the need for continued research on swallowing function in the normal adult if efforts to maximize functional independence in eating and swallowing in the institutionalized adult are to be realized.

Interobserver Agreement on Normal Swallowing Physiology as Viewed by Videoendoscopy

This study examines the agreement of 2 observers in identifying selected normal oropharyngeal swallow events in the 1- and 5-ml swallows of 3 normal young adult males as identified by videoendoscopy at each of two endoscopic positions: (1) with the tip of the endoscope just at or below the tip of the uvula (high position), and (2) with the tip of the endoscope just below the tip of the epiglottis (low position), and thereby defines the needed focus for observer training in endoscopic assessment of swallowing. Overall, the more and less experienced examiners agreed on seeing or not seeing the onsets and terminations of the 12 events 83% of the time. Scope position affected observer agreement on several events while bolus volume did not.

Normal Swallowing Physiology as Viewed by Videofluoroscopy and Videoendoscopy

This study examines normal oropharyngeal swallow physiology in 8 young adult males with concurrent videofluoroscopy and videoendoscopy. Twelve swallows were examined for each subject, 3 swallows each of 1 and 5 ml of thin liquid at each of two endoscopic positions: (1) the tip of the endoscope just at or below the tip of the uvula (high position), and (2) the tip of the endoscope just below the tip of the epiglottis (low position). Results indicate that if the clinician is interested in laryngeal events occurring before and after swallow, videoendoscopy with the endoscope in the low position is the procedure of choice. To evaluate pharyngeal anatomy and/or the presence of food in the pharynx before or after swallow, either endoscopy with the endoscope in the high position or videofluoroscopy can be used. However, if the clinician is interested in pharyngeal physiology during swallow, videofluoroscopy is a better diagnostic procedure.

Influence of gravity and body position on normal oropharyngeal swallowing.

The influence of gravity, if any, on pharyngeal bolus transport is unknown. The aim of the present study was to evaluate the effect of gravity and body position on the radiological and manometric events during the normal oropharyngeal swallow. In eight healthy male volunteers, we performed simultaneous videoradiography and manometry, using a manometry catheter incorporating a perfused sleeve measuring upper esophageal sphincter pressure and three solid-state transducers recording pharyngeal pressures. Swallows of 5 and 10 ml of barium were performed in three different body positions: upright, horizontal, and 30 degrees head down (inverted). Hypopharyngeal intrabolus pressure increased significantly in the horizontal and inverted positions compared with upright, P = 0.0001. This resulted in increased maximal sphincter diameters during bolus flow (P = 0.0001) and shorter duration of sphincter opening (P = 0.03). As a result, transsphincteric flow increased in the horizontal and inverted positions, P = 0.04. Total swallowing duration, oral and pharyngeal transit time, pharyngeal peristaltic amplitude and duration, the length of the bolus in the pharynx, and excursions of the hyoid and larynx were unaffected by body position. We conclude that intrabolus pressure is an important determinant of upper esophageal sphincter opening in the healthy oropharynx and that gravity does not influence pharyngeal bolus transport. The healthy upper esophageal sphincter has residual opening capacity that can be demonstrated by altering body posture.