Lingual Discoordination and Dysphagia following Acute Stroke: Analyses of Lesion Localization

The mechanism and neural substrates that mediate lingual coordination during swallowing have not been well characterized. Although lingual discoordination during swallowing has been difficult to quantify, it has been defined as the random disorganization of anterior–posterior tongue movements evident in bolus propulsion. In a sample of consecutive acute stroke patients (n= 59), videofluoroscopic evaluation showed a 19% incidence of lingual discoordination during swallowing. Lingual discoordination during swallowing was not commonly associated with buccofacial apraxia, apraxia of speech, nor limb apraxia. Hemisphere and anterior–posterior localization did not predict occurrence of lingual discoordination. Lingual discoordination during swallowing occurred commonly in patients with subcortical lesions with the periventricular white matter (PVWM), the most common site of involvement. PVWM lesions may disconnect anterior and posterior cortical regions that are critical to oral control and coordination in swallowing, thereby producing lingual discoordination during swallowing. These data also suggest that the neural mechanisms that mediate lingual coordination may at least in part be independent of the neural systems that mediate buccofacial, limb, and speech praxis functions.     

Coordination of mastication and swallowing

The coordination of mastication, oral transport, and swallowing was examined during intake of solids and liquids in four normal subjects. Videofluorography (VFG) and electromyography (EMG) were recorded simultaneously while subjects consumed barium-impregnated foods. Intramuscular electrodes were inserted in the masseter, suprahyoid, and infrahyoid muscles. Ninety-four swallows were analyzed frame-by-frame for timing of bolus transport, swallowing, and phases of the masticatory gape cycle. Barium entered the pharynx a mean of 1.1 s (range −0.3 to 6.4 s) before swallow onset. This interval varied significantly among foods and was shortest for liquids. A bolus of food reached the valleculae prior to swallow onset in 37% of sequences, but most of the food was in the oral cavity at the onset of swallowing. Nearly all swallows started during the intercuspal (minimum gape) phase of the masticatory cycle. Selected sequences were analyzed further by computer, using an analog-to-digital convertor (for EMG) and frame grabber (for VFG). When subjects chewed solid food, there were loosely linked cycles of jaw and hyoid motion. A preswallow bolus of chewed food was transported from the oral cavity to the oropharynx by protraction (movement forward and upward) of the tongue and hyoid bone. The tongue compressed the food against the palate and squeezed a portion into the pharynx one or more cycles prior to swallowing. This protraction was produced by contraction of the geniohyoid and anterior digastric muscles, and occurred during the intercuspal (minimum gape) and opening phases of the masticatory cycle. The mechanism of preswallow transport was highly similar to the oral phase of swallowing. Alternation of jaw adductor and abductor activity during mastication provided a framework for integration of chewing, transport, and swallowing.     

The Dynamics of Lingual-Mandibular Coordination During Liquid Swallowing

Previous literature on tongue-jaw relationships during swallowing has focused on behaviors observed with chewable solid foods. The present investigation was undertaken to evaluate both the nature and stability of coordinative relationships between the jaw and three points located along the midsagittal groove of the tongue—anterior (blade), middle (body), and posterior (dorsum)—during swallowing of thin and honey-thick liquids. A reiterative swallowing paradigm was used, with two task conditions (discrete and sequential), to explore the stability of tongue-jaw coordination across different frequencies of swallowing. Eight healthy participants in two age groups (young, older) performed sets of repeated swallows. Tongue and jaw movements were measured using electromagnetic midsagittal articulography. The data were analyzed in terms of variability in the spatiotemporal movement pattern for each fleshpoint of interest, and the temporal coupling (frequency entrainment) and relative phasing of movement for each tongue segment compared to the mandible. The results illustrate a stereotypical but not invariant sequence of movement phasing in the tongue-jaw complex during liquid swallowing and task-related reductions in variability at higher frequencies of swallowing in tongue dorsum movements. This evidence supports the idea that different segments of the tongue couple with the jaw as a synergy for swallowing, but can modify their coupling relationship to accommodate task demands.     

