Reliability of the global cortical atrophy visual rating scale applied to computed tomography versus magnetic resonance imaging scans in acute stroke.

INTRODUCTION: Research using magnetic resonance imaging (MRI) suggests regional cerebral atrophy measures (e.g., frontal lobe, temporal lobe) may predict post-stroke outcomes. Clinical CT scans have excellent potential for use in research but it is unclear whether regional atrophy measures from CT are reliable compared to MRI reference standards. METHODS: We used the Global Cortical Atrophy (GCA) scale to investigate reliability of atrophy measures on CT versus MRI scans from stroke patients originally recruited to the Oxford Cognitive Screening programme. Two raters provided standardised visual ratings at two timepoints. Weighted Kappa statistics assessed the reliability of regional atrophy scores. Spearman's correlation and a two-way repeated measures ANOVA assessed the reliability of the total score. RESULTS: On clinically acquired neuroimaging from 98 stroke patients (mean/SD age = 70.97/11.99, 42 female, 84 ischaemic stroke), regional GCA scores on CT versus MRI showed fair to almost perfect intra-rater agreement (κ = .50-.87), substantial to almost perfect intra-rater agreement on CT (κ = .67-.88), and moderate to almost perfect intra-rater reliability on MRI (κ = .50-.89). Regional GCA scores showed mostly moderate to substantial inter-rater reliability on both CT and MRI (κ = .43-.69), except the temporal horns and parieto-occipital region. There was a strong correlation between total GCA scores on CT and MRI (r (96) = .87-.88, p < .001). CONCLUSIONS: These results support the use of cerebral atrophy measures from CT in clinical research, as visual ratings showed generally good agreement between CT and MRI, between raters, and between timepoints.

Poststroke Executive Function in Relation to White Matter Damage on Clinically Acquired CT Brain Imaging.

BACKGROUND: Executive function (EF) impairments are prevalent post stroke and are associated with white matter (WM) damage on MRI. However, less is known about the relationship between poststroke EF and WM damage on CT imaging. OBJECTIVE: To investigate the relationship between poststroke EF and WM damage associated with stroke lesions and WM hypointensities (WMHs) on clinically acquired CT imaging. METHOD: This study analyzed data from the Oxford Cognitive Screening Program, which recruited individuals aged ≥18 years with a confirmed stroke from an acute stroke unit. The individuals completed a follow-up assessment 6 months post stroke. We included individuals with a CT scan showing a visible stroke who completed follow-up EF assessment using the Oxford Cognitive Screen-Plus rule-finding task. We manually delineated stroke lesions and quantified then dichotomized WM damage caused by the stroke using the HCP-842 atlas. We visually rated then dichotomized WMHs using the Age-Related White Matter Changes Scale. RESULTS: Among 87 stroke survivors (M age = 73.60 ± 11.75; 41 female; 61 ischemic stroke), multivariable linear regression showed that stroke damage to the medial lemniscus ( B = -8.86, P < 0.001) and the presence of WMHs ( B = -5.42, P = 0.005) were associated with poorer EF 6 months post stroke after adjusting for covariates including age and education. CONCLUSION: Poorer EF was associated with WM damage caused by stroke lesions and WMHs on CT. These results confirm the importance of WM integrity for EF post stroke and demonstrate the prognostic utility of CT-derived imaging markers for poststroke cognitive outcomes.

Comparing the Oxford Digital Multiple Errands Test (OxMET) to a real-life version: Convergence, feasibility, and acceptability.

We aimed to assess the convergence, feasibility, and acceptability of the Oxford Digital Multiple Errands Test (OxMET) and the in-person Multiple Errands Test-Home version (MET-Home). Participants completed OxMET, MET-Home, Montreal Cognitive Assessment (MoCA), and questionnaires on activities of daily living, depression, technology usage, mobility, and disability. Forty-eight stroke survivors (mean age 69.61, 41.67% female, and average 16.5 months post-stroke) and 50 controls (mean age 71.46, 56.00% female) took part. No performance differences were found for healthy and stroke participants for MET-Home, and only found below p = .05 for OxMET but not below the corrected p = .006. Convergent validity was found between MET-Home and OxMET metrics (most r ≥ .30, p < .006). MET-Home accuracy was related to age (B = -.04, p = .03), sex (B = -.98, p = .03), disability (B = -0.63, p = .04), and MoCA (B = .26, p < .001), whereas OxMET accuracy was predicted by MoCA score (B = .40, p < .001). Feedback indicated that the OxMET was easy and fun and more acceptable than the MET-Home. The MET-Home was more stressful and interesting. The MET tasks demonstrated good convergent validity, with the OxMET digital administration providing a more feasible, inclusive, and acceptable assessment, especially to people with mobility restrictions and more severe stroke.

