Post-stroke dysphagia: clinical and radiological outcomes and efficacy

Upwards of 50% of stroke survivors show symptoms of swallowing impairment (dysphagia) post-stroke. Dysphagia is clinically important as it results in poorer outcomes and affects quality of life. Despite this, there are few proven treatments. In addition, the act of swallowing is intricate and complex and may be best measured using multiple outcomes. This thesis had three principal aims: firstly, to evaluate the current evidence base for swallowing therapy by updating the Cochrane review into swallowing therapy in acute and subacute stroke. Secondly, to evaluate the use of multiple measures of swallowing (timing and clearance measures) to detect change following a swallowing treatment (Pharyngeal Electrical Stimulation - PES) as opposed to only using a single measure of safety, the Penetration Aspiration Scale (PAS). This was done using retrospective data analysis of videofluoroscopic data from the Swallowing Treatment using Electrical Pharyngeal Stimulation Trial (STEPS) which had already been evaluated for safety using only the PAS. And thirdly, to expand the range of outcome measures available for measuring dysphagia by validating the dysphagia severity rating scale (DSRS), a clinical outcome measure currently in use but not yet validated. The results of this thesis have confirmed three main findings with regards to clinical and radiological outcomes post-stroke. Firstly, the Cochrane review has highlighted that currently, swallowing therapy does show some positive benefits but this is based on evidence of variable quality. Recommendations for conducting more robust trials in the future are discussed. Secondly, with regards to using multiple measures, videofluoroscopic data analysis revealed that additional measures of timing and clearance did not result in the identification of any improvements that may have gone undetected using safety measures alone (PAS). However, final numbers were reduced due to data quality and lower frame rate acquisition and hence it would be premature to conclude that using the PAS alone is sufficient when measuring swallowing outcomes post-stroke. Finally, with regards to measuring dysphagia severity post-stroke, the DSRS was validated. The results showed that it 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 delivery

Post-stroke dysphagia: clinical and radiological outcomes and efficacy

Upwards of 50% of stroke survivors show symptoms of swallowing impairment (dysphagia) post-stroke. Dysphagia is clinically important as it results in poorer outcomes and affects quality of life. Despite this, there are few proven treatments. In addition, the act of swallowing is intricate and complex and may be best measured using multiple outcomes. This thesis had three principal aims: firstly, to evaluate the current evidence base for swallowing therapy by updating the Cochrane review into swallowing therapy in acute and subacute stroke. Secondly, to evaluate the use of multiple measures of swallowing (timing and clearance measures) to detect change following a swallowing treatment (Pharyngeal Electrical Stimulation - PES) as opposed to only using a single measure of safety, the Penetration Aspiration Scale (PAS). This was done using retrospective data analysis of videofluoroscopic data from the Swallowing Treatment using Electrical Pharyngeal Stimulation Trial (STEPS) which had already been evaluated for safety using only the PAS. And thirdly, to expand the range of outcome measures available for measuring dysphagia by validating the dysphagia severity rating scale (DSRS), a clinical outcome measure currently in use but not yet validated. The results of this thesis have confirmed three main findings with regards to clinical and radiological outcomes post-stroke. Firstly, the Cochrane review has highlighted that currently, swallowing therapy does show some positive benefits but this is based on evidence of variable quality. Recommendations for conducting more robust trials in the future are discussed. Secondly, with regards to using multiple measures, videofluoroscopic data analysis revealed that additional measures of timing and clearance did not result in the identification of any improvements that may have gone undetected using safety measures alone (PAS). However, final numbers were reduced due to data quality and lower frame rate acquisition and hence it would be premature to conclude that using the PAS alone is sufficient when measuring swallowing outcomes post-stroke. Finally, with regards to measuring dysphagia severity post-stroke, the DSRS was validated. The results showed that it 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 delivery