Preliminary Ultrasound Observation of Lingual Movement Patterns During Nutritive versus Non-nutritive Sucking in a Premature Infant

Term neonates must suck, swallow, and respire in a coordinated manner during successful oral feeding. When infants are born prematurely, these skills may not be fully mature. To stimulate sucking responses, premature infants are offered pacifiers under the premise that non-nutritive sucking experiences facilitate oral feeding readiness. This case reported examined the lingual-hyoid mechanics of non-nutritive suck (NNS) patterns with a pacifier versus nutritive suck (NS) during a bottle feed in a premature infant using a noninvasive ultrasound imaging technique as a pilot to discern aspects of oral feeding candidacy. Lingual patterns during NS resulted in significantly greater displacements and excursions than NNS (p < 0.0001) in both anterior and posterior regions of the tongue (p < 0.0001). In addition, the angle of hyoid movement during NNS was significantly smaller (p < 0.05) than the angle recorded during NS tasks. Unlike an expected neonatal sucking pattern of horizontal anterior-posterior movements of the tongue body, vertical tongue body excursions occurred as described in the literature of representing a 6–9-month developmental skill level. Through the integration of semiautomatic computerized analyses of tongue surface configurations and hyoid activity, these data may enhance knowledge of oral swallowing function in developing preterm neonates. The Physical Disabilities Branch is a collaboration between the Warren G. Magnuson Clinical Center and the National Institute of Child Health and Human Development, NIH.     

Influence of Bolus Consistency on Lingual Behaviors in Sequential Swallowing

Thickened liquids are a commonly recommended intervention for dysphagia. Previous research has documented differences in temporal aspects of bolus transit for paste versus liquid consistencies; however, the influence of liquid viscosity on tongue movements during swallowing remains unstudied. We report an analysis of the influence of bolus consistency on lingual kinematics during swallowing. Electromagnetic midsagittal articulography was used to trace tongue body and dorsum movement during sequential swallows of three bolus consistencies: thin, nectar-thick, and honey-thick liquids. Rheological profiling was conducted to characterize viscosity and density differences among six liquids (two of each consistency). Eight healthy volunteers participated; four were in a younger age cohort (under age 30) and four were over the age of 50. The primary difference observed across the liquids of interest was a previously unreported phenomenon of sip-mass modulation; both flavor and density appeared to influence sip-sizing behaviors. Additionally, significantly greater variability in lingual movement patterns was observed in the older subject group. Systematic variations in lingual kinematics related to bolus consistency were restricted to the variability of downward tongue dorsum movement. Otherwise, the present analysis failed to find empirical evidence of significant modulations in tongue behaviors across the thin to honey-thick consistency range.     

Effect of Tactile Stimulation on Lingual Motor Function in Pediatric Lingual Dysphagia

There is a scarcity of empirical evidence on effective treatments of swallowing dysfunction in young children who do not suck or swallow. There is no literature testing the effects of shaping a reflex or specifically shaping a swallow reflex. The purpose of this retrospective study was to investigate and isolate the specific regional mechanical functions of the tongue during swallowing. This study included 45 patients who did not swallow because of multiple congenital anomalies and gastroenterologic dysfunctions before and after corrective surgery and had histories of unsuccessful traditional feeding therapies. Evaluation included clinical gastroenterologic, nutritional, and neurologic examination, routine laboratory tests, and radiologic swallowing studies. A ten-year study analyzed the behavioral science procedures shaping both a swallow reflex and lingual surface geometry. Treatment variables were (1) a tactile stimulus to the posterior tongue and (2) sequential tactile stimuli to varied locations on the lingual surface. There were significant differences in lingual responses for all patients who were transferred from artificial feedings to independent prototypical swallowing capability and acquired oral consumption of recommended daily hydration and nutrition in 5-7 days of treatment. The initial tactile stimulus and six-level sequential stimuli resulted in six sequential lingual responses within each wavelike swallow reflex. Results of stimuli shaping varied lingual responses across 45 patients with severe multiple medical and anatomical deficits in swallowing, suggest that the etiology was not relevant in this population. These behavioral science approaches are novel treatment for pediatric lingual dysphagia.     

Timing of videofluoroscopic,manometric events,and bolus transit during the oral and pharyngeal phases of swallowing

The aims of this study were to evaluate and quantify the timing of events associated with the oral and pharyngeal phases of liquid swallows. For this purpose, we recorded 0–20 ml barium swallows in three groups of volunteers using videoradiographic, electromyographic, and manometric methods. The study findings indicated that a leading complex of tongue tip and tongue base movement as well as onset of superior hyoid movement and mylohyoid myoelectric activity occurred in a tight temporal relationship at the inception of swallowing. Two distinct general types of normal swallows were observed. The common “incisor-type” swallow began with the bolus positioned on the tongue with the tongue tip pressed against the upper incisors and maxillary alveolar ridge. At the onset of the “dipper-type” swallow the bolus was located beneath the anterior tongue and the tongue tip scooped the bolus to a supralingual location. Beginning with tongue-tip peristaltic movement at the upper incisors, the two swallow types were identical. Swallow events that occurred after lingual peristaltic movement at the maxillary incisors showed a volume-dependent forward migration in time that led to earlier movement of the hyoid and larynx as well as earlier opening of the upper esophageal sphincter in order to receive the large boluses that arrived sooner in the pharynx during the swallow sequence than did smaller boluses. The study findings indicated that timing of swallow events should be considered in reference to both swallow type and bolus volume. The findings also indicated an important distinction between peristaltic transit and bolus clearance.     

