Search

PURPOSE The purpose of this study was to elucidate the effects of the tongue-hold swallow (THS) on the pharyngeal wall by quantifying posterior pharyngeal wall (PPW) anterior bulge during the THS. In addition, the effect of tongue protrusion length on the extent of pharyngeal wall anterior bulge was analysed. METHODS Thirteen healthy subjects (6 males and 7 females, 23-43 years) underwent 320-row area detector CT during saliva swallow (SS) and THS at two tongue protrusion lengths (THS1 protrude the tongue as much as 1/3 of premeasured maximum tongue protrusion length (MTP-L) and THS2 protrude the tongue as much as 2/3 of MTP-L). To acquire images of the pharynx at rest, single-phase volume scanning was performed three times during usual breathing with no tongue protrusion (rest), protrusion of the tongue at 1/3 of MTP-L (rTHS1) and protrusion of the tongue at 2/3 of MTP-L (rTHS2). Length from cervical spine to PPW (PPW-AP) and the volume of pharyngeal cavity was measured and was compared between rest, rTHS1 and rTHS2 and between SS, THS1 and THS2. Correlation between MTP-L and PPW-AP was calculated in three conditions, SS, THS1 and THS2. RESULTS PPW-AP at rest, rTHS1 and rTHS2 was 2.9 ± 0.6 mm, 3.0 ± 0.5 mm and 3.0 ± 0.5 mm, respectively, showing no significant differences across swallows. PPW-AP at the maximum pharyngeal constriction was 8.1 ± 2.0 mm, 9.1 ± 2.4 mm and 8.7 ± 2.0 mm in SS, THS1 and THS2, respectively. Compared to SS, PPW-AP in THS1 was significantly larger (p = 0.04) and PPW-AP in THS2 was not significantly different (p = 0.09). Pharyngeal volume at rest, rTHS1 and rTHS2 was 16.4 ± 5.2 mm3 , 18.4 ± 4.5 mm3 and 21.3 ± 6.2 mm3 , respectively. It was significantly larger during rTHS2 compared with rest or rTHS1 (rTHS2-rest p = 0.007, rTHS2-rTHS1 p = 0.007). Pharyngeal volume was completely obliterated (zero volume) at maximum pharyngeal contraction in all except one subject. There was no correlation between MTP-L and PPW-AP in any of the three conditions (SS, THS1 and THS2). DISCUSSION This study demonstrated that the expanded pharyngeal cavity due to the tongue protrusion was completely obliterated by the increase in anterior motion of pharyngeal wall during THS. It also became clear that the degree of tongue protrusion did not linearly correlate with the movement of PPW during THS. There was no relationship between PPW motion and the MTP-L, suggesting that the effect of tongue protrusion is better determined in each subject by analysing the motion of PPW using imaging tools.

Objective To determine differences between continuous videofluoroscopic swallow studies (VFSS) with a pulse rate and frame rate of 30 and the same swallows reduced to 15 frames per second (fps) on measures of swallowing function in patients after acute ischemic stroke. Design Blinded comparison. Setting Acute hospital. Participants Patients after ischemic stroke (N=20). Interventions Not applicable. Main Outcome Measures Single and sequential sips of thin liquids, single sips of nectar liquids, pudding, and cookie boluses were rated on measures of timing of swallowing events, Modified Barium Swallowing Impairment Profile component scores, and Penetration-Aspiration Scale scores. The ratings for videos at 15 fps and 30 fps were compared by Wilcoxon signed rank tests. Results Pharyngeal transit time was longer and bolus entry into the hypopharynx was later for 30 fps than for 15 fps. Components of Oral Residue and Pharyngoesophageal Segment Opening ratings were more severe for 15 fps than 30 fps, whereas Bolus Transport and Initiation of Pharyngeal Swallow were rated as more severe for 30 fps than for 15 fps. There was no difference between 30 fps and 15 fps on the remaining measures, including Penetration-Aspiration Scale scores. Conclusion Continuous VFSS recorded at 30 fps and their down-sampled 15 fps duplicates yielded contrasting results on certain durational and functional measures of swallowing, though not on others. VFSS should be administered continuously or at 30 pulses per second for valid assessment of swallowing while using other methods to reduce radiation exposure.

