Kikuo Ota

The Effect of Bolus Viscosity on Laryngeal Closure in Swallowing: Kinematic Analysis Using 320-Row Area Detector CT

The present study examined the effect of bolus viscosity on the onset of laryngeal closure (relative to hyoid elevation), the duration of laryngeal closure, and other key events of swallowing in ten healthy volunteers. All volunteers underwent 320-row area detector computed tomography swallow studies while swallowing 10xa0ml of honey-thick barium (5xa0% v/w) and thin barium (5xa0% v/w) in a 45° reclining position. Three-dimensional images of both consistencies were created in 29 phases at an interval of 0.10xa0s (100xa0ms) over a 2.90-s duration. The timing of the motions of the hyoid bone, soft palate, and epiglottis; the opening and closing of the laryngeal vestibule, true vocal cords (TVC), and pharyngoesophageal segment; and the bolus movement were measured and compared between the two consistencies. The result showed differing patterns of bolus movement for thin and thick liquids. With thin liquids, the bolus reached the hypopharynx earlier and stayed in the hypopharynx longer than with thick liquids. Among events of laryngeal closure, only the timing of TVC closure differed significantly between the two consistencies. With thin liquids, TVC closure started earlier and lasted longer than with thick liquids. This TVC movement could reflect a response to the faster flow of thin liquids. The results suggest that bolus viscosity alters the temporal characteristics of swallowing, especially closure of the TVC.

The Secretion Severity Rating Scale: A Potentially Useful Tool for Management of Acute-Phase Fasting Stroke Patients

This retrospective clinical investigation was conducted to evaluate the usefulness of the Secretion Severity Rating Scale (Secretion Scale) in predicting the risk of pneumonia in acute-phase fasting stroke patients. Videoendoscopic (VE) evaluation of swallowing was performed in 72 consecutive stroke patients with a nonoral status. The patients were classified into 2 groups based on the Secretion Scale: the pharyngeal residual group (n=38; Secretion Scale level 0, 8 [11.1%]; level 1, 30 [41.7%]) and the laryngeal residual group (n=34: Secretion Scale level 2, 13 [18.1%]; level 3, 21 [29.2%]). The higher the Secretion Scale score, the more severe the swallowing dysfunction. The results of the evaluation were compared with the frequency of aspiration as well as with the incidence of pneumonia in the period from VE examination to discharge. In addition, the incidence of pneumonia was compared in the aspiration-positive and aspiration-negative groups. After VE evaluation, 4 patients (10.5%) in the pharyngeal residual group developed pneumonia versus 12 (35.3%) in the laryngeal residual group; the incidence of pneumonia was significantly higher in the laryngeal residual group (P < .05; Fishers exact test). Our data indicate that the Secretion Scale can be a useful risk-management tool for predicting pneumonia in acute-phase fasting stroke patients.

Dysphagia associated with unilateral vocal cord immobility after cardiovascular surgery.

Objective: Dysphagia associated with unilateral vocal cord immobility (UVCI) has received much less attention than did voice and phonation. The aim of this descriptive study was to evaluate the outcome of dysphagia associated with UVCI. Design: Between June 2006 and September 2009, 69 hospitalized patients who underwent cardiovascular surgery were referred for dysphagia. Video endoscopic evaluation of swallowing was used for the detection of swallowing difficulties. Severity of dysphagia was assessed using the Dysphagia Severity Scale. Results: Among the 69 patients, 31 UVCI patients who underwent video endoscopic evaluation of swallowing at least twice were used for analysis. All patients had severe to mild dysphagia at the first evaluation. Nineteen patients recovered from the UVCI at a mean follow-up of 125 days, whereas 12 had persistent UVCI at a mean follow-up of 216 days. Dysphagia Severity Scale at the first evaluation was not significantly different in both groups. At the last follow-up, the Dysphagia Severity Scale improved considerably without a significant difference in the magnitude of improvement in both groups. In the recovered and persistent UVCI groups, 16 and 7 patients, respectively, resumed their regular diets. Conclusions: Dysphagia associated with UVCI after surgery recovers, irrespective of the functional results of the UVCI.

