RESUMO
Background: The extent of ischemic injury in acute stroke is assessed in clinical practice using the Acute Stroke Prognosis Early CT Score (ASPECTS) rating system. However, current ASPECTS semi-quantitative topographic scales assess only the middle cerebral artery (MCA) (original ASPECTS) and posterior cerebral (PC-ASPECTS) territories. For treatment decision-making in patients with anterior cerebral artery (ACA) occlusions and internal carotid artery (ICA) occlusions with large ischemic cores, measures of all hemispheric regions are desirable. Methods: In this cohort study, anatomic rating systems were developed for the anterior cerebral (AC-ASPECTS, 3 points) and anterior choroidal artery (ACh-ASPECTS, 1 point) territories. In addition, a total supratentorial hemisphere (H-ASPECTS, 16 points) score was calculated as the sum of the MCA ASPECTS (10 regions), supratentorial PC-ASPECTS (2 regions), AC-ASPECTS (3 regions), and ACh-ASPECTS (1 region). Three raters applied these scales to initial and 24 h CT and MR images in consecutive patients with ischemic stroke (IS) due to ICA, M1-MCA, and ACA occlusions. Results: Imaging ratings were obtained for 96 scans in 50 consecutive patients with age 74.8 (±14.0), 60% female, NIHSS 15.5 (9.25-20), and occlusion locations ICA 34%; M1-MCA 58%; and ACA 8%. Treatments included endovascular thrombectomy +/- thrombolysis in 72%, thrombolysis alone in 8%, and hemicraniectomy in 4%. Among experienced clinicians, inter-rater reliability for AC-, ACh-, and H-ASPECTS scores was substantial (kappa values 0.61-0.80). AC-ASPECTS abnormality was present in 14% of patients, and ACh-ASPECTS abnormality in 2%. Among patients with ACA and ICA occlusions, H-ASPECTS scores compared with original ASPECTS scores were more strongly associated with disability level at discharge, ambulatory status at discharge, discharge destination, and combined inpatient mortality and hospice discharge. Conclusion: AC-ASPECTS, ACh-ASPECTS, and H-ASPECTS expand the scope of acute IS imaging scores and increase correlation with functional outcomes. This additional information may enhance prognostication and decision-making, including endovascular thrombectomy and hemicraniectomy.
RESUMO
Puesto que cada año se realizan docenas de estudios transversales que estiman la prevalencia de factores de riesgo de las enfermedades no transmisibles, es posible que exista mucha información de gran utilidad desde el punto de vista de la vigilancia de dichos factores. No obstante, hay fuertes motivos para poner en tela de juicio el rigor metodológico y la fe que se puede depositar en los resultados de muchos de estos estudios. Los posibles beneficios que aportan estos datos se ven limitados por las deficiencias de los estudios, en parte porque no hay información metodológica clara y explícita con los detalles necesarios para evaluar los procedimientos empleados y porque no se aplica una metodología uniforme que permita hacer comparaciones a lo largo del tiempo y entre distintos estudios. Este trabajo tiene por objetivo servir como herramienta didáctica y práctica. En él se describe la construcción de un instrumento para evaluar la utilidad de los estudios de prevalencia efectuados en el contexto de las actividades de vigilancia, utilizando a manera de ejemplo el caso de la hipertensión. El trabajo también examina e ilustra las deficiencias más comunes de los estudios de prevalencia y ofrece pautas metodológicas que servirán para orientar cualquier estudio futuro y estimular investigaciones adicionales en este campo
Every year dozens of cross-sectional studies are carried out that estimate the prevalence of risk factors for chronic noncommunicable diseases. Given that, there is potentially a large amount of information that could be extremely useful for risk factor surveillance. However, there are good reasons to question the methodological rigor and the reliability of the results coming from many of these studies. The potential benefits of the data are curtailed by the studies' shortcomings, in part often because there is no clear and explicit methodological information providing the details needed to assess the procedures that were actually used, as well as a failure to apply a uniform methodology that would allow comparisons over time or across studies. This paper is intended to be both a didactic and practical tool. It describes the construction of an instrument for assessing the usefulness of prevalence studies done within the context of surveillance activities, using the example of hypertension. The paper discusses and illustrates the most common pitfalls found with prevalence studies, and it also offers methodological standards that can guide future prevalence studies as well as stimulate future research efforts in this area