The Swallowing Characteristics of Thickeners, Jellies and Yoghurt Observed Using an In Vitro Model

© The Author(s) 2019 Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.Drinks and foods may be thickened to improve swallowing safety for dysphagia patients, but the resultant consistencies are not always palatable. Characterising alternative appetising foods is an important task. The study aims to characterise the in vitro swallowing behaviour of specifically formulated thickened dysphagia fluids containing xanthan gum and/or starch with standard jellies and yoghurt using a validated mechanical model, the “Cambridge Throat”. Observing from the side, the model throat can follow an experimental oral transit time (in vitro-OTT) and a bolus length (BL) at the juncture of the pharynx and larynx, to assess the velocity and cohesion of bolus flow. Our results showed that higher thickener concentration produced longer in vitro-OTT and shorter BL. At high concentration (spoon-thick), fluids thickened with starch-based thickener showed significantly longer in vitro-OTT than when xanthan gum-based thickener was used (84.5 s ± 34.5 s and 5.5 s ± 1.6 s, respectively, p < 0.05). In contrast, at low concentration (nectar-like), fluids containing xanthan gum-based thickener demonstrated shorter BL than those of starch-based thickener (6.4 mm ± 0.5 mm and 8.2 mm ± 0.8 mm, respectively, p < 0.05). The jellies and yoghurt had comparable in vitro-OTT and BL to thickeners at high concentrations (honey-like and spoon-thick), indicating similar swallowing characteristics. The in vitro results showed correlation with published in vivo data though the limitations of applying the in vitro swallowing test for dysphagia studies were noted. These findings contribute useful information for designing new thickening agents and selecting alternative and palatable safe-to-swallow foods.Peer reviewe

Acceptability of oral solid medicines in older adults with and without dysphagia : a nested pilot validation questionnaire based observational study

This document is the accepted manuscript version of the following article: Fang Liu, Ambreen Ghaffur, Jackreet Bains, and Shaheen Hamdy, “Acceptability of oral solid medicines in older adults with and without dysphagia: a nested pilot validation questionnaire based observational study”, International Journal of Pharmaceutics, Vol 512 (2): 374-381, March 2016. DOI: 10.1016/j.ijpharm.2016.03.007 This Manuscript version is distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs https://creativecommons.org/licenses/by-nc-nd/3.0/Older patients (aged 65 years and over) are the major consumers of medicines and many barriers affect their ability in taking medicines orally, especially swallowing difficulties. Moreover, the characteristics of differing medicine formulations might have an impact on their acceptability in older patients. The aims of this study were to validate a Medicines Acceptability Questionnaire (MAQ) and to assess acceptability of oral solid medicines in older ambulatory patients with and without dysphagia. One hundred and fifty six older patients attending community pharmacies were recruited and attended face to face interviews. Two questionnaires were administered during the interviews, the validated Sydney Swallow Questionnaire (SSQ) assessing oral and pharyngeal swallowing function and the newly developed Medicines Acceptability Questionnaire (MAQ) evaluating patient acceptability of oral solid medicines. Seventeen (11%) participants displayed symptoms compatible with swallowing difficulties identified by the SSQ. Participants with swallowing difficulties were considered themselves more likely to have problems in swallowing tablets and capsules of large sizes (11mm and 13mm tablets and size #00 capsules) compared to participants without dysphagia. Dispersible/effervescent tablets and orally disintegrating tablets were considered to be the most acceptable in this cohort, followed by mini-tablets. Chewable tablets and granules were the least favoured. Consistently higher acceptability scores were seen in the dysphagic population than in the non-dysphagic population for all of the dosage forms that were easier to swallow than tablets and capsules. The development of these formulations will assist in medication taking in older patients with dysphagia and potentially their adherence to drug treatments.Peer reviewedFinal Accepted Versio

Pharyngeal electrical stimulation for treatment of poststroke dysphagia: individual patient data meta-analysis of randomised controlled trials