Fluoroscopic Evaluation of Tongue and Jaw Movements During Mastication in Healthy Humans

When chewing solid food, part of the bolus is propelled into the oropharynx before swallowing; this is named stage II transport (St2Tr). However, the tongue movement patterns that comprise St2Tr remain unclear. We investigated coronal jaw and tongue movements using videofluorography. Fourteen healthy young adults ate 6 g each of banana, cookie, and meat (four trials per foodstuff). Small lead markers were glued to the teeth and tongue surface to track movements by videofluorography in the anteroposterior projection. Recordings were divided into jaw motion cycles of four types: stage I transport (St1Tr), chewing, St2Tr, and swallowing. The range of horizontal tongue motion was significantly larger during St1Tr and chewing than during St2Tr and swallowing, whereas vertical tongue movements were significantly larger during chewing and St2Tr than during swallowing. Tongue movements varied significantly with food consistency. We conclude that the small horizontal tongue marker movements during St2Tr and swallowing were consistent with a “squeeze-back” mechanism of bolus propulsion. The vertical dimension was large in chewing and St2Tr, perhaps because of food particle reduction and transport in chewing and St2Tr.     

A Study of the Early Stage of Dysphagia in Amyotrophic Lateral Sclerosis

Abstract In amyotrophic lateral sclerosis (ALS) patients, dysphagia eventually occurs independent of time of onset. We studied dysphagia conditions in the early stage of ALS, principally at the oral phase. Videofluoroscopic and manometric studies were conducted on 11 patients (5 males and 6 females, age range = 47–82 years) who were diagnosed at our Neurology Clinic as having ALS. All patients were able to ingest orally. Swallowing scores on the ALS severity scale were from 10 to 5. In the oral phase of swallowing, abnormal movements of the anterior and/or posterior tongue were recognized in 8 cases. Dysphagia severity tended to be particularly influenced by dysfunction of the posterior tongue. Manometric studies were almost normal in all cases except one. These results suggested that the early stage of dysphagia in ALS was mainly caused by oral dysfunction, and the oral phase disorders began in some cases with a decreased function of bolus transport at the anterior part of the tongue, and in other cases with a deteriorated function of holding the bolus at the posterior part of the tongue. In conclusion, the tongue function of holding the bolus in the oral cavity mainly affects the severity of the early stage of dysphagia in ALS.     

Biochemistry of Anterior,Medial, and Posterior Genioglossus Muscle in the Rat

The tongue plays a vital role in swallowing actions. However, tongue muscles have been understudied, and it is unclear if tongue muscles are homogeneous with respect to muscle fiber-type distribution. We examined myosin heavy chain (MHC) composition of anterior, medial, and posterior sections of the genioglossus muscle (GG) using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in ten adult (9 months old) male Fischer 344/Brown Norway hybrid rats. We found that Type IIx MHC predominated in the anterior, medial, and posterior regions of the GG muscle (p = 0.002), followed by IIa, then IIb. The anterior GG contained a significantly greater (p = 0.004) proportion of Type IIa than did the medial or posterior regions, while the posterior GG contained a significantly greater (p = 0.002) proportion of Type IIb MHC than did the medial or anterior GG. Accordingly, we found variable expression of MHC isoforms across anterior, medial, and posterior portions of the GG muscle, with more fast-contracting isoforms found posteriorly. Because motor control of the tongue requires precise and rapid movements for bolus manipulation and airway protection, variable expression of MHC isoforms along the anteroposterior axis of the GG muscle may be required to efficiently achieve deglutition and maintenance of airway patency. This work was funded by a grant from the National Institute of Deafness & Other Communication Disorders (R01 DC005935) and the University of Wisconsin School of Medicine and Public Health.     

