Texture modification has become one of the most common forms of intervention for dysphagia, and is widely considered important for promoting safe and efficient swallowing. However, to date, there is no single convention with respect to the terminology used to describe levels of liquid thickening or food texture modification for clinical use. As a first step toward building a common taxonomy, a systematic review was undertaken to identify empirical evidence describing the impact of liquid consistency and food texture on swallowing behavior. A multi-engine search yielded 10,147 non-duplicate articles, which were screened for relevance. A team of ten international researchers collaborated to conduct full-text reviews for 488 of these articles, which met the study inclusion criteria. Of these, 36 articles were found to contain specific information comparing oral processing or swallowing behaviors for at least two liquid consistencies or food textures. Qualitative synthesis revealed two key trends with respect to the impact of thickening liquids on swallowing: thicker liquids reduce the risk of penetration–aspiration, but also increase the risk of post-swallow residue in the pharynx. The literature was insufficient to support the delineation of specific viscosity boundaries or other quantifiable material properties related to these clinical outcomes. With respect to food texture, the literature pointed to properties of hardness, cohesiveness, and slipperiness as being relevant both for physiological behaviors and bolus flow patterns. The literature suggests a need to classify food and fluid behavior in the context of the physiological processes involved in oral transport and flow initiation.

Purpose Thickened liquids are frequently used as an intervention for dysphagia, but gaps persist in our understanding of variations in swallowing behavior based on incremental thickening of liquids. The goal of this study was to establish reference values for measures of bolus flow and swallowing physiology in healthy adults across the continuum from thin to extremely thick liquids. Method A sex-balanced sample of 38 healthy adults underwent videofluoroscopy and swallowed 20% weight-to-volume concentration barium prepared in thin and slightly, mildly, moderately, and extremely thick consistencies using a xanthan gum thickener. Participants took comfortable sips and swallowed without a cue; sip volume was measured based on presip and postsip cup weights. A standard operating procedure (the ASPEKT method: Analysis of Swallowing Physiology: Events, Kinematics and Timing) was used to analyze videofluoroscopy recordings. Results The results clarify that, for thin liquid sips (10–14 ml), a single swallow without clearing swallows is typical and is characterized by complete laryngeal vestibule closure, complete pharyngeal constriction, and minimal postswallow residue. Aspiration was not seen, and penetration was extremely rare. Bolus position at swallow onset was variable, extending as low as the pyriform sinuses in 37% of cases. With thicker liquids, no changes in event sequencing, laryngeal vestibule closure, pharyngeal constriction, or postswallow residue were seen. The odds of penetration were significantly reduced. A longer timing interval until onset of the hyoid burst movement was seen, with an associated higher bolus position at swallow onset. Other timing measures remained unaffected by changes in bolus consistency. Conclusion The results include new reference data for swallowing in healthy adults across the range from thin to extremely thick liquids.

This White Paper by the European Society for Swallowing Disorders (ESSD) reports on the current state of screening and non-instrumental assessment for dysphagia in adults. An overview is provided on the measures that are available, and how to select screening tools and assessments. Emphasis is placed on different types of screening, patient-reported measures, assessment of anatomy and physiology of the swallowing act, and clinical swallowing evaluation. Many screening and non-instrumental assessments are available for evaluating dysphagia in adults; however, their use may not be warranted due to poor diagnostic performance or lacking robust psychometric properties. This white paper provides recommendations on how to select best evidence-based screening tools and non-instrumental assessments for use in clinical practice targeting different constructs, target populations and respondents, based on criteria for diagnostic performance, psychometric properties (reliability, validity, and responsiveness), and feasibility. In addition, gaps in research that need to be addressed in future studies are discussed. The following recommendations are made: (1) discontinue the use of non-validated dysphagia screening tools and assessments; (2) implement screening using tools that have optimal diagnostic performance in selected populations that are at risk of dysphagia, such as stroke patients, frail older persons, patients with progressive neurological diseases, persons with cerebral palsy, and patients with head and neck cancer; (3) implement measures that demonstrate robust psychometric properties; and (4) provide quality training in dysphagia screening and assessment to all clinicians involved in the care and management of persons with dysphagia.

BackgroundIncreasing viscosity with thickening agents is a valid therapeutic strategy for oropharyngeal dysphagia (OD). To assess the therapeutic effect of a xanthan gum‐based thickener (Nutilis Clear®) at six viscosities compared with thin liquid in poststroke OD (PSOD) patients.MethodsA total of 120 patients with PSOD were studied in this controlled, multiple‐dose, fixed‐order, and single‐blind study using videofluoroscopy (VFSS). A series of boluses of 10 mL thin liquid and 2000, 1400, 800, 450, 250, and 150 mPa s viscosities were given in duplicate, interrupted in case of aspiration. We assessed the safety and efficacy of swallow and the kinematics of the swallow response.Key ResultsA total of 41.2% patients had safe swallow at thin liquid which significantly increased for all viscosities from 71.9% at 150 mPa s to 95.6% at 1400 mPa s (P < .001). PAS score (3.7 ± 2.3) at thin liquid was also reduced by increasing bolus viscosity (P < .001). The prevalence of patients with aspiration at thin liquid was 17.5% and decreased at all viscosities (P < .01), except at 150 mPa s. Increasing viscosity shortened time to laryngeal vestibule closure (LVC) at all viscosities (P < .01) and reduced bolus velocity at ≥450 mPa s (P < .05). The prevalence of patients with pharyngeal residue at each viscosity 37.7%‐44.7% was similar to that at thin liquid (41.2%).Conclusions and InferencesThe prevalence of unsafe swallow with thin liquids is very high in PSOD. Increasing shear bolus viscosity with this xanthan gum‐based thickener significantly increased the safety of swallow in patients with PSOD in a viscosity‐dependent manner without increasing the prevalence of pharyngeal residue.