Videofluoroscopy and videoendoscopy dramatically changed the evaluation and management of swallowing disorders. Later advancements in techniques for the instrumental evaluation of swallowing were limited by technique and positioning. The advent of 320-row area detector CT solved previous challenges and allowed for the study of swallowing physiology and dysphagia in greater detail. In this summary, we describe the history and evolution of CT technology and describe research and clinical applications for the evaluation of swallowing physiology and pathophysiology.

Contains fulltext : 229044.pdf (Publisher’s version ) (Closed access) Postextubation dysphagia may impose a substantial burden on intensive care unit patients and healthcare systems. Approximately 517,000 patients survive mechanical ventilation during critical care annually. Reports of postextubation dysphagia prevalence are highly variable ranging between 3% and 93%. Of great concern is aspiration leading to the development of aspiration pneumonia when patients resume oral feeding. Screening for aspiration with a water swallow test has been reported to be positive for 12% of patients in the intensive care unit after extubation. This review aims to increase awareness of postextubation dysphagia and provide an updated overview of the current knowledge regarding prevalence, pathophysiology, diagnostic modalities, and treatment options.

Older adults may evidence changes in swallowing physiology. Our goals were to identify dysphagia risk in community-dwelling older adults with no history of dysphagia, and to compare swallowing physiology and safety between older and younger adults. Thirty-two older adults with no history of dysphagia were prospectively recruited and completed the Dysphagia Handicap Index (DHI), two trials of a 3 oz. swallow screen, and videofluoroscopy (VFSS). Self-ratings of swallowing function were compared to published norms by paired t tests, and multivariate logistic regression models were generated to determine whether these ratings and VFSS analysis of swallowing function were associated with failure of one or both swallow screen trials. Archived VFSS of 33 younger adults were compared to older adults with Wilcoxon rank-sum tests. The DHI scores of older adults were higher than published non-dysphagic adults but lower than dysphagic adults. Older participants with greater Oral Residue scores were more likely to fail both swallow screen trials. Older adults received higher median MBSImP™© scores for select pharyngeal components than younger adults. The two age groups did not differ on Penetration-Aspiration Scale scores, and no aspiration was observed. Measures of swallowing in older individuals may reflect age-related sensory and motor changes in the context of functional swallowing and adequate airway protection.

Objective This study investigated the effects of bolus consistency on pharyngeal volume during swallowing using three-dimensional kinematic analysis. Methods Eight subjects (2 males and 6 females, mean ± SD 44 ± 10 years old) underwent a 320-row area detector scan during swallows of 10 mL of honey-thick liquid and thin liquid. Critical event timing (hyoid, soft palate, UES) and volume of pharyngeal cavity and bolus were measured and compared between two swallows. Results The pharynx is almost completely obliterated by pharyngeal constriction against the tongue base for both consistencies. There were no significant differences in maximum volume, minimum volume and pharyngeal volume constriction ratio values between thick and thin liquids. However, the pattern of pharyngeal volume change (decrease) was different. For thick liquids, the air volume started to decrease before the onset of hyoid anterosuperior movement and decreased rapidly after onset of hyoid anterosuperior movement. During thin liquid swallowing, air volume remained relatively large throughout the swallow and started to decrease later when compared to swallowing thick liquids. At onset of UES opening, the bolus volume was not significantly different between thin and thick liquids; however, air volume was significantly larger when swallowing thin liquids, which made the total volume of the pharyngeal cavity larger. Conclusion This difference between the two consistencies is associated with differences in tongue motion to propel the bolus and clear the pharynx from possible residue.

