scholarly journals Intra-domain task-adaptive transfer learning to determine acute ischemic stroke onset time

2021 ◽  
Vol 90 ◽  
pp. 101926
Author(s):  
Haoyue Zhang ◽  
Jennifer S Polson ◽  
Kambiz Nael ◽  
Noriko Salamon ◽  
Bryan Yoo ◽  
...  
Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Nandakumar Nagaraja ◽  
Marie Luby ◽  
Matthew Edwardson ◽  
Ramin Zand ◽  
Lawrence L Latour

Objective: FLAIR hyperintensity is being used in clinical trials as a surrogate imaging biomarker for stroke onset time to test the safety of thrombolysis. Studies have shown that patients with negative and positive FLAIR hyperintensity overlap at similar time points from stroke onset in the early phase of acute ischemic stroke (AIS). Hyperintensity on FLAIR MRI likely represents increased tissue water content. We sought to determine if cerebral blood volume (CBV) mediates FLAIR hyperintensity in the early phase of AIS. Methods: AIS patients seen in 2012 were included in the study if i) onset time was known, ii) an MRI with perfusion was performed within 12 hours of onset time, iii) had imaging confirmed vascular occlusion of ICA, M1, or M2. Following co-registration of raw perfusion images with FLAIR, CBV maps were generated using PMA ASIST™ software. Two raters blinded to clinical information separately evaluated the DWI, FLAIR and CBV maps and measured the signal intensity ratio (SIR) for the brightest region on FLAIR normalized by homologous contra-lateral tissue. The SIR was similarly measured for CBV in same region. FLAIR negative was defined as SIR<1.15, “Low CBV” was defined as CBV SIR <0.5. Results: One hundred eighty two patients were screened and 30 met all study criteria; 21 women, with mean age of 71 (± 16) years and median NIHSS 18 (IQR 9-22). Using linear regression analysis, CBV SIR was associated with FLAIR SIR (p <0.049). In the 0-3hr time window, overall CBV was not associated with FLAIR hyperintensity. However, in the 3-7.5hr time window, patients with negative FLAIR were more likely to have low CBV and conversely, patients with positive FLAIR were more likely to have normal CBV. Conclusion: CBV likely mediates FLAIR hyperintensity in 3-7.5hr of stroke onset but it has less impact on FLAIR hyperintensity in the first 3 hours of AIS. Low CBV could be a potential surrogate imaging biomarker in addition to FLAIR hyperintensity in the early phase of AIS.


2017 ◽  
Vol 13 (1) ◽  
pp. 74-82 ◽  
Author(s):  
Aoife De Brún ◽  
Darren Flynn ◽  
Laura Ternent ◽  
Christopher I Price ◽  
Helen Rodgers ◽  
...  

Background Treatment with intravenous alteplase for eligible patients with acute ischemic stroke is underused, with variation in treatment rates across the UK. This study sought to elucidate factors influencing variation in clinicians’ decision-making about this thrombolytic treatment. Methods A discrete choice experiment using hypothetical patient vignettes framed around areas of clinical uncertainty was conducted with UK-based clinicians. Mixed logit regression analyses were conducted on the data. Results A total of 138 clinicians completed the discrete choice experiment. Seven patient factors were individually predictive of increased likelihood of immediately offering IV alteplase (compared to reference levels in brackets): stroke onset time 2 h 30 min [50 min]; pre-stroke dependency mRS 3 [mRS 4]; systolic blood pressure 185 mm/Hg [140 mm/Hg]; stroke severity scores of NIHSS 5 without aphasia, NIHSS 14 and NIHSS 23 [NIHSS 2 without aphasia]; age 85 [68]; Afro-Caribbean [white]. Factors predictive of withholding treatment with IV alteplase were: age 95 [68]; stroke onset time of 4 h 15 min [50 min]; severe dementia [no memory problems]; SBP 200 mm/Hg [140 mm/Hg]. Three clinician-related factors were predictive of an increased likelihood of offering IV alteplase (perceived robustness of the evidence for IV alteplase; thrombolyzing more patients in the past 12 months; and high discomfort with uncertainty) and one with a decreased likelihood (high clinician comfort with treating patients outside the licensing criteria). Conclusions Both patient- and clinician-related factors have a major influence on the use of alteplase to treat patients with acute ischemic stroke. Clinicians’ views of the evidence, comfort with uncertainty and treating patients outside the license criteria are important factors to address in programs that seek to reduce variation in care quality regarding treatment with IV alteplase. Further research is needed to further understand the differences in clinical decision-making about treating patients with acute ischemic stroke with IV alteplase.


