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Introduction: In emergency rooms (ERs), 5% of patients experiencing an acute ischemic stroke (AIS) receive an alternative diagnosis; these cases are known as stroke chameleons (SC). The percentage of SC treated with intravenous thrombolysis (IVT) and the characteristics have not been well described. We aimed at investigating the variables associated with the probability receiving IVT. Methods: In this prospective study, we included consecutive patients with SC admitted at the ER of Clínica Alemana between September 2014 and October 2023. Results: Among 1193 stroke patients; sixty-three (5.2%) corresponded to SC. Ten of these cases (15.8%, 95%CI 8.8-26.8) were treated with IVT, mean door to needle time (DTN) of 85.7 (SD 35) minutes, median of 73.5 (IQR 62-113) minutes. SC who underwent IVT were younger (p=0.01), with higher NIHSS (p=0.05). They presented more frequently with altered level of consciousness in the NIHSS (p=0.01), language abnormities (p=0.001) and dysarthria (p=0.01). In multivariate analysis, none of the variables were significantly associated with IVT. A secondary analysis showed that only time to brain imaging was significantly associated with IVT (OR: 0.99; 95%CI, 0.98-0.99. p=0.01). Conclusions: almost 1 out of every 7 SC could be treated with IVT but with a prolongued DTN; the chance of being treated is associated with time to brain imaging

Background The efficacy of intravenous thrombolysis (IVT) is time-dependent.

Introduction: The World Health Organization predicts that the global population aged 60 years and older will double by 2050, leading to a significant rise in the public health impact of acute ischemic stroke (AIS). Existing stroke guidelines do not specify an upper age limit for the administration of intravenous thrombolysis (IVT), although some suggest a relative exclusion criterion in patients aged ≥ 80 in the 3 – 4.5 hour window. Many physicians avoid treating these patients with IVT, argumenting high risk and little benefit. Our aim was to investigate the efficacy and safety of IVT treatment in patients with non-minor AIS aged ≥ 90, admitted to our institution. The primary efficacy endpoint was the ability to walk at discharge (mRS 0-3) and the primary safety endpoints were death and symptomatic intracerebral hemorrhagic transformation (sIHT) at discharge. Methods: Patients with AIS aged ≥ 90 admitted to our center from January 2003 to December 2022 were included. They were selected if had an NIHSS ≥ 5, were previously ambulatory (prestroke mRS score 3 or less) and arrived within 6 hours from symptom onset. Those treated or not with IVT were compared with univariate analysis. Results: The mean age was 93.2 (2.4) years and 51 (73.9%) were female. The admission mRS and NIHSS were 1 (IQR 0 – 2) and 14 (IQR 7 – 22), respectively. Thrombolysed patients had a shorter time from symptom onset to door and lower glycemia on admission. IVT was associated with a higher proportion of patients achieving mRS 0 – 3 at discharge (p=0.03) and at 90 days (p=0.04). There were no differences between groups in the risk of death (p=0.55) or sIHT (p=0.38). Conclusion: In this small sample, ambulatory patients aged ≥ 90 with moderate or severe AIS treated with IVT, had increased odds of being able to walk independently at discharge than those not treated, without safety concerns.

Abstract Fuel produced from CO2 and H2O using solar energy can contribute to making aviation more sustainable. Particularly attractive is the thermochemical production pathway via a ceria‐based redox cycle, which uses the entire solar spectrum as the source of high‐temperature process heat to directly produce a syngas mixture suitable for synthetizing kerosene. However, its solar‐to‐fuel energy efficiency is hindered by the inadequate isotropic topology of the ceria porous structure, which fails to absorb the incident concentrated solar radiation within its entire volume. This study presents the design and 3D‐print of hierarchically channeled structures of pure ceria by direct ink writing (DIW) to enable volumetric radiative absorption while maintaining high effective densities required for maximizing the fuel yield. The complex interplay between radiative heat transfer and thermochemical reaction is investigated in a solar thermogravimetric analyzer with samples exposed to high‐flux irradiation, mimicking realistic operation of solar reactors. Channeled structures with a stepwise optical thickness achieve a higher and more uniform temperature profile compared to that of state‐of‐art isotropic structures, doubling the volume‐specific fuel yield for the same solar flux input. Thermomechanical stability of the ceria graded structures, DIW‐printed using a novel ink formulation with optimal rheological behavior, is validated by performing 100 consecutive redox cycles.

Objective. A narrative overview of regional academic research collaborations to address the increasing burden and gaps in care for patients at risk of, and who suffer from, stroke in Latin America (LA). Materials and methods. A summary of experiences and knowledge of the local situation is presented. No systematic literature review was performed. Results. The rapidly increasing burden of stroke poses immense challenges in LA, where prevention and manage­ment strategies are highly uneven and inadequate. Clinical research is increasing through various academic consortia and networks formed to overcome structural, funding and skill barriers. However, strengthening the ability to generate, analyze and interpret randomized evidence is central to further develop effective therapies and healthcare systems in LA. Conclusions. Regional networks foster the conduct of multicenter studies –particularly randomized controlled trials–, even in resource-poor regions. They also contribute to the external validity of international studies and strengthen systems of care, clinical skills, critical thinking, and international knowledge exchange.