A qualitative study investigating the views of stroke survivors and their family members on discussing post-stroke cognitive trajectories.

Cognitive impairment is common early after stroke but trajectories over the long term are variable. Some stroke survivors make a full recovery, while others retain a stable impairment or decline. This study explored the perceived advantages and disadvantages of discussing potential cognitive trajectories with stroke survivors and their family members. Stroke survivors at least six-months post-stroke were purposively sampled from an existing pool of research volunteers recruited originally for the OCS-Recovery study. They were invited, alongside a family member, to participate in a semi-structured interview. Interviews were audio recorded, transcribed, and analyzed using reflexive thematic analysis. Twenty-six stroke survivors and eleven family members participated. We identified one overarching theme and three related subthemes. The overarching theme was: One size does not fit all. The subthemes were: (1) Hearing about potential cognitive trajectories helps to develop realistic expectations; (2) Discussions about cognitive trajectories may be motivating; (3) Cognitive decline and post-stroke dementia discussions may be anxiety-provoking and depressing. Healthcare professionals should adopt a person-centred approach to sharing information about post-stroke cognitive trajectories. Discussions should be tailored to individual needs and preferences, with dementia-related topics in particular addressed with the utmost selectivity and sensitivity.

The cultural and linguistic adaptation of the Oxford Cognitive Screen to Tamil.

OBJECTIVE: The Oxford Cognitive Screen (OCS) is a screening tool to assess stroke patients for deficits in attention, executive functions, language, praxis, numeric cognition, and memory. In this study, the OCS was culturally and linguistically adapted to Tamil, for use in India (OCS TA), considering the differences between formal and spoken versions of Tamil and consideration of its phonetic complexity. METHOD: We adopted two-parallel form versions of the OCS and generated normative data for them. We recruited 181 healthy controls (Mean = 39.27 years, SD 16.52) (141 completed version A, 40 completed version B, 33 completed version A and B) and compared the data with the original UK normative sample. In addition, 28 native Tamil-speaking patients who had a stroke in the past three years (Mean = 62.76 years, SD 9.14) were assessed. Convergent validity was assessed with subtasks from Addenbrooke's Cognitive Examination III (ACE-III). RESULTS: We found significant differences between the UK normative group and the OCS TA normative group in age and education. Tamil-specific norms were used to adapt the cutoffs for the memory, gesture imitation, and executive function tasks. When domain-specific scores on the ACE-III were compared, OCS TA exhibited strong convergent validity. CONCLUSIONS: The OCS TA has shown the potential to be a useful screening tool for stroke survivors among Tamil speakers with the two-parallel forms demonstrating good equivalence. Further empirical evidence from larger studies is required to establish their psychometric performance and clinical validity.

Long-term psychological outcomes following stroke: the OX-CHRONIC study.

