| 11. |
- Bourached, Anthony, et al.
(författare)
-
Scaling behaviours of deep learning and linear algorithms for the prediction of stroke severity
- 2023
-
Ingår i: BRAIN COMMUNICATIONS. - 2632-1297. ; 6:1
-
Tidskriftsartikel (refereegranskat)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).
|
|
| 12. |
- Dorvall, Malin, 1991, et al.
(författare)
-
Mosaic Loss of Chromosome Y Is Associated With Functional Outcome After Ischemic Stroke.
- 2023
-
Ingår i: Stroke. - : Wolters Kluwer. - 1524-4628 .- 0039-2499. ; 54:9, s. 2434-2437
-
Tidskriftsartikel (refereegranskat)abstract
- Mosaic loss of chromosome Y (LOY) is associated with cardiovascular and neurodegenerative diseases in men, and genetic predisposition to LOY is associated with poor poststroke outcome. We, therefore, tested the hypothesis that LOY itself is associated with functional outcome after ischemic stroke.The study comprised male patients with ischemic stroke from the cohort studies SAHLSIS2 (Sahlgrenska Academy Study on Ischemic Stroke Phase 2; n=588) and LSR (Lund Stroke Register; n=735). We used binary logistic regression to analyze associations between LOY, determined by DNA microarray intensity data, and poor 3-month functional outcome (modified Rankin Scale score, >2) in each cohort separately and combined. Patients who received recanalization therapy were excluded from sensitivity analyses.LOY was associated with about 2.5-fold increased risk of poor outcome in univariable analyses (P<0.001). This association withstood separate adjustment for stroke severity and diabetes in both cohorts but not age. In sensitivity analyses restricted to the nonrecanalization group (n=987 in the combined cohort), the association was significant also after separate adjustment for age (odds ratio, 1.6 [95% CI, 1.1-2.4]) and when additionally adjusting for stroke severity and diabetes (odds ratio, 1.6 [95% CI, 1.1-2.5]).We observed an association between LOY and poor outcome after ischemic stroke in patients not receiving recanalization therapy. Future studies on LOY and other somatic genetic alterations in larger stroke cohorts are warranted.
|
|
| 13. |
- Falcone, Guido J., et al.
(författare)
-
Genetically Elevated LDL Associates with Lower Risk of Intracerebral Hemorrhage
- 2020
-
Ingår i: Annals of Neurology. - : Wiley. - 0364-5134 .- 1531-8249. ; 88:1, s. 56-66
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: Observational studies point to an inverse correlation between low-density lipoprotein (LDL) cholesterol levels and risk of intracerebral hemorrhage (ICH), but it remains unclear whether this association is causal. We tested the hypothesis that genetically elevated LDL is associated with reduced risk of ICH. Methods: We constructed one polygenic risk score (PRS) per lipid trait (total cholesterol, LDL, high-density lipoprotein [HDL], and triglycerides) using independent genomewide significant single nucleotide polymorphisms (SNPs) for each trait. We used data from 316,428 individuals enrolled in the UK Biobank to estimate the effect of each PRS on its corresponding trait, and data from 1,286 ICH cases and 1,261 matched controls to estimate the effect of each PRS on ICH risk. We used these estimates to conduct Mendelian Randomization (MR) analyses. Results: We identified 410, 339, 393, and 317 lipid-related SNPs for total cholesterol, LDL, HDL, and triglycerides, respectively. All four PRSs were strongly associated with their corresponding trait (all p < 1.00 × 10-100). While one SD increase in the PRSs for total cholesterol (odds ratio [OR] = 0.92; 95% confidence interval [CI] = 0.85–0.99; p = 0.03) and LDL cholesterol (OR = 0.88; 95% CI = 0.81–0.95; p = 0.002) were inversely associated with ICH risk, no significant associations were found for HDL and triglycerides (both p > 0.05). MR analyses indicated that 1mmol/L (38.67mg/dL) increase of genetically instrumented total and LDL cholesterol were associated with 23% (OR = 0.77; 95% CI = 0.65–0.98; p = 0.03) and 41% lower risks of ICH (OR = 0.59; 95% CI = 0.42–0.82; p = 0.002), respectively. Interpretation: Genetically elevated LDL levels were associated with lower risk of ICH, providing support for a potential causal role of LDL cholesterol in ICH. ANN NEUROL 2020.
|
|
| 14. |
- Gaceb, Abderahim, et al.