Background and Purpose: Transcranial Doppler (TCD) identifies acute stroke patients with arterial occlusion where treatment may not effectively open the blocked vessel. This study aimed to examine the clinical utility and prognostic value of TCD flow findings in patients enrolled in a multicenter prospective study (CLOTBUST‐PRO). Methods: Patients enrolled with intracranial occlusion on computed tomography angiography (CTA) who underwent urgent TCD evaluation before intravenous thrombolysis was included in this analysis. TCD findings were assessed using the mean flow velocity (MFV) ratio, comparing the reciprocal ratios of the middle cerebral artery (MCA) depths bilaterally (affected MCA‐to‐contralateral MCA MFV [aMCA/cMCA MFV ratio]). Results: A total of 222 patients with intracranial occlusion on CTA were included in the study (mean age: 64 ± 14 years, 62% men). Eighty‐eight patients had M1 MCA occlusions; baseline mean National Institutes of Health Stroke Scale (NIHSS) score was 16, and a 24‐hour mean NIHSS score was 10 points. An aMCA/cMCA MFV ratio of <.6 had a sensitivity of 99%, specificity of 16%, positive predictive value (PV) of 60%, and negative PV of 94% for identifying large vessel occlusion (LVO) including M1 MCA, terminal internal carotid artery, or tandem ICA/MCA. Thrombolysis in Brain Ischemia scale, with (grade ≥1) compared to without flow (grade 0), showed a sensitivity of 17.1%, specificity of 86.9%, positive PV of 62%, and negative PV of 46% for identifying LVO. Conclusions: TCD is a valuable modality for evaluating arterial circulation in acute ischemic stroke patients, demonstrating significant potential as a screening tool for intravenous/intra‐arterial lysis protocols. [ABSTRACT FROM AUTHOR]

Abstract Background: Low-dose alteplase (LrtPA) has been shown not to be inferior to the standard-dose (SrtPA) with respect to death/disability. Objective: We aim to evaluate the percentage of patients treated with LrtPA at our center after the ENCHANTED trial and the factors associated with the use of this dosage. Methods: Prospective study in consecutive patients with an acute stroke admitted between June 2016 and November 2018. Results: 160 patients were treated with intravenous thrombolysis, 50% female; mean age 65.4±18.5 years. Of these, 48 patients (30%) received LrtPA. In univariate analysis, LrtPA was associated with patient's age (p=0.000), previous modified Rankin scale scores (mRS) (p

IntroductionThe frequency of intravenous thrombolysis (IVT) in acute ischemic stroke (AIS) is lower than it should be in several regions of the world. It is unclear what interventions can produce significant improvements in IVT utilization. We aimed to investigate the temporal trends in IVT in AIS and identify changes in time that could be associated with specific interventions.MethodsWe included patients with AIS who were admitted from January 1998 to December 2019 in our institution. To analyze trends in utilization and time points in which they changed, we performed a Joinpoint regression analysis. Interventions were assigned to a specific category according to the Behavior Change Wheel framework intervention function criteria.ResultsA total of 3,361 patients with AIS were admitted, among which 538 (16%) received IVT. There were 245 (45.5%) women, and the mean age and median National Institutes of Health Stroke Scale (NIHSS) scores were 68.5 (17.2) years and 8 (interquartile range, 4–15), respectively. Thrombolysis use significantly increased by an average annual 7.6% (95% CI, 5.1–10.2), with one Joinpoint in 2007. The annual percent changes were.45% from 1998 to 2007 and 9.57% from 2007 to 2019, concurring with the stroke code organization, the definition of door-to-needle times as an institutional performance measure quality indicator, and the extension of the therapeutic window.ConclusionsThe IVT rates consistently increased due to a continuous process of protocol changes and multiple interventions. The implementation of a complex multidisciplinary intervention such as the stroke code, as well as the definition of a hospital quality control metric, were associated with a significant change in this trend.