BACKGROUND: Stroke survivors rate longer-term (> 2 years) psychological recovery as their top priority, but data on how frequently psychological consequences occur is lacking. Prevalence of cognitive impairment, depression/anxiety, fatigue, apathy and related psychological outcomes, and whether rates are stable in long-term stroke, is unknown. METHODS: N = 105 long-term stroke survivors (M [SD] age = 72.92 [13.01]; M [SD] acute NIH Stroke Severity Score = 7.39 [6.25]; 59.0% Male; M [SD] years post-stroke = 4.57 [2.12]) were recruited (potential N = 208). Participants completed 3 remote assessments, including a comprehensive set of standardized cognitive neuropsychological tests comprising domains of memory, attention, language, and executive function, and questionnaires on emotional distress, fatigue, apathy and other psychological outcomes. Ninety participants were re-assessed one year later. Stability of outcomes was assessed by Cohen's d effect size estimates and percent Minimal Clinically Important Difference changes between time points. RESULTS: On the Montreal Cognitive Assessment 65.3% scored < 26. On the Oxford Cognitive Screen 45.9% had at least one cognitive impairment. Attention (27.1%) and executive function (40%) were most frequently impaired. 23.5% and 22.5% had elevated depression/anxiety respectively. Fatigue (51.4%) and apathy (40.5%) rates remained high, comparable to estimates in the first-year post-stroke. Attention (d = -0.12; 85.8% stable) and depression (d = 0.09, 77.1% stable) were the most stable outcomes. Following alpha-adjustments, only perceptuomotor abilities (d = 0.69; 40.4% decline) and fatigue (d = -0.33; 45.3% decline) worsened over one year. Cognitive impairment, depression/anxiety, fatigue and apathy all correlated with worse quality of life. CONCLUSION: Nearly half of participants > 2 years post-event exhibited psychological difficulties including domains of cognition, mood, and fatigue, which impact long-term quality of life. Stroke is a chronic condition with highly prevalent psychological needs, which require monitoring and intervention development.

Decision-making capacity in older medical in-patients: frequency of assessment and rates of incapacity by decision-type and underlying brain/mind impairment.

BACKGROUND: Hospital clinicians find mental capacity assessment challenging and may lack the necessary skills. Given high rates of cognitive impairment, data on mental capacity assessment in real-world hospital cohorts are required to inform the need for staff training and workforce planning. OBJECTIVES: In unselected medical inpatients, we determined the rate and outcome of mental capacity assessment by decision type and underlying brain/mind disorder, and recorded the discipline of the assessor. METHODS: We included consecutive patients (October-November 2018; November-December 2019) admitted to the complex medicine unit providing acute multidisciplinary care for multi-morbid patients (age ≥ 16 years, average age > 80 years). Audit data were collected at ward multidisciplinary meetings and extracted from electronic patient records. RESULTS: Among 892 patients (mean/SD age = 82.8/8.6, 465 male), 140 (16%) required mental capacity assessment (40/140 (29%) had ≥2 assessments) with 203 assessments in total of which 162 (80%) were done by doctors. Capacity was deemed lacking in 124 (61%) assessments, most commonly in delirium with/without other co-morbid conditions (94/114, 82%) or dementia (9/12, 75%) with lower rates in other disorders (15/27, 56%), and no formal diagnosis of brain/mind disorder (6/50, 12%). Cognitive test scores were overall lower in those lacking capacity (mean/SD abbreviated-mental-test-score = 5.2/2.6, range = 0-10 versus 6.8/2.8, P = 0.001, range = 1-10). Decisions involving discharge planning were most often assessed (48%) followed by treatment (29%), discharge against medical advice (12%) and others (11%). CONCLUSION: Mental capacity assessments were performed frequently and often repeated, justifying the need for robust training in the practical application of the principles of capacity assessment for staff managing complex older patients.

Predictive validity of the Oxford digital multiple errands test (OxMET) for functional outcomes after stroke.

The Oxford Digital Multiple Errands Test (OxMET) is a brief computer-tablet based cognitive screen, intended as an ecologically valid assessment of executive dysfunction. We examined aspects of predictive validity in relation to functional outcomes. Participants (≤ 2 months post-stroke) were recruited from an English-speaking stroke rehabilitation in-patient setting. Participants completed OxMET. The Barthel Index, Therapy Outcome Measure (TOMS), and modified Rankin Scale (mRS) were collected from medical notes. Participants were followed up after 6-months and completed the Nottingham Extended Activities of Daily Living (NEADL) scale. 117 participants were recruited (M = 26.18 days post-stroke (SD = 25.16), mean 74.44yrs (SD = 12.88), median NIHSS 8.32 (IQR = 5-11)). Sixty-six completed a follow-up (M = 73.94yrs (SD = 12.68), median NIHSS 8 (IQR = 4-11)). Significant associations were found between TOMS and mRS. At 6-month follow up, we found a moderate predictive relationship between the OxMET accuracy and NEADL (R2 = .29, p < .001), and we did not find this prediction with MoCA taken at 6-months. The subacute OxMET associated with measures of functionality and disability in a rehabilitation context, and in activities of daily living. The OxMET is an assessment of executive function with good predictive validity on clinically relevant functional outcome measures that may be more predictive than other cognitive tests.

