Administration Of Recombinant Tissue Plasminogen Activator Research Articles

DWI-ASPECTS as a Predictor of Dramatic Recovery After Intravenous Recombinant Tissue Plasminogen Activator Administration in Patients With Middle Cerebral Artery Occlusion

In patients with middle cerebral artery trunk occlusion we investigated whether the diffusion-weighted imaging- the Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECTS) predicts short-term neurological recovery after intravenous recombinant tissue plasminogen activator administration, and investigated how DWI-ASPECTS relates to clinical outcome. Dramatic recovery was defined as a ≥ 10-point reduction or a total National Institutes of Health Stroke Scale score of 0 to 1 at 24 hours and 7 days. Early recanalization was defined as recanalization within 1 hours after intravenous recombinant tissue plasminogen activator. Favorable outcome at 3 months was defined as a modified Rankin Scale score of 0 to 2. Sixty-six patients (median age [interquartile], 79 [70-85] years, male; 34 [52%]) were enrolled. DWI-ASPECTS was 6 (5-9). Dramatic recovery was seen in 16 (24%) and 26 (39%) patients at 24 hours and on day 7, respectively. Early recanalization occurred in 22 (33%) patients. DWI-ASPECTS ≥ 7 was an independent predictor of dramatic recovery at 24 hours (odds ratio, 100.85; 95% confidence interval, 4.29-2371.40; P=0.004) and 7 days (odds ratio, 14.15; 95% confidence interval, 2.21-90.48; P=0.005). Although the favorable outcome rate was not significantly different between patients with DWI-ASPECTS ≥ 7 with and without early recanalization (60% versus 31%; P=0.228), it was statistically more frequent in patients with DWI-ASPECTS <7 with early recanalization than those without early recanalization (38% versus 0%; P=0.017). DWI-ASPECTS predicted short-term recovery in patients with middle cerebral artery trunk occlusion receiving intravenous recombinant tissue plasminogen activator. In patients with lower DWI-ASPECTS, there may still be benefit from early recanalization.

Utilization of Intravenous Thrombolysis is Increasing in the United States

Evaluating recombinant tissue plasminogen activator utilization rates is important, as many studies have demonstrated that administration of recombinant tissue plasminogen activator to qualified patients significantly improves prognosis. We investigated recent trends in the utilization and outcomes of administration of intravenous recombinant tissue plasminogen activator in the United States using the National Inpatient Sample between 2001 and 2008. We identified patients with a primary diagnosis of acute ischemic stroke who underwent treatment with intravenous recombinant tissue plasminogen activator and studied utilization rates and clinical outcomes: discharge to long-term facility (morbidity), in-hospital death (mortality), and intracranial hemorrhage. Information on demographics, hospital characteristics, and comorbidities was collected. A multivariate logistic regression analysis was performed to determine independent predictors of morbidity, mortality, and intracranial hemorrhage. Intravenous recombinant tissue plasminogen activator utilization increased from 1·3% in 2001 to 3·5% in 2008. On multivariate analysis, variables associated with increased morbidity after intravenous recombinant tissue plasminogen activator administration included advanced age (P < 0·001), female gender (P < 0·001), and comorbidities of atrial fibrillation (P < 0·001) and hypertension (P < 0·001). Increased mortality was associated with increased age (P < 0·001) and comorbidities of atrial fibrillation, congestive heart failure, coronary artery disease, and diabetes (P < 0·001 for all comorbidities). Intravenous recombinant tissue plasminogen activator utilization rates increased between 2001 and 2008. Advanced age and atrial fibrillation were significantly associated with increased morbidity and mortality among patients treated with intravenous recombinant tissue plasminogen activator.

Intravenous rt-PA is not Associated with Increased Risk of Hemorrhage in Patients with Intracranial Aneurysms

