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14
result(s) for
"Hsieh, Kety"
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Clinical prediction of large vessel occlusion in anterior circulation stroke: mission impossible?
2016
Simple clinical scores to predict large vessel occlusion (LVO) in acute ischemic stroke would be helpful to triage patients in the prehospital phase. We assessed the ability of various combinations of National Institutes of Health Stroke Scale (NIHSS) subitems and published stroke scales (i.e., RACE scale, 3I-SS, sNIHSS-8, sNIHSS-5, sNIHSS-1, mNIHSS, a-NIHSS items profiles A–E, CPSS1, CPSS2, and CPSSS) to predict LVO on CT or MR arteriography in 1085 consecutive patients (39.4 % women, mean age 67.7 years) with anterior circulation strokes within 6 h of symptom onset. 657 patients (61 %) had an occlusion of the internal carotid artery or the M1/M2 segment of the middle cerebral artery. Best cut-off value of the total NIHSS score to predict LVO was 7 (PPV 84.2 %, sensitivity 81.0 %, specificity 76.6 %, NPV 72.4 %, ACC 79.3 %). Receiver operating characteristic curves of various combinations of NIHSS subitems and published scores were equally or less predictive to show LVO than the total NIHSS score. At intersection of sensitivity and specificity curves in all scores, at least 1/5 of patients with LVO were missed. Best odds ratios for LVO among NIHSS subitems were best gaze (9.6, 95 %-CI 6.765–13.632), visual fields (7.0, 95 %-CI 3.981–12.370), motor arms (7.6, 95 %-CI 5.589–10.204), and aphasia/neglect (7.1, 95 %-CI 5.352–9.492). There is a significant correlation between clinical scores based on the NIHSS score and LVO on arteriography. However, if clinically relevant thresholds are applied to the scores, a sizable number of LVOs are missed. Therefore, clinical scores cannot replace vessel imaging.
Journal Article
Baseline Troponin T level in stroke and its association with stress cardiomyopathy
2018
Differential diagnosis of elevated high sensitive Troponin T (hsTnT) in acute ischemic stroke includes myocardial infarction (MI) and neurogenic stunned myocardium (NSM). The aim of this study was to identify factors associated with baseline hsTnT levels and MI or NSM in acute ischemic stroke.
We studied 204 consecutive patients of the prospective acquired Bern Stroke Database with acute ischemic stroke diagnosed by brain MR. All patient histories and cardiac examinations were reviewed retrospectively. Volumetry of lesions on diffusion and perfusion weighted brain imaging (circular singular value decomposition, Tmax >6sec) was performed. Voxel based analysis was performed to identify brain areas associated with hsTnT elevation. Linear regression analysis was used to identify predictors of baseline hsTnT levels and myocardial infarction.
Elevated hsTnT was observed in 58 of the 204 patients (28.4%). The mean age was 68.3 years in the normal hsTnT group and 69.7 years in the elevated hsTnT group. Creatinine (p<0.001, OR 6.735, 95% CI 58.734-107.423), baseline NIHSS score (p = 0.029, OR 2.207, 95% CI 0.675-12.096), ST segment depression (p = 0.025, OR 2.259, 95% CI 2.419-35.838), and negative T waves in baseline ECG (p = 0.002, OR 3.209, 95% CI 13.007-54.564) were associated with hsTnT elevation, while infarct location and size were not. Coronary angiography was performed in 30 of the 204 patients (14.7%) and myocardial infarction was diagnosed in 7 of them (23.3%). Predictive factors for myocardial infarction could not be identified.
Elevated baseline baseline hsTnT was associated with NIHSS, creatinine, ST segment depression and inverted T waves, but not with stroke location or size. None of the factors was helpful to differentiate MI and NSM. Therefore, ancillary investigations such as coronary angiography, cardiac MRI or both may be needed to solve the differential diagnosis.
Journal Article
Infarction Distribution Pattern in Acute Stroke May Predict the Extent of Leptomeningeal Collaterals
2015
The aim of this study was to evaluate whether the distribution pattern of early ischemic changes in the initial MRI allows a practical method for estimating leptomeningeal collateralization in acute ischemic stroke (AIS).