(författare)
-
Pericyte Microvesicles as Plasma Biomarkers Reflecting Brain Microvascular Signaling in Patients with Acute Ischemic Stroke
- 2024
-
Ingår i: Stroke. - 0039-2499. ; 55:3, s. 558-568
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Blood-based biomarkers have the potential to reflect cerebrovascular signaling after microvascular injury; yet, the detection of cell-specific signaling has proven challenging. Microvesicles retain parental cell surface antigens allowing detection of cell-specific signaling encoded in their cargo. In ischemic stroke, the progression of pathology involves changes in microvascular signaling whereby brain pericytes, perivascular cells wrapping the microcapillaries, are one of the early responders to the ischemic insult. Intercepting the pericyte signaling response peripherally by isolating pericyte-derived microvesicles may provide not only diagnostic information on microvascular injury but also enable monitoring of important pathophysiological mechanisms. METHODS: Plasma samples were collected from patients with acute ischemic stroke (n=39) at 3 time points after stroke onset: 0 to 6 hours, 12 to 24 hours, and 2 to 6 days, and compared with controls (n=39). Pericyte-derived microvesicles were isolated based on cluster of differentiation 140b expression and quantified by flow cytometry. The protein content was evaluated using a proximity extension assay, and vascular signaling pathways were examined using molecular signature hallmarks and gene ontology. RESULTS: In this case-control study, patients with acute ischemic stroke showed significantly increased numbers of pericyte-derived microvesicles (median, stroke versus controls) at 12 to 24 hours (1554 versus 660 microvesicles/μL; P=0.0041) and 2 to 6 days after stroke (1346 versus 660 microvesicles/μL; P=0.0237). Their proteome revealed anti-inflammatory properties mediated via downregulation of Kirsten rat sarcoma virus and IL (interleukin)-6/JAK/STAT3 signaling at 0 to 6 hours, but proangiogenic as well as proinflammatory signals at 12 to 24 hours. Between 2 and 6 days, proteins were mainly associated with vascular remodeling as indicated by activation of Hedgehog signaling in addition to proangiogenic signals. CONCLUSIONS: We demonstrate that the plasma of patients with acute ischemic stroke reflects (1) an early and time-dependent increase of pericyte-derived microvesicles and (2) changes in the protein cargo of microvesicles over time indicating cell signaling specifically related to inflammation and vascular remodeling.
|
|
| 15. |
- Gorcenco, Sorina, et al.
(författare)
-
New generation genetic testing entering the clinic
- 2020
-
Ingår i: Parkinsonism and Related Disorders. - : Elsevier BV. - 1353-8020. ; 73, s. 72-84
-
Tidskriftsartikel (refereegranskat)abstract
- New generation sequencing (NGS) genetic testing is a powerful diagnostic tool and is increasingly used in the clinical workup of patients, especially in unusual presentations or where a positive family history suggests heritable disease. This review addresses the NGS technologies Targeted sequencing (TS), Whole exome sequencing (WES), Whole genome sequencing (WGS), and the use of gene panels or gene lists for clinical diagnostic purposes. These methods primarily assess nucleotide sequence but can also detect copy number variants and many tandem repeat expansions, greatly simplifying diagnostic algorithms for movement disorders. Studies evaluating the efficacy of NGS in diagnosing movement disorders have reported a diagnostic yield of up to 10.1% for familial and 15.7% for early-onset PD, 11.7–37.5% for dystonia, 12.1–61.8% for ataxia/spastic paraplegia and 11.3–28% for combined movement disorders. Patient selection and stringency in the interpretation of the detected variants and genotypes affect diagnostic yield. Careful comparison of the patient's or family's disease features with the previously reported phenotype associated with the same variant or gene can avoid false-positive diagnoses, although some genes are implicated in various phenotypes. Moving from TS to WES and WGS increases the number of patients correctly diagnosed, but for many patients, a genetic cause cannot be identified today. However, new genetically defined entities are discovered at rapid pace, and genetic databases and our knowledge of genotype-phenotype correlations expand steadily. We discuss the need for clear communication of genetic results and suggest a list of aspects to consider when reporting neurogenetic disorders using NGS testing.
|
|
| 16. |
- Grönberg, Angelina, et al.