Abstract Background High adherence to a Mediterranean Diet is associated with reduced incidence and mortality of acute ischemic stroke (AIS) but may also be associated with severity. Our purpose was to investigate the association of adherence to a Mediterranean diet and severity in a prospective hospital register of AIS patients. Methods We included AIS patients admitted from February 2017 to July 2019. All were assessed by a neurologist with a standard stroke protocol, including NIHSS. Adherence to Mediterranean diet was prospectively measured by the 14-point Mediterranean Diet Adherence Screener (MEDAS) and defined as low (0–6 points) or high (7–14 points). Demographic and clinical characteristics were compared by group with univariate analysis. A Generalized Linear Model (GLM) was used to investigate the association of admission NIHSS as a continuous ordinal variable and an ordinal logistic regression (OLR) analysis to determine the independent association of the NIHSS quartiles with adherence to Mediterranean diet. Results Three hundred sixty-eight patients were included, mean age 68.3 (17.7), 158 (42.9%) females. The median NIHSS score was 3 (IQR 1–9) and the median MEDAS score was 6 (IQR 4.5–8). Patients with high MEDAS scores had significantly lower; admission NIHSS scores, sedentary lifestyle, body mass index, total and LDL cholesterol levels, but higher alcohol consumption. After adjustments, high adherence to Mediterranean diet remained independently associated with lower stroke severity both in the GLM (β coefficient = − 0.19, p = 0.01) and in the OLR model (OR for lower NIHSS quartiles 0.6 (95% CI 0.37–0.98, p = 0.04). Conclusions Higher pre-stroke adherence to a Mediterranean diet is independently associated with lower AIS severity.

Background and Purpose Although onset-to-treatment time is associated with early clinical recovery in acute ischemic stroke (AIS) patients treated with intravenous tissue plasminogen activator (tPA), the effect of the timing of tPA-induced recanalization on functional outcomes remains debatable. Methods We conducted a multicenter, prospective observational cohort study to determine whether early (within 1-hour from tPA-bolus) complete or partial recanalization assessed during 2-hour real-time transcranial Doppler monitoring is associated with improved outcomes in patients with proximal occlusions. Outcome events included dramatic clinical recovery (DCR) within 2 and 24-hours from tPA-bolus, 3-month mortality, favorable functional outcome (FFO) and functional independence (FI) defined as modified Rankin Scale (mRS) scores of 0–1 and 0–2 respectively. Results We enrolled 480 AIS patients (mean age 66±15 years, 60% men, baseline National Institutes of Health Stroke Scale score 15). Patients with early recanalization (53%) had significantly (jos-2019-01648P

Abstract Background: Topographic patterns may correlate with causes of ischemic stroke. Objective: To investigate the association between diffusion-weighted imaging (DWI) and Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification. Methods: We included 1019 ischemic stroke patients. DWI were classified as: i) negative; ii) DWI single lesion (cortico-subcortical, cortical, subcortical ≥20 mm, or subcortical

Purpose: To determine the intra- and interrater agreement of mean flow velocity (MFV) and pulsatility index (PI) measurement in middle cerebral arteries, assessed by transcranial Doppler (TCD) with M-mode. Methods: Masked experienced neurosonologists performed TCD with M-mode using handheld probe in healthy adult volunteers. The Bland–Altman method for concordance and intraclass correlation coefficient were used. Results: Seventy-seven healthy volunteers and seven raters participated (3 on regular TCD shift and 4 off-shift). The intrarater absolute mean difference between measurements was 5.5 cm/s [95% confidence interval (CI), 4.7–6.3] for MVF and 0.073 (95% CI, 0.063–0.083) for PI. The difference between MFV measurements was significantly higher in off-shift raters (p=0.015). The interrater absolute mean difference between measurements was 6.5 cm/s (95% CI, 5.5–7.5) for MVF and 0.065 (95% CI, 0.059–0.071) for PI. No influence was found for the middle cerebral artery side, volunteer's sex, or age, and there was no significant difference between raters. The intraclass correlation coefficient was 82.2% (95% CI 77.8–85.6) and 72.9% (95% CI 67.4–77.6) for MFV and PI, respectively. Conclusions: There exists good intra- and interrater agreement in MFV and PI measurements using M-mode TCD. These results support the use of this noninvasive tool and are important for clinical and investigational purposes.

Sin resumen.

Background: Distribution shifts of the modified Rankin scale (mRs) is used as outcome measure in acute ischemic stroke (AIS) randomized controlled trials (RCT). Distribution across strata of mRs is relevant for sample size calculations and may be affected by eligibility criteria. Aim: We aimed to assess the distribution of mRs scores across its different strata in AIS according to usual eligibility criteria. Methods: We computed follow-up mRs strata distribution between an unselected cohort and samples with (a) time from symptom onset 3 and