Seventy-four patients with AIS underwent MRI followed by conventional angiogram and mechanical thrombectomy. Diffusion restriction in Diffusion weighted imaging (DWI) and correlated T2-hyperintensity of the infarct were retrospectively analyzed and subdivided in accordance with Alberta Stroke Program Early CT score (ASPECTS). Patients were angiographically graded in collateralization groups according to the method of Higashida, and dichotomized in 2 groups: 29 subjects with collateralization grade 3 or 4 (well-collateralized group) and 45 subjects with grade 1 or 2 (poorly-collateralized group). Individual ASPECTS areas were compared among the groups.
Means for overall DWI-ASPECTS were 6.34 vs. 4.51 (well vs. poorly collateralized groups respectively), and for T2-ASPECTS 9.34 vs 8.96. A significant difference between groups was found for DWI-ASPECTS (p<0.001), but not for T2-ASPECTS (p = 0.088). Regarding the individual areas, only insula, M1-M4 and M6 showed significantly fewer infarctions in the well-collateralized group (p-values <0.001 to 0.015). 89% of patients in the well-collateralized group showed 0-2 infarctions in these six areas (44.8% with 0 infarctions), while 59.9% patients of the poor-collateralized group showed 3-6 infarctions.
Patients with poor leptomeningeal collateralization show more infarcts on the initial MRI, particularly in the ASPECTS areas M1 to M4, M6 and insula. Therefore DWI abnormalities in these areas may be a surrogate marker for poor leptomeningeal collaterals and may be useful for estimation of the collateral status in routine clinical evaluation.
Journal Article
Symptomatic and asymptomatic intracranial atherosclerotic stenosis: 3 years’ prospective study
by
Arnold, Marcel
,
Heldner, Mirjam R.
,
Jung, Simon
in
Aged
,
Arterial Occlusive Diseases - complications
,
Arterial Occlusive Diseases - diagnostic imaging
2020
Background
Intracranial stenoses can cause TIA/ischaemic stroke. The purpose of this study was to assess vascular risk factors, clinical and imaging findings and outcome in Caucasians with intracranial stenosis under best prevention management.
Methods
In this prospective observational study (from 05/2012, to last follow-up 06/2017) we compared vascular risk factors, imaging findings and long-term outcome in Swiss patients with symptomatic versus asymptomatic intracranial atherosclerotic stenoses on best prevention management.
Results
62 patients were included [35.5% women, median age 68.3 years], 33 (53.2%) with symptomatic intracranial stenoses. Vascular risk factors (
p
= 0.635) and frequency of anterior circulation stenoses (66.7% vs. 55.2%;
p
= 0.354) did not differ between symptomatic and asymptomatic patients, but CT/MR-perfusion deficits in the territory of the stenosis (81.8% vs. 51.7%;
p
= 0.011) were more common in symptomatic patients. Outcome in symptomatic and asymptomatic patients at last follow-up was similar (mRS 0–1:66.7% vs. 75%;
adj
p
= 0.937, mRS
adj
p
-shift = 0.354, survival:100% vs. 96.4%;
adj
p
= 0.979). However, during 59,417 patient follow-up days, symptomatic patients experienced more cerebrovascular events (ischaemic stroke or TIA) [37.5% vs. 7.1%;
adj
HR 7.58;
adj
p
= 0.012], mainly in the territory of the stenosis [31.3% vs. 3.6%;
adj
HR 12.69;
adj
p
= 0.019], more vascular events (i.e. ischaemic stroke/TIA/TNA and acute coronary/peripheral vascular events) [62.5% vs. 14.3%;
adj
HR 6.37;
adj
p
= 0.001]) and more multiple vascular events (
p
-trend = 0.006; ≥ 2:37.5% vs. 10.7%;
adj
OR 5.37;
adj
p
= 0.022) than asymptomatic patients.
Conclusions
Despite best prevention management, one in three patients with a symptomatic intracranial stenosis suffered a cerebrovascular event, three in five a vascular event and two in five ≥ 2 vascular events. There is an unmet need for more rigorous and effective preventive strategies in patients with symptomatic intracranial stenoses.
Journal Article
Thrombus imaging in acute stroke: correlation of thrombus length on susceptibility-weighted imaging with endovascular reperfusion success
2014
Objectives
Susceptibility-weighted imaging (SWI) enables visualization of thrombotic material in acute ischemic stroke. We aimed to validate the accuracy of thrombus depiction on SWI compared to time-of-flight MRA (TOF-MRA), first-pass gadolinium-enhanced MRA (GE-MRA) and digital subtraction angiography (DSA). Furthermore, we analysed the impact of thrombus length on reperfusion success with endovascular therapy.