The presence of an intracranial aneurysm is listed as an exclusion criterion for the administration of recombinant tissue-plasminogen activator (rt-PA). This study was designed to test the hypothesis that the administration of rt-PA is safe in patients who have an unruptured intracranial aneurysm. We performed a retrospective analysis of all acute ischemic stroke patients treated with rt-PA at our tertiary care academic medical center from June 2006 to June 2010 who also received intracranial vessel imaging. Baseline clinical characteristics were prospectively determined. Identification of hemorrhage and the presence of aneurysm were obtained from radiology report, and neuro-imaging findings were confirmed by study investigators. Symptomatic intracerebral hemorrhage (sICH) was defined according to National Institutes of Neurological Disorders and Stroke criteria. Five percent of patients (8/172) had at least one intracranial aneurysm on vessel imaging. A total of seven patients (4%) had sICH. There was no significant difference in intracranial aneurysms between patients with or without sICH [1/7 (14%) vs. 7/165 (4.2%), p=0.29]. In one patient with sICH and an intracranial aneurysm, the location of hemorrhage was distant from the aneurysm. The only predictors found for sICH in our cohort were atrial fibrillation (p=0.03) and infarct size (p=0.0004). Incidental intracranial aneurysms are common in patients who were present with acute ischemic stroke and not associated with sICH in our population. The concern that these patients are at increased risk of hemorrhage after thrombolysis may not be warranted.

Ictus embólico de circulación anterior secundario a una oclusión trombótica del tronco braquiocefálico: utilidad del estudio neurosonológico

INTRODUCTION. Atherosclerotic occlusion of the brachiocephalic trunk (CBT) is a rare clinical entity and its presentation in the form of arterio-arterial embolism is uncommon. Early identification of patients with CBT occlusion may have important therapeutic implications. CASE REPORT. A man aged 49 presents with sudden onset symptoms involving the territory of the right middle cerebral artery. Emergent transcranial doppler evaluation showed a flow pattern of proximal right M1 occlusion. After intravenous recombinant tissue plasminogen activator administration, partial recanalization of the vessel was found and the patient improved clinically. Cervical and transcranial duplex sonography demonstrated an occlusion in CBT, which was later confirmed on CT angiography and digital angiography of supraaortic vessels. After aorto-innominate bypass, pathological analysis confirmed the atherosclerotic origin. CONCLUSIONS. The most common clinical presentation of CBT occlusion are transient ischemic symptoms related to steal phenomenon in the vertebro-basilar territory. Symptoms of carotid circulation stroke usually result from arterio-arterial embolic mechanism. Early recognition is important for its therapeutic implications, therefore thrombolytic therapy should be indicated. Neurosonologic study allows rapid and reliable examination on hemodynamic status and the presence of distal embolic phenomena.

Closed loop communication to prevent delay in recombinant tissue plasminogen activator administration

Closed loop communication to prevent delay in recombinant tissue plasminogen activator administration

An Institutional Approach to Interventional Strategies for Complete Vascular Occlusions

Complete vascular occlusions are rare but potentially lethal. Reports on transcatheter therapy are limited to solitary case reports. The study was conducted as a single-center retrospective chart review. Between January 2003 and December 2009, 26 patients underwent cardiac catheterizations for either a known complete thoracic vascular occlusion or for incidental complete vascular occlusion that was noted during cardiac catheterization. Procedural technique, risk factors, and outcomes are reviewed. Median age at the time of diagnosis was 13.3 years (range 2 months to 54 years). In 6 of 26 (23%) patients, the vascular occlusion was of acute onset. Ninety-two percent of patients had at least 1 known risk factor for vascular occlusion, whereas 54% of patients had ≥ 2 risk factors. Successful rehabilitation was achieved in 19 patients, with direct catheter and/or wire manipulation being used to cross the occluded vessel in 15 (75%) patients, radiofrequency (RF) perforation in 3 patients, and perforation with Brockenbrough needle in 1 patient. Subsequent techniques included AngioJet (n = 2), balloon angioplasty and/or stent implantation (n = 18), and adjuvant local administration of recombinant tissue-plasminogen activator (n = 3). Reinterventions were required in 5 patients, and 8 patients died during the study period from causes unrelated to the catheterization procedure(s). Median follow-up of patients after successful recanalization was 12.6 months (range 1 day to 64 months), and the median duration of survival free from reintervention was 11.8 months (range 1 day to 64 months). In most patients, risk factors can be identified that are associated with the occurrence of a complete vascular occlusion. Different treatment strategies are used in patients having chronic compared with acute occlusions. Residual vascular lesions (hypoplasia or stenosis) are often associated with occurrence of reobstructions and should therefore be treated to prevent such an occurrence. Postprocedural anticoagulation is important in maintaining vascular patency.

