| 1. |
- Johansson, Elias, 1984-
(författare)
-
Carotid stenosis
- 2011
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Carotid stenosis is one of several causes of ischemic stroke and entails a high risk of ischemic stroke recurrence. Removal of a carotid stenosis by carotid endarterectomy results in a risk reduction for ischemic stroke, but the magnitude of risk reduction depends on several factors. If the delay between the last symptom and carotid endarterectomy is less than 2 weeks, the absolute risk reduction is >10%, regardless of age, sex, or if the degree of carotid stenosis is 50–69% or 70–99%. Thus, speed is the key. However, if many patients suffers an ischemic stroke recurrence within the first 2 weeks of the presenting event, an additional benefit is likely be obtained if carotid endarterectomy is performed even earlier than within 2 week after the presenting event. Carotid endarterectomy for asymptomatic carotid stenoses carries a small risk reduction for stroke. Screening for asymptomatic carotid stenosis requires a prevalence of >5% in the examined population, i.e., higher than in the general population; however, directed screening in groups with a prevalence of >5% is beneficial. The aims of this thesis were to investigate the length of the delay to carotid endarterectomy, determine the risk of recurrent stroke before carotid endarterectomy, and determine if a calcification in the area of the carotid arteries seen on dental panoramic radiographs is a valid selection method for directed ultrasound screening to detect asymptomatic carotid stenosis. Consecutive patients with a symptomatic carotid stenosis who underwent a preoperative evaluation aimed at carotid endarterectomy at Umeå Stroke Centre between January 1, 2004–March 31, 2006 (n=275) were collected retrospectively and between August 1, 2007–December 31, 2009 (n=230) prospectively. In addition, 117 consecutive persons, all preliminarily eligible for asymptomatic carotid endarterectomy and with a calcification in the area of the carotid arteries seen on panoramic radiographs, were prospectively examined with carotid ultrasound. The median delay between the presenting event and carotid endarterectomy was 11.7 weeks in the first half year of 2004, dropped to 6.9 weeks in the first quarter year of 2006, and had dropped to 3.6 weeks in the second half year of 2009. The risk of ipsilateral ischemic stroke recurrence was 4.8% within 2 days, 7.9% within 1 week, and 11.2% within 2 weeks of the presenting event. For patients with a stroke or transient ischemic attack as the presenting event, this risk was 6.0% within 2 days, 9.7% within 1 week, and 14.3% within 2 weeks of the presenting event. For the 10 patients with a near-occlusion, the risk of ipsilateral ischemic stroke recurrence was 50% at 4 weeks after the presenting event. Among the 117 persons with a calcification in the area of the carotid arteries seen on panoramic radiographs, eight had a 50–99% carotid stenosis, equalling a prevalence of 6.8% (not statistically significantly over the pre-specified 5% threshold). Among men, the prevalence of 50–99% carotid stenosis was 12.5%, which was statistically significantly over the pre-specified 5% threshold. In conclusion: The delay to carotid endarterectomy was longer than 2 weeks. Additional benefit is likely to be gained by performing carotid endarterectomy within a few days of the presenting event instead of at 2 weeks because many patients suffer a stroke recurrence within a few days; speed is indeed the key. The finding that near-occlusion entails an early high risk of stroke recurrence stands in sharp contrast to previous studies; one possible explaination is that this was a high-risk period missed in previous studies. The incidental finding of a calcification in the area of the carotid arteries on a panoramic radiograph is a valid indication for carotid ultrasound screening in men who are otherwise eligible for asymptomatic carotid endarterectomy.
|
|
| 2. |
- Lindgren, Arne, et al.
(författare)
-
Electrocardiographic changes in stroke patients without primary heart disease
- 1994
-
Ingår i: Clinical Physiology. - 1365-2281. ; 14:2, s. 223-231
-
Tidskriftsartikel (refereegranskat)abstract
- Consecutive electrocardiograms were recorded in 28 stroke patients without signs of primary heart disease. Individuals with subarachnoidal haemorrhage, or electrolyte disturbances were excluded. A computerized tomography of the brain was performed in each case and showed a cerebral haemorrhage (n = 4), cortical infarction (n = 6), subcortical infarction (n = 14) and normal finding (n = 4). One patient developed atrial fibrillation but no other case of serious disturbances in rate of rhythm occurred. None developed AV block, bundle branch blocks or significant changes in QRS complexes. The most common abnormalities in ECG were transient STT changes in lateral leads, which were seen in 13 cases. The typical findings were flat or slightly negative T waves, horizontal or down-sloping ST segments and sometimes a small ST depression. In no case did ECG show typical signs of acute myocardial infarction. A transient prolonged QT interval was seen in three patients and transient U waves in four. ECG did not correlate to the location of the vascular lesion seen on CT or the clinical outcome. It is concluded that STT changes of a small magnitude are seen in about half of the cases of stroke patients without primary heart disease and that they do not resemble the typical pattern of acute myocardial ischaemia.
|
|
| 3. |
- Roijer, Anders, et al.
