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Background and Purpose— Physiological effects of stroke are best assessed over entire brain networks rather than just focally at the site of structural damage. Resting-state functional magnetic resonance imaging can map functional-anatomic networks by analyzing spontaneously correlated low-frequency activity fluctuations across the brain, but its potential usefulness in predicting functional outcome after acute stroke remains unknown. We assessed the ability of resting-state functional magnetic resonance imaging to predict functional outcome after acute stroke. Methods— We scanned 37 consecutive reperfused stroke patients (age, 69±14 years; 14 females; 3-day National Institutes of Health Stroke Scale score, 6±5) on day 3 after symptom onset. After imaging preprocessing, we used a whole-brain mask to calculate the correlation coefficient matrices for every paired region using the Harvard-Oxford probabilistic atlas. To evaluate functional outcome, we applied the modified Rankin Scale at 90 days. We used region of interest analyses to explore the functional connectivity between regions and graph-computation analysis to detect differences in functional connectivity between patients with good functional outcome (modified Rankin Scale score ≤2) and those with poor outcome (modified Rankin Scale score >2). Results— Patients with good outcome had greater functional connectivity than patients with poor outcome. Although 3-day National Institutes of Health Stroke Scale score was the most accurate independent predictor of 90-day modified Rankin Scale (84.2%), adding functional connectivity increased accuracy to 94.7%. Preserved bilateral interhemispheric connectivity between the anterior inferior temporal gyrus and superior frontal gyrus and decreased connectivity between the caudate and anterior inferior temporal gyrus in the left hemisphere had the greatest impact in favoring good prognosis. Conclusions— These data suggest that information about functional connectivity from resting-state functional magnetic resonance imaging may help predict 90-day stroke outcome.

Background and Purpose— Contrary to usual static vascular imaging techniques, contrast-enhanced dynamic magnetic resonance angiography (dMRA) enables dynamic study of cerebral vessels. We evaluated dMRA ability to assess arterial occlusion, cerebral hemodynamics, and collateral circulation in acute ischemic stroke. Methods— Twenty-five acute ischemic stroke patients with proximal anterior circulation occlusion underwent dMRA on a 3T scanner within 12 hours of symptoms onset. Diffusion weighted imaging, T max 6 s lesion volumes and hypoperfusion intensity ratio as volume of T max >6 s/volume of T max >10 s were measured. Site and grade of occlusion (Thrombolysis in Myocardial Infarction criteria) were evaluated on time-of-flight MRA and dMRA. Leptomeningeal collaterality (American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology [ASITN/SIR] Scale) and asymmetries in venous clearance were assessed exclusively on dMRA. Collateral filling was dichotomized into incomplete (ASITN/SIR 0–2) or complete (ASITN/SIR 3–4). Results— On dMRA, site of occlusion was M1 in 21 patients, tandem internal carotid artery/M1 in 2 and tandem internal carotid artery/terminal internal carotid artery in 2 patients. Three tandem occlusions were not detected on time-of-flight–MRA. All patients had Thrombolysis in Myocardial Infarction 0 to 1 on time-of-flight–MRA, but three of them had Thrombolysis in Myocardial Infarction 2 on dMRA. Complete collateral filling (n=12, 48%) was associated with smaller diffusion weighted imaging lesion volume ( P =0.039), smaller hypoperfused volume ( P =0.018), and lower hypoperfusion intensity ratio ( P =0.006). Patients with symmetrical clearance of transverse sinuses (52%) were more likely to have complete collateral filling ( P =0.015). Conclusions— As a fast, direct, feasible, noninvasive, and reliable method to assess site of occlusion, collateral circulation and hemodynamic alterations, dMRA provides profound insights in acute stroke.

