1. |
- Jönsson, Ann-Cathrin, et al.
(author)
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Falls After Stroke : A Follow-up after Ten Years in Lund Stroke Register
- 2021
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In: Journal of Stroke & Cerebrovascular Diseases. - : Elsevier BV. - 1532-8511 .- 1052-3057. ; 30:6
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Journal article (peer-reviewed)abstract
- OBJECTIVES: To evaluate incidence of self-reported falls and associated factors in a ten-year perspective after stroke.METHODS: From a population-based cohort of first-ever stroke patients (n = 416) included in the Lund Stroke Register between March 1, 2001, and February 28, 2002, we performed a follow up of all 145 survivors ten years after stroke. We collected data on age, gender, main stroke type, living and housing situation, general health status (question 1 in the Short Form Health Survey (SF-36), dizziness, physical activity, Barthel Index, mobility aids, moving ability inside/outside, and health-related quality of life as defined by the EuroQol 3 dimension scale (EQ-5D-3L). Factors that may relate to falls were compared between those who had experienced falls after stroke or not.RESULTS: Ten years after stroke, 49 patients (34 %) reported falls and 96 patients (66 %) reported no falls. Compared to patients with no falls, those who reported falls were older (median age 83.3 years vs 75.6 years; p < 0.001), more often lived alone, were more dependent in daily living, had less physical activity, poorer general health status, more often needed mobility aids, were more often unable to move alone outside, and had poorer health-related quality of life in all items in EQ-5D-3L except pain/discomfort.CONCLUSIONS: Falls had occurred in approximately one third of the participants ten years after the stroke, and were strongly associated with several measures of frailty. Our results indicate that fall prevention should in particular focus on those at high risk of falls.
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2. |
- Veltkamp, R., et al.
(author)
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Characteristics of Recurrent Ischemic Stroke after Embolic Stroke of Undetermined Source: Secondary Analysis of a Randomized Clinical Trial
- 2020
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In: JAMA Neurology. - : American Medical Association (AMA). - 2168-6149. ; 77:10, s. 1233-1240
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Journal article (peer-reviewed)abstract
- Importance: The concept of embolic stroke of undetermined source (ESUS) unifies a subgroup of cryptogenic strokes based on neuroimaging, a defined minimum set of diagnostic tests, and exclusion of certain causes. Despite an annual stroke recurrence rate of 5%, little is known about the etiology underlying recurrent stroke after ESUS. Objective: To identify the stroke subtype of recurrent ischemic strokes after ESUS, to explore the interaction with treatment assignment in each category, and to examine the consistency of cerebral location of qualifying ESUS and recurrent ischemic stroke. Design, Setting, and Participants: The NAVIGATE-ESUS trial was a randomized clinical trial conducted from December 23, 2014, to October 5, 2017. The trial compared the efficacy and safety of rivaroxaban and aspirin in patients with recent ESUS (n = 7213). Ischemic stroke was validated in 309 of the 7213 patients by adjudicators blinded to treatment assignment and classified by local investigators into the categories ESUS or non-ESUS (ie, cardioembolic, atherosclerotic, lacunar, other determined cause, or insufficient testing). Five patients with recurrent strokes that could not be defined as ischemic or hemorrhagic in absence of neuroimaging or autopsy were excluded. Data for this secondary post hoc analysis were analyzed from March to June 2019. Interventions: Patients were randomly assigned to receive rivaroxaban, 15 mg/d, or aspirin, 100 mg/d. Main Outcomes and Measures: Association of recurrent ESUS with stroke characteristics. Results: A total of 309 patients (205 men [66%]; mean [SD] age, 68 [10] years) had ischemic stroke identified during the median follow-up of 11 (interquartile range [IQR], 12) months (annualized rate, 4.6%). Diagnostic testing was insufficient for etiological classification in 39 patients (13%). Of 270 classifiable ischemic strokes, 156 (58%) were ESUS and 114 (42%) were non-ESUS (37 [32%] cardioembolic, 26 [23%] atherosclerotic, 35 [31%] lacunar, and 16 [14%] other determined cause). Atrial fibrillation was found in 27 patients (9%) with recurrent ischemic stroke and was associated with higher morbidity (median change in modified Rankin scale score 2 [IQR, 3] vs 0 (IQR, 1]) and mortality (15% vs 1%) than other causes. Risk of recurrence did not differ significantly by subtype between treatment groups. For both the qualifying and recurrent strokes, location of infarct was more often in the left (46% and 54%, respectively) than right hemisphere (40% and 37%, respectively) or brainstem or cerebellum (14% and 9%, respectively). Conclusions and Relevance: In this secondary analysis of randomized clinical trial data, most recurrent strokes after ESUS were embolic and of undetermined source. Recurrences associated with atrial fibrillation were a minority but were more often disabling and fatal. More extensive investigation to identify the embolic source is important toward an effective antithrombotic strategy. Trial Registration: ClinicalTrials.gov Identifier: NCT02313909.. © 2020 American Medical Association. All rights reserved.