Changes in both swallowing and taste commonly occur in advanced age, though the relationship between the two is unknown. This study examined the association between a water swallow screen test and taste identification and intensity rating. Participants included 47 community-dwelling women aged 85&ndash, 94 years. Participants completed three trials of a water swallow screen and were observed for signs of aspiration, which, if present, indicated failure. Four pure taste stimuli at low and high concentrations and water were presented, and participants selected one of five taste labels and rated their intensity on the generalized Labeled Magnitude Scale. Ratios of intensity ratings were computed for each taste stimulus to compare the perception of low and high concentrations. The association between water swallow screen failure, correct taste identification, and taste intensity ratio was evaluated with logistic regression modeling, with mediating factors of frailty and number of comorbidities. Failure of three water swallow screen trials was associated with a higher taste intensity ratio for caffeine (bitter) and a lower taste intensity ratio for sucrose (sweet). Correct identification of taste, frailty, and number of comorbidities were not associated with failure of any number of water swallow screen trials. Intensity ratings of certain tastes may be associated with swallowing in old-old women. Heightened vigilance in this population may be necessary to prevent complications related to dietary intake.

Pharyngeal residue, the material that remains in the pharynx after swallowing, is an important marker of impairments in swallowing and prandial aspiration risk. The goals of this study were to determine whether the 2D area of post-swallow residue accurately represents its 3D volume, and if the laterality of residue would affect this association. Thirteen patients with dysphagia due to brainstem stroke completed dynamic 320-detector row computed tomography while swallowing a trial of 10 ml honey-thick barium. 3D volumes of pharyngeal residue were compared to 2D lateral and anterior–posterior areas, and a laterality index for residue location was computed. Although the anteroposterior area of residue was larger than the lateral area, the two measures were positively correlated with one another and with residue volume. On separate bivariate regression analyses, residue volume was accurately predicted by both lateral (R2 = 0.91) and anteroposterior (R2 = 0.88) residue areas, with limited incidence of high residuals. Half of the sample demonstrated a majority of pharyngeal residue lateralized to one side of the pharynx, with no effect of laterality on the association between areas and volume. In conclusion, the area of post-swallow pharyngeal residue was associated with volume, with limitations in specific cases. Direct measurement of pharyngeal residue volume and swallowing physiology with 3D-CT can be used to validate results from standard 2D instrumentation.

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 20 mL of honey-thick liquid barium. Three-dimensional images were created at 10 images/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 20 mL compared to 3 mL (P < .05). Consequently, the onset of UES opening was significantly earlier with increased volume (P < .05). LV and TVC closure occurred later in 20 mL compared to 3 mL (P < .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.

Endotracheal intubation is associated with postextubation swallowing dysfunction, but no guidelines exist for postextubation swallowing assessments.We evaluated the prevalence, patient demographic and clinical factors, and intensive care unit (ICU) and hospital organizational factors associated with swallowing assessment after oral endotracheal intubation and mechanical ventilation in patients with acute lung injury (ALI).We performed a secondary analysis of a prospective cohort study in which investigators evaluated 178 eligible patients with ALI who were mechanically ventilated via oral endotracheal tube. The patients were recruited from 13 ICUs at four teaching hospitals in Baltimore, Maryland. Patient demographic and clinical factors, types of ICU, and hospital study sites were evaluated for their association with completion of a swallowing assessment both in the ICU and after the ICU stay before hospital discharge. Factors significantly associated with a swallow assessment were evaluated in a multivariable logistic regression model.Before hospital discharge, 79 (44%) patients completed a swallowing assessment, among whom 59 (75%) had their assessments initiated in ICU and 20 (25%) had their assessments initiated on the hospital ward. Female sex (odds ratio [OR] = 2.01; 95% confidence interval [95% CI] = 1.03-3.97), orotracheal intubation duration (OR = 1.13 per day; 95% CI = 1.05-1.22), and hospital study site (Site 3: OR = 2.41; 95% CI = 1.00-5.78) were independently associated with swallowing assessment. Although Site 3 had a twofold increase in swallowing assessments in the ICU, there was no significant difference between hospitals in the frequency of swallowing assessments completed after ICU discharge (P = 0.287) or in the proportion of patients who failed a swallowing assessment conducted in the ICU (P = 0.468) or on the ward (P = 0.746).In this multisite prospective study, female sex, intubation duration, and hospital site were associated with postextubation swallowing assessment. These results demonstrate variability in practice patterns between institutions and highlight the need to determine the appropriate timing and indications for swallowing assessment and to more fully understand swallowing dysfunction after intubation.