Chemokine-related gene expression in the brain following ischemic stroke: No role for CXCR2 in outcome

This study sought to identify potential targets for acute stroke therapy that can be exploited pharmacologically beyond the current 4.5h time limit for clinical administration of recombinant tissue-plasminogen activator. We used PCR arrays to initially screen the temporal expression profiles of several chemokine-related genes in the brain at 4, 24 and 72h after stroke. We identified large increases (>10-fold) in mRNA at 24 or 72h for the neutrophil CXCR2 receptor, and for CXCL1 and CXCL2—two chemokine ligands expressed by monocytes and neutrophils with strong neutrophil chemoattractant activity via CXCR2. We then tested the efficacy of a CXCR2 antagonist as a therapeutic. Mice were treated with vehicle (1% DMSO) or SB225002 (2mg/kg per day, ip) commencing at reperfusion, and we evaluated chemokine gene expression, neutrophil infiltration and functional and histological endpoints of stroke outcome. Expression levels of CXCL1, CXCL2 and CXCR2 after 24h were markedly reduced to near normal levels in SB225002-treated mice. Myeloperoxidase-positive cell infiltration was significantly reduced in SB225002-treated mice compared with vehicle-treated mice, and was similar to levels in sham-operated mice. However, although SB225002 evidently antagonised the interaction between CXCR2 and its chemokine ligands in the ischemic brain, mice treated with either SB225002 or vehicle had similar motor impairment and infarct volume at 72h. Thus, the reduced expression of CXC chemokine subfamily genes and neutrophil-related infiltration following SB225002 administration did not improve outcome after cerebral ischemia–reperfusion. CXCR2 antagonists are therefore unlikely to be a potential therapy for ischemic stroke.

The Successful Use of Low-Dose Recombinant Tissue Plasminogen Activator for Treatment of Intracardiac/Pulmonary Thrombosis During Liver Transplantation

Intracardiac thrombosis and pulmonary embolism are uncommon complications during liver transplantation but carry a high mortality rate. We report the successful use of low-dose recombinant tissue plasminogen activator (0.5-4 mg) administration in 4 patients. Early diagnosis through transesophageal echocardiography and pulmonary artery catheterization may have contributed to the rapid thrombolysis.

No Benefit from Intravenous Alteplase When Given After 4.5 Hours of Stroke Onset

What is the optimal interval between stroke onset and intravenous recombinant tissue plasminogen activator (rt-PA) administration? Researchers

Incidence and Clinical Correlation of Intracranial Hemorrhages Observed by 3-Tesla Gradient Echo T2*-Weighted Images following Intravenous Thrombolysis with Recombinant Tissue Plasminogen Activator

Background: The purpose of this study was to determine the incidence and clinical correlation of intracranial hemorrhages (ICHs) detected by 3-tesla gradient echo T₂*-weighted images after intravenous recombinant tissue plasminogen activator (rt-PA) administration. Methods: We included 43 consecutive patients with anterior-circulation ischemia who underwent MRI studies before and after thrombolysis. Each hemorrhage was classified as a hemorrhagic infarction (HI) or parenchymal hemorrhage (PH) according to the European Cooperative Acute Stroke Study definition. The clinical outcome was defined as an improvement (≧4-point reduction) or deterioration (≧4-point increase) based on a comparison between the initial and the 30-day NIHSS scores. Results: The incidence of ICHs was 58%, and the HI rate was 52%; both were higher than the rates reported in the literature. Most of the patients with HI improved clinically, and these patients had second MRAs that showed recanalization. None of the patients with PH demonstrated improvement. Conclusions: Three-tesla MRI may reveal a higher frequency of HI type hemorrhages than lower-field MRIs, and HI may be a predictor of good recovery by reflecting the presence of recanalization. The rate of PH in our study was low compared to other studies, probably due to the lower dosage of rt-PA.