(författare)
-
Incidence of Aphasia in Ischemic Stroke
- 2022
-
Ingår i: Neuroepidemiology. - : S. Karger AG. - 0251-5350 .- 1423-0208. ; 56:3, s. 174-182
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: A decrease in ischemic stroke (IS) incidence has been observed in high income countries during the last decades. Whether this has influenced the occurrence of aphasia in IS is uncertain. We therefore examined the incidence rate and potentially related determinants of aphasia in IS. Methods: We prospectively examined consecutive patients admitted to hospital with first-ever acute IS between March 1, 2017, and February 28, 2018, as part of the Lund Stroke Register (LSR) Study, comprising patients from the uptake area of Skåne University Hospital, Lund, Sweden. Patients were assessed with National Institutes of Health Stroke Scale (NIHSS) at stroke onset. Presence of aphasia was evaluated with NIHSS item 9 (language). We registered IS subtypes and risk factors. To investigate possible temporal changes in aphasia incidence, we made comparisons with corresponding LSR data from 2005 to 2006. Incidence rates were calculated and adjusted to the European Standard Population (ESP) and to the Swedish population. Results: Among 308 included IS patients, 30% presented with aphasia (n = 91; 95% CI: 25-35), a proportion of aphasia in IS that was similar to 2005-2006. The incidence rate of aphasia was 31 per 100,000 person-years adjusted to the ESP (95% CI: 25-38 per 100,000 person-years) corresponding to a significant decrease of 30% between 2005-2006 and 2017-2018. The decrease was significantly more pronounced in men. The initial severity of aphasia remained unchanged, with the majority of patients having severe to global aphasia. No significant differences between vascular stroke risk factors were noted among stroke patients with or without aphasia. Conclusion: Even though the overall IS incidence rate has decreased during the first decades of the 21st century, the proportion of IS patients with aphasia at stroke onset remains stable at 30%. Aphasia continues to be an important symptom that needs to be considered in stroke care and rehabilitation.
|
|
| 17. |
- Grönberg, Angelina, et al.
(författare)
-
Long-term prognosis and health-related quality of life for people with Aphasia in Sweden
- 2024
-
Ingår i: Aphasiology. - 0268-7038 .- 1464-5041.
-
Tidskriftsartikel (refereegranskat)abstract
- Background: People with aphasia (PWA) after ischemic stroke often have difficulties in communication and social participation. To individualise rehabilitation and optimise recovery, there is a need for knowledge regarding prevalence of aphasia, and language functions in relation to long-term recovery and health-related quality of life (HRQoL). In this study, we examined these issues in a Swedish setting. Methods: We screened consecutive persons with first-ever ischemic stroke admitted to Skåne University Hospital, Sweden, at baseline (median day 4 post stroke onset) for aphasia with the Language Screening Test (LAST). We then performed a detailed follow-up of PWA at 1, 3, and 12months after stroke onset with the Swedish version of the Comprehensive Aphasia Test (CAT) for evaluation of cognition and language, and with the self-reported Aphasia Impact Questionnaire (AIQ) for evaluation of HRQoL. We analysed aphasia recovery and potential associations between aphasia severity, language functions, stroke severity according to National Institutes of Health Stroke Scale (NIHSS), and HRQoL. Results: Initial aphasia was present in 27% (n=60 of 221) of stroke persons in the acute phase. At 1month after stroke onset, 74% (n=40 of 54 survivors with initial aphasia) had remaining aphasia, at 3months 67% (n=34 of 51) had aphasia and at 12months post stroke 61% (n=30 of 49) had remaining aphasia. Improvement of aphasia was greatest during the first months after onset, with significant improvement regarding naming (p=0.01), repetition (p=0.03) and comprehension of written language (p=0.01). HRQoL remained significantly associated with aphasia severity after adjusting for stroke severity and age. At 3months, 87% (n=26) of PWA reported that aphasia affected their ability to communicate with the environment, had negative consequences on level of participation (73%, n =22), and their emotional well-being (87%, n =26). There were no significant temporal changes regarding HRQoL between 3 and 12months post stroke. Conclusion: Chronic aphasia was observed in 61% of all alive persons presenting with baseline aphasia after ischemic stroke. Aphasia has negative consequences on HRQoL for PWA and aphasia severity impacts HRQoL regardless of stroke severity.
|
|
| 18. |
- Hong, S. M., et al.