Swallowing dysfunction is common after stroke. More than 50% of the 665 thousand stroke survivors will experience dysphagia acutely of which approximately 80 thousand will experience persistent dysphagia at 6 months. The physiologic impairments that result in post-stroke dysphagia are varied. This review focuses primarily on well-established dysphagia treatments in the context of the physiologic impairments they treat. Traditional dysphagia therapies including volume and texture modifications, strategies such as chin tuck, head tilt, head turn, effortful swallow, supraglottic swallow, super-supraglottic swallow, Mendelsohn maneuver and exercises such as the Shaker exercise and Masako (tongue hold) maneuver are discussed. Other more recent treatment interventions are discussed in the context of the evidence available.

Objectives To determine whether symptoms and clinical signs of swallowing dysfunction could be easily identified in community-dwelling elderly adults and to examine the association between self-report and direct observation of symptoms and signs of swallowing dysfunction. Design Physiological substudy conducted as a home visit within an observational cohort study. Setting Baltimore City and County, Maryland. Participants Community-dwelling elderly women without history of dysphagia or neurological disease aged 85 to 94 enrolled in the Women's Health and Aging Study II (N = 47). Measurements Three trials of the 3-ounce water swallowing test, swallowing function questionnaire, and frailty status. Results Thirty-four (72%) subjects demonstrated swallowing dysfunction in at least one swallowing trial and 16 (34%) in all three trials. The most common signs of dysfunction were throat clear and wet voice. Conversely, participants reported few symptoms of dysphagia on a swallowing function questionnaire. The most common symptom, reported by approximately 15% of participants, was the sensation of the food going “down the wrong way,” 8.5% or fewer participants reported other symptoms. Conclusion Signs of swallowing dysfunction were present in a large majority of community-dwelling old-old women, but they were largely unrecognized and reported. Formal evaluation of swallowing function in community-dwelling elderly adults is necessary to determine the clinical consequences of these findings.

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.

Purpose To determine the clinical performance characteristics of the Mann Assessment of Swallowing Ability (MASA) for predicting aspiration (determined by videofluoroscopic swallowing study [VFSS]) in a mixed population. Method We selected 133 cases clinically evaluated using MASA and VFSS from January through June 2007. Ordinal risk rating (ORR) and total numeric score (TNS) were evaluated as predictors of aspiration on VFSS. To account for missing items, the maximum possible score was determined and a weighted percentage score calculated for each patient. We used receiver operating characteristic (ROC) analysis to compare the sensitivity and specificity of ORR and TNS for predicting aspiration. Results VFSS identified 51 (38.4%) aspirators, while ORR identified 54 (40.6%) as probable or definite aspiration and TNS 19 (14.3%) as moderate to severe aspiration risk. ROC analysis demonstrated an area under the curve of 0.74, 95% CI [0.66, 0.82], for ORR and 0.51, 95% CI [0.41, 0.61], for TNS. These ROC scores suggest that the MASA ORR is better at predicting aspiration on VFSS than the numeric score. Conclusion In this sample, the subjective ORR had good predictive ability, while the percentage TNS failed to predict aspiration on VFSS. The MASA ORR assessment was a better predictor for a patient’s aspiration risk in this population.