Mechanical Clot Disruption Following Intravenous Recombinant Tissue Plasminogen Activator Administration in Non-Responders

The efficacy of selecting non-responders to intravenous recombinant tissue plasminogen activator (rt-PA) for mechanical clot disruption (MCD) was investigated based on cerebral angiography in the acute stage following rt-PA therapy. rt-PA therapy using 0.6 mg/kg was performed in eligible patients within 3 hours of onset. Patients who did not show recanalization on cerebral angiography 1 hour after rt-PA initiation immediately underwent MCD. Clinical outcome was evaluated by National Institutes of Health Stroke Scale (NIHSS) score at baseline, 24 hours, and 1 month, and by modified Rankin scale (mRS) score at 3 months. Eighteen patients were initially treated with intravenous rt-PA, with mean time from stroke onset to rt-PA therapy of 120 +/- 27 minutes. Eight of these patients underwent MCD. Seven of these eight patients had complete recanalization. Time to recanalization by percutaneous transluminal angioplasty from stroke onset was 258 +/- 59 minutes. Final recanalization was achieved in 16 of the 18 patients. Baseline NIHSS score improved significantly at 1 month (median from 22.5 to 4). Twelve of the 18 patients treated according to our protocol were classified as independent (mRS scores 0-2). No patients had symptomatic hemorrhage. MCD for non-responders determined by cerebral angiography at the end of intravenous rt-PA infusion can decrease the time to recanalization and improve recanalization rates, leading to good clinical outcome after acute stroke.

Ultrasound- and Microspheres-Enhanced Thrombolysis for Stroke Treatment: State of the Art

Intravenous administration of recombinant tissue-plasminogen activator (rt-PA) remains the fastest and widely feasible strategy to initiate treatment in acute ischemic stroke. Because it works by inducing recanalization of an occluded vessel, augmentation of this process is desirable and diagnostic transcranial Doppler (TCD) ultrasound can accomplish this safely. A 2-MHz pulsed-wave monitoring can at least double the chance of early complete arterial recanalization at no increase in the risk of symptomatic intracerebral hemorrhage. Gaseous microspheres, initially developed as ultrasound contrast agents, can further increase the effectiveness of rt-PA. A recent microsphere dose-escalation study called TUCSON showed sustained complete recanalization rates of 67% in patients receiving TCD monitoring with a 1.4-mL perflutren-lipid microsphere dose compared with controls receiving rt-PA alone with no increase in hemorrhage rate. In this article, we review the current and emerging applications of ultrasound and microspheres in stroke management including augmentation of systemic thrombolysis and implications for future reperfusion strategies.

Monthly recombinant tissue plasminogen activator administration to implantable central venous access devices decreases infections in children with haemophilia

Central venous access devices (CVAD) have been effectively used in the care of haemophilia patients. This is particularly true in children, who often have difficult venous access. CVAD complications (infection and thrombosis), risk factors, and complication rates, have been well-documented. However, effective interventions which decrease complication rates have not been identified. In this study, we review our experience with the use of monthly recombinant tissue plasminogen activator (rtPA) administration in haemophilia patients with fully implanted CVADs. Data on 19 haemophilia patients with 24 CVADs were available for analysis, with a total of 24 520 CVAD days. An infection rate of 0.04 infections per 1000 CVAD days and a thrombosis rate of 0.04 thrombi per 1000 CVAD days was observed. The observed infectious complication rate is at least one logarithm lower than many published CVAD infection rates in haemophilia patients who have not received rtPA administration. No bleeding complications were noted. Monthly rtPA is safe and appears to be effective in decreasing CVAD infection rates. Larger, randomized controlled studies are indicated to validate this finding.

Increasing number of stroke specialists should contribute to utilization of IV rt-PA: Results of questionnaires from 1466 hospitals in Japan

Purpose To determine the present status of intravenous recombinant tissue plasminogen activator (IV rt-PA) administration in Japan, we investigated the components of stroke case related to IV rt-PA utilization using a questionnaire sent to hospitals. Methods Questionnaires about the infrastructure of acute stroke care were sent to 8589 hospitals between August and October 2007. Responses were categorized as follows: 1) stroke service run by stroke physicians (SPs) 24 h/day, 7 days/week (24/7); 2) IV rt-PA utilizable 24/7 (rt-PA hospitals); 3) the total number of SPs. The components related to rt-PA hospitals were analyzed and the significance of the number in SPs to the rt-PA hospital was investigated. Results Responses were received from 4690 (54.7%) of 8569 hospitals. Of these, 1466 hospitals were admitting acute stroke patients. 519 of those hospitals were rt-PA hospitals. Of the 1466 (35.4%), 48.4% were serviced 24/7 by SPs, with 75.2% having < 5 SPs. Multivariate analysis revealed administration of rt-PA was significantly associated with > 4 SPs (odds ratios (OR), 2.8; 95% confidence interval (95%CI), 1.9–4.1; p < 0.001). Compared to hospitals with 0–1 SPs as a reference, the OR for rt-PA utilization was 5.6 (95%CI, 2.5–12.9; p < 0.001) with 5 SPs, 10.8 (95%CI, 5.0–23.6; p < 0.001) with 6–10 SPs, and 37.3 (95%CI, 6.5–213.1; p < 0.001) with > 10 SPs. Conclusions An increased number of SPs was associated with increased IV rt-PA utilization. Development of stroke centers with larger numbers of SPs is therefore urgently needed.