Swallowing Physiology of Toddlers with Long-Term Tracheostomies: A Preliminary Study

This study investigated the swallowing physiology of toddler-aged patients with long-term tracheostomies. Structural movements and motility of the pharyngeal stage of swallowing were studied in four toddlers ranging in age from 1:2 (years:months) to 2:9 with long-term tracheostomies. A patient aged 1:2 years with no tracheostomy served as a toddler model for comparison. Videofluoroscopic recordings of the patients' liquid and puree bolus swallows were analyzed for a) onset times for pharyngeal stage events, laryngeal vestibule closure, and tracheostomy tube movement; b) timeliness of swallow response initiation; and c) pharyngeal transport function. Results found differences in timing of pharyngeal stage movements between the tracheostomized patients and the patient with no tracheostomy. Laryngeal vestibule closure occurred before or within the same 0.033-s video frame as onset of upper esophageal sphincter (UES) opening in the patient with no tracheostomy, but occurred 0.033–.099 s after onset of UES opening in the tracheostomized patients. The time line required to close the laryngeal vestibule once the arytenoids began their anterior movement was longer in the tracheostomized patients than in the patient with no tracheostomy and was associated with laryngeal penetration. The patient with no tracheostomy displayed superior excursion of the arytenoid and epiglottis during the swallowing; the tracheostomized patients did not. No association was found between onset of tracheostomy tube movement and laryngeal vestibule closure. Delayed swallow response initiation was observed across tracheostomized patients at a mean frequency of 45% with associated penetration. Pharyngeal dysmotility was not observed. Findings supported the concept that long-term tracheostomy in toddler-aged patients affects swallowing physiology.     

Dynamic aspects of lingual propulsive activity in swallowing

This investigation concerned the effect of different bolus volumes on the characteristics of lingual propulsive activity in swallowing. Young normal subjects were asked to perform dry swallows and swallows of 5, 10, and 15 ml of water. Tongue activity was recorded by tracking multiple gold pellets affixed to the tongue, utilizing the specialized research capabilities of the X-ray Microbeam facility at the University of Wisconsin. The major differences were between dry and liquid swallows, with dry swallows showing smaller range of movement, higher tongue position at the initiation of lingual propulsive activity, a slightly different direction of motion, a humped or flat rather than grooved cross-sectional contour of the tongue, lower peak velocity of motion, and slower progression of activity from tongue blade to dorsum. Within the 5–15 ml range of liquid bolus volumes, fewer consistent differences were found as a function of bolus size, and some marked individual differences in swallowing patterns were seen. Data are presented on normal within-subject variability in swallowing, with discussion of the possible contribution of sensory assessment of bolus size to the modification of oral and pharyngeal characteristics of swallowing.     

健康老年妇女吞咽功能的研究

目的　通过电视X线透视吞咽功能的研究 ,评价健康老年妇女液体吞咽运动 ,并对液体吞咽运动的影响因素进行分析。　方法　 4 0例健康老年妇女 ,老年前期组 (5 0～ 5 9岁 ) 2 0例 ;老年组 2 0例 ,年龄 6 0～ 79岁。进行电视X线透视液体吞咽功能检查 ,分别对口咽部相关结构进行运动学分析 ,比较不同液体食团体及年龄对健康老年妇女吞咽的影响。　结果　 (1 )老年组较老年前期组渗透、口咽部滞留发生率增高 ,两组渗透发生率分别为 :7 5 %、3 8% ;口腔滞留发生率分别为 :1 2 5 %、6 3% ;咽腔滞留发生率分别为 :2 6 5 %、1 7 5 % ;口咽传递时间、腭咽部关闭时间及环咽部开放时间延长 (均为P <0 0 5 ) ;喉、舌骨向上运动距离增大 (P <0 0 5 )。 (2 ) 1 0ml食团较 1ml渗透、口咽部滞留发生率增高 ,两组渗透发生率分别为 :8 8%、2 5 % ;口腔滞留发生率分别为 :1 3 8%、5 0 % ;咽腔滞留发生率分别为 :31 3%、1 3 8% ;口传递时间缩短而环咽部开放时间延长 (均为P <0 0 5 ) ;喉向上、前运动 ,舌骨向前、向上运动的距离增大 (P <0 0 5 )。　结论　临床应用电视X线透视吞咽功能检查并对口咽期吞咽功能进行运动学分析是可行的 ;年龄及食团体积均影响健康老年妇女的液体吞咽功能     