(författare)
-
Cardiac changes in stroke patients and controls evaluated with transoesophageal echocardiography
- 1997
-
Ingår i: Scandinavian Cardiovascular Journal. - : Informa UK Limited. - 1651-2006 .- 1401-7431. ; 31:6, s. 329-337
-
Tidskriftsartikel (refereegranskat)abstract
- In stroke patients several cardiac changes associated with embolism can be detected with transoesophageal echocardiography. Potential major cardiac embolic sources (e.g. atrial fibrillation, thrombi of left ventricle/atrium, vegetation, myxoma, dilated cardiomyopathy) have a causal relationship to embolism. Other changes with no certain causal relationship are regarded as potential minor cardiac embolic sources (e.g. atrial septal aneurysm, patent foramen ovale, mitral annular calcification, mitral valve prolapse, protruding atheroma of the aorta). We compared the prevalences of major and minor potential cardiac embolic sources in a stroke population with that in controls. One hundred and twenty-one patients with first-ever stroke were compared with 68 randomly selected controls. All subjects underwent magnetic resonance imaging of the brain, carotid ultrasound and transthoracic/transoesophageal echocardiography. The patients were slightly older (mean age 70.7 +/- 10.3 years) than the controls (65.5 +/- 15.5 years) (p < 0.05). Potential major cardiac embolic sources were found in 27% of the patients and in 4% of the controls (p < 0.001). The most common major potential embolic source was atrial fibrillation, detected in 22/121 patients. Fifteen of these also had spontaneous echocontrast in the left atrium. Eleven left atrial thrombi were found (four of these patients had atrial fibrillation and seven had sinus rhythm). A history of heart disease was more common in patients with a potential major cardiac embolic source or a carotid artery stenosis (77%) than in those patients without (44%) (p < 0.01). After excluding subjects with a major potential cardiac embolic source and/or carotid artery stenosis, no differences in the prevalence of minor potential cardiac embolic sources were found between patients (55%) and control subjects (47%) (p = NS). Even when subjects without a major potential cardiac embolic source or a carotid artery stenosis were categorized into three age groups (35-54, 55-74 and > 74 years) the prevalence of potential minor cardiac embolic sources did not differ between patients and controls. To conclude, major potential cardiac embolic sources are more common in an older population with first-ever stroke than in a comparable control group. However, potential minor cardiac embolic sources did not differ in prevalence in the patients compared with controls. Certain changes (e.g. atrial septal aneurysm) might have a potential embolic role in younger stroke patients but in our study no difference was found between older stroke patients and controls.
|
|
| 4. |
- Schirmer, M. D., et al.
(författare)
-
White matter hyperintensity quantification in large-scale clinical acute ischemic stroke cohorts - The MRI-GENIE study
- 2019
-
Ingår i: Neuroimage-Clinical. - : Elsevier BV. - 2213-1582. ; 23
-
Tidskriftsartikel (refereegranskat)abstract
- White matter hyperintensity (WMH) burden is a critically important cerebrovascular phenotype linked to prediction of diagnosis and prognosis of diseases, such as acute ischemic stroke (AIS). However, current approaches to its quantification on clinical MRI often rely on time intensive manual delineation of the disease on T2 fluid attenuated inverse recovery (FLAIR), which hinders high-throughput analyses such as genetic discovery. In this work, we present a fully automated pipeline for quantification of WMH in clinical large-scale studies of AIS. The pipeline incorporates automated brain extraction, intensity normalization and WMH segmentation using spatial priors. We first propose a brain extraction algorithm based on a fully convolutional deep learning architecture, specifically designed for clinical FLAIR images. We demonstrate that our method for brain extraction outperforms two commonly used and publicly available methods on clinical quality images in a set of 144 subject scans across 12 acquisition centers, based on dice coefficient (median 0.95; inter-quartile range 0.94-0.95; p < 0.01) and Pearson correlation of total brain volume (r = 0.90). Subsequently, we apply it to the large-scale clinical multi-site MRI-GENIE study (N = 2783) and identify a decrease in total brain volume of -2.4 cc/year. Additionally, we show that the resulting total brain volumes can successfully be used for quality control of image preprocessing. Finally, we obtain WMH volumes by building on an existing automatic WMH segmentation algorithm that delineates and distinguishes between different cerebrovascular pathologies. The learning method mimics expert knowledge of the spatial distribution of the WMH burden using a convolutional auto-encoder. This enables successful computation of WMH volumes of 2533 clinical AIS patients. We utilize these results to demonstrate the increase of WMH burden with age (0.950 cc/year) and show that single site estimates can be biased by the number of subjects recruited.