Videofluoroscopic examination of swallowing (VF) is the gold standard in diagnosis and management of dysphagia. During VF, the patient ingests radiopaque foods and liquids, and oral, pharyngeal, and esophageal stages of swallowing physiology are observed and evaluated. Aspiration is defined as passage of materials through the vocal folds, and laryngeal penetration is defined as passage of materials into the larynx, but not through the vocal folds. In this study, we compared the risk of laryngeal penetration or aspiration during VF using various liquid volumes and food consistencies. Between January 2006 and September 2008, 229 patients with suspected dysphagia each were fed at least 2 out of 6 types of liquids or foods during VF in an upright posture without compensatory maneuvers. The 6 types were pudding-thick barium of 4 ml (PD), thin liquid barium of 4 ml (LQ4) and 10 ml (LQ10), one swallow of thin liquid barium from a cup (CUP), corned beef hash (8 g) with barium (CB), and a two-phase mixture of corned beef hash (4 g) with barium and thin liquid barium of 5 ml (MX). The paired comparisons revealed that laryngeal penetration risk increased in the following order: PD, CB, LQ4, LQ10, MX and CUP, while aspiration risk after PD increased in the following order: CB, LQ4, LQ10, CUP and MX. Thus, risk of laryngeal penetration or aspiration varies, depending on food types. In conclusion, risk of aspiration is highest with the two-phase food, and multi-textured foods should be used with caution in individuals with dysphagia.

During feeding, solid food is chewed and propelled to the oropharynx, where the bolus gradually aggregates while the larynx remains open and breathing continues. The aggregated bolus in the valleculae is exposed to respiratory airflow, yet aspiration is rare in healthy individuals. The mechanism for preventing aspiration during bolus aggregation is unclear. One possibility is that alterations in the pattern of respiration during feeding could help prevent inhalation of food from the pharynx. We hypothesized that respiration was inhibited during bolus aggregation in the valleculae. Videofluorography was performed on 10 healthy volunteers eating solid foods with barium. Respiration was monitored concurrently with plethysmography and nasal air pressure. The timing of events during mastication, food transport, pharyngeal bolus aggregation, and swallowing were measured in relation to respiration. Respiratory cycle duration decreased during chewing ( P < 0.001) but increased with swallowing ( P < 0.001). During 66 recordings of vallecular bolus aggregation, there was inspiration in 8%, expiration in 41%, a pause in breathing in 17%, and multiple phases (including inspiration) in 35%. Out of 98 swallows, 47% started in the expiratory phase and 50% started during a pause in breathing, irrespective of bolus aggregation in the valleculae. Plethysmography was better than nasal manometry for determining the end of active expiration during feeding and swallowing with solid food. The hypothesis is rejected in that respiration was not inhibited during bolus aggregation. These findings suggest that airflow through the pharynx does not have a role in preventing aspiration during bolus aggregation in the oropharynx.

Communication and swallowing disorders are common after stroke. Targeted surveillance followed by prompt evaluation and treatment is of paramount importance. The overall goals of rehabilitation for impaired swallowing and communication and swallowing deficits may differ based on the specific deficits caused by the stroke but the main goal is always to improve the patient's everyday interpersonal interactions and optimize participation in society. Fortunately, therapeutic or compensatory interventions can decrease the effects that communication and swallowing deficits have on the quality of life of stroke survivors.

Few studies have examined the intensity of muscle activity during swallowing in healthy humans. We examined selected hyoid muscles using fine wire intramuscular electromyography (EMG) during swallowing of four food consistencies. Thirteen healthy adults were studied using videofluorography and EMG of the anterior belly of digastric (ABD), geniohyoid (GH), sternohyoid (SH), and masseter (MA; surface electrodes) while ingesting thin liquid (three trials) and solid food of three consistencies (banana, tofu, and cookie, three trials each). After rectification, integration, and normalization, peak EMG amplitudes for each muscle in each trial were measured. Hyoid displacements were measured in two dimensions. Data were analyzed using repeated measures ANOVA with Bonferroni correction. GH had the highest adjusted amplitude for both solids and liquid. For MA and ABD, amplitude was highest with triturated cookie. For ABD, amplitude was lowest with liquid. There were no significant food consistency effects for GH or SH. Hyoid displacements were greatest for cookie and the lowest for liquid. EMG amplitude varied with initial food consistency. The high peak EMG amplitude of GH is consistent with its essential role in opening the upper esophageal sphincter. High MA amplitude with hard solid foods is likely due to the higher tongue-palate pressure with triturated solids. The higher ABD amplitude with solid food is associated with greater hyoid displacement. These findings support the existence of a central pattern generator that modifies the level of muscle activity during pharyngeal swallowing in response to input from mechanoreceptors in the oral cavity.