Normobaric Hyperoxia and Delayed tPA Treatment in a Rat Embolic Stroke Model

In a rat embolic stroke (eMCAO) model, the effects of 100% normobaric hyperoxia (NBO) with delayed recombinant tissue plasminogen activator (tPA) administration on ischemic lesion size and safety were assessed by diffusion- and perfusion (PWI)-weighted magnetic resonance imaging. NBO or room air (Air) by a face mask was started at 30 mins posteMCAO and continued for 3.5 h. Tissue plasminogen activator or saline was started at 3 h posteMCAO. Types and location of hemorrhagic transformation were assessed at 24 h and a spectrophotometric hemoglobin assay quantified hemorrhage volume at 10 h. In NBO-treated animals the apparent diffusion coefficient/PWI mismatch persisted during NBO treatment. Relative to Air groups, NBO treatment significantly reduced 24 h infarct volumes by approximately 30% and approximately 15% with or without delayed tPA, respectively (P<0.05). There were significantly more hemorrhagic infarction type 2 hemorrhages in Air/tPA versus Air/saline animals (P<0.05). Compared with Air/tPA, the combination of NBO with tPA did not increase hemorrhage volume at 10 h (4.0+/-2.4 versus 6.6+/-2.6 microL, P=0.065) or occurrence of confluent petechial hemorrhages at 24 h (P>0.05), respectively. Our results suggest that early NBO treatment in combination with tPA at a later time point may represent a safe and effective strategy for acute stroke treatment.

Reperfusion Seizures: A Manifestation of Cerebral Reperfusion Injury After Administration of Recombinant Tissue Plasminogen Activator for Acute Ischemic Stroke

Reperfusion injury has been well described in medical literature; cerebral reperfusion injury is commonly seen in association with vascular surgical procedures such as carotid endarterectomies and stent placement procedures. Cerebral reperfusion injury can manifest as blood-brain barrier breakdown, cortical irritability, and epileptic seizures. Seizures induced by cerebral reperfusion have not been documented or reported after thrombolytic therapy for acute ischemic stroke. We report a patient who received intravenous recombinant tissue plasminogen activator within 3 hours of stroke symptom onset and developed the new-onset symptom of continuous, primary motor seizure activity within 20 minutes of recombinant tissue plasminogen activator administration. These epileptic seizures originated in the same area as the acute brain ischemia and occurred during the anticipated period of cerebral reperfusion. In this article we describe a case report and then discuss the pathophysiology and mechanisms that may underlie reperfusion epileptic seizures as a manifestation of cerebral reperfusion injury.

Case report: Management of immediate post-car-diopulmonary bypass massive intra-cardiac thrombosis

To describe the management of severe acute intracardiac thrombosis in a patient who underwent redo multiple valve replacement and valvular repair. The diagnostic features, associated risk factors, and anesthetic management are reviewed. A 67-yr-old woman undergoing redo mitral and aortic mechanical valve replacement and tricuspid annuloplasty under aprotinin prophylaxis exhibited severe refractory hypotension that began immediately after protamine reversal of intraoperative heparin anticoagulation following separation from cardiopulmonary bypass. Intraoperative transesophageal echocardiography revealed severe thrombosis in the right atrium, right ventricle and pulmonary artery. The patient was managed by immediate reheparinization and return to cardiopulmonary bypass (CPB), surgical thrombectomy, and intraoperative administration of recombinant tissue-plasminogen activator. After removal of the thrombi, and separation from CPB, no further protamine was given. One hundred units of blood products and two surgical re-explorations were required to manage subsequent massive postoperative bleeding. Acute heparin-induced thrombocytopenia (HIT) was ruled out using sensitive assays for HIT antibodies. After 16 days in the intensive care unit and 30 more days in hospital, the patient was subsequently transferred to a chronic care facility and succumbed several weeks later. Acute intraoperative thrombosis is a rare and potentially fatal complication of cardiac surgery. Intraoperative transesophageal echocardiography was essential for rapid diagnosis in this case. Multiple interacting prothrombotic factors (e.g., aprotinin use, acquired antithrombin deficiency, long pump time, post-protamine status, transfusion of blood components) were likely contributing factors related to this rare complication.