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Background Neurorehabilitation strategies for chronic poststroke (PS) oropharyngeal dysphagia (OD) have been mainly focused on the neurostimulation of the pharyngeal motor cortex with only marginal effects. In contrast, treatments targeting the PS oropharyngeal sensory pathway dysfunction offer very promising results, but there is little knowledge on the underlying mechanisms. We aimed to explore the neurophysiological mechanisms behind the effect of three sensory neurostimulation strategies. Methods We carried out a randomized two‐blinded parallel group's crossover sham‐controlled clinical trial in 36 patients with unilateral stroke and chronic unsafe swallow to investigate the effect of repetitive transcranial magnetic stimulation (rTMS) of the primary sensory cortex (A), oral capsaicin (B) and intra‐pharyngeal electrical stimulation (IPES; C). The effect was evaluated immediately after the interventions with videofluoroscopy (VFS) and motor/sensory evoked potentials (MEP/SEP). Key Results Interventions induced no changes in the biomechanics of the swallow response during VFS. However, an enhancement of motor cortex excitability (latency shortening and increased size of thenar MEP) was found with active interventions (A + B + C, and B/C alone; P < .05 for all) but not with sham. Active but not sham interventions shortened pharyngeal SEP latency in the ipsilesional hemisphere (A + B + C: P2‐peak, P = .039; A: N2‐peak, P = .034) and antagonized the physiological habituation in pharyngeal MEP (A + B + C and A alone, P < .05 for both). Conclusions and Inferences Sensory pathway neurostimulation strategies caused immediate enhancement of motor cortex excitability with peripheral strategies (capsaicin and IPES) and of pharyngeal sensory conduction with rTMS. These changes support the use of sensory neurorehabilitation strategies in promoting swallow recovery in chronic PS‐OD.

Thickened fluids are a therapeutic strategy for oropharyngeal dysphagia (OD). However, its therapeutic effect among different phenotypes of OD patients has not yet been compared. We aimed to assess the therapeutic effect and α-amylase resistance of a mixed gum/starch thickener [Fresubin Clear Thickener® (FCT)] on four phenotypes of OD patients: G1) 36 older; G2) 31 head/neck cancer (HNC); G3) 30 Parkinson’s disease; and G4) 31 chronic post-stroke. Therapeutic effect of FCT was assessed during videofluoroscopy using the Penetration-Aspiration Scale (PAS), for 5/20 mL boluses, at four levels of shear-viscosity (<50, 250, 1000 and 2000 mPa·s). The effect of α-amylase was assessed after 30 s of oral incubation. Patients had high prevalence of VFS signs of impaired efficacy (98.44%) and safety (70.31%) of swallow with a severe PAS score (4.44 ± 0.20). Most severe OD was in HNC (80.6% unsafe swallows). FCT showed a strong therapeutic effect on the safety of swallow at a range between 250–1000 mPa·s (74.19–96.67%, safe swallows in G1, G3, G4, and 58.06% in G2), without increasing pharyngeal residue. Viscosity was unaffected by α-amylase. Increasing shear-viscosity with FCT causes a strong viscosity-dependent therapeutic effect on the safety of swallow. This effect depends on the phenotype and is similar among older, Parkinson’s and post-stroke patients.

Background and aims Prevalence and complications of oropharyngeal dysphagia (OD) and malnutrition (MN) in COVID-19 patients is unknown. Our aim was to assess the prevalence, risk factors and clinical outcomes of OD and MN in a general hospital during the first wave of the COVID-19 pandemic. Methods This was a prospective, observational study involving clinical assessment of OD (Volume-Viscosity Swallowing Test), and nutritional screening (NRS2002) and assessment (GLIM criteria) in COVID-19 patients hospitalized in general wards at the Consorci Sanitari del Maresme, Catalonia, Spain. The clinical characteristics and outcomes of patients were assessed at pre-admission, admission and discharge, and after 3 and 6-months follow-up. Results We included 205 consecutive patients (69.28 ±17.52 years, Charlson 3.74 ±2.62, mean hospital stay 16.8 ±13.0 days). At admission, Barthel Index was 81.3 ±30.3; BMI 28.5 ±5.4 kg/m 2 ; OD prevalence 51.7% (44.1% impaired safety of swallow); and 45.5% developed MN with a mean weight loss of 10.1 ±5.0 kg during hospitalization. OD was an independent risk factor for MN during hospitalization (OR 3.96 [1.45–10.75]), and hospitalization was prolonged in patients with MN compared with those without (21.9 ±14.8 vs 11.9 ±8.9 days, respectively; p<0.0001). OD was independently associated with comorbidities, neurological symptoms, and low functionality. At 6-month follow-up, prevalence of OD was still 23.3% and that of MN only 7.1%. Patients with OD at discharge showed reduced 6-month survival than those without OD at discharge (71.6% vs 92.9%, p<0.001); in contrast, those with MN at discharge did not show 6-month survival differences compared to those without (85.4% vs 83.8%, p=0.8). Conclusions Prevalence and burden of OD and MN in patients hospitalized in COVID-19 wards is very high. Our results suggest that optimizing the management of MN might shorten the hospitalization period but optimizing the management of OD will likely impact the nutritional status of COVID-19 patients and improve their clinical outcomes and survival after hospital discharge. ClinicalTrials.gov Identifier: NCT04346212.