Unravelling the complex interactions between self-awareness, cognitive change, and mood at 6-months post-stroke using the Y-shaped model.

We investigated the relationships between cognitive change following stroke, awareness of cognitive impairments, and mood to further understanding of change processes influencing psychological outcomes post-stroke in line with the "Y-shaped" process model. Patients (n = 143; Mage = 73 years, SD = 13.73; 74 males) were assessed at 3-weeks (T1) and 6-months (T2) post-stroke and had completed the Oxford Cognitive Screen (T1 and T2), the Cognitive Failures Questionnaire (CFQ; T2), and the Hospital Anxiety and Depression Scale (HADS; T2). An ANCOVA controlling for disability relating to activities of daily living (ADL) revealed that awareness of cognitive impairment was significantly lower in participants with moderate-severe cognitive impairment. Regression analysis indicated that greater awareness of cognitive impairment and reduced independence in ADL were associated with greater emotional distress at T2. Cognitive improvement was associated with lower emotional distressat T2. Contrary to the awareness hypothesis, moderation analyses suggest that this effect was largest for those most cognitively impaired at T1. Findings emphasize the importance of monitoring stroke patients' capacity to be self-aware when assessing and formulating long-term post-stroke distress and have potential implications for improving long-term emotional status in those most cognitively impaired post-stroke, e.g., through psychoeducation, cognitive rehabilitation, and emotional support.

The Oxford Cognitive Screen for use with Australian people after stroke (OCS-AU): The adaptation process and determining cut scores for cognitive impairment using a cross-sectional normative study.

INTRODUCTION: Two parallel versions (A and B) of the Oxford Cognitive Screen (OCS) were developed in the United Kingdom (UK) as a stroke-specific screen of five key cognitive domains commonly affected post-stroke. We aimed to develop the Australian versions A and B (OCS-AU), including Australian cut-scores indicative of impairment. We hypothesised there to be no difference in performance between the UK and Australian normative data cohorts. METHODS: Our multidisciplinary expert panel used the UK pre-defined process to develop the OCS-AU versions A and B. We then conducted a cross-sectional normative study. We purposively recruited community-dwelling, Australian-born, and educated adults; with no known cognitive impairment; representative of age, sex, education level, and living location; at seven sites (four metropolitan, three regional) across four Australian states. Participants completed one or both OCS-AU versions in a randomised order. Australian cohorts were compared with the corresponding UK cohorts for demographics using Pearson's chi-squared test for sex and education, and Welch two-sample t test for age. For the cut-scores indicating cognitive impairment, the fifth (95th) percentiles and group mean performance score for each scored item were compared using Welch two-sample t tests. The pre-defined criteria for retaining OCS cut-scores had no statistically significant difference in either percentile or group mean scores for each scored item. RESULTS: Participants (n = 83) were recruited: fifty-eight completed version A [age (years) mean = 61,SD = 15; 62% female], 60 completed version B [age (years) mean = 62,SD = 13, 53% female], and 35 completed both [age (years) mean = 64,SD = 11, 54% female]. Education was different between the cohorts for version B (12 years, p = 0.002). Cut-scores for all 16 scored items for the OCS-AU version B and 15/16 for version A met our pre-defined criteria for retaining the OCS cut scores. CONCLUSIONS: The OCS-AU provides clinicians with an Australian-specific, first-line cognitive screening tool for people after stroke. Early screening can guide treatment and management.

Rapid screening for neglect following stroke: A systematic search and European Academy of Neurology recommendations.