Methods
Consecutive patients with acute ischemic stroke due to middle cerebral artery (MCA) occlusions undergoing endovascular recanalization were screened. Only patients with a pretreatment SWI were included. Thrombus visibility and location on SWI were compared to those on TOF-MRA, GE-MRA and DSA. The association between thrombus length on SWI and reperfusion success was studied.
Results
Eighty-four of the 88 patients included (95.5 %) showed an MCA thrombus on SWI. Strong correlations between thrombus location on SWI and that on TOF-MRA (Pearson’s correlation coefficient 0.918,
P
< 0.001), GE-MRA (0.887,
P
< 0.001) and DSA (0.841,
P
< 0.001) were observed. Successful reperfusion was not significantly related to thrombus length on SWI (
P
= 0.153; binary logistic regression).
Conclusions
In MCA occlusion thrombus location as seen on SWI correlates well with angiographic findings. In contrast to intravenous thrombolysis, thrombus length appears to have no impact on reperfusion success of endovascular therapy.
Key Points
•
SWI helps in assessing location and length of thrombi in the MCA
•
SWI, MRA and DSA are equivalent in detecting the MCA occlusion site
•
SWI is superior in identifying the distal end of the thrombus
•
Stent retrievers should be deployed over the distal thrombus end
•
Thrombus length did not affect success of endovascular reperfusion guided by SWI
Journal Article
Successful Mechanical Thrombectomy of a Middle Cerebral Artery Occlusion 14 Hours after Stroke Onset
by
Fischer, Urs
,
Bassetti, Claudio L.
,
Gralla, Jan
in
Aneurysms
,
Arterial occlusions
,
Care and treatment
2017
A 54-year-old patient presented with mild right-sided weakness of hand and face with a National Institutes of Health Stroke Scale (NIHSS) of 2 and occlusion of the left middle cerebral artery (MCA) in the M1 segment with a large perfusion deficit on computed tomography (CT). Due to mild neurological deficits no IVT was performed. Nine hours after symptom onset the patient gradually deteriorated with a NIHSS fluctuating between 9 and 15. MRI showed a persistent occlusion of the MCA with a large diffusion-perfusion mismatch. Immediate endovascular thrombectomy was performed 14 hours after symptom onset with complete recanalization and complete clinical recovery. Although mechanical thrombectomy is generally considered an effective alternative strategy up to 8 hours after stroke onset, selected patients with a large diffusion/perfusion mismatch and small infarct cores may benefit from an expanded therapeutic window.
Journal Article
Protected stent retriever thrombectomy prevents iatrogenic emboli in new vascular territories
by
Verma, Rajeev K.
,
Heldner, Mirjam R.
,
Arnold, Marcel
in
Aged
,
Angiography, Digital Subtraction - methods
,
Brain
2015
Introduction
Diagnostic tools to show emboli reliably and protection techniques against embolization when employing stent retrievers are necessary to improve endovascular stroke therapy. The aim of the present study was to investigate iatrogenic emboli using susceptibility-weighted imaging (SWI) in an open series of patients who had been treated with stent retriever thrombectomy using emboli protection techniques.
Methods
Patients with anterior circulation stroke examined with MRI before and after stent retriever thrombectomy were assessed for iatrogenic embolic events. Thrombectomy was performed in flow arrest and under aspiration using a balloon-mounted guiding catheter, a distal access catheter, or both.
Results
In 13 of 57 patients (22.8 %) post-interventional SWI sequences detected 16 microemboli. Three of them were associated with small ischemic lesions on diffusion-weighted imaging (DWI). None of the microemboli were located in a new vascular territory, none showed clinical signs, and all 13 patients have been rated as Thrombolysis in Cerebral Infarction (TICI) 2b (
n
= 3) or 3 (
n
= 10). Retrospective reevaluation of the digital subtraction angiography (DSA) detected discrete flow stagnation nearby the iatrogenic microemboli in four patients with a positive persistent collateral sign in one.
Conclusion
Our study demonstrates two things: First, SWI seems to be more sensitive to detect emboli than DWI and DSA and, second, proximal or distal protected stent retriever thrombectomy seems to prevent iatrogenic embolization into new vascular territories during retraction of the thrombus, but not downstream during mobilization of the thrombus. Both techniques should be investigated and refined further.