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3. |
- Aked, Joseph, et al.
(author)
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Completeness of case ascertainment in Swedish hospital-based stroke registers
- 2020
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In: Acta Neurologica Scandinavica. - : Hindawi Limited. - 0001-6314 .- 1600-0404. ; 141:2, s. 148-155
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Journal article (peer-reviewed)abstract
- Background: There is a worldwide development toward using data from hospital-based stroke registers to estimate epidemiological trends. However, incomplete case ascertainment may cause selection bias. We examined the completeness of case ascertainment and selection bias in two hospital-based Swedish stroke registers. Methods: First-ever stroke cases between March 2015 and February 2016 in the catchment area of Skåne University Hospital, Lund, Sweden, were included from multiple overlapping sources: two hospital-based stroke registers, Riksstroke-Lund and Lund Stroke Register (LSR); local outpatient and inpatient registers; primary care registers; and autopsy registers. The resulting population-based cohort was used as reference to assess completeness of case ascertainment and patient characteristics in Riksstroke-Lund and LSR. Results: In total, 400 stroke patients were identified. Riksstroke-Lund detected 328 (82%) patients, whereas LSR detected 363 (91%). Patients undetected by hospital-based registers had higher 28-day case fatality than those detected (44% vs 9%; P =.001). Patients only detected in primary care (n = 11) more often lived in healthcare facilities compared with those detected by hospital-based registers (57% vs 7%; P =.001). Patients not detected by Riksstroke-Lund, but detected by population-based sources, had less severe strokes (median NIHSS 3 vs 5; P =.013). Conclusions: Some first-ever stroke patients, such as those with high early case fatality and those with mild stroke, may go undetected with hospital-based screening used in clinical stroke registers. This can result in selection bias due to not identifying specific groups of patients including some with high early case fatality and those living in healthcare facilities.
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4. |
- Aked, Joseph, et al.
(author)
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Survival, causes of death and recurrence up to 3 years after stroke : A population-based study
- 2021
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In: European Journal of Neurology. - : Wiley. - 1351-5101 .- 1468-1331. ; 28:12, s. 4060-4068
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Journal article (peer-reviewed)abstract
- Background and purpose: Up-to-date population-based information about long-term survival, causes of death and recurrence after stroke is needed. Methods: Four hundred consecutive individuals in a population-based cohort of first-ever stroke between 2015 and 2016 in Lund, Sweden, were followed up to 3 years regarding (i) survival (Swedish Population Register); (ii) causes of death (Swedish Causes of Death Register); and (iii) stroke recurrence (interview and medical chart review). Index and recurrent ischaemic stroke cases were classified using the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) and Oxfordshire Community Stroke Project; and comorbidities were classified using the Charlson Comorbidity Index. Cox regression was used to determine predictors for 3-year mortality. Survival rates were compared with three local studies over a 30-year timespan. Results: Amongst 400 first-ever stroke patients, 265 (66%) survived 3 years post-stroke. Age (hazard ratio [HR] 1.09; 95% confidence interval [CI] 1.06–1.11), stroke severity (HR 1.11; 95% CI 1.08–1.13) and comorbidities (HR 1.36; 95% CI 1.22–1.53) were independently related to 3-year mortality. Amongst index ischaemic stroke patients, survival was lowest amongst those with cardio-aortic embolism (51/91; 56%). Cerebrovascular disease (54/135; 40%) and ischaemic heart disease (25/135; 19%) were the most common causes of death. Within 3 years, 30 (8%) had recurrent stroke. Amongst patients with index ischaemic stroke, 16/29 (55%) had a different TOAST pathogenetic mechanism or hemorrhagic stroke upon recurrence. Stroke survival improved between 1983–1985 and 2015–2016 (p = 0.002), but no significant change was observed between 2001–2002 and 2015–2016 (p = 0.48). Conclusions: Stroke survival rates are relatively high, but their improvement over recent decades may be slowing down, possibly due to the composition of the first-ever stroke population. The common occurrence of changed pathogenetic mechanisms between first-ever and recurrent stroke highlights the value of reassessment in recurrent stroke.