BACKGROUND AND PURPOSE: Unilateral neglect is a common cognitive disorder following stroke. Neglect has a significant impact on functional outcomes, so it is important to detect. However, there is no consensus on which are the best screening tests to administer to detect neglect in time-limited clinical environments. METHODS: Members of the European Academy of Neurology Scientific Panel on Higher Cortical Functions, neuropsychologists, occupational therapists, and researchers produced recommendations for primary and secondary tests for bedside neglect testing based on a rigorous literature review, data extraction, online consensus meeting, and subsequent iterations. RESULTS: A total of 512 articles were screened, and 42 were included. These reported data from 3367 stroke survivors assessed using 62 neglect screens. Tests were grouped into cancellation, line bisection, copying, reading/writing, and behavioral. Cancellation tasks were most frequently used (97.6% of studies), followed by bisection, copying, behavioral, and reading/writing assessments. The panel recommended a cancellation test as the primary screening test if there is time to administer only one test. One of several cancellation tests might be used, depending on availability. If time permits, one or more of line bisection, figure copying, and baking tray task were recommended as secondary tests. Finally, if a functional and ecological test is feasible, the Catherine Bergego Scale was recommended. Overall, the literature suggests that no single test on its own is sufficient to exclude a diagnosis of neglect. Therefore, the panel recommended that multiple neglect tests should be used whenever possible. CONCLUSIONS: This study provides consensus recommendations for rapid bedside detection of neglect in real-world, clinical environments.

The European Portuguese version of the Oxford Cognitive Screening (OCS-Pt): a screening test for acute stroke patients.

In Portugal, there is no gold standard test to assess acute stroke patients in the hospital context. However, cognitive deficits are common after a stroke episode and are followed by a negative impact on a patient's quality of life and rehabilitation. Here, we first aimed to adapt the Oxford Cognitive Screening to European Portuguese speakers (OCS-Pt), develop normative data cut-offs, and report the psychometric properties of the OCS-Pt. The second aim was to test the incidence of impairments in acute stroke patients. We tested 137 healthy participants aged between 25 and 92 years old, and we report normative cut-offs based on the 5th and 95th percentile, and on the patterns for age and education level. Our results are similar to other European OCS versions, and results using convergent and divergent validity show satisfactory values ranged between moderate to high. Additionally, 146 acute stroke patients, in the first week after the stroke episode, performed the OCS-Pt. Results show that this is an inclusive test and allows to discriminate between impaired and preserved functions. In conclusion, OCS-Pt is a promising cognitive screening tool to assess acute stroke survivors to be used in stroke care in Portugal.

The Dutch Oxford Cognitive Screen (OCS-NL): psychometric properties in Flemish stroke survivors.

BACKGROUND AND PURPOSE: The Oxford Cognitive Screen is a stroke-specific screen to evaluate attention, executive functions, memory, praxis, language, and numeric cognition. It was originally validated in England for acute stroke patients. In this study, we examined the psychometric properties of the Dutch OCS (OCS-NL). METHODS: A total of 193 (99 acute stroke unit, 94 rehabilitation unit) patients were included in our study. A subset of patients (n = 128) completed a retest with the parallel version of the OCS-NL. RESULTS: First, we did not find evidence for a difference in prevalence of impairment between patients in the acute stroke versus rehabilitation unit on all but one of the subtests. For praxis, we observed a 14% lower prevalence of impairment in the rehabilitation than the acute stroke unit. Second, the parallel-form reliability ranged from weak to excellent across subtests. Third, in stroke patients below age 60, the OCS-NL had a 92% sensitivity relative to the MoCA, while the MoCA had a 55% sensitivity relative to the OCS-NL. Last, although left-hemispheric stroke patients performed worse on almost all MoCA subdomains, they performed similarly to right-hemispheric stroke patients on non-language domains on the OCS-NL. CONCLUSIONS: Our results suggest that the OCS-NL is a reliable cognitive screen that can be used in acute stroke and rehabilitation units. The OCS-NL may be more sensitive to detect cognitive impairment in young stroke patients and less likely to underestimate cognitive abilities in left-hemispheric stroke patients than the MoCA.

Aligning formal and functional assessments of Visuospatial Neglect: A mixed-methods study.