Swallowing therapy for dysphagia in acute and subacute stroke

Background: Dysphagia (swallowing problems), which is common after stroke, is associated with increased risk of death or dependency, occurrence of pneumonia, poor quality of life, and longer hospital stay. Treatments provided to improve dysphagia are aimed at accelerating recovery of swallowing function and reducing these risks. This is an update of the review first published in 1999 and updated in 2012.Objectives: To assess the effects of swallowing therapy on death or dependency among stroke survivors with dysphagia within six months of stroke onset.Search methods: We searched the Cochrane Stroke Group Trials Register (26 June 2018), the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 6) in the Cochrane Library (searched 26 June 2018), MEDLINE (26 June 2018), Embase (26 June 2018), the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (26 June 2018),Web of Science Core Collection (26 June 2018), Speech BITE (28 June 2016), ClinicalTrials.Gov (26 June 2018), and the World Health Organization International Clinical Trials Registry Platform (26 June 2018). We also searched Google Scholar (7 June 2018) and the reference lists of relevant trials and review articles.Selection criteria: We sought to include randomised controlled trials (RCTs) of interventions for people with dysphagia and recent stroke (within six months).Data collection and analysis: Two review authors independently applied the inclusion criteria, extracted data, assessed risk of bias, used the GRADE approach to assess the quality of evidence, and resolved disagreements through discussion with the third review author (PB). We used random effects models to calculate odds ratios (ORs), mean differences (MDs), and standardised mean differences (SMDs), and provided 95% confidence intervals (CIs) for each. The primary outcome was functional outcome, defined as death or dependency (or death or disability), at the end of the trial. Secondary outcomes were case fatality at the end of the trial, length of inpatient stay, proportion of participants with dysphagia at the end of the trial, swallowing ability, penetration aspiration score, or pneumonia, pharyngeal transit time, institutionalisation, and nutrition.Main results: We added 27 new studies (1777 participants) to this update to include a total of 41 trials (2660 participants). We assessed the efficacy of swallowing therapy overall and in subgroups by type of intervention: acupuncture (11 studies), behavioural interventions (nine studies), drug therapy (three studies), neuromuscular electrical stimulation (NMES; six studies), pharyngeal electrical stimulation (PES; four studies), physical stimulation (three studies), transcranial direct current stimulation (tDCS; two studies), and transcranial magnetic stimulation (TMS; nine studies). Swallowing therapy had no effect on the primary outcome (death or dependency/disability at the end of the trial) based on data from one trial (two data sets) (OR 1.05, 95% CI 0.63 to 1.75; 306 participants; 2 studies; I² = 0%; P = 0.86; moderate-quality evidence). Swallowing therapy had no effect on case fatality at the end of the trial (OR 1.00, 95% CI 0.66 to 1.52; 766 participants; 14 studies; I² = 6%; P = 0.99; moderate-quality evidence). Swallowing therapy probably reduced length of inpatient stay (MD -2.9, 95% CI -5.65 to -0.15; 577 participants; 8 studies; I² = 11%; P = 0.04; moderate-quality evidence). Researchers found no evidence of a subgroup effect based on testing for subgroup differences (P = 0.54). Swallowing therapy may have reduced the proportion of participants with dysphagia at the end of the trial (OR 0.42, 95% CI 0.32 to 0.55; 1487 participants; 23 studies; I² = 0%; P = 0.00001; low-quality evidence). Trial results show no evidence of a subgroup effect based on testing for subgroup differences (P = 0.91). Swallowing therapy may improve swallowing ability (SMD -0.66, 95% CI -1.01 to -0.32; 1173 participants; 26 studies; I² = 86%; P = 0.0002; very low quality evidence).We found no evidence of a subgroup effect based on testing for subgroup differences (P = 0.09). We noted moderate to substantial heterogeneity between trials for these interventions. Swallowing therapy did not reduce the penetration aspiration score (i.e. it did not reduce radiological aspiration) (SMD -0.37, 95% CI -0.74 to -0.00; 303 participants; 11 studies; I² = 46%; P = 0.05; low-quality evidence). Swallowing therapy may reduce the incidence of chest infection or pneumonia (OR 0.36, 95% CI 0.16 to 0.78; 618 participants; 9 studies; I² = 59%; P = 0.009; very low-quality evidence).Authors’ conclusions: Moderate- and low-quality evidence suggests that swallowing therapy did not have a significant effect on the outcomes of death or dependency/disability, case fatality at the end of the trial, or penetration aspiration score. However, swallowing therapy may have reduced length of hospital stay, dysphagia, and chest infections, and may have improved swallowing ability. However, these results are based on evidence of variable quality, involving a variety of interventions. Further high-quality trials are needed to test whether specific interventions are effective

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

HEXACO personality predicts counterproductive work behavior and organizational citizenship behavior in low-stakes and job applicant contexts

This study examined the degree to which the predictive validity of personality declines in job applicant settings. Participants completed the 200-item HEXACO Personality Inventory-Revised, either as part of confidential research (347 non-applicants) or an actual job application (260 job applicants). Approximately 18-months later, participants completed a confidential survey measuring organizational citizenship behavior (OCB) and counterproductive work behavior (CWB). There was evidence for a small drop in predictive validity among job applicants, however honesty-humility, extraversion, agreeableness, and conscientiousness predicted lower levels of CWB and higher levels of OCB in both job applicants and non -applicants. The study also informs the use of the HEXACO model of personality in selection settings, reporting typical levels of applicant faking and facet-level predictive validity. (C) 2018 Elsevier Inc. All rights reserved

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

Does therapy with biofeedback improve swallowing in adults with dysphagia?: a systematic review and meta-analysis