Dysphagia affects the vast majority of acute stroke patients. Although it improves within 2 weeks for most, some face longstanding swallowing problems that place them at risk for pneumonia, malnutrition, dehydration, and significantly affect quality of life. This paper discusses the scope, the disease burden, and the tools available for screening and formal evaluation of dysphagia. The most common and recently developed treatment interventions that might be useful in the treatment of this population are discussed.

Although the goal of dysphagia rehabilitation is the same, population needs, clinical practice patterns, availability of resources, and dysphagia research varies greatly around the world. The goal of this review is to introduce the reader to the context in which dysphagia rehabilitation is practiced, to describe practice patterns, and to highlight the dysphagia research being performed in three distinct regions of the world: North America, New Zealand and Australia, and Japan.

Few studies have reported the activation sequence of the swallowing muscles in healthy human participants. We examined temporal characteristics of selected hyoid muscles using fine wire intramuscular electromyography (EMG). Thirteen healthy adults were studied using EMG of the anterior belly of digastric (ABD), geniohyoid (GH), sternohyoid (SH), and masseter (MA, with surface electrodes) while ingesting thin liquid, banana, tofu, and cookie (3 trials each). Onset timing was measured from rectified and integrated EMG. Data were analyzed using repeated-measures ANOVA with Bonfer- roni correction. When drinking thin liquid, MA, GH, and ABD were activated almost simultaneously, but SH was activated later (using GH onset as 0 s, MA -0.07 (-0.20 to 0.17) second (median (interquartile range)); ABD 0.00 (-0.10 to 0.07) second; SH 0.17 (0.02 to 0.37) second; P \ 0.01). With solid foods, MA contraction preceded GH and ABD; SH was last and delayed relative to liquid swallows (GH 0 s; MA -0.17 (-0.27 to 0.07) second; ABD 0.00 (-0.03 to 0.03) second; SH 0.37 (0.23 to 0.50) second; P \ 0.01). The role of the MA differs between solids and liquids so the variation in its timing is expected. The synchronous contraction of GH and ABD was con- sistent with their role in hyolaryngeal elevation. The SH contracted later with solids, perhaps because if the longer duration of the swallow. The consistent pattern among foods supports the concept of a central pattern generator for pharyngeal swallowing.

Stage II transport (St2Tr) is propulsion of triturated food into the pharynx for storage before swallowing via tongue squeeze-back against the palate. To clarify the phenomenology of St2Tr, we examined the effects of food consistency and the number of chewing cycles on the number of St2Tr cycles in a chew-swallow sequence. We recorded chew-swallow sequences in lateral projection with videofluoroscopy of 13 healthy volunteers eating 6 g of hard (shortbread cookie), and soft foods (ripe banana and tofu) with barium. We counted the number of chewing and St2Tr cycles from food intake to terminal swallow. We used the Friedman test for bivariate analyses and negative binomial regression for multivariable analyses. On bivariate analysis, food consistency had a positive association with the number of chewing cycles (P = 0.013), but not with the number of St2Tr cycles (P = 0.27). Multivariable analysis, however, revealed a greater number of St2Tr cycles with hard than soft food (P ≤ 0.01) and a trend toward negative correlation between the numbers of St2Tr and chewing cycles (P = 0.083). The number of chewing cycles needed to clear the mouth differs among food consistencies as demonstrated previously. Greater numbers of both St2Tr and chewing cycles were elicited with the hard than with the soft foods. Given the trend toward negative correlation, the association between the number of St2Tr cycles and that of chewing cycles deserves further study.