The effect of bolus volume on laryngeal closure and UES opening in swallowing: Kinematic analysis using 320-row area detector CT study

This study investigated the effects of three different volumes of honey-thick liquid on the temporal characteristics of swallowing. Twenty-six healthy subjects (15 males, 11 females) underwent 320-row area detector CT scan while swallowing 3, 10 and 20xa0mL of honey-thick liquid barium. Three-dimensional images were created at 10xa0images/s. Kinematic events involving six structures (velopharynx, hyoid bone, epiglottis, laryngeal vestibule (LV), true vocal cords (TVC), upper esophageal sphincter (UES)) and timing of bolus movement were timed using frame by frame analysis. The overall sequence of events did not differ across three volumes; however, increasing bolus volume significantly changed the onset and termination of events. The bolus head reached to pharynx and esophagus earlier and the duration of bolus passing through UES was significantly longer in 10 and 20xa0mL compared to 3xa0mL (Pxa0<xa0.05). Consequently, the onset of UES opening was significantly earlier with increased volume (Pxa0<xa0.05). LV and TVC closure occurred later in 20xa0mL compared to 3xa0mL (Pxa0<xa0.05). These changes in motion of pharynx and larynx appeared to promote swallow safety by preventing aspiration, suggesting that anatomical structure movements adapt in response to bolus volume. Our findings also suggest that the pharyngeal swallow behaviours may be modified by afferents in the oral cavity. The three-dimensional visualization and quantitative measurements provided by 320-ADCT provide essential benchmarks for understanding swallowing, both normal and abnormal.

The Mendelsohn Maneuver and its Effects on Swallowing: Kinematic Analysis in Three Dimensions Using Dynamic Area Detector CT

This study investigated the effects of Mendelsohn maneuver with three-dimensional kinematic analysis. Nine female speech-language pathologists (nine females, meanxa0±xa0SD 27.1xa0±xa03.5xa0years old) underwent 320-row area detector scan during swallows of 4-ml nectar-thick liquid using with no maneuvers (control) and with Mendelsohn maneuver (MM). Critical event timing (hyoid, soft palate, epiglottis, laryngeal vestibule, true vocal cords (TVC), UES), hyoid and laryngeal excursion, cross-sectional area of UES, and volume of pharyngeal cavity and bolus were measured and compared between two swallows. In MM, all the events were significantly prolonged with delayed termination time (pxa0<xa00.05) except UES opening. The onset, termination, and duration of UES opening were not significantly affected by MM nor was timing of bolus transport. The hyoid bone was positioned significantly higher at maximum displacement (pxa0=xa00.011). Pharyngeal constriction ratio was 95.1% in control and 100% of all subjects in MM. Duration of minimum pharyngeal volume was significantly longer in MM than in control (pu2009=u20090.007). The MM produces several distinct changes in the kinematics of swallowing in healthy subjects with no dysphagia. The changes in the timing and magnitude of hyoid displacements and prolonged closure of the pharynx during swallowing suggest the utility of MM for improving the safety and efficiency of swallowing in selected cases.

The secretion severity rating scale: A potentially useful tool for management of acute phase fasting stroke patients

This study aimed to determine if performing fiber-optic endoscopic evaluation of swallowing (FEES) simultaneously with video fluoroscopic swallowing study (VFSS) improved detection of both dysphagia and anatomic and physiologic abnormalities of the pharynx and larynx. A total of 69 participants (47M, 22F, mean age = 64 years, range = 37–87 years), the majority of whom had a diagnosis of stroke (62%), were evaluated. FEES and VFSS were analyzed by two raters using a modified version of the Penetration-Aspiration Scale: levels 2 and 3 were combined for a new level 2, levels 4 and 5 were combined for a new level 3, and levels 6 and 7 were combined for a new level 4, for a total of 5 levels. Performing FEES simultaneously with VFSS increased both detection rates of pharyngeal residue, laryngeal penetration, tracheal aspiration, and anatomic abnormalities of the pharynx and larynx. Comment