(författare)
-
Excessive White Matter Hyperintensity Increases Susceptibility to Poor Functional Outcomes After Acute Ischemic Stroke
- 2021
-
Ingår i: Frontiers in Neurology. - : Frontiers Media SA. - 1664-2295. ; 12
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: To personalize the prognostication of post-stroke outcome using MRI-detected cerebrovascular pathology, we sought to investigate the association between the excessive white matter hyperintensity (WMH) burden unaccounted for by the traditional stroke risk profile of individual patients and their long-term functional outcomes after a stroke. Methods: We included 890 patients who survived after an acute ischemic stroke from the MRI-Genetics Interface Exploration (MRI-GENIE) study, for whom data on vascular risk factors (VRFs), including age, sex, atrial fibrillation, diabetes mellitus, hypertension, coronary artery disease, smoking, prior stroke history, as well as acute stroke severity, 3- to-6-month modified Rankin Scale score (mRS), WMH, and brain volumes, were available. We defined the unaccounted WMH (uWMH) burden via modeling of expected WMH burden based on the VRF profile of each individual patient. The association of uWMH and mRS score was analyzed by linear regression analysis. The odds ratios of patients who achieved full functional independence (mRS < 2) in between trichotomized uWMH burden groups were calculated by pair-wise comparisons. Results: The expected WMH volume was estimated with respect to known VRFs. The uWMH burden was associated with a long-term functional outcome (beta = 0.104, p < 0.01). Excessive uWMH burden significantly reduced the odds of achieving full functional independence after a stroke compared to the low and average uWMH burden [OR = 0.4, 95% CI: (0.25, 0.63), p < 0.01 and OR = 0.61, 95% CI: (0.42, 0.87), p < 0.01, respectively]. Conclusion: The excessive amount of uWMH burden unaccounted for by the traditional VRF profile was associated with worse post-stroke functional outcomes. Further studies are needed to evaluate a lifetime brain injury reflected in WMH unrelated to the VRF profile of a patient as an important factor for stroke recovery and a plausible indicator of brain health.
|
|
| 19. |
- Ilinca, Andreea, et al.
(författare)
-
MAP3K6 Mutations in a Neurovascular Disease Causing Stroke, Cognitive Impairment, and Tremor
- 2021
-
Ingår i: Neurology: Genetics. - 2376-7839. ; 7:1
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: To describe a possible novel genetic mechanism for cerebral small vessel disease (cSVD) and stroke.Methods: We studied a Swedish kindred with ischemic stroke and intracerebral hemorrhage, tremor, dysautonomia, and mild cognitive decline. Members were examined clinically, radiologically, and by histopathology. Genetic workup included whole-exome sequencing (WES) and whole-genome sequencing (WGS) and intrafamilial cosegregation analyses.Results: Fifteen family members were examined clinically. Twelve affected individuals had white matter hyperintensities and 1 or more of (1) stroke episodes, (2) clinically silent lacunar ischemic lesions, and (3) cognitive dysfunction. All affected individuals had tremor and/or atactic gait disturbance. Mild symmetric basal ganglia calcifications were seen in 3 affected members. Postmortem examination of 1 affected member showed pathologic alterations in both small and large arteries the brain. Skin biopsies of 3 affected members showed extracellular amorphous deposits within the subepidermal zone, which may represent degenerated arterioles. WES or WGS did not reveal any potentially disease-causing variants in known genes for cSVDs or idiopathic basal ganglia calcification, but identified 1 heterozygous variant, NM_004672.4 MAP3K6 c.322G>A p.(Asp108Asn), that cosegregated with the disease in this large family. MAP3K6 has known functions in angiogenesis and affects vascular endothelial growth factor expression, which may be implicated in cerebrovascular disease.Conclusions: Our data strongly suggest the MAP3K6 variant to be causative for this novel disease phenotype, but the absence of functional data and the present lack of additional families with this disease and MAP3K6 mutations still limit the formal evidence for the variant's pathogenicity.
|
|
| 20. |
- Ilinca, Andreea, et al.
(författare)
-
Updated Stroke Gene Panels : Rapid evolution of knowledge on monogenic causes of stroke
- 2023
-
Ingår i: European Journal of Human Genetics. - : Springer Science and Business Media LLC. - 1476-5438 .- 1018-4813. ; 31:2, s. 239-242
-
Tidskriftsartikel (refereegranskat)abstract
- This article updates our previous Stroke Gene Panels (SGP) from 2017. Online Mendelian Inheritance in Man and PubMed were searched. We divided detected genes into two SGP groups, SGP1: genes reported in at least one person with stroke and associated with one or more clinical subgroups: large artery atherosclerotic, large artery non-atherosclerotic (tortuosity, dolichoectasia, aneurysm, non-atherosclerotic dissection or occlusion), cerebral small vessel diseases, cardio-embolic (arrhythmia, heart defect, cardiomyopathy), coagulation dysfunctions (venous thrombosis, arterial thrombosis, bleeding tendency), intracerebral hemorrhage, vascular malformations (cavernoma, arteriovenous malformations) and metabolism disorders; and SGP2: genes related to diseases that may predispose to stroke. We identified 168 SGP1 genes, 70 of these were validated for clinical practice. We also detected 72 SGP2 genes. Nine genes were removed because of conflicting evidence. The number of genes increased from 168 to 240 during 4.5-years, reflecting a dynamic evolution and the need for regular updates for research and clinical use.
|
|