Background. Dysphagia after stroke is common, associated independently with poor outcome, and has limited treatment options. Pharyngeal electrical stimulation (PES) is a novel treatment being evaluated for treatment of poststroke dysphagia. Methods. We searched electronically for randomised controlled trials of PES in dysphagic patients within 3 months of stroke. Individual patient data were analysed using regression, adjusted for trial, age, severity, and baseline score. The coprimary outcomes were radiological aspiration (penetration aspiration score, PAS) and clinical dysphagia (dysphagia severity rating scale, DSRS) at 2 weeks; secondary outcomes included functional outcome, death, and length of stay in hospital. Results. Three completed trials were identified: 73 patients, age 72 (12) years, severity (NIHSS) 11 (6), DSRS 6.7 (4.3), mean PAS 4.3 (1.8). Compared with no/sham stimulation, PES was associated with lower PAS, 3.4 (1.7) versus 4.1 (1.7), mean difference −0.9 (), and lower DSRS, 3.5 (3.8) versus 4.9 (4.4), mean difference −1.7 (). Length of stay in hospital tended to be shorter: 50.2 (25.3) versus 71.2 (60.4) days (). Functional outcome and death did not differ between treatment groups. Conclusions. PES was associated with less radiological aspiration and clinical dysphagia and possibly reduced length of stay in hospital across three small trials

The pattern of penetration and aspiration in acute stroke survivors

Background and Aims: Aspiration is common in acute stroke survivors with dysphagia, is associated with increased pneumonia rates, and is an independent predictor of mortality. However, studies evaluating the nature and pattern of penetration and aspiration post-stroke are lacking. Method: The Penetration-Aspiration Scale (PAS) was used to rate baseline videofluoroscopic swallowing studies of 17 dysphagic stroke survivors from the STEPS trial of pharyngeal electrical stimulation (onset <14 days, mean 74 years). Analysis was performed on 6 x 5ml boli and 1 x 50ml bolus (thin fluids with contrast agent at 40% wt/vol), recorded at 25 f/s. Every swallow to clear each 5ml or 50ml bolus was counted, given a PAS score and labelled a primary or secondary (clearing) swallow. Results: In total, 285 swallows were viewed. Due to poor image quality, 7% of swallows were excluded. At a bolus level, for 5ml/50ml swallows, results showed 68%/42% normal swallows, 14%/27% penetration and 18%/31% aspiration respectively. At a subject level, 5ml: only 3 patients scored within normal limits for all boli; 50ml: no subject swallowed without showing penetration or aspiration at some point. Higher penetration and aspiration scores occurred on 50ml. Aspirated material was rarely fully cleared, even in those subjects who demonstrated a cough response (5ml: 2%, 50 ml: 0%). Conclusion: Aspiration in post-stroke dysphagia appears to fluctuate in presentation within and between boli. Bedside assessments should take into account variability and sample enough swallows. In addition, clinicians should not assume coughing clears aspirated material. Quality of image capture must be optimised for future studies

Effects of pharmacological agents for neurogenic oropharyngeal dysphagia: A systematic review and meta‐analysis

From Wiley via Jisc Publications RouterHistory: received 2021-04-30, rev-recd 2021-06-09, accepted 2021-06-25, pub-electronic 2021-08-01Article version: VoRPublication status: PublishedAbstract: Background: This systematic review and meta‐analysis aimed to evaluate the effects of pharmacological agents for neurogenic oropharyngeal dysphagia based on evidence from randomized controlled trials (RCTs). Methods: Electronic databases were systematically searched between January 1970 and March 2021. Two reviewers independently extracted and synthesized the data. The outcome measure was changed in (any) relevant clinical swallowing‐related characteristics. Key results: Data from 2186 dysphagic patients were collected from 14 RCT studies across a range of pharmacotherapies. The pooled effect size of transient receptor potential (TRP) channel agonists was large compared to placebo interventions (SMD[95%CI] =1.27[0.74,1.80], p < 0.001; I2 = 79%). Data were limited for other pharmacological agents and the overall pooled effect size of these agents was non‐significant (SMD [95% CI] =0.25 [−0.24, 0.73]; p = 0.31; I2 = 85%). When analyzed separately, large effect sizes were observed with Nifedipine (SMD[95%CI] =1.13[0.09,2.18]; p = 0.03) and Metoclopramide (SMD[95%CI] =1.68[1.08,2.27]; p < 0.001). By contrast, the effects of angiotensin‐converting enzyme (ACE) inhibitors (SMD[95%CI] = −0.67[−2.32,0.99]; p = 0.43; I2 = 61%), Physostigmine (SMD[95%CI] = −0.05[−1.03,0.93]; p = 0.92) and Glyceryl Trinitrate (GTN) (SMD [95% CI] = −0.01 [−0.11, 0.08]; p = 0.78) were non‐significant. Within stroke patients, subgroup analysis showed that TRP channel agonists had a moderate pooled effect size (SMD[95%CI] =0.74[0.10,1.39]; p = 0.02; I2 = 82%) whereas the effects of other agents were non‐significant (SMD[95%CI] =0.40[−0.04,0.84]; p = 0.07; I2 = 87%). Conclusions & Inferences: Our results showed that TRP channel agonists, Nifedipine and Metoclopromide may be beneficial for neurogenic dysphagic patients. Large scale, multicenter clinical trials are warranted to fully explore their therapeutic effects on swallowing