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5. |
- Aldridge, Chad M., et al.
(author)
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Genome-Wide Association Studies of 3 Distinct Recovery Phenotypes in Mild Ischemic Stroke
- 2024
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In: Neurology. - 1526-632X. ; 102:3
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Journal article (peer-reviewed)abstract
- BACKGROUND AND OBJECTIVES: Stroke genetic research has made substantial progress in the past decade. Its recovery application, however, remains behind, in part due to its reliance on the modified Rankin Scale (mRS) score as a measure of poststroke outcome. The mRS does not map well to biological processes because numerous psychosocial factors drive much of what the mRS captures. Second, the mRS contains multiple disparate biological events into a single measure further limiting its use for biological discovery. This led us to investigate the effect of distinct stroke recovery phenotypes on genetic variation associations with Genome-Wide Association Studies (GWASs) by repurposing the NIH Stroke Scale (NIHSS) and its subscores. METHODS: In the Vitamin Intervention for Stroke Prevention cohort, we estimated changes in cognition, motor, and global impairments over 2 years using specific measures. We included genotyped participants with a total NIHSS score greater than zero at randomization and excluded those with recurrent stroke during the trial. A GWAS linear mixed-effects model predicted score changes, with participant as a random effect, and included initial score, age, sex, treatment group, and the first 5 ancestry principal components. RESULTS: In total, 1,270 participants (64% male) were included with a median NIHSS score of 2 (interquartile range [IQR] 1-3) and median age 68 (IQR 59-75) years. At randomization, 20% had cognitive deficits (NIHSS Cog-4 score >0) and 70% had ≥1 motor deficits (impairment score >1). At 2 years, these percentages improved to 7.2% with cognitive deficits and 30% with motor deficits. GWAS identified novel suggestive gene-impairment associations (p < 5e-6) for cognition (CAMK2D, EVX2, LINC0143, PTPRM, SGMS1, and SMAD2), motor (ACBD6, KDM4B, MARK4, PTPRS, ROBO1, and ROBO2), and global (MSR1 and ROBO2) impairments. DISCUSSION: Defining domain-specific stroke recovery phenotypes and using longitudinal clinical trial designs can help detect novel genes associated with chronic recovery. These data support the use of granular endpoints to identify genetic associations related to stroke recovery.
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6. |
- Bonkhoff, A.K., et al.
