Browsing by Author "Olavarria, Verónica"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Publication Association of Dual-Phase Computed Tomography Angiography and CTPerfusion in Patients with Acute Ischemic Stroke Beyond the 6-Hour Window(2023) Gallardo, Andrés; Lavados, Pablo; Cox, Pablo; De la Barra, Camila; Cavada, Gabriel; Olavarria, VerónicaBackground: There is controversy regarding the need to use advanced imaging to select candidates for thrombectomy in late window acute ischemic stroke (AIS). Hypoattenuation on CT angiography source images (CTA-SI) in arterial phase has been shown to be more sensitive than Alberta Stroke Program Early CT score (ASPECTS) of brain parenchyma to determine tissue at risk of ischemia. Our hypothesis is that the addition of a second acquisition at 35-50 seconds could complement the assessment of hypoperfused tissue that fails to receive flow through pial vessels. Methods: Patients with large vessel occlusion and 6-16 hours from symptom onset, admitted between August 2019 and July 2022 were evaluated with dualphase CT angiography (CTA) and CT-perfusion. The association between automated CT-perfusion valuesand dual-phase CTA was assessed through a correlation coefficient. Results: Pearson's coefficient demonstrated a high correlation between ischemic core volume and delayed CTA-SI with an inverse association of -0.91 and between Tmax≥6 sec volume and arterial CTA-SI with a value of -0.83. Conclusion: CTA-derived source images (CTA-SI) in two phases may be useful in the selection of patients with AIS presenting beyond the 6-hour window.Item Exclusion Criteria for Intravenous Thrombolysis in Stroke Mimics: An Observational Study(2013) Brunser, Alejandro M.; Illanes, Sergio; Lavados, Pablo; Muñoz, Paula; Carcamo, Daniel; Hoppe, Arnold; Olavarria, Verónica; Delgado, Iris; Dıaz, VioletaBackground: Stroke mimics (SMs) are frequent in emergency departments (EDs), but are treated infrequently with intravenous recombinant tissue plasminogen activator (rt-PA) thrombolysis. We aimed at identifying the factors that lead to the exclusion of SMs from thrombolytic therapy.Methods: Consecutive patients presenting to the ED between December 2004 and March 2011 with symptoms that suggested acute ischemic stroke were included.Results: Eight hundred forty-two patients were included in this study; 113 (13.4%) were considered SMs; these patients were younger (P = .01), more frequently diabetic (P = .001), arrived later to the ED (P = .03), had lower National Institutes of Health Stroke Scale scores (P < .001), and higher frequencies of negative diffusion-weighted imaging studies (P = .002). The most common causes of cases of SM were toxic metabolic disorders (n = 34 [30.1%]) and seizures (n = 22 [19.5%]). The most frequent cause of consultation was aphasia (n = 43 [37.6%]). SM patients had a total of 152 contraindications for rt-PA, with 34 (30%) patients having >1 contraindication. The most frequent of these were being beyond the therapeutic window for thrombolysis (n = 96) and having deficits not measurable by the National Institutes of Health Stroke Scale or very mild symptoms before the start of rt-PA (n = 37). Twenty-four (21.2%) patients had both contraindications simultaneously. Two patients (1.76%) in the SM group were candidates for rt-PA but did not receive this treatment because they or their family rejected it. Of 729 stroke patients, 87 (11.9%) did receive rt-PA.Conclusions: SM patients frequently had exclusion criteria for systemic thrombolysis, the most frequent being presenting beyond the established thrombolytic window