Exploring parameters of gamma transcranial alternating current stimulation (tACS) and full‐spectrum transcranial random noise stimulation (tRNS) on human pharyngeal cortical excitability

From Wiley via Jisc Publications RouterHistory: received 2020-12-21, rev-recd 2021-04-25, accepted 2021-04-28, pub-electronic 2021-06-03Article version: VoRPublication status: PublishedFunder: Sun Yat‐sen University; Id: http://dx.doi.org/10.13039/501100002402Funder: Salford Royal NHS Foundation TrustAbstract: Background: Transcranial alternating current stimulation (tACS) and transcranial random noise stimulation (tRNS) have been shown to have physiological and functional effects on brain excitability and motor behavior. Yet, little is known about their effects in the swallowing system. Aim: To examine the effects and optimal stimulation parameters of tACS and tRNS for modulating excitability of human pharyngeal motor cortex. Methods: 10 Hz (alpha), 20 Hz (beta), 70 Hz (gamma) tACS, 0.1–640 Hz (full‐spectrum) tRNS, and sham were applied over pharyngeal motor cortices at 1.5 mA current intensity for 10 min in 15 healthy participants. Pharyngeal motor–evoked and thenar motor–evoked potentials (PMEPs and TMEPs) were assessed before and up to 2 h after stimulation with single‐pulse transcranial magnetic stimulation. Averaged MEP amplitude and latency changes were analyzed using repeated measures ANOVA (rmANOVA). Key Results: Two‐way rmANOVA across all active interventions demonstrated a significant MEP interaction both in the stimulated pharyngeal cortex (F (4, 56) = 1.731, p = 0.038) and in the ipsilateral thenar cortex (F (4, 56) = 1.506, p = 0.048). Compared to sham, subsequent post hoc tests showed site‐specific and sustained (60–120 min) increases in PMEPs with gamma tACS and tRNS (p = 0.005, p = 0.027, respectively) and for TMEPs with beta tACS (p = 0.006). Conclusions and Inferences: Our findings suggest that the effects of tACS and tRNS are frequency‐dependent and cortical (representation) site‐specific with both gamma tACS and full‐spectrum tRNS enhancing human pharyngeal cortical excitability. These techniques hold promise as potential treatments for neurological dysphagia

Psychometric assessment and validation of the dysphagia severity rating scale in stroke patients

Post stroke dysphagia (PSD) is common and associated with poor outcome. The Dysphagia Severity Rating Scale (DSRS), which grades how severe dysphagia is based on fluid and diet modification and supervision requirements for feeding, is used for clinical research but has limited published validation information. Multiple approaches were taken to validate the DSRS, including concurrent- and predictive criterion validity, internal consistency, inter- and intra-rater reliability and sensitivity to change. This was done using data from four studies involving pharyngeal electrical stimulation in acute stroke patients with dysphagia, an individual patient data meta-analysis and unpublished studies (NCT03499574, NCT03700853). In addition, consensual- and content validity and the Minimal Clinically Important Difference (MCID) were assessed using anonymous surveys sent to UK-based Speech and Language Therapists (SLTs). Scores for consensual validity were mostly moderate (62.5–78%) to high or excellent (89–100%) for most scenarios. All but two assessments of content validity were excellent. In concurrent criterion validity assessments, DSRS was most closely associated with measures of radiological aspiration (penetration aspiration scale, Spearman rank rs = 0.49, p [less than] 0.001) and swallowing (functional oral intake scale, FOIS, rs =−0.96, p [less than] 0.001); weaker but statistically significant associations were seen with impairment, disability and dependency. A similar pattern of relationships was seen for predictive criterion validity. Internal consistency (Cronbach’s alpha) was either “good” or “excellent”. Intra and inter-rater reliability were largely “excellent” (intraclass correlation >0.90). DSRS was sensitive to positive change during recovery (medians: 7, 4 and 1 at baseline and 2 and 13 weeks respectively) and in response to an intervention, pharyngeal electrical stimulation, in a published meta-analysis. The MCID was 1.0 and DSRS and FOIS scores may be estimated from each other. The DSRS appears to be a valid tool for grading the severity of swallowing impairment in patients with post stroke dysphagia and is appropriate for use in clinical research and clinical service deliver