2021 ◽  
Vol 12 ◽  
Author(s):  
Jingjing Xiao ◽  
Huazheng Liang ◽  
Yue Wang ◽  
Shaoshi Wang ◽  
Yi Wang ◽  
...  

Objective: Hypoperfusion is an important factor determining the prognosis of ischemic stroke patients. The present study aimed to investigate possible predictors of hypoperfusion on MRI of ischemic stroke patients within 7 days of stroke onset.Methods: Ischemic stroke patients, admitted to the comprehensive Stroke Center of Shanghai Fourth People's Hospital affiliated to Tongji University within 7 days of onset between January 2016 and June 2017, were recruited to the present study. Magnetic resonance imaging (MRI), including both diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI), was performed within 7 days of the symptom onset. Time to maximum of the residue function (Tmax) maps were automatically evaluated using the RAPID software. The volume of hypoperfusion was measured outside the infarct area based on ADC &lt; 620 × 10−6 mm2/s. The 90 d mRS score was assessed through either clinic visits or telephone calls. Multivariate step-wise analysis was used to assess the correlation between MR findings and clinical variables, including the demographic information, cardio-metabolic characteristics, and functional outcomes.Results: Among 635 patients admitted due to acute ischemic stroke within 7 days of onset, 241 met the inclusion criteria. Hypoperfusion volume of 38 ml was the best cut-off value for predicting poor prognosis of patients with cerebral infarction (90 d-mRS score ≥ 2). The incidences of MR perfusion Tmax &gt; 4–6 s maps with a volume of 0–38 mL or &gt;38 mL were 51.9% (125/241) and 48.1% (116/241), respectively. Prior stroke and vascular stenosis (≥70%) were associated with MR hypoperfusion. Multivariate step-wise analysis showed that prior stroke and vascular stenosis (≥70%) were risk factors of Tmax &gt; 4–6 s maps, and the odds ratios (OR) were 3.418 (adjusted OR 95% CI: 1.537–7.600), and 2.265 (adjusted OR, 95% CI: 1.199–4.278), respectively.Conclusion: Our results suggest that prior stroke and vascular stenosis (≥70%) are strong predictors of hypoperfusion in patients with acute ischemic stroke within 7 days of stroke onset.


Author(s):  
Iskandar Nasution ◽  
Khairul Putra Surbakti ◽  
Netty Delvrita Lubis ◽  
Etiya Ekayana

Background: Alberta Stroke Program Early CT Score (ASPECTS) is a valid method for assessing early ischemic changes in the middle cerebral artery from a CT scan of patient with acute ischemic stroke. One of the factors that influence ASPECTS is stroke onset time, where a very subtle level of hypodensity in early onset can provide poor reliability on ASPECTS assessments. Aim of the study was to determine the relationship between the onset of acute ischemic stroke and ASPECTS.Methods: This study used a cross-sectional design with Chi-Square method in patients with acute ischemic stroke and anterior circulation stroke treated in The Stroke Corner and Integrated Ward of Haji Adam Malik General Hospital during the months of February - May 2019. All patients were evaluated for ASPECTS and stroke onset at admission. Stroke onset was divided into 3 parts: Under 24 hours, 24 - <48 hours and 48-72 hours. ASPECTS value was assessed by 2 observers. Authors categorized the ASPECT value into 2 groups: Low (≤7) and High (˃7).Results: Among 36 patients with Acute Ischemic Stroke, mean age was 55.7±13.9 years old, which male and female shares equal number by 18 persons (50%). Mean ASPECTS score was 7.2±2.0. This research found 5 patients (13.9%) with less than 24 hours onset and low ASPECTS score, 3 patients (8.3%) with 24 - <48 hours onset and low ASPECTS score, 7 patients (19.4%) with 24 - <48 hours onset and high ASPECTS score, 8 patients (22.2%) with 48-72 hours onset and low ASPECTS score, and 2 patients (5.6%) with 48-72 hours of onset and high ASPECTS score. Valuation of ASPECTS from both observers was considered as excellent (statistic K value = 0.9).Conclusions: ASPECTS has a significant relationship with stroke onset (p=0.029) and the initial ischemic change will be seen more clearly with increasing stroke onset time. 


Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Rami-James Assadi ◽  
Hongyu An ◽  
Yasheng Chen ◽  
Andria Ford ◽  
Jin-Moo Lee

Introduction: White matter hyperintensity volume (WMHv), a quantitative neuroimaging biomarker of cerebral small vessel disease (CSVD), is associated worse outcomes after ischemic stroke. In this study, we hypothesized that worse outcomes in CSVD patients were due to poor collateral flow during acute ischemia. Methods: 47 patients with acute ischemic stroke (AIS) were prospectively enrolled in this study. Serial MRIs were performed at 3 hours and 30 days after stroke onset. 3-hour FLAIR images were used to determine WMHv, after manually delineating lesions with MIPAV. An index of collateral flow (delayed perfusion to the penumbra) was determined by subtracting core volume (volume of tissue with ADC<600) from the volume of brain tissue with Tmax>2. Patient’s NIHSS was scored at 3 hours and 30 days after stroke onset and the difference was calculated (ΔNIHSS). Log-transformed WMHv was correlated to ΔNIHSS and the collateral flow index, using Pearson correlation. Results: Mean age = 63.9 years (SD 13.5); 37% female; median 3-hour NIHSS = 13 (IQR 6.5-20); median change in NIHSS between 3h and 30d = 4 (IQR: 0-7); median core volume = 13cm3 (IQR 4.3-35.6); median WMHv = 1.257cm3 (IQR 641-3595). WMHv was associated with reduced improvement in ΔNIHSS (R=-0.42, ρ=0.005). Furthermore, WMHv demonstrated a trend for association with poor collateral flow (R=-0.28, ρ=0.062). In this dataset, we will explore the relationship between WMHv and other tissue-based metrics of collateral flow, including the hypoperfusion intensity ratio (HIR) and the cerebral blood volume ratio (rCBV). Conclusions: Our study confirms that patients with CSVD have worse outcomes after AIS. The data also raise the possibility that these worse outcomes in CSVD patients may be mediated by compromised collateral flow in the setting of acute ischemia.


Stroke ◽  
2021 ◽  
Author(s):  
Victor Lopez-Rivera ◽  
Sergio Salazar-Marioni ◽  
Rania Abdelkhaleq ◽  
Sean I. Savitz ◽  
Alexandra L. Czap ◽  
...  

Background and Purpose: The optimal endovascular stroke therapy (EVT) care delivery structure is unknown. Here, we present our experience in creating an integrated stroke system (ISS) to expand EVT availability throughout our region while maintaining hospital and physician quality standards. Methods: We identified all consecutive patients with large vessel occlusion acute ischemic stroke treated with EVT from January 2014 to February 2019 in our health care system. In October 2017, we implemented the ISS, in which 3 additional hospitals (4 total) became EVT-performing hospitals (EPHs) and physicians were rotated between all centers. The cohort was divided by time into pre-ISS and post-ISS, and the primary outcome was time from stroke onset to EPH arrival. Secondary outcomes included hospital and procedural quality metrics. We performed an external validation using data from the Southeast Texas Regional Advisory Council. Results: Among 513 patients with large vessel occlusion acute ischemic stroke treated with EVT, 58% were treated pre-ISS and 43% post-ISS. Over the study period, EVT procedural volume increased overall but remained relatively low at the 3 new EPHs (<70 EVT/y). After ISS, the proportion of patients who underwent interhospital transfer decreased (46% versus 37%; P <0.05). In adjusted quantile regression, ISS implementation resulted in a reduction of time from stroke onset to EPH arrival by 40 minutes ( P <0.01) and onset to groin puncture by 29 minutes ( P <0.05). Rates of postprocedural hemorrhage, modified Thrombolysis in Cerebral Infarction (TICI) 2b/3, and 90-day modified Rankin Scale were comparable at the higher and lower volume EPHs. The improvement in onset-to-arrival time was not reflective of overall improvement in secular trends in regional prehospital care. Conclusions: In our system, increasing EVT availability decreased time from stroke onset to EPH arrival. The ISS provides a framework to maintain quality in lower volume hospitals.


Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Laura Blanco-García ◽  
Elisa Cortijo ◽  
Mercedes De Lera ◽  
Ana Calleja ◽  
María Usero ◽  
...  

Objective: We aimed to evaluate the parameter core growth speed (CGS) as a marker of collateral circulation status (CC) in acute ischemic stroke, and to compare it with other brain perfusion-derived markers of collateral capacity. Methods: We retrospectively studied acute ischemic stroke patients who were evaluated with urgent computed tomography perfusion (CTP) and CT angiography. Inclusion criteria comprised known time of onset and anterior circulation proximal occlusion. Collateral circulation was assessed on CTP-source images and rated as poor (0-1) vs. good (2-3) following a previously published scale. CTP maps were computed using Neuroscape 2.0 software by Olea Medical. Infarct core volume was calculated as the brain tissue with >70% reduction in cerebral blood flow (CBF) as compared to the unaffected side. CGS was obtained by dividing core volume by the time from stroke onset to CTP acquisition. Relative cerebral blood volume (rCBV), relative CBF, and hypoperfusion index ratio (HIR = Tmax>10s/Tmax>6s) were used as comparators. Results: We included 41 patients (mean age 71 years; median NIHSS 17; median onset-CTP time 150 minutes). We observed a positive correlation between CGS and HIR (ρ= 0.517 p< 0.001), and negative correlations between rCBV and CGS (ρ= -0.669 p<0.0001), and rCBF and CGS (ρ= -0.749 p<0.0001). Collateral circulation was categorized as poor or good in 15 and 26 patients respectively. A gradual descend in CGS was seen as CC improved (p=0.0005). A logistic regression model adjusted by rCBV, rCBF and HIR identified CGS as independently associated with CC. The association of CGS with good CC in a ROC curve was highly significant (p=0.002, area under the curve 0.8). Conclusion: Core growth speed is robustly associated with collateral circulation status. This parameter can be directly obtained from infarct core volume without the need to process other perfusion or angiographic images, if the time of onset is well known.


Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Zhifeng Qi ◽  
Ke Jian Liu

Fear of hemorrhage transformation (HT) has been the primary reason for withholding the effective recanalization therapies (thrombolysis or thrombectomy) from most acute ischemic stroke (AIS) patients. Currently there is no reliable indicator available to predict HT before recanalization. The degradation of tight junction proteins plays a critical role in blood-brain barrier (BBB) disruption in ischemic stroke. We hypothesize that since occludin fragment in peripheral blood is derived from the degradation of occludin on cerebral microvessels, elevated blood occludin level directly reflects BBB disruption and may serve as a biomarker for BBB damage to predict the risk of HT after recanalization. In this study, we determined occludin fragment in the blood of rats, non-human primates and human patients after AIS using ELISA assay, and evaluated its level with BBB damage, HT, and other neurological outcomes. We found that ischemia induced rapid occludin degradation and BBB disruption, while occludin fragment was released into the blood circulation. Cerebral ischemia resulted in a dramatic increase of occludin fragments in rat blood samples after 4-hr ischemia, which was correlated well with occludin loss from ischemic cerebral microvessels. In the blood sample from ischemic rhesus monkeys, occludin level significantly increased after 2h ischemia from baseline, which correlated well with brain infarction shown in MRI images. We further collected the sera of AIS patients as early as they arrived at hospital. Our results indicated that the level of occludin increased in accord with ischemia onset time and neurological dysfunctions. The level of blood occludin in AIS patients with HT was much higher that those without HT. Together, our findings from rats, non-human primates and patients suggest that the level of occludin fragment in blood could serve as a biomarker for HT and neurological outcome following AIS, which could be used to safely guide recanalization for AIS in the clinic.