Tongue Pressure Patterns During Water Swallowing

Bolus propulsion during the normal oral phase of swallowing is thought to be characterised by the sequential elevation of the front, middle, and posterior regions of the dorsum of the tongue. However, the coordinated orchestration of lingual movement is still poorly understood. This study examined how pressures generated by the tongue against the hard palate differed between three points along the midline of the tongue. Specifically, we tested three hypotheses: (1) that there are defined individual patterns of pressure change within the mouth during liquid swallowing; (2) that there are significant negative pressures generated at defined moments during normal swallowing; and, (3) that liquid swallowing is governed by the interplay of pressures generated in an anteroposterior direction in the mouth. Using a metal appliance described previously, we measured absolute pressures during water swallows in six healthy volunteers (4 male, 2 female) with an age range of 25–35 years. Participants performed three 10-ml water swallows from a small cup on five separate days, thus providing data for a total of 15 separate water swallows. There was a distinct pattern to the each of the pressure signals, and this pattern was preserved in the mean obtained when the data were pooled. Furthermore, raw signals from the same subjects presented consistent patterns at each of the five testing sessions. In all subjects, pressure at the anterior and hind palate tended to be negative relative to the preswallow value; at mid–palate, however, pressure changes were less consistent between individuals. When the pressure differences between the sites were calculated, we found that during the swallow a net negative pressure difference developed between anterior and mid-palate and a net positive pressure difference developed between mid-palate and hind palate. Large, rapid fluctuations in pressure occurred at all sites and these varied several-fold between subjects. When the brief sharp reduction in pressure that occurred early in each swallow was used to determine the sequence of events, we found that activity occurred first at the anterior of the palate followed by the mid-palate and then the hind palate. There was a considerably longer and more variable delay between the start of activity at the front of the palate than at the rear of the palate. To obtain an index of the “effort” involved in generating the pressures at each site regardless of direction (positive or negative), we obtained the product of the root mean square (RMS) pressure change during each swallow (kPa) and its duration (s). Overall, the most effort appears to have occurred at the front of the palate and the least at mid-palate. Our results also showed that some participants exerted a small amount of midline pressure when swallowing, while others used a relatively large amount of tongue pressure. We conclude that while tongue behaviour during swallowing follows a classical sequence of rapid shape changes intended to contain and then propel the bolus from the oral cavity to the pharynx, there is a large range of individual variability in how this process is accomplished.     

Lateral Pharyngeal Wall Motion during Swallowing Using Real Time Ultrasound

B-mode ultrasound imaging has been used primarily to detect temporal and spatial movements of the tongue during the oral preparatory and oral stages of swallowing. The purpose of this study was to investigate the application of M-mode (motion mode) ultrasound imaging as a method to quantify the duration and displacement of single regions along the lateral pharyngeal wall during swallows of two bolus volumes and during three swallow maneuvers (supraglottic, super-supraglottic and Mendelsohn maneuver). In 5 normal subjects, simultaneous B/M-mode images were captured at two regions along the lateral pharyngeal wall. Computer-assisted video analysis of each swallow sequence provided spatial coordinates and durational measures. Results indicated no significant differences in displacements of the lateral pharyngeal wall across bolus volumes, swallow maneuvers, or recording sites. Significant differences (p < 0.001) in lateral pharyngeal wall duration occurred as a function of volitional swallow maneuvers. Greater durations (p < 0.05) were found for the Mendelsohn and super-supraglottic swallow maneuvers. The data demonstrate that B/M-mode ultrasound imaging provides a simple, noninvasive method to visually examine movements of the lateral pharyngeal wall and may provide a clinical method for assessing the effects of direct swallowing therapies at the level of the mid-oropharynx.     

The influence of bolus volume and viscosity on anterior lingual force during the oral stage of swallowing

The influence of bolus volume and viscosity on the distribution of anterior lingual force during the oral stage of swallowing was investigated using a new force transducer technology. The maximum force amplitudes from 5 normal adults were measured simultaneously at the mid-anterior, right, and left lateral tongue margins during 10 volitional swallows of 5-, 10-, and 20-ml volumes of water, applesauce, and pudding. Results indicated significant increases in peak force amplitude as viscosity increased. Volume did not significantly influence maximum lingual force amplitudes. Individual subjects demonstrated consistent patterns of asymmetrical force distribution across the lingual margins tested. The results suggest that bolus-specific properties influence the mechanics of oral stage lingual swallowing. This finding has important clinical implications in the assessment and treatment of dysphagic individuals.     