Background and Purpose— Nearly 50% of patients have residual motor deficits after stroke, and long-term motor outcome is difficult to predict. We assessed the predictive value of axonal damage to the corticospinal tract indexed by diffusion tensor imaging fractional anisotropy for long-term motor outcome. Methods— Consecutive patients with middle cerebral artery stroke underwent multimodal MRI, including diffusion tensor imaging ≤12 hours, 3 days, and 30 days after onset. Clinical severity, infarct volume, location of corticospinal tract damage on diffusion tensor tractography, and ratios of fractional anisotropy (rFA) between affected and unaffected sides of the corticospinal tract at the pons were evaluated. Severity of motor deficit at 2 years was categorized using the Motricity Index as no deficit (Motricity Index, 100), slight-moderate deficit (Motricity Index, 99–50), or severe deficit (Motricity Index, Results— We evaluated 70 patients (28 women; 72±12 years). rFA values at day 30 correlated with the degree of motor deficit at 2 years ( P P Conclusions— rFA at day 30 is an independent predictor of long-term motor outcome after stroke.

Background and Purpose: Malignant infarction (MI) is a life-threatening complication in patients with hemispheric stroke. Although few biochemical and neuroimaging markers have been published to be useful for the prediction of MI development, information about predictors of this complication is scarce. Leptomeningeal collateral circulation (LMC) has been associated in few studies with poor clinical outcome and infarct growth in patients with acute ischemic stroke, but no data have been reported about the possible association about LMC and MI. In this study, we investigated wether LMC baseline status can be a predictor of MI in patients treated with tissue plasminogen activator (tPA). Methods: One hundred and thirty-six patients with hemispheric stroke treated with tPA and angio-CT perfusion before tPA administration were evaluated. MI was diagnosed following Schwab et al. criteria (complete space-occupying MCA infarction with midline shift and compression of the basal cisterns on follow-up CT and further neurological deterioration consisting of a decrease in the level of consciousness to somnolence or stupor compared with baseline clinical status at admission). ASPECTS score was evaluated on CT at admission. LMC baseline status was also scored on CT angiography maps before tPA and classified as good or poor according to Tan et al. criteria and Lima et al. criteria Results: Sixty-six patients (48.2%) had good LMC and 70 patients (51.1%) had poor LMC, regardless of the classification used. Patients with poor LMC had a significantly higher NIHSS at admission and ASPECTS score < 7 was also found more frequently in this group. With regards to LMC, 14 patients (93%) developed MI in the group with poor LMC whereas just 1 patient (6.7%) had MI in the group with good LMC (p Conclusions: Poor LMC at admission is a predictor of MI in patients treated with tPA and, so this neuroimaging finding might be useful to identify those patients at higher risk to develop this fatal complication.

Objectives: The administration of rt-PA increases the risk of hemorrhagic transformation (HT) due to an increase in the permeability of the neurovascular unit which allows the extravasation of erythrocytes. In this study we compared the predictive capacity of different neurovascular unit components and their correlation with blood brain barrier (BBB) permeability abnormalities evaluated by advanced neuroimaging. Patients and methods: Eighty-three patients with hemispheric stroke treated with rt-PA who had angio-CT perfusion before fibrinolysis were evaluated. Lesion volumes were calculated on perfusion and permeability maps. HT was assessed in the cranial CT at 24±12h after rt-PA and classified following ECASS II criteria. HT was considered symptomatic (sHT) when it was associated with an increase ≥ 4 points in the NIHSS. The levels of cellular-fibronectin (cFn), total MMP-9, laminin, heparan-sulphate, collagen type IV and protein S100β pre-rtPA and at 2, 24 and 72h post-rtPA were analyzed. Results: Fourteen patients (16.8%) had HT, which was symptomatic in 3 (3.6%). On comparing patients with and without HT independently of the type, only MMP-9 and protein S100β levels at 24h were found to be higher in the HT group. However, baseline cFn levels were higher in patients with PH2 (12.5±5.6 vs. 6.6±3.8μg/mL, p=0.013) and sHT (13.8±6.7 vs. 6.7± 3.9μg/mL, p=0.003) and laminin levels were also lower in patients with PH2 (1.5±0.8 vs. 3.5±2.5ng/mL, p=0.016). In the multivariate analysis, only cFn levels remained as an independent predictor of sHT (OR 1.40;CI 95%, 1.02-1.93; p=0.037). The analysis of the permeability maps yielded cut-off values for the prediction of HT with high specificity and negative predictive values regardless of the threshold used for visualization of the abnormal permeability area. Conclusions: Among different neurovascular unit markers, this study seems to confirm the utility of cFn levels as potential predictors of sHT after rt-PA. Permeability maps would seem to predict the likelihood of not bleeding with high probability.