(author)
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Association of Stroke Lesion Pattern and White Matter Hyperintensity Burden With Stroke Severity and Outcome
- 2022
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In: Neurology. - 0028-3878. ; 99:13, s. 1364-1379
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Journal article (peer-reviewed)abstract
- Background and ObjectivesTo examine whether high white matter hyperintensity (WMH) burden is associated with greater stroke severity and worse functional outcomes in lesion pattern-specific ways.MethodsMR neuroimaging and NIH Stroke Scale data at index stroke and the modified Rankin Scale (mRS) score at 3-6 months after stroke were obtained from the MRI-Genetics Interface Exploration study of patients with acute ischemic stroke (AIS). Individual WMH volume was automatically derived from fluid-attenuated inversion recovery images. Stroke lesions were automatically segmented from diffusion-weighted imaging (DWI) images, parcellated into atlas-defined brain regions and further condensed to 10 lesion patterns via machine learning-based dimensionality reduction. Stroke lesion effects on AIS severity and unfavorable outcomes (mRS score >2) were modeled within purpose-built Bayesian linear and logistic regression frameworks. Interaction effects between stroke lesions and a high vs low WMH burden were integrated via hierarchical model structures. Models were adjusted for age, age2, sex, total DWI lesion and WMH volumes, and comorbidities. Data were split into derivation and validation cohorts.ResultsA total of 928 patients with AIS contributed to acute stroke severity analyses (age: 64.8 [14.5] years, 40% women) and 698 patients to long-term functional outcome analyses (age: 65.9 [14.7] years, 41% women). Stroke severity was mainly explained by lesions focused on bilateral subcortical and left hemispherically pronounced cortical regions across patients with both a high and low WMH burden. Lesions centered on left-hemispheric insular, opercular, and inferior frontal regions and lesions affecting right-hemispheric temporoparietal regions had more pronounced effects on stroke severity in case of high compared with low WMH burden. Unfavorable outcomes were predominantly explained by lesions in bilateral subcortical regions. In difference to the lesion location-specific WMH effects on stroke severity, higher WMH burden increased the odds of unfavorable outcomes independent of lesion location.DiscussionHigher WMH burden may be associated with an increased stroke severity in case of stroke lesions involving left-hemispheric insular, opercular, and inferior frontal regions (potentially linked to language functions) and right-hemispheric temporoparietal regions (potentially linked to attention). Our findings suggest that patients with specific constellations of WMH burden and lesion locations may have greater benefits from acute recanalization treatments. Future clinical studies are warranted to systematically assess this assumption and guide more tailored treatment decisions. © American Academy of Neurology.
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7. |
- Bonkhoff, A. K., et al.
(author)
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Outcome after acute ischemic stroke is linked to sex-specific lesion patterns
- 2021
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12:1
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Journal article (peer-reviewed)abstract
- Acute ischemic stroke affects men and women differently. In particular, women are often reported to experience higher acute stroke severity than men. We derived a low-dimensional representation of anatomical stroke lesions and designed a Bayesian hierarchical modeling framework tailored to estimate possible sex differences in lesion patterns linked to acute stroke severity (National Institute of Health Stroke Scale). This framework was developed in 555 patients (38% female). Findings were validated in an independent cohort (n=503, 41% female). Here, we show brain lesions in regions subserving motor and language functions help explain stroke severity in both men and women, however more widespread lesion patterns are relevant in female patients. Higher stroke severity in women, but not men, is associated with left hemisphere lesions in the vicinity of the posterior circulation. Our results suggest there are sex-specific functional cerebral asymmetries that may be important for future investigations of sex-stratified approaches to management of acute ischemic stroke.
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8. |
- Bonkhoff, A. K., et al.
(author)
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Sex-specific lesion pattern of functional outcomes after stroke
- 2022
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In: Brain Communications. - : Oxford University Press (OUP). - 2632-1297. ; 4:2
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Journal article (peer-reviewed)abstract
- Relying on neuroimaging and clinical data of 822 acute stroke patients, Bonkhoff et al. report substantially more detrimental effects of lesions in left-hemispheric posterior circulation regions on functional outcomes in women compared to men. These findings may motivate a sex-specific clinical stroke management to improve outcomes in the longer term. Stroke represents a considerable burden of disease for both men and women. However, a growing body of literature suggests clinically relevant sex differences in the underlying causes, presentations and outcomes of acute ischaemic stroke. In a recent study, we reported sex divergences in lesion topographies: specific to women, acute stroke severity was linked to lesions in the left-hemispheric posterior circulation. We here determined whether these sex-specific brain manifestations also affect long-term outcomes. We relied on 822 acute ischaemic patients [age: 64.7 (15.0) years, 39% women] originating from the multi-centre MRI-GENIE study to model unfavourable outcomes (modified Rankin Scale >2) based on acute neuroimaging data in a Bayesian hierarchical framework. Lesions encompassing bilateral subcortical nuclei and left-lateralized regions in proximity to the insula explained outcomes across men and women (area under the curve = 0.81). A pattern of left-hemispheric posterior circulation brain regions, combining left hippocampus, precuneus, fusiform and lingual gyrus, occipital pole and latero-occipital cortex, showed a substantially higher relevance in explaining functional outcomes in women compared to men [mean difference of Bayesian posterior distributions (men - women) = -0.295 (90% highest posterior density interval = -0.556 to -0.068)]. Once validated in prospective studies, our findings may motivate a sex-specific approach to clinical stroke management and hold the promise of enhancing outcomes on a population level.