Journal Article
Monitoring Cerebral Oxygenation during Balloon Occlusion with Multichannel NIRS
2014
We report on oxygenation changes noninvasively recorded by multichannel continuous-wave near infrared spectroscopy (CW-NIRS) during endovascular neuroradiologic interventions requiring temporary balloon occlusion of arteries supplying the cerebral circulation. Digital subtraction angiography (DSA) provides reference data on the site, timing, and effectiveness of the flow stagnation as well as on the amount and direction of collateral circulation. This setting allows us to relate CW-NIRS findings to brain specific perfusion changes. We focused our analysis on the transition from normal perfusion to vessel occlusion, i.e., before hypoxia becomes clinically apparent. The localization of the maximal response correlated either with the core (occlusion of the middle cerebral artery) or with the watershed areas (occlusion of the internal carotid artery) of the respective vascular territories. In one patient with clinically and angiographically confirmed insufficient collateral flow during carotid artery occlusion, the total hemoglobin concentration became significantly asymmetric, with decreased values in the ipsilateral watershed area and contralaterally increased values. Multichannel CW-NIRS monitoring might serve as an objective and early predictive marker of critical perfusion changes during interventions—to prevent hypoxic damage of the brain. It also might provide valuable human reference data on oxygenation changes as they typically occur during acute stroke.
Journal Article
Age dependency of safety and outcome of endovascular therapy for acute stroke
2014
Elderly patients generally experience less favorable outcomes and higher mortality after acute stroke than younger patients. The aim of this study was to analyze the influence of age on outcome and safety after endovascular therapy in a large cohort of patients aged between 20 and 90 years. We prospectively acquired data of 1,000 stroke patients treated with endovascular therapy at a single center. Logistic regression analysis was performed to determine predictors of outcome and linear regression analysis to evaluate the association of age and outcome after 3 months. Younger age was an independent predictor of favorable outcome (OR 0.954,
p
< 0.001) and survival (OR 0.947,
p
< 0.001) in multivariate regression analysis. There was a linear relationship between age and outcome. Ever increase in 26 years of age was associated with an increase in the modified Rankin Scale of 1 point (
p
< 0.001). However, increasing age was not a risk factor for symptomatic (
p
= 0.086) or asymptomatic (
p
= 0.674) intracerebral hemorrhage and did not influence recanalization success (
p
= 0.674). Advancing age was associated with a decline of favorable outcomes and survival after endovascular therapy. This decline was linear from age 20 to 90 years, but was not related to lower recanalization rates or higher bleeding risk in the elderly. The efficacy of endovascular stroke therapy seems to be preserved also in the elderly and other factors than efficacy of endovascular therapy such as decreased plasticity are likely to explain the worse outcome with advancing age.
Journal Article
Candidate Genetic Risk Factors of Stroke: Results of a Multilocus Genotyping Assay
by
Mannhalter, Christine
,
Lang, Wilfried
,
Wagner, Oswald
in
Acute Disease
,
Analytical, structural and metabolic biochemistry
,
Biological and medical sciences
2007
Background: Epidemiological studies indicate that genetic factors play a role in the risk of stroke, particularly in younger individuals, but the role of single-nucleotide polymorphisms (SNPs) is controversial. We tested the possible association of a number of previously described SNPs with stroke risk. Methods: We investigated the prevalence of 60 polymorphisms located in 35 genes in 450 white patients who suffered an acute stroke or transient ischemic attack before the age of 60 years and in 817 healthy control individuals by a multilocus PCR-based assay. The controls were randomly selected from attendees of a health service program. Genetic variations were detected by hybridization to nylon strips (Roche Molecular Systems) containing detection oligonucleotides for the SNPs. We used P values of <0.05 for confirmatory analysis of the SNPs in the genes for APOE (allele 4), angiotensin converting enzyme, factor V, prothrombin, and methylenetetrahydrofolate reductase. To account for multiple testing we defined a P value of <0.001 as statistically significant for all exploratory tests. The genes represented in the test panel by more than 1 SNP were also evaluated by haplotype analysis. Results: Frequencies of all 60 tested SNPs among patients and controls were very similar. No SNP reached an odds ratio of 2, and no association with stroke risk was statistically significant. Conclusions: Our results do not indicate a clinically relevant role of any of the investigated SNPs for stroke risk in individuals hospitalized for ischemic stroke/transient ischemic attack before or at 60 years of age. These results are in accordance with previous metaanalyses showing at most a very modest or no significant effect of these SNPs on stroke risk.
Journal Article