2009 ◽  
Vol 1 ◽  
pp. JCNSD.S2221
Author(s):  
Byron R. Spencer ◽  
Omar M. Khan ◽  
Bentley J. Bobrow ◽  
Bart M. Demaerschalk

Background Emergency Medical Services (EMS) is a vital link in the overall chain of stroke survival. A Primary Stroke Center (PSC) relies heavily on the 9-1-1 response system along with the ability of EMS personnel to accurately diagnose acute stroke. Other critical elements include identifying time of symptom onset, providing pre-hospital care, selecting a destination PSC, and communicating estimated time of arrival (ETA). Purpose Our purpose was to evaluate the EMS component of thrombolysed acute ischemic stroke patient care at our PSC. Methods In a retrospective manner we retrieved electronic copies of the EMS incident reports for every thrombolysed ischemic stroke patient treated at our PSC from September 2001 to August 2005. The following data elements were extracted: location of victim, EMS agency, times of dispatch, scene, departure, emergency department (ED) arrival, recordings of time of stroke onset, blood pressure (BP), heart rate (HR), cardiac rhythm, blood glucose (BG), Glasgow Coma Scale (GCS), Cincinnati Stroke Scale (CSS) elements, emergency medical personnel field assessment, and transport decision making. Results Eighty acute ischemic stroke patients received thrombolysis during the study interval. Eighty-one percent arrived by EMS. Two EMS agencies transported to our PSC. Mean dispatch-to-scene time was 6 min, on-scene time was 16 min, transport time was 10 min. Stroke onset time was recorded in 68%, BP, HR, and cardiac rhythm each in 100%, BG in 81%, GCS in 100%, CSS in 100%, and acute stroke diagnosis was made in 88%. Various diagnostic terms were employed: cerebrovascular accident in 40%, unilateral weakness or numbness in 20%, loss of consciousness in 16%, stroke in 8%, other stroke terms in 4%. In 87% of incident reports there was documentation of decision-making to transport to the nearest PSC in conjunction with pre-notification. Conclusion The EMS component of thrombolysed acute ischemic stroke patients care at our PSC appeared to be very good overall. Diagnostic accuracy was excellent, field assessment, decision-making, and transport times were very good. There was still room for improvement in documentation of stroke onset and in employment of a common term for acute stroke.


Stroke ◽  
2020 ◽  
Vol 51 (6) ◽  
pp. 1690-1695
Author(s):  
Jeroen C. de Jonge ◽  
Richard A.P. Takx ◽  
Frans Kauw ◽  
Pim A. de Jong ◽  
Jan W. Dankbaar ◽  
...  

Background and Purpose— In patients with acute stroke, the occurrence of pneumonia has been associated with poor functional outcomes and an increased risk of death. We assessed the presence and consequences of signs of pulmonary infection on chest computed tomography (CT) before the development of clinically overt pneumonia. Methods— In 200 consecutive patients with acute ischemic stroke who had CT angiography from skull to diaphragm (including CT of the chest) within 24 hours of symptom onset, we assessed the presence of consolidation, ground-glass-opacity and the tree-in-bud sign as CT signs of pulmonary infection and assessed the association with the development of clinically overt pneumonia and death in the first 7 days and functional outcome after 90 days with logistic regression. Results— The median time from stroke onset to CT was 151 minutes (interquartile range, 84–372). Thirty patients (15%) had radiological signs of infection on admission, and 22 (11.0%) had a clinical diagnosis of pneumonia in the first 7 days. Patients with radiological signs of infection had a higher risk of developing clinically overt pneumonia (30% versus 7.6%; adjusted odds ratios, 4.2 [95% CI, 1.5–11.7]; P =0.006) and had a higher risk of death at 7 days (adjusted odds ratios, 3.7 [95% CI, 1.2–11.6]; P =0.02), but not at 90 days. Conclusions— About 1 in 7 patients with acute ischemic stroke had radiological signs of pulmonary infection within hours of stroke onset. These patients had a higher risk of clinically overt pneumonia or death. Early administration of antibiotics in these patients may lead to better outcomes.


Sign in / Sign up

Export Citation Format

Share Document