ABSTRACTThe occurrence of visuospatial neglect acts as a key predictor of recovery outcome following stroke. However, the specific behavioural profiles associated with various neglect subtypes are not well understood. This study aims to identify real-world functional impairments associated with neglect, to determine whether functional impairment profiles differ across patients with egocentric and allocentric neglect, and to investigate how neglect severity predicts functional impairments.Notes from 290 stroke patients' occupational therapy functional assessments were qualitatively and quantitatively analysed in the context of neglect type and severity as reported by the OCS Cancellation Task. Overall, neglect patients had more references to having difficulty initiating tasks, finding items, exhibiting spatial inattention, and having difficulty using both arms than patients without neglect. The proportion of theme references did not differ significantly across patients with egocentric and allocentric neglect. The quantitative severity of egocentric neglect was acted as a significant predictor of reference occurrence over and above stroke severity within difficulty finding items, spatial inattention, body inattention, and upper limb use.This study expands on previous findings by identifying real-world functional impairments differentiating patients with and without neglect. This data provides novel insight into the impact of neglect on functional abilities.

The Oxford digital multiple errands test (OxMET): Validation of a simplified computer tablet based multiple errands test.

Impairments in executive functioning are common following Acquired Brain Injury, though there are few screening tools which present a time efficient and ecologically valid approach to assessing the consequences of executive impairments. We present the Oxford Digital Multiple Errands Test (OxMET), a novel and simplified computer-tablet version of a Multiple Errands Test. We recruited 124 neurologically healthy controls and 105 stroke survivors to complete the OxMET task. Normative data and internal consistency were established from the healthy control data. Convergent and divergent validation was assessed in a mixed subset of 158 participants who completed the OxMET and OCS-Plus. Test-retest reliability was examined across a mixed subset of 39 participants. Finally, we investigated the known-group discriminability of the OxMET. The OxMET demonstrated very high internal consistency, and stable group level test-retest performance as well as good convergent and divergent validity. The OxMET demonstrated high sensitivity and good specificity in overall differentiation of stroke survivors from controls. The Oxford Digital Multiple Errands Test is a brief, easy to administer tool, designed to quickly screen for potential consequences of executive impairments in a virtual environment shopping task on a computer tablet. Initial normative data and validation within a chronic stroke cohort is presented.

The relationship between executive function, risky behaviour and HIV in young women from the HPTN 068 study in rural South Africa.

Executive function (EF) may predict sexual risk-taking and HIV risk in young women in rural South Africa. We tested associations between EF and seven risky behavioural outcomes: binge drinking, illicit substance use, unprotected vaginal sex, concurrent sexual relationships, transactional sex, herpes simplex virus type 2 (HSV-2) infection, and HIV infection. We compared EF in young women with HIV to matched controls. 1080 young women underwent cognitive assessments. Better verbal short-term memory was associated with a lower risk of HSV-2 (OR 0.77; 95% CI 0.69, 0.86; p < 0.001). Uncorrected trends (p < 0.05) were better verbal working memory being associated with a lower risk of concurrency, better planning with a lower risk of illicit drug use, and better affective inhibition with a lower risk of transactional sex. 78 participants with sexually acquired HIV were matched with 153 HIV-negative controls and had poorer verbal working memory than controls (Hedge's g = -0.38; 95% CI -0.66, -0.10; p = 0.0076), but this was non-significant after adjustment. EF's contribution to young women's risky behaviour in this context does not hold when stringent statistical corrections are applied, with only verbal short term memory reaching statistical significance as predictor. Replication in other samples is recommended.

Validation of Oxford Cognitive Screen: Executive Function (OCS-EF), a tablet-based executive function assessment tool amongst adolescent females in rural South Africa.

Short, reliable, easily administered executive function (EF) assessment tools are needed to measure EF in low- and middle-income countries, particularly in sub-Saharan Africa given the prevalence of human immunodeficiency virus (HIV)-associated neurocognitive disorder. We administered Oxford Cognitive Screen-Executive Function (OCS-EF) to 932 rural South African females (mean age 19.7 years). OCS-EF includes seven tasks: two hot inhibition tasks (a modified Iowa Gambling Task, emotional go/no-go) and five cool EF tasks, two switching tasks (visuospatial rule-finding, geometric trails) and three working memory tasks (digit recall, selection and figure drawing). We performed confirmatory factor analysis testing whether a three-factor, two-factor hot-cool, two-factor working memory and inhibition/switching, or one-factor EF model fitted the data better. The three-factor (switching, inhibition and working memory) model had the best local and global fit (χ2 (11) 24.21, p = 0.012; RMSEA 0.036; CFI 0.920; CD 0.617). We demonstrated the feasibility of OCS-EF administration by trained laypeople, the tripartite structure of EF amongst adolescent females and the factorial validity of OCS-EF in this population and context. OCS-EF tablet-based cognitive assessment tool can be administered by trained laypeople and is a valid tool for assessing cognition at scale amongst adolescents in rural South Africa and similar environments.

