952 research outputs found
sj-docx-1-asm-10.1177_10731911221127904 – Supplemental material for Using Multiverse Analysis to Highlight Differences in Convergent Correlation Outcomes Due to Data Analytical and Study Design Choices
No full textSupplemental material, sj-docx-1-asm-10.1177_10731911221127904 for Using Multiverse Analysis to Highlight Differences in Convergent Correlation Outcomes Due to Data Analytical and Study Design Choices by Sam S. Webb and Nele Demeyere in Assessment</p
Principal Component Analysis of Oxford Cognitive Screen in Patients With Stroke
No full textCognitive deficits occur in most patients with stroke and are the important predictors of adverse long-term outcome. Early identification is fundamental to plan the most appropriate care, including rehabilitation and discharge decisions. The Oxford Cognitive Screen (OCS) is a simple, valid, and reliable tool for the assessment of cognitive deficits in patients with stroke. It contains 10 subtests, providing 14 scores referring to 5 theoretically derived cognitive domains: attention, language, number, praxis, and memory. However, an empirical verification of the domain composition of the OCS subtests in stroke data is still lacking in the literature. A principal component analysis (PCA) was performed on 1,973 patients with stroke who were enrolled in OCS studies in the UK and in Italy. A number of six main components were identified relating to the domains of language and arithmetic, memory, visuomotor ability, orientation, spatial exploration, and executive functions. Bootstrapped split-half reliability analysis on patients and comparison between patients and 498 healthy participants, as that between patients with left and right hemisphere damage, confirmed the results obtained by the principal component analysis. A clarification about the contribution of each score to the theoretical original domains and to the components identified by the PCA is provided with the aim to foster the usability of OCS for both clinicians and researchers
sj-docx-1-wso-10.1177_17474930231205787 – Supplemental material for Domain-specific cognitive impairment 6 months after stroke: The value of early cognitive screening
No full textSupplemental material, sj-docx-1-wso-10.1177_17474930231205787 for Domain-specific cognitive impairment 6 months after stroke: The value of early cognitive screening by Elise T Milosevich, Margaret J Moore, Sarah T Pendlebury and Nele Demeyere in International Journal of Stroke</p
Neuropsychological deficits of visuospatial attention: subtypes, clinical utility, and underlying mechanisms
No full textVisuospatial neglect is a common neuropsychological syndrome characterised by consis- tently lateralised spatial attentional deficits. The purpose of this thesis is to investigate patterns of heterogeneity within visuospatial neglect, to determine this syndrome’s underlying mechanisms, and to investigate the practical utility of considering this heterogeneity within clinical settings.
Chapter Two presents a critical analysis of common neglect assessment methods and in- vestigates the utility of neglect severity metrics which can be extracted from neuropsychological measures. Chapter Three analyses behavioural heterogeneity in neglect dyslexia to investigate the relationship between reading-related and domain-general neglect impairments. Chapter Four presents three case studies characterising representation-level neglect dyslexia in order to evalu- ate existing models of spatial attention. Chapter Five presents a detailed, lesion-mapping analysis of visuospatial neglect deficits aiming to determine whether right neglect is anatomically homolo- gous to left-lateralised neglect. Finally, Chapter Six analyses the relationship between the occur- rence of acute neglect and poor long term recovery outcomes to determine whether the specific behavioural phenotype of acute neglect impairment acts as a useful prognostic indicator.