Dysphagia following Anterior Cervical Spine Surgery

Although previous reports have identified dysphagia as a potential complication of anterior cervical spine surgery (ACSS), current understanding of the nature and etiologies of ACSS-related dysphagia remains limited. The present study was undertaken to describe the patterns of dysphagia that may occur following ACSS. Thirteen patients who exhibited new-onset dysphagia following ACSS were studied retrospectively by means of chart review and videofluoroscopic swallow study analysis. Results indicated that a variety of swallowing impairments occurred following ACSS. In 2 patients, prevertebral soft tissue swelling near the surgical site, deficient posterior pharyngeal wall movement, and impaired upper esophageal sphincter opening were the most salient videofluoroscopic findings. In another 5 patients, the pharyngeal phase of swallowing was absent or very weak, with resulting aspiration in 3 cases. In contrast, an additional 4 patients exhibited deficits primarily of the oral preparatory and oral stages of swallowing including deficient bolus formation and reduced tongue propulsive action. Finally, 2 patients exhibited impaired oral preparatory and oral phases, a weak pharyngeal swallow, as well as prevertebral swelling. Thus, a variety of swallowing deficits, due possibly to neurological and/or soft tissue injuries, may occur following ACSS.     

Training Effects of the Effortful Swallow Under Three Exercise Conditions

The effortful swallow achieves overload through high effort. It was predicted that both immediate effects on biomechanics and long-term neuromuscular adaptations would be facilitated by maximal overload during this exercise. This study examined how high-effort sips from small-diameter straws influenced linguapalatal swallow pressures. Additionally, training effects of effortful swallows preceded by high-effort sips were compared to two other exercise conditions: effortful swallows preceded by maximum effort lingual elevation and effortful swallows performed in isolation. Training outcomes included linguapalatal pressures produced during effortful and noneffortful swallows, and maximum isometric pressure (MIP) produced during tongue elevation and interlabial compression. Forty healthy adults participated in the experiment. Lingual–palatal swallowing pressure during non effortful and effortful swallows and MIPs were measured prior to and after 4 weeks of training. Prior to training, anterior linguapalatal pressures were significantly higher during effortful compared to noneffortful swallows. Anterior linguapalatal pressures did not significantly differ during swallows preceded by sips from high-resistance straws. Weak correlations were observed between tongue MIP and linguapalatal pressures during effortful swallows. After training, anterior linguapalatal pressures significantly increased, with training effects more dramatic for effortful swallows. Anterior tongue MIP also significantly increased. Gains in anterior linguapalatal pressure were not correlated with gains in tongue MIP. Training effects did not vary across exercise condition. The study failed to find a training advantage of pairing the effortful swallow with a precursor movement. The results demonstrated specificity of training, with more dramatic benefits observed for effortful swallows relative to noneffortful swallows. Further investigation is needed to characterize training effects in older adults and patients with dysphagia.     

A new application for electropalatography: Swallowing

Electropalatography (EPG) has been applied to linguistic research and speech pathology. This study evaluated whether EPG could provide useful information on swallow-related tongue action. Specifically, the investigation focused on the quantification of tongue-palate contact patterns for swallowing and on the effects of bolus volume and consistency. Five normal subjects were tested during swallows of 5 and 30 ml of water, 5 and 30 ml of gelatin, and saliva. By segmenting the EPG time-motion sequences into four stages (prepropulsion, propulsion, full contact, withdrawal) and compartmentalizing the palate into six bins (front, central, back, lateral, medial, midline), temporal and spatial characteristics of deglutitive tongue-palate contact were revealed. Significant differences (p<0.01) were found in contact timing across bolus sizes and consistencies for the propulsion and full contact stages. Water was propelled faster than gelatin, and 30-ml gelatin faster than 5-ml gelatin. Dry swallows had a longer full contact stage than water. Contact patterns, though not statistically analyzed at this time, appeared to vary little as a function of bolus properties. Our findings suggest potential value in using EPG to investigate the timing and patterning of abnormal tongue movements associated with disordered swallowing.     

Sounds of swallowing following total laryngectomy

Accelerometer transduced sounds of swallowing in total laryngectomees did not show acoustical differences for liquid vs paste swallows, as are found in normals. Compared with normal swallows, tongue propulsion of the bolus in laryngectomee swallows occurred closer in time to a distinctive spectral change associated with bolus flow into the esophagus. Interpretation stressed the lack of mechanical traction from laryngeal elevation contributing to pharyngoesophageal sphincter opening, and the increased role of tongue propulsion in laryngectomee swallows. Supported by grant no. CA 43838 from the National Cancer Institute