Acute Stroke Management in the Elderly

Background and Purpose: Though the proportion of elderly stroke patients is increasing, patients >80 years are often excluded from clinical stroke trials. We reviewed the management of older patients presenting with acute ischemic stroke (AIS) and assessed the safety and efficacy of recombinant tissue plasminogen activator (rtPA) administration in a community-based setting. Methods: A retrospective review of patients >80 years (n = 341) admitted to a community stroke center with AIS were compared to their younger counterparts (n = 690) using the stroke center database from April 2003 to December 2005. Parameters that were measured included admission and discharge NIH Stroke Scale (NIHSS), rate of thrombolytic treatment, the frequency and etiology of thrombolytic exclusion criteria and complications from rtPA for the different aged populations. Additional data were collected for Barthel Index at 12 months. Results: A total of 166 patients underwent thrombolysis. Older patients were not delayed in reaching the hospital within 3 h of stroke onset (182/690, 26%, in the <80 cohort vs. 98/341, 29%, in the ≧80 cohort). Although the overall rates of tPA use were similar in both the young and aged cohort, older patients were less likely to be treated with rtPA because of reasons not listed as exclusion criteria (17% in the <80 cohort vs. 32% in the ≧80 cohort).The older group did not have an excess risk of intracranial hemorrhage following rtPA infusion despite equivalent NIHSS on admission (13.5 in the <80 cohort vs. 12.4 in the ≧80 cohort). Both groups showed improvement in NIHSS following thrombolytic treatment with a drop of 7.7 points in the younger age group and 5.6 points in the older group. Elderly patients treated with rtPA had a comparable 12-month modified Barthel Index score to younger cohorts. Conclusions: Early treatment with rtPA in patients >80 years appears to be both safe and efficacious. Treated patients showed improvements both acutely (a decrease in NIHSS at 72 h) and chronically, as shown by a sustained improvement in the Barthel Index. A large number of elderly patients were excluded from rtPA treatment despite arriving within the time frame of treatment for reasons not considered as traditional exclusion criteria. Older patients with AIS can be treated safely with thrombolytic therapy in a community setting. This therapy should not be withheld on the basis of age.

Predicting abnormal coagulation in ischemic stroke: Reducing delay in rt-PA use

Normal prothrombin time (PT) and partial thromboplastin time (PTT) are recommended for administration of recombinant tissue-plasminogen activator (rt-PA) in stroke, but waiting for results can delay use. We examined the charts of 365 stroke patients to assess predetermined risk factors associated with elevated PT/PTT. Elevated PT/PTT can be predicted in patients taking warfarin or heparin/heparinoid or on hemodialysis, according to emergency department triage, with 100% sensitivity and 94.7% specificity. These results could be applied to rt-PA candidates and reduce potential delays.

The ASPECTS template is weighted in favor of the striatocapsular region

The extent of cerebral infarction correlates with increased risk of intracerebral hemorrhage (ICH) following recombinant tissue plasminogen activator (rt-PA) administration. The Alberta Stroke Program Early CT Score (ASPECTS) is a widely used, validated method which assesses involvement of 10 selected regions of the MCA territory. An ASPECTS score >7 is associated with a higher risk of ICH following thrombolysis than lower scores. To understand the internal structure of the ASPECTS template better, we estimated the infarct volume corresponding to each region. We hypothesized that, in the ASPECTS scoring system, the striatocapsular region is weighted disproportionally. Four experienced radiologists rated individual ASPECTS regions on subacute CT images (day 5–day 10) of 19 patients with MCA territory stroke. Infarct volume was determined from manual segmentation of infarcts on CT images. Linear regression was used to estimate the regional volume associated with each ASPECTS region. The ASPECTS regions are weighted unequally with the striatocapsular region accounting for 21% of the MCA territory infarct volume. Together, the 10 ASPECTS regions account for approximately 51% of the maximum MCA infarct territory volume. These findings should provide impetus for research to develop a scoring system explicitly based on regional hemorrhage risk as an aid to selecting patients for thrombolysis.