The findings of these data chapters are then cumulatively discussed to extend fundamental understanding of the neglect syndrome, establish a novel conceptualisation of representation- level neglect dyslexia, evaluate current neglect-related clinical practices, and clarify the recovery outcome of stroke survivors exhibiting acute neglect impairment
The Dutch version of the Oxford Cognitive Screen (OCS-Nederlands): A stroke-specific cognitive screening tool
No full textThe Oxford Cognitive Screen (OCS) is a short screening instrument for cognitive disorders after stroke. It provides a screening for disorders in the cognitive domains most often affected by stroke, that is: attention, memory, language, numerical cognition and praxis in 15 – 20 minutes administration time. The test has been designed to be suitable for patients with aphasia, by providing multiple choice questions, as well as for patients with hemispatial neglect or visual field deficits, by aligning test items in the center of the visual field of patients. The English version of the OCS has already been shown to have good reliability and validity (Demeyere et al., 2015, Psychological Assessment). We present the recently developed Dutch translation and adaptation of the OCS and some preliminary data collected in a small sample of older-aged healthy volunteers.sponsorship: FWOstatus: Publishe
Ego-and allocentric visuospatial neglect: dissociations, prevalence and laterality in acute stroke
No full textObjective: Visuospatial neglect, whereby patients are unable to attend to stimuli on their contralesional side, is a neuropsychological condition commonly experienced after stroke. We aimed to investigate whether egocentric and allocentric neglect are functionally dissociable and differ in prevalence and laterality in the early poststroke period. Method: A consecutive sample of 366 acute stroke patients completed the Broken Hearts test from the Oxford Cognitive Screen. We evaluated the association between egocentric and allocentric neglect and contrasted the prevalence and severity of left-sided versus right-sided neglect. Results: Clinically, we found a double dissociation between ego- and allocentric neglect, with 50% of the neglect patients showing only egocentric neglect and 25% only allocentric neglect. Left-sided egocentric neglect was more prevalent and more severe than was right-sided egocentric neglect, though right-sided neglect was still highly prevalent in the acute stroke sample (35%). Left-sided allocentric neglect was more severe but not more prevalent than was right-sided allocentric neglect. At 6 months, in a representative subsample of 160 patients, we found neglect recovery rates to be 81% and 74% for egocentric and allocentric neglect, respectively. Conclusion: Dissociable ego- and allocentric neglect symptoms support a heterogeneous account of visuospatial neglect, which was shown to be highly prevalent for both the left and the right hemifields.sponsorship: This work was supported by National Institute for Health Research Grants RP-DG-0610-10046 and Oxford Cognitive Health CRF, Stroke Association United Kingdom Grant TSA LECT 2015/02 to Nele Demeyere, Sir Henry Wellcome Postdoctoral Fellowship Grant 098771/Z/12/Z to Celine R. Gillebert, and Research Foundation Flanders Grant G072517N. We would like to express our sincere thanks and admiration to the late Glyn W. Humphreys, without whose support this study would not have come to pass. We would also like to thank Liam Loftus, who conducted preliminary analyses on an initial subset of this data for his final honors research project; Elitsa Slavkova and Rachel King for help in data collection; and Rachel Teal, stroke research nurse at the John Radcliffe Stroke Unit. (National Institute for Health Research|RP-DG-0610-10046, Oxford Cognitive Health CRF, Stroke Association United Kingdom|TSA LECT 2015/02, Sir Henry Wellcome Postdoctoral Fellowship Grant|098771/Z/12/Z, Research Foundation Flanders Grant|G072517N, National Institutes of Health Research (NIHR)|RP-DG-0610-10046)status: Publishe
Development of a complex intervention providing cognitive care after stroke
No full textPost-stroke cognitive impairment is highly prevalent and recent systematic reviews have identified managing cognitive changes as one of the most commonly reported unmet needs in the long term after stroke. In the UK, national clinical guidelines provide a clear outline of ‘best practice’ cognitive care, but audit data have shown that cognitive care falls below recommended standards in many respects. A pragmatic and scalable intervention that provides enhanced post-stroke cognitive care may help to address these clinical gaps and stroke survivor needs.
The overarching aim of the research presented in this thesis was to develop a UK-based intervention providing Level 1 post-stroke cognitive care. The research was guided by the Medical Research Council framework for complex intervention development and thus prioritised evidence, theory, and stakeholder perspectives. Four highly iterative and mutually informative research projects were conducted to develop the intervention. First, an online modified Delphi survey was conducted to establish expert consensus on the intervention features. Then, stroke survivors and family members participated in semi-structured interviews to share their perspectives on two of the core intervention features (cognitive screening and cognitive trajectory discussions). A scoping review was conducted to map and identify gaps within the current literature describing stroke survivor and family member psychoeducation needs about cognition. Finally, stroke survivors, family members, and healthcare professionals participated in a series of co-production activities to develop a novel cognition-focused psychoeducation resource to be used in the intervention. After synthesising key findings from these four projects to design the intervention and corresponding programme theory, the final empirical chapter presents preliminary results from initial feasibility testing of the intervention and the protocol for a future planned study to assess the feasibility of running a full-scale cluster randomised controlled trial to evaluate clinical effectiveness.