The hyoid bone and larynx elevate to protect the airway during swallowing. However, it is unknown whether hyolaryngeal movements during swallowing can adjust and adapt to predict the presence of a persistent perturbation in a feed-forward manner (adaptive motor learning). We investigated adaptive motor learning in nine healthy adults. Electrical stimulation was administered to the anterior neck to reduce hyolaryngeal elevation, requiring more strength to swallow during the perturbation period of this study. We assessed peak hyoid bone and laryngeal movements using videofluoroscopy across thirty-five 5-ml water swallows. Evidence of adaptive motor learning of hyolaryngeal movements was found when (1) participants showed systematic gradual increases in elevation against the force of electrical stimulation and (2) hyolaryngeal elevation overshot the baseline (preperturbation) range of motion, showing behavioral aftereffects, when the perturbation was unexpectedly removed. Hyolaryngeal kinematics demonstrates adaptive, error-reducing movements in the presence of changing and unexpected demands. This is significant because individuals with dysphagia often aspirate due to disordered hyolaryngeal movements. Thus, if rapid motor learning is accessible during swallowing in healthy adults, patients may be taught to predict the presence of perturbations and reduce errors in swallowing before they occur.

Swallowing is an intricate, yet fundamental process which is often interrupted by neurologic disease and senescence and has a major impact on the overall health, quality of life, and nutritional status of those affected. A number of neurologic conditions are associated with dysphagia including Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), dementia, and traumatic brain injury (TBI). Of these, stroke is the most common. Although swallowing problems may be exclusive to one phase of swallowing, deficits can be seen in multiple stages – oral, pharyngeal, and/or esophageal. The health risk is enormous, particularly in the elderly, and includes aspiration pneumonia, malnutrition, dehydration, and weight loss. There are several challenges when caring for these individuals who often are socially estranged and besieged by other medical conditions, physical impairments, cognitive dysfunction, immune system deficiencies, and poor nutrition at baseline which together complicate medical decision making often causing further decline. Age-related changes, whether anatomic, physiologic, or psychologic, also accompany normal swallowing and are not considered to be pathologic. As the number of individuals 65 years of age and older increases, the ability to diagnose and manage swallowing disorders will be of extreme importance. For the most part, treatment focuses on dietary modification, compensatory, and rehabilitative techniques. When swallowing is not permissible, consideration of enteral feeding via percutaneous endoscopic gastrostomy tube or, for short-term purposes, with use of oral or nasogastric feeding tubes is necessary. With a better knowledge and awareness of the swallowing process, including its relation to the existing disease state, complication risk, and importance of rehabilitation services, care can be coordinated effectively to improve overall health, wellbeing, and quality of life.

Dysphagia is a common problem in neurologic disease. The authors describe rates of dysphagia in selected neurologic diseases, and the evaluation and treatment of dysphagia in this population. Applicable physiology and aspects of neural control are reviewed. The decision-making process to determine oral feeding versus alternative means of alimentation is examined.

The aim of this study was to determine the accuracy of dysphagia coding using the International Classification of Diseases version 9 (ICD-9) code 787.2. We used the administrative database of a tertiary hospital and sequential videofluorographic swallowing study (VFSS) reports for patients admitted to the same hospital from January to June 2007. The VFSS reports were abstracted and the hospital’s database was queried to abstract the coding associated with the admission during which the VFSS was performed. The VFSS and administrative data were merged for data analysis. Dysphagia was coded (using code 787.2) in 36 of 168 cases that had a VFSS. Of these, 34 had dysphagia diagnosed by VFSS (our gold standard) and one had a prior history of dysphagia. Code 787.2 had sensitivity of 22.8, specificity of 89.5, and positive and negative predictive values of 94.4 and 12.9, respectively. Dysphagia was largely undercoded in this database, but when the code was present those individuals were very likely to be dysphagic. Selection of dysphagic cases using the ICD-9 code is appropriate for within-group comparisons. Absence of the code, however, is not a good predictor of the absence of dysphagia.

Purpose The authors write this letter to clarify some of the points raised by Dr. Giselle Carnaby about their article titled “Clinical Experience Using the Mann Assessment of Swallowing Ability (MASA) for Identification of Patients at Risk for Aspiration in a Mixed-Disease Population” (González-Fernández, Sein, & Palmer, 2011). The intention of this letter is to ensure that the reader has a balanced perspective and the information necessary to interpret the results of the original publication.