A feasibility pilot study of the effects of neurostimulation on swallowing function in Parkinson’s Disease [version 2; peer review: 1 approved, 1 approved with reservations, 1 not approved]

Introduction: Dysphagia often occurs during Parkinson’s disease (PD) and can have severe consequences. Recently, neuromodulatory techniques have been used to treat neurogenic dysphagia. Here we aimed to compare the neurophysiological and swallowing effects of three different types of neurostimulation, 5 Hertz (Hz) repetitive transcranial magnetic stimulation (rTMS), 1 Hz rTMS and pharyngeal electrical stimulation (PES) in patients with PD. Method: 12 PD patients with dysphagia were randomised to receive either 5 Hz rTMS, 1 Hz rTMS, or PES. In a cross-over design, patients were assigned to one intervention and received both real and sham stimulation. Patients received a baseline videofluoroscopic (VFS) assessment of their swallowing, enabling penetration aspiration scores (PAS) to be calculated for: thin fluids, paste, solids and cup drinking. Swallowing timing measurements were also performed on thin fluid swallows only. They then had baseline recordings of motor evoked potentials (MEPs) from both pharyngeal and (as a control) abductor pollicis brevis (APB) cortical areas using single-pulse TMS. Subsequently, the intervention was administered and post interventional TMS recordings were taken at 0 and 30 minutes followed by a repeat VFS within 60 minutes of intervention. Results: All interventions were well tolerated. Due to lower than expected recruitment, statistical analysis of the data was not undertaken. However, with respect to PAS swallowing timings and MEP amplitudes, there was small but visible difference in the outcomes between active and sham. Conclusion: PES, 5 Hz rTMS and 1 Hz rTMS are tolerable interventions in PD related dysphagia. Due to small patient numbers no definitive conclusions could be drawn from the data with respect to individual interventions improving swallowing function and comparative effectiveness between interventions. Larger future studies are needed to further explore the efficacy of these neuromodulatory treatments in Parkinson’s Disease associated dysphagia

The Effects of Midline Cerebellar rTMS on Human Pharyngeal Cortical Activity in the Intact Swallowing Motor System

From Springer Nature via Jisc Publications RouterHistory: registration 2020-09-09, accepted 2020-09-09, online 2020-09-26, pub-electronic 2020-09-26, pub-print 2021-02Publication status: PublishedFunder: Medical Research Council; doi: http://dx.doi.org/10.13039/501100000265; Grant(s): MR/P006183/1Abstract: We sought to compare the effects of 10 Hz cerebellar vermis (vs. unilateral hemispheric and sham) repetitive transcranial magnetic stimulation (rTMS) on cortical neuroelectrical activity and thereafter 10 Hz cerebellar vermis (vs. sham) rTMS on swallowing behaviour. Healthy participants (n = 25) were randomly allocated to receive vermis, unilateral hemisphere or sham 10 Hz cerebellar rTMS. Recordings were made using pharyngeal electromyography and manometry catheters, obtaining motor-evoked potentials (MEPs) and pressure recordings. The amplitudes of MEPs elicited using single-pulse TMS delivered to the pharyngeal areas of the motor cortex bilaterally were measured pre- and post-cerebellar stimulation. As in previous studies, abductor policis brevis (APB) MEPs were measured to assess post-rTMS modulation specificity. Swallowing was assessed using a swallowing accuracy task. Measurements were made at baseline and 15-min intervals for an hour post-intervention. Measurements involved TMS being used to elicit 10 MEPs bilaterally over the pharyngeal areas of the motor cortex, over the APB cortical representation adjacent to the pharyngeal area with the lowest resting motor threshold and 5 MEPs bilaterally over pharyngeal areas of the cerebellar hemispheres. Swallowing accuracy was assessed by giving participants 10 attempts to swallow and hit a digital target. Cerebellar vermis rTMS caused significant suppression of cortical pharyngeal MEP amplitudes compared with unilateral rTMS and sham (P = 0.0005, 0.002). APB and cerebellar MEP amplitudes were unaffected as were pharyngeal and APB MEP latencies. Following cerebellar vermis rTMS there was a significant reduction in swallowing accuracy compared with sham (P = 0.001). Our findings demonstrate cerebellar vermis rTMS exerts a suppressive effect on pharyngeal motor cortical activity and swallowing behaviour