Objective To describe and systematically review the current evidence on the effects of swallow therapy augmented by biofeedback in adults with dysphagia (PROSPERO 2016:CRD42016052942). Data sources Two independent reviewers conducted searches which included MEDLINE, EMBASE, trial registries and grey literature up to December 2016. Study selection Randomised controlled trials (RCTs) and non-RCTs were assessed, including for risk of bias and quality. Data extraction Data were extracted by one reviewer and verified by another on biofeedback type, measures of swallow function, physiology and clinical outcome, and analysed using Cochrane Review Manager (random effects models). Results are expressed as weighted mean difference (WMD) and odds ratio (OR). Data Synthesis Of 675 articles, we included 23 studies (n=448 participants). Three main types of biofeedback were used: accelerometry, surface electromyography and tongue manometry. Exercises included saliva swallows, manoeuvres and strength exercises. Dose varied between 6-72 sessions for 20-60 minutes. Five controlled studies (stroke n=95; head and neck cancer n=33; mixed aetiology n=10) were included in meta-analyses. Compared to control, biofeedback augmented dysphagia therapy significantly enhanced hyoid displacement (three studies, WMD=0.22cm; 95% CI [0.04, 0.40], p=0.02) but there was no significant difference in functional oral intake (WMD=1.10; 95%CI [-1.69, 3.89], p=0.44) or dependency on tube feeding (OR =3.19; 95%CI [0.16, 62.72], p=0.45). Risk of bias was high and there was significant statistical heterogeneity between trials in measures of swallow function and number tube fed (I2 70-94%). Several non-validated outcome measures were used. Subgroup analyses were not possible due to a paucity of studies. Conclusions Dysphagia therapy augmented by biofeedback using surface electromyography and accelerometry enhances hyoid displacement but functional improvements in swallowing are not evident. However data are extremely limited and further larger well-designed RCTs are warranted

Diagnostic accuracy of the Dysphagia Trained Nurse Assessment tool in acute stroke

Background and purposeComprehensive swallow screening assessments to identify dysphagia and make early eating and drinking recommendations can be used by trained nurses. This study aimed to validate the Dysphagia Trained Nurse Assessment (DTNAx) tool in acute stroke patients.MethodsParticipants with diagnosed stroke were prospectively and consecutively recruited from an acute stroke unit. Following a baseline DTNAx on admission, participants underwent a speech and language therapist (SLT) bedside assessment of swallowing (speech and language therapist assessment [SLTAx]), videofluoroscopy (VFS) and a further DTNAx by the same or a different nurse.ResultsForty-seven participants were recruited, of whom 22 had dysphagia. Compared to SLTAx in the identification of dysphagia, DTNAx had a sensitivity of 96.9% (95% confidence interval [CI] 83.8–99.9) and specificity of 89.5% (95% CI 75.2–97.1). Compared to VFS in the identification of aspiration, DTNAx had a sensitivity of 77.8% (95% CI 40.0–97.2) and a specificity of 81.6% (95% CI 65.7–92.3). Over 81% of the diet and fluid recommendations made by the dysphagia trained nurses were in absolute agreement compared to SLTAx. Both DTNAx and SLTAx had low diagnostic accuracy compared to the VFS-based definition of dysphagia.ConclusionsNurses trained in DTNAx showed good diagnostic accuracy in identifying dysphagia compared to SLTAx and in identifying aspiration compared to VFS. They made appropriate diet and fluid recommendations in line with SLTs in the early management of dysphagia

Pharyngeal electrical stimulation for neurogenic dysphagia following stroke, traumatic brain injury or other causes: Main results from the PHADER cohort study

BackgroundNeurogenic dysphagia is common and has no definitive treatment. We assessed whether pharyngeal electrical stimulation (PES) is associated with reduced dysphagia.MethodsThe PHAryngeal electrical stimulation for treatment of neurogenic Dysphagia European Registry (PHADER) was a prospective single-arm observational cohort study. Participants were recruited with neurogenic dysphagia (comprising five groups – stroke not needing ventilation; stroke needing ventilation; ventilation acquired; traumatic brain injury; other neurological causes). PES was administered once daily for three days. The primary outcome was the validated dysphagia severity rating scale (DSRS, score best-worst 0–12) at 3 months.FindingsOf 255 enrolled patients from 14 centres in Austria, Germany and UK, 10 failed screening. At baseline, mean (standard deviation) or median [interquartile range]: age 68 (14) years, male 71%, DSRS 11·4 (1·7), time from onset to treatment 32 [44] days; age, time and DSRS differed between diagnostic groups. Insertion of PES catheters was successfully inserted in 239/245 (98%) participants, and was typically easy taking 11·8 min. 9 participants withdrew before the end of treatment. DSRS improved significantly in all dysphagia groups, difference in means (95% confidence intervals, CI) from 0 to 3 months: stroke (n = 79) –6·7 (–7·8, –5·5), ventilated stroke (n = 98) –6·5 (–7·6, –5·5); ventilation acquired (n = 35) –6·6 (–8·4, –4·8); traumatic brain injury (n = 24) -4·5 (–6·6, –2·4). The results for DSRS were mirrored for instrumentally assessed penetration aspiration scale scores. DSRS improved in both supratentorial and infratentorial stroke, with no difference between them (p = 0·32). In previously ventilated participants with tracheotomy, DSRS improved more in participants who could be decannulated (n = 66) –7·5 (–8·6, –6·5) versus not decannulated (n = 33) –2·1 (–3·2, –1·0) (