|
|
| 5. |
- 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.
|
|
| 6. |
- Grönholm, Erik, et al.
(författare)
-
Predominance of caudate nucleus lesions in acute ischemic stroke patients with impairments in language and speech
- 2016
-
Ingår i: European Journal of Neurology. - : Wiley. - 1351-5101 .- 1468-1331. ; 23:1, s. 148-153
-
Tidskriftsartikel (refereegranskat)abstract
- Background and purpose. Whereas traditional views of language processing in the brain have assumed that the language function is concentrated to a limited number of cortical areas (Broca’s and Wernicke’s areas), current knowledge points at a much more complex system of language and speech processing involving many brain areas, both cortical and subcortical. The purpose of the current study was to make an unbiased assessment of which cerebral areas are affected in first-ever acute ischemic stroke patients identified as having language and speech impairments according to the National Institute of Health Stroke Scale (NIHSS). Methods. Data from thirty-four patients with language and speech impairments, with a score of 1-3 on item 9 on the NIHSS, following ischemic stroke was collected from the Lund Stroke Register. MRI images acquired up to 20 days after stroke onset were used to create an overlap lesion image using MRIcron software. Results. The classical language areas, Wernicke’s and Broca’s area, were affected in less than one fourth of the patients. The most frequently affected region was a subcortical region - the left caudate nucleus and the adjacent corona radiata. Conclusions. These findings contribute to the growing body of evidence that the basal ganglia have a crucial role in the control over language and speech processing.
|
|
| 7. |
- Drake, Mattias, et al.
(författare)
-
Diffusion-Weighted Imaging, MR Angiography, and Baseline Data in a Systematic Multicenter Analysis of 3,301 MRI Scans of Ischemic Stroke Patients-Neuroradiological Review Within the MRI-GENIE Study
- 2020
-
Ingår i: Frontiers in Neurology. - : Frontiers Media SA. - 1664-2295. ; 11
-
Tidskriftsartikel (refereegranskat)abstract
- Background:Magnetic resonance imaging (MRI) serves as a cornerstone in defining stroke phenotype and etiological subtype through examination of ischemic stroke lesion appearance and is therefore an essential tool in linking genetic traits and stroke. Building on baseline MRI examinations from the centralized and structured radiological assessments of ischemic stroke patients in the Stroke Genetics Network, the results of the MRI-Genetics Interface Exploration (MRI-GENIE) study are described in this work. Methods:The MRI-GENIE study included patients with symptoms caused by ischemic stroke (N= 3,301) from 12 international centers. We established and used a structured reporting protocol for all assessments. Two neuroradiologists, using a blinded evaluation protocol, independently reviewed the baseline diffusion-weighted images (DWIs) and magnetic resonance angiography images to determine acute lesion and vascular occlusion characteristics. Results:In this systematic multicenter radiological analysis of clinical MRI from 3,301 acute ischemic stroke patients according to a structured prespecified protocol, we identified that anterior circulation infarcts were most prevalent (67.4%), that infarcts in the middle cerebral artery (MCA) territory were the most common, and that the majority of large artery occlusions 0 to 48 h from ictus were in the MCA territory. Multiple acute lesions in one or several vascular territories were common (11%). Of 2,238 patients with unilateral DWI lesions, 52.6% had left-sided infarct lateralization (P= 0.013 for chi(2)test). Conclusions:This large-scale analysis of a multicenter MRI-based cohort of AIS patients presents a unique imaging framework facilitating the relationship between imaging and genetics for advancing the knowledge of genetic traits linked to ischemic stroke.
|
|
| 8. |
- Thorlin, Thorleif, et al.
(författare)
-
[Neurological issues common during internship. A questionnaire study as a basis for continuous development of neurology teaching].