Non-Spatial Impairments Affect False-Positive Neglect Diagnosis Based on Cancellation Tasks.

OBJECTIVE: To diagnose egocentric neglect after stroke, the spatial bias of performance on cancellation tasks is typically compared to a single cutoff. This standard procedure relies on the assumption that the measurement error of cancellation performance does not depend on non-spatial impairments affecting the total number of cancelled targets. Here we assessed the impact of this assumption on false-positive diagnoses. METHOD: We estimated false positives by simulating cancellation data using a binomial model. Performance was summarised by the difference in left and right cancelled targets (R-L) and the Centre of Cancellation (CoC). Diagnosis was based on a fixed cutoff versus cutoffs adjusted for the total number of cancelled targets and on single test performance versus unanimous or proportional agreement across multiple tests. Finally, we compared the simulation findings to empirical cancellation data acquired from 651 stroke patients. RESULTS: Using a fixed cutoff, the rate of false positives depended on the total number of cancelled targets and ranged from 10% to 30% for R-L scores and from 10% to 90% for CoC scores. The rate of false positives increased even further when diagnosis was based on proportional agreement across multiple tests. Adjusted cutoffs and unanimous agreement across multiple tests were effective at controlling false positives. For empirical data, fixed versus adjusted cutoffs differ in estimation of neglect prevalence by 13%, and this difference was largest for patients with non-spatial impairments. CONCLUSIONS: Our findings demonstrate the importance of considering non-spatial impairments when diagnosing neglect based on cancellation performance.

The relationship between early post-stroke cognition and longer term activities and participation: A systematic review.

This systematic review examined whether early cognitive impairment after stroke is predictive of outcome within the "activity" and "participation" domains of the International Classification of Functioning, Disability and Health (ICF) at 6-12 months post-injury. Studies were included if cognitive functioning was assessed within 6 weeks of injury and outcome was measured at least 6 months post-injury. PsycINFO, MEDLINE, CINAHL and EMBASE databases were searched and 14 studies were identified. Studies were categorised according to whether "domain-general" or "domain-specific" cognitive assessment was undertaken and whether outcomes measured the ICF activities or participation domains, as determined by three independent raters using previous established linking rules. Quality of studies was assessed using a modified version of Downs and Black's Quality Index. Overall, early cognitive impairment predicted activities and participation 6-12 months post-stroke. This relationship was more consistent when domain-specific cognitive assessment was used. For the domain of activities, visuospatial perception/construction, visual memory, visual neglect, and attention/executive functioning predicted functioning 6-12 months post-stroke. Early domain-specific cognitive assessment may be clinically informative of longer term activities. For the domain of participation, further well-controlled studies are needed to determine the relationship with early post-stroke cognitive impairments.

Manipulating perceptual parameters in a continuous performance task.

Sustained attention (SA) is among the most studied faculties of human cognition, and thought to be crucial for many aspects of behavior. Measuring SA often relies on performance on a continuous, low-demanding task. Such continuous performance tasks (CPTs) have many variations, and sustained attention is typically estimated based on variability in reaction times. While relying on reaction times may be useful in some cases, it can pose a challenge when working with clinical populations. To increase interpersonal variability in task parameters that do not rely on speed, researchers have increased demands for memory and response inhibition. These approaches, however, may be confounded when used to assess populations that suffer from multiple cognitive deficits. In the current study, we propose a new approach for increasing task variability by increasing the attentional demands. In order to do so, we created a new variation of a CPT - a masked version, where inattention is more likely to cause misidentifying a target. After establishing that masking indeed decreases target detection, we further investigated which task parameter may influence response biases. To do so, we contrasted two versions of the CPT with different target/distractor ratio. We then established how perceptual parameters can be controlled independently in a CPT. Following the experimental manipulations, we tested the MCCPT with aging controls and chronic stroke patients to assure the task can be used with target populations. The results confirm the MCCPT as a task providing high sensitivity without relying on reaction speed, and feasible for patients.