Background: Although variables associated with mortality in patients with intracerebral hemorrhage (ICH) are well known, there are few data about which factors are related to functional prognosis in these patients. Therefore, the aim of our study was to study the factors that determine poor functional outcome at three months in patients with ICH. Material and methods: We prospectively studied 241 patients consecutively admitted to our stroke unit due to a primary ICH within 12 hours of symptom onset. Clinical, radiological, and analytical data during hospitalisation were collected. Patients were also evaluated at three months. We defined as good outcome if modified Rankin scale (mRS) at three months was ≤2 and bad outcome if mRS was between 3 and 5. Results: At three months, 36.1% of patients presented good outcome (group A), 38.2% of patients poor outcome (group B) and 25.7% had died (85.5% of them during hospitalization). Patients of group B were significantly older (67 years vs 63), had a higher NIHSS at admission (15 vs 6), greater basal hematoma volume (23.8 cc vs 6.2 cc) and basal edema volume (10.9 cc vs 3.2 cc), a higher proportion of women (31.4% vs 14.9%), early neurological deterioration (END) (19.8% vs 3.4%), lobar localization of the hematoma (18.6% vs 11.4%), frontal lobe impairment (34.9% vs 9.1%) and insular ribbon (30.2% vs 6.8%), higher mass effect (26.9% vs 16.9%), relevant hematoma growth at 24 hours (78.4% vs 50%) and a greater frequency of more than 2 spot sings on neuroimage (47.8% vs 12.9%). In the logistic regression analysis, baseline NIHSS, END, lobar localization of the hematoma, frontal lobe and insular ribbon impairment, the presence of mass effect, hematoma and edema volume on baseline CT and a number of spot signs > 2 were significantly associated with poor outcome of patients. Conclusions: New radiological variables have to be considered for predicting poor outcome in patients with intracerebral hemorrhage in addition to classical factors.

Introduction: The European drug license for rt-PA considers diabetes plus previous stroke as an exclusion criterion for the administration of the treatment due to an increased risk of symptomatic intracranial hemorrhage (SICH). However, given that data from different studies have not confirmed this association, we were interested in analyzing whether the presence of these pathologies was associated with the development of SICH in our population of rt-PA-treated patients. Patients and methods: For the purpose of this study, we evaluated 667 patients treated with rt-PA at our center between October 1999 and December 2012. The existence of bleeding was assessed in the cranial CT performed at 24±12 h after rt-PA administration and was considered to be symptomatic when it was associated with neurological deterioration, which was defined as an increase ≥4 points in the NIHSS. Previous history of diabetes and stroke was collected from all patients. Results: 176 (26.4%) had hemorrhagic transformation (HT), which was symptomatic in 30 cases (4.5%). In the univariate analysis, neither diabetes and previous stroke together, nor alone, were associated with HT. However, previous stroke (10% vs. 4%, p=0.028) but not diabetes or both, was associated with SICH. After adjustment for the rest of the variables associated with the development of SICH, only the history of prior stroke remained as an independent predictor of this complication (OR 4.3;CI 95%, 1.12-16.19; p=0.03). Conclusions: In our large cohort of patients treated with rt-PA, only a prior history of stroke predicted the development of SICH. No association was found with diabetes.

To the Editor: We read with interest the article by Moftakhar et al,1 who report a strong correlation between thrombus density measured in Hounsfield units on preintervention nonenhanced computed tomography and postintervention thrombolysis in cerebral infarction grade. Thrombi with lower Hounsfield units are more resistant to treatment, so measuring the Hounsfield units of the intracranial thrombus on the admission nonenhanced computed tomography may help to determine the composition of the clot, and thus, be the most appropriate reperfusion …