Overall, the research provides an important contribution to the field of post-stroke rehabilitation by offering a clearly delineated and pragmatic psychological care intervention. Should the intervention prove clinically and financially effective in a future planned cluster randomised controlled trial, it might meaningfully improve post-stroke psychological care within the UK. In the meantime, while this ambitious research programme is ongoing, key findings presented in this thesis may usefully inform local clinical service improvements
Post-stroke neuropsychological screening and assessment: psychometrics, validation, and predictive value for functional outcomes
No full textNeuropsychological screening and assessment of cognitive changes following stroke requires the use of standardised and well validated tools to ensure the most accurate and evidence-based assessment of a patient’s abilities.The importance of cognitive assessment comes from the high relation between cognitive impairment and later recovery [1–3]. In my DPhil, I aimed to examine different cognitive screening tools and provide validity evidence for their use in assessing post-stroke cognitive impairment.
The first chapter examined the shift in modality of cognitive assessment during the COVID-19 pandemic in a completed web-based questionnaire of 114 allied health professionals (majority UK). This study was conducted at the height of the pandemic and provided time sensitive information about how the use of cognitive testing had changed. I found that the frequency of cognitive testing did not necessarily decrease, but that the modality changed to more remote and video based assessments. The rates of change were lower than other studies at the time, that primarily sampled neuropsychologists from the United States. Within the same chapter, I detailed a study, that provided some evidence for the valid use of a remote version of the Oxford Cognitive Screen (OCS). This study used 40 stroke survivors who had been administered the OCS both in person and remotely, in counterbalanced order. I found that there were minimal meaningful differences in performance across versions, and limited occurrences of a participant being considered impaired on one version and not on the other. This meant that, in light of the pandemic, I had provided some validity evidence for a tool usable via remote administration.
The second chapter provided some clinical validation evidence of a computer tablet-based extension of the OCS, named the OCS-Plus. OCS-plus is a recently standardized and normed domain-general cognitive screening tool. Prior to this DPhil, there was only psychometric validation in 320 healthy ageing adults and no evidence for use in stroke. Here I examined OCS-Plus data from 347 stroke survivors (n=181 =6 months post-stroke) and compared performance of a subset of them to a neuropsychological battery and/or the Montreal Cognitive Assessment (MoCA). I found that the OCS-Plus met convergent and divergent validation criteria compared to the neuropsychological battery, and detected cognitive impairments in a large proportion of those classed as unimpaired on MoCA (100%) and OCS(98.50%). This project showed that the OCS-Plus is valid as a screening tool in stroke from subacute to chronic usage.
The third chapter detailed work regarding the Oxford Digital Multiple Errands Test (OxMET), which had previously been standardised and normed in 124 healthy controls and compared to 105 chronic (>6 months post-stroke) stroke survivors. In part one of chapter 3, I examined the OxMET in relation to the in-person Multiple Errands Test - Home version (MET-Home) in 98 participants, to determine evidence for convergence between the MET, as well as feasibility and acceptability for each MET. I recruited 48 stroke survivors and 50 healthy ageing adults to take part. I found that both METs met convergence criteria (r>=.30). I found the OxMET to be more feasible and acceptable by participants, but that there was an appropriate time and sample to use for each MET and thus both are satisfactory tools.
In part 2 of chapter 3, I examined the predictive validity of the OxMET taken subacutely with stroke survivors to clinically relevant future functional outcomes. The findings were clear that the OxMET was associated with both basic (n=117) and instrumental (n=66) activities of daily living, although more so with instrumental, over and above the contribution of other demographic and cognitive factors.
The aim of the work presented in this thesis was to provide clinicians with an evidence base to make judgement about which tools are best practice for use, and to highlight both strengths and weaknesses of each tool presented. None of the tests presented in this thesis are able to fully capture the full depth of human cognition nor the rich idiosyncrasies of real everyday behavior. Health care professionals should always follow latest guidance and be educated in best evidence-based screening use and trained in tools they administer
Cognitive Reserve and Cognitive Functioning in a Chronic Stroke Sample
No full textStroke is a debilitating condition and is the third key cause of disability and second leading cause of mortality (Lorenzo et al., 2019; Feigen et al., 2010). Post-stroke cognitive impairment is highly prevalent, affecting areas such as memory, attention, executive function, number processing, and language (Bickerton et al., 2012; Humphreys et al., 2012, Demeyere et al., 2016). Impairments can occur more generally across these domains or can be specific to a particular domain. However, there is considerable variability in post-stroke cognitive recovery (Demeyere et al., 2021), with current predictive models of post-stroke cognitive recovery incomplete (Rosenich et al., 2020). The James Lind Alliance recently identified tracking and understanding progression in all areas of cognition as their number 2 priority for Stroke Rehabilitation and Long-term Care (JLA PSP Priority 2, 2021), highlighting the importance of identifying factors which might help explain variability in post-stroke cognitive impairment.