Background The uptake of proven stroke treatments varies widely. We aimed to determine the association of evidence‐based processes of care for acute ischemic stroke (AIS) and clinical outcome of patients who participated in the HEADPOST (Head Positioning in Acute Stroke Trial), a multicenter cluster crossover trial of lying flat versus sitting up, head positioning in acute stroke. Methods and Results Use of 8 AIS processes of care were considered: reperfusion therapy in eligible patients; acute stroke unit care; antihypertensive, antiplatelet, statin, and anticoagulation for atrial fibrillation; dysphagia assessment; and physiotherapist review. Hierarchical, mixed, logistic regression models were performed to determine associations with good outcome (modified Rankin Scale scores 0–2) at 90 days, adjusted for patient and hospital variables. Among 9485 patients with AIS, implementation of all processes of care in eligible patients, or “defect‐free” care, was associated with improved outcome (odds ratio, 1.40; 95% CI, 1.18–1.65) and better survival (odds ratio, 2.23; 95% CI, 1.62–3.09). Defect‐free stroke care was also significantly associated with excellent outcome (modified Rankin Scale score 0–1) (odds ratio, 1.22; 95% CI, 1.04–1.43). No hospital characteristic was independently predictive of outcome. Only 1445 (15%) of eligible patients with AIS received all processes of care, with significant regional variations in overall and individual rates. Conclusions Use of evidence‐based care is associated with improved clinical outcome in AIS. Strategies are required to address regional variation in the use of proven AIS treatments. Clinical Trial Registration URL: https://www.clinicaltrials.gov. Unique Identifier: NCT02162017.

Fuel produced from CO2 and H2O using solar energy can contribute to making aviation more sustainable. Particularly attractive is the thermochemical production pathway via a ceria‐based redox cycle, which uses the entire solar spectrum as the source of high‐temperature process heat to directly produce a syngas mixture suitable for synthetizing kerosene. However, its solar‐to‐fuel energy efficiency is hindered by the inadequate isotropic topology of the ceria porous structure, which fails to absorb the incident concentrated solar radiation within its entire volume. This study presents the design and 3D‐print of hierarchically channeled structures of pure ceria by direct ink writing (DIW) to enable volumetric radiative absorption while maintaining high effective densities required for maximizing the fuel yield. The complex interplay between radiative heat transfer and thermochemical reaction is investigated in a solar thermogravimetric analyzer with samples exposed to high‐flux irradiation, mimicking realistic operation of solar reactors. Channeled structures with a stepwise optical thickness achieve a higher and more uniform temperature profile compared to that of state‐of‐art isotropic structures, doubling the volume‐specific fuel yield for the same solar flux input. Thermomechanical stability of the ceria graded structures, DIW‐printed using a novel ink formulation with optimal rheological behavior, is validated by performing 100 consecutive redox cycles. [ABSTRACT FROM AUTHOR]

The diagnosis of brain death (BD) is complex. For this reason, we aimed to evaluate the accuracy of power mode transcranial Doppler (PMD-TCD) in diagnosing BD. Patients and methods: Patients admitted to an intensive care unit between December 2003 and January 2012 were included in this study if they were in a structural coma, had no craniectomy, and were evaluated blind by a neurologist using PMD-TCD. The diagnosis of BD was based on an evaluation that took into consideration the absence of sedative drugs, a median blood pressure >60 mmHg, a body temperature >35°C, and the absence of brainstem reflexes. A neurosonologist followed a protocol using PMD-TCD that considered the examination as positive for brain circulatory arrest given the presence of reverberating, small systolic peaks or the disappearance of a previous signal present in both middle cerebral arteries and intracranial vertebral arteries. Results: A total of 74 patients were evaluated. In 61 (82.4%) patients the interval between both evaluations was less than 1 hour. The sensitivity and specificity for the diagnosis of BD with PMD-TCD were 100% and 98%, respectively. The positive and negative likelihood ratios for BD were 45 and 0, respectively. Conclusion: PMD-TCD is accurate for the diagnosis of BD.

Background and purposeUntil now, stroke and transient ischemic attack (TIA) have been clinically based terms which describe the presence and duration of characteristic neurological deficits attributable to intrinsic disorders of particular arteries supplying the brain, retina, or (sometimes) the spinal cord. Further, infarction has been pathologically defined as death of neural tissue due to reduced blood supply. Recently, it has been proposed we shift to definitions of stroke and TIA determined by neuroimaging results alone and that neuroimaging findings be equated with infarction.MethodsWe examined the scientific validity and clinical implications of these proposals using the existing published literature and our own experience in research and clinical practice.ResultsWe found that the proposals to change to imaging-dominant definitions, as published, are ambiguous and inconsistent. Therefore, they cannot provide the standardization required in research or its application in clinical practice. Further, we found that the proposals are scientifically incorrect because neuroimaging findings do not always correlate with the clinical status or the presence of infarction. In addition, we found that attempts to use the proposals are disrupting research, are otherwise clinically unhelpful and do not solve the problems they were proposed to solve.ConclusionWe advise that the proposals must not be accepted. In particular, we explain why the clinical focus of the definitions of stroke and TIA should be retained with continued sub-classification of these syndromes depending neuroimaging results (with or without other information) and that infarction should remain a pathological term. We outline ways the established clinically based definitions of stroke and TIA, and use of them, may be improved to encourage better patient outcomes in the modern era.