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9. |
- Bonkhoff, Anna K, et al.
(author)
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The relevance of rich club regions for functional outcome post-stroke is enhanced in women.
- 2023
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In: Human brain mapping. - : Wiley. - 1097-0193 .- 1065-9471. ; 44:4, s. 1579-1592
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Journal article (peer-reviewed)abstract
- This study aimed to investigate the influence of stroke lesions in predefined highly interconnected (rich-club) brain regions on functional outcome post-stroke, determine their spatial specificity and explore the effects of biological sex on their relevance. We analyzed MRI data recorded at index stroke and ~3-months modified Rankin Scale (mRS) data from patients with acute ischemic stroke enrolled in the multisite MRI-GENIE study. Spatially normalized structural stroke lesions were parcellated into 108 atlas-defined bilateral (sub)cortical brain regions. Unfavorable outcome (mRS>2) was modeled in a Bayesian logistic regression framework. Effects of individual brain regions were captured as two compound effects for (i) six bilateral rich club and (ii) all further non-rich club regions. In spatial specificity analyses, we randomized the split into "rich club" and "non-rich club" regions and compared the effect of the actual rich club regions to the distribution of effects from 1000 combinations of six random regions. In sex-specific analyses, we introduced an additional hierarchical level in our model structure to compare male and female-specific rich club effects. A total of 822 patients (age: 64.7[15.0], 39% women) were analyzed. Rich club regions had substantial relevance in explaining unfavorable functional outcome (mean of posterior distribution: 0.08, area under the curve: 0.8). In particular, the rich club-combination had a higher relevance than 98.4% of random constellations. Rich club regions were substantially more important in explaining long-term outcome in women than in men. All in all, lesions in rich club regions were associated with increased odds of unfavorable outcome. These effects were spatially specific and more pronounced in women.
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10. |
- Bourached, Anthony, et al.
(author)
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Scaling behaviours of deep learning and linear algorithms for the prediction of stroke severity
- 2023
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In: BRAIN COMMUNICATIONS. - 2632-1297. ; 6:1
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Journal article (peer-reviewed)abstract
- Deep learning has allowed for remarkable progress in many medical scenarios. Deep learning prediction models often require 105-107 examples. It is currently unknown whether deep learning can also enhance predictions of symptoms post-stroke in real-world samples of stroke patients that are often several magnitudes smaller. Such stroke outcome predictions however could be particularly instrumental in guiding acute clinical and rehabilitation care decisions. We here compared the capacities of classically used linear and novel deep learning algorithms in their prediction of stroke severity. Our analyses relied on a total of 1430 patients assembled from the MRI-Genetics Interface Exploration collaboration and a Massachusetts General Hospital-based study. The outcome of interest was National Institutes of Health Stroke Scale-based stroke severity in the acute phase after ischaemic stroke onset, which we predict by means of MRI-derived lesion location. We automatically derived lesion segmentations from diffusion-weighted clinical MRI scans, performed spatial normalization and included a principal component analysis step, retaining 95% of the variance of the original data. We then repeatedly separated a train, validation and test set to investigate the effects of sample size; we subsampled the train set to 100, 300 and 900 and trained the algorithms to predict the stroke severity score for each sample size with regularized linear regression and an eight-layered neural network. We selected hyperparameters on the validation set. We evaluated model performance based on the explained variance (R2) in the test set. While linear regression performed significantly better for a sample size of 100 patients, deep learning started to significantly outperform linear regression when trained on 900 patients. Average prediction performance improved by similar to 20% when increasing the sample size 9x [maximum for 100 patients: 0.279 +/- 0.005 (R2, 95% confidence interval), 900 patients: 0.337 +/- 0.006]. In summary, for sample sizes of 900 patients, deep learning showed a higher prediction performance than typically employed linear methods. These findings suggest the existence of non-linear relationships between lesion location and stroke severity that can be utilized for an improved prediction performance for larger sample sizes. Bourached et al. contrast linear and deep learning-based algorithms in their prediction performances of stroke severity depending on the training set sample sizes. They find that linear regression outperforms deep learning-based algorithms for smaller training samples comprising lesion location information of 100 patients, while deep learning excels in the case of larger samples (N = 900).
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