One possible factor contributing to these individual differences in cognitive outcomes is cognitive reserve, or an individual’s resilience to cognitive decline based on lifetime accumulation of enriching educational, occupational, and leisure activities (Stern et al., 1999; Stern & Barulli, 2019; Nucci et al., 2011). There is growing evidence that, in non-stroke older adult populations, cognitive reserve is supported by right frontoparietal network functions (Brosnan et al., 2017; Shalev et al., 2020), suggesting stroke-related pathology (i.e., left versus right hemisphere) may play a role in understanding differences in cognitive outcome. There is a limited understanding of the role of cognitive reserve in cognitive impairment trajectories following stroke, particularly in chronic stroke (> 12 months post-stroke), and whether differences in cognitive outcome post-stroke vary as a function of stroke hemisphere. The present study aims to investigate the relationship between cognitive reserve and cognitive outcomes in chronic stroke. Here, we seek to investigate how cognitive reserve relates to cognitive impairment in adults with chronic stroke. This will be done by examining the relationship between cognitive reserve, as measured by the cognitive reserve index questionnaire (CRIq, Nucci et al., 2011), and global and domain-specific cognitive functioning as measured by the Oxford Cognitive Screen (OCS, Demeyere et al., 2015).
The present study aims to extend the current literature on our understanding of domain-specific impairment in acute stroke by asking the following question:
1. Is there a difference between cognitive reserve and cognitive impairment scores in left vs right hemisphere strokes?
The present study also aims to investigate the relationships between cognitive reserve and cognitive impairment in long term stroke survivors (>2 years post stroke) by answering the following research question:
2. What is the relationship between cognitive reserve and the change over time in domain-general and domain-specific cognitive impairment from the acute to chronic phase of stroke?
A further exploratory aim of this study is:
3. Do individuals with right frontoparietal stroke see less benefit of cognitive reserve in acute and longitudinal outcomes, relative to individuals with stroke with the same areas damaged in the left hemisphere
Cognitive impairment following stroke: prevalence, predictors, and trajectories of domain-specific deficits
No full textCognition is not a unitary construct and encompasses multiple domains, therefore it is critical to consider the diverse range of deficits a stroke survivor may experience and how different impairments might impact other stroke outcomes. The purpose of this thesis is to investigate the prevalence, trajectories, impact, risk factors, and measures of both general and domain-specific cognitive impairment after stroke. First, I determined the prevalence and predictive value of domain-specific cognitive impairments measured with the Oxford Cognitive Screen in a cohort of 866 acute stroke patients, 430 of which completed 6-month follow-up. Next, I investigated the prevalence of acute infection, positive systemic inflammatory response syndrome (SIRS), and elevated inflammatory markers at and during hospital admission, and examined the associations of acute inflammatory markers and systemic infection, with cognitive function in a subset of 255 stroke patients. Subsequently, I analyzed the relationship between domain-general and domain-specific cognitive impairment and overall quality of life 6 months after stroke, as measured by the Stroke Impact Scale. Next, I completed a systematic review and meta-analysis investigating the prevalence of cognitive impairment beyond the first year after stroke and the methods being used to assess cognition in long-term survivors. Lastly, I examined the prevalence of domain-specific cognitive impairment in a chronic stroke cohort of at least 2 years post-stroke, determined the relationship between acute, 6-month and long-term cognitive function, as well as assessed longitudinal trajectories of domain-specific cognitive changes. The findings of these five empirical chapters are then discussed collectively to clarify the prevalence and temporal evolution of domain-specific impairments after stroke, expand the current knowledge of how cognitive impairment may impact functional and mood outcomes after stroke, and establish whether acute domain impairments and systemic inflammation may serve as risk factors for longer-term cognitive impairment. Finally, I highlight potential clinical and research implications, as well as future directions
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