Diversity and carbon storage across the tropical forest biome

Tropical forests are global centres of biodiversity and carbon storage. Many tropical countries aspire to protect forest to fulfil biodiversity and climate mitigation policy targets, but the conservation strategies needed to achieve these two functions depend critically on the tropical forest tree diversity-carbon storage relationship. Assessing this relationship is challenging due to the scarcity of inventories where carbon stocks in aboveground biomass and species identifications have been simultaneously and robustly quantified. Here, we compile a unique pan-tropical dataset of 360 plots located in structurally intact old-growth closed-canopy forest, surveyed using standardised methods, allowing a multi-scale evaluation of diversity-carbon relationships in tropical forests. Diversity-carbon relationships among all plots at 1 ha scale across the tropics are absent, and within continents are either weak (Asia) or absent (Amazonia, Africa). A weak positive relationship is detectable within 1 ha plots, indicating that diversity effects in tropical forests may be scale dependent. The absence of clear diversity-carbon relationships at scales relevant to conservation planning means that carbon-centred conservation strategies will inevitably miss many high diversity ecosystems. As tropical forests can have any combination of tree diversity and carbon stocks both require explicit consideration when optimising policies to manage tropical carbon and biodiversity.Additional co-authors: Kofi Affum-Baffoe, Shin-ichiro Aiba, Everton Cristo de Almeida, Edmar Almeida de Oliveira, Patricia Alvarez-Loayza, Esteban Álvarez Dávila, Ana Andrade, Luiz E. O. C. Aragão, Peter Ashton, Gerardo A. Aymard C., Timothy R. Baker, Michael Balinga, Lindsay F. Banin, Christopher Baraloto, Jean-Francois Bastin, Nicholas Berry, Jan Bogaert, Damien Bonal, Frans Bongers, Roel Brienen, José Luís C. Camargo, Carlos Cerón, Victor Chama Moscoso, Eric Chezeaux, Connie J. Clark, Álvaro Cogollo Pacheco, James A. Comiskey, Fernando Cornejo Valverde, Eurídice N. Honorio Coronado, Greta Dargie, Stuart J. Davies, Charles De Canniere, Marie Noel Djuikouo K., Jean-Louis Doucet, Terry L. Erwin, Javier Silva Espejo, Corneille E. N. Ewango, Sophie Fauset, Ted R. Feldpausch, Rafael Herrera, Martin Gilpin, Emanuel Gloor, Jefferson S. Hall, David J. Harris, Terese B. Hart, Kuswata Kartawinata, Lip Khoon Kho, Kanehiro Kitayama, Susan G. W. Laurance, William F. Laurance, Miguel E. Leal, Thomas Lovejoy, Jon C. Lovett, Faustin Mpanya Lukasu, Jean-Remy Makana, Yadvinder Malhi, Leandro Maracahipes, Beatriz S. Marimon, Ben Hur Marimon Junior, Andrew R. Marshall, Paulo S. Morandi, John Tshibamba Mukendi, Jaques Mukinzi, Reuben Nilus, Percy Núñez Vargas, Nadir C. Pallqui Camacho, Guido Pardo, Marielos Peña-Claros, Pascal Pétronelli, Georgia C. Pickavance, Axel Dalberg Poulsen, John R. Poulsen, Richard B. Primack, Hari Priyadi, Carlos A. Quesada, Jan Reitsma, Maxime Réjou-Méchain, Zorayda Restrepo, Ervan Rutishauser, Kamariah Abu Salim, Rafael P. Salomão, Ismayadi Samsoedin, Douglas Sheil, Rodrigo Sierra, Marcos Silveira, J. W. Ferry Slik, Lisa Steel, Hermann Taedoumg, Sylvester Tan, John W. Terborgh, Sean C. Thomas, Marisol Toledo, Peter M. Umunay, Luis Valenzuela Gamarra, Ima Célia Guimarães Vieira, Vincent A. Vos, Ophelia Wang, Simon Willcock & Lise Zemagh