- 2011
-
Ingår i: Läkartidningen. - 0023-7205 .- 1652-7518. ; 108:4, s. 152-155
-
Tidskriftsartikel (refereegranskat)abstract
- To obtain knowledge if basic medical education satisfies the demands the medical graduates face during internship is a basis for the design and evaluation of teaching.The aim of the study was to evaluate the physicians’ satisfaction with the teaching of neurology at universities in Sweden subsequent to having tested the obtained skills in the 21 months internship needed for Swedish physician licence.A questionnaire with 23 questions was sent in 2007 to 1628 newly licensed doctors who received their cards between 2005-01-01 and 2007-10-09, after completing Swedish internship.Onethousand-fiftyone physicians (65%) answered the questionnaire. Most felt that the quality of the theoretical and practical education in neurology obtained at the university was good or very good. Physicians with less coherent university neurology teaching time indicated to a greater degree that teaching time at the undergraduate level was too short. The physicians indicated that neurological issues are common during the internship. A majority indicated that that they had received too little training in neurology during their internship. The results give a good feedback for further development of neurology teaching. Similar studies could be carried out also for other areas of graduate medical education.
|
|
| 9. |
- Chauhan, Ganesh, et al.
(författare)
-
Identification of additional risk loci for stroke and small vessel disease: a meta-analysis of genome-wide association studies
- 2016
-
Ingår i: The Lancet Neurology. - 1474-4465 .- 1474-4422. ; 15:7, s. 695-707
-
Tidskriftsartikel (refereegranskat)abstract
- Background Genetic determinants of stroke, the leading neurological cause of death and disability, are poorly understood and have seldom been explored in the general population. Our aim was to identify additional loci for stroke by doing a meta-analysis of genome-wide association studies. Methods For the discovery sample, we did a genome-wide analysis of common genetic variants associated with incident stroke risk in 18 population-based cohorts comprising 84 961 participants, of whom 4348 had stroke. Stroke diagnosis was ascertained and validated by the study investigators. Mean age at stroke ranged from 45·8 years to 76·4 years, and data collection in the studies took place between 1948 and 2013. We did validation analyses for variants yielding a significant association (at p<5 × 10−6) with all-stroke, ischaemic stroke, cardioembolic ischaemic stroke, or non-cardioembolic ischaemic stroke in the largest available cross-sectional studies (70 804 participants, of whom 19 816 had stroke). Summary-level results of discovery and follow-up stages were combined using inverse-variance weighted fixed-effects meta-analysis, and in-silico lookups were done in stroke subtypes. For genome-wide significant findings (at p<5 × 10−8), we explored associations with additional cerebrovascular phenotypes and did functional experiments using conditional (inducible) deletion of the probable causal gene in mice. We also studied the expression of orthologs of this probable causal gene and its effects on cerebral vasculature in zebrafish mutants. Findings We replicated seven of eight known loci associated with risk for ischaemic stroke, and identified a novel locus at chromosome 6p25 (rs12204590, near FOXF2) associated with risk of all-stroke (odds ratio [OR] 1·08, 95% CI 1·05–1·12, p=1·48 × 10−8; minor allele frequency 21%). The rs12204590 stroke risk allele was also associated with increased MRI-defined burden of white matter hyperintensity—a marker of cerebral small vessel disease—in stroke-free adults (n=21 079; p=0·0025). Consistently, young patients (aged 2–32 years) with segmental deletions of FOXF2 showed an extensive burden of white matter hyperintensity. Deletion of Foxf2 in adult mice resulted in cerebral infarction, reactive gliosis, and microhaemorrhage. The orthologs of FOXF2 in zebrafish (foxf2b and foxf2a) are expressed in brain pericytes and mutant foxf2b−/− cerebral vessels show decreased smooth muscle cell and pericyte coverage. Interpretation We identified common variants near FOXF2 that are associated with increased stroke susceptibility. Epidemiological and experimental data suggest that FOXF2 mediates this association, potentially via differentiation defects of cerebral vascular mural cells. Further expression studies in appropriate human tissues, and further functional experiments with long follow-up periods are needed to fully understand the underlying mechanisms. Funding NIH, NINDS, NHMRC, CIHR, European national research institutions, Fondation Leducq. © 2016 Elsevier Ltd
|
|
| 10. |
- Pedersen, Annie, 1981, et al.
(författare)
-
TFPI gene variation and ischemic stroke.
- 2012
-
Ingår i: Thrombosis research. - : Elsevier BV. - 1879-2472 .- 0049-3848. ; 130:3, s. 565-7
-
Tidskriftsartikel (refereegranskat)
|
|
