Significance of Early CT Signs in Acute Stroke

157

110

Background and Purpose-Early neurological deterioration (END) occurs in approximately one third of all ischemic stroke patients and is associated with a poor outcome. Our study sought to assess the value of ultra-early MRI in the prediction of END in stroke patients. Methods-Between August 1999 and November 2001, 38 stroke patients with a proven middle cerebral artery (MCA) or intracranial internal carotid artery (ICA) occlusion on MR angiography underwent perfusion-weighted imaging (PWI) and diffusion-weighted imaging (DWI) within 6 hours after onset, and 30 fulfilled all inclusion criteria. Control DWI and MR angiography were performed between days 3 and 5. Cranial CT was performed to rule out hemorrhagic transformation. Vascular risk factors, temperature, blood pressure, glycemia, and blood count were assessed on admission. National Institutes of Health Stroke Scale (NIHSS) scores were obtained at baseline and at 6, 12, 24, and 48 hours. At the same time points, transcranial Doppler (TCD) examinations were conducted to assess arterial recanalization. END was defined as an increase in the NIHSS score Ͼ4. A logistic regression model was applied to detect independent predictors of END. The Kruskal-Wallis test was used to evaluate the relationship between infarct growth and duration of vessel occlusion. Results-Initial MR angiography showed an occlusion of intracranial ICA in 7 patients (23.3%), of proximal MCA in 14 (46.6%), and of distal MCA in the remaining 9 (30%). A PWI-DWI mismatch Ͼ20% was observed in 28 patients (93.3%). END occurred in 7 patients (23.3%). Baseline NIHSS score (Pϭ0.05), proximal site of occlusion (Pϭ0.002), initial DWI (Pϭ0.002) and PWI (Pϭ0.003) volumes, and reduced PWI-DWI mismatch (Pϭ0.038) were associated with END in the univariate analysis. Only hyperacute DWI volume remained as a predictor of END when a logistic regression model was applied (odds ratio, 11.5; 95% CI, 2.31 to 57.10; Pϭ0.0028). A receiver operator characteristic curve identified a cutoff point of DWI Ͼ89 cm 3 (sensitivity, 85.7%; specificity, 95.7%) to predict END. A graded response was seen in DWI lesion expansion in relation to duration of arterial occlusion (Pϭ0.017). Conclusions-Ultra-early

Section: Discussionmentioning

confidence: 54%

Prediction of Early Neurological Deterioration Using Diffusion- and Perfusion-Weighted Imaging in Hyperacute Middle Cerebral Artery Ischemic Stroke

Arenillas

Rovira

Molina

et al. 2002

157

110

“…Signs of ischemia on CT scan reflect early tissue edema and/or tissue hypoperfusion 11,24 Regions of ischemic brain showing hypoattenuation as a manifestation of tissue edema are probably always irreversibly damaged and therefore, unsalvageable with thrombolysis. 11 Rarely, cortical sulcal *There was no difference between the risk ratios in the 2 ASPECTS groups using a test for interaction from logistic regression analysis.…”

Section: Discussionmentioning

confidence: 99%

Selection of Acute Ischemic Stroke Patients for Intra-Arterial Thrombolysis With Pro-Urokinase by Using ASPECTS

Hill

Rowley

Adler

et al. 2003

256

183

Background-Previous studies have suggested that baseline computed tomographic (CT) scans might be a useful tool for selecting particular ischemic stroke patients who would benefit from thrombolysis. The aim of the present study was to assess whether the baseline CT scan, assessed with the Alberta Stroke Program Early CT Score (ASPECTS), could identify ischemic stroke patients who might particularly benefit from intra-arterial thrombolysis of middle cerebral artery occlusion. Methods-Baseline and 24-hour follow-up CT scans of patients randomized within 6 hours of symptoms to intra-arterial thrombolysis with recombinant pro-urokinase or control in the PROACT-II study were retrospectively scored by using ASPECTS. Patients were stratified into those with ASPECTS Ͼ7 or Յ7. Independent functional outcome at 90 days was compared between the 2 strata according to treatment assignment. Results-The analysis included 154 patients with angiographically confirmed middle cerebral artery occlusion. The unadjusted risk ratio of an independent functional outcome, in favor of treatment, in the ASPECTS Ͼ7 group was 5.0 (95% confidence interval [CI], 1.3 to 19.2) compared with 1.0 (95% CI, 0.6 to 1.9) in the ASPECTS Յ7 group. After adjustment for baseline characteristics, the risk ratio in the ASPECTS score Ͼ7 was 3.2 (95% CI, 1.2 to 9.1). Similar favorable treatment effects were observed when secondary outcomes were used, but these did not reach statistical significance. Conclusions-Ischemic stroke patients with a baseline ASPECTS Ͼ7 were 3 times more likely to have an independent functional outcome with thrombolytic treatment compared with control. Patients with a baseline ASPECTS Յ7 were less likely to benefit from treatment. This observation suggests that ASPECTS can be both a useful clinical tool and an important method of baseline risk stratification in future clinical trials of acute stroke therapy.

“…A study design similar to our own revealed that sulcal effacement was sometimes followed by diffusion-weighted imaging lesion growth, but could also be associated with resolution of symptoms and lack of infarction. 19 It appears that elevated rCBV can maintain tissue viability for varying lengths of time in different patients. In some patients, blood flow shunting appears to be sufficient to prevent infarction.…”

Section: Prognostic Significance Of Ischemic Changesmentioning

confidence: 99%

Differential Prognosis of Isolated Cortical Swelling and Hypoattenuation on CT in Acute Stroke

Butcher

Lee

Parsons

et al. 2007

Background and Purpose-The Alberta Stroke Program Early CT Score (ASPECTS) is a validated method of assessing parenchymal ischemic changes, including focal swelling and hypoattenuation. The hypothesis that these signs result from different pathophysiological processes was tested by comparing CT with diffusion and perfusionweighted MRI. Methods-MRI and CT were performed, within 2 hours of each other, in 30 ischemic stroke patients Ͻ17 hours after symptom onset. Relative apparent diffusion coefficient, relative cerebral blood flow, and relative cerebral blood volume were calculated for individual cortical ASPECTS regions. Regional infarction was assessed on days 3 to 5. Results-Isolated focal swelling was seen in 25 ASPECTS cortical regions from 6 patients.