Acute Posterior Circulation Stroke Research Articles

Early Imaging Prediction of Malignant Cerebellar Edema Development in Acute Ischemic Stroke.

Malignant cerebellar edema (MCE) is a life-threatening complication of acute ischemic stroke that requires timely diagnosis and management. Aim of this study was to identify imaging predictors in initial multiparametric computed tomography (CT), including whole-brain CT perfusion (WB-CTP). We consecutively selected all subjects with cerebellar ischemic WB-CTP deficits and follow-up-confirmed cerebellar infarction from an initial cohort of 2635 patients who had undergone multiparametric CT because of suspected stroke. Follow-up imaging was assessed for the presence of MCE, measured using an established 10-point scale, of which scores ≥4 are considered malignant. Posterior circulation-Acute Stroke Prognosis Early CT Score (pc-ASPECTS) was determined to assess ischemic changes on noncontrast CT, CT angiography (CTA), and parametric WB-CTP maps (cerebellar blood flow [CBF]; cerebellar blood volume; mean transit time; time to drain). Fisher's exact tests, Mann-Whitney U tests, and receiver operating characteristics analyses were performed for statistical analyses. Out of a total of 51 patients who matched the inclusion criteria, 42 patients (82.4%) were categorized as MCE- and 9 (17.6%) as MCE+. MCE+ patients had larger CBF, cerebellar blood volume, mean transit time, and time to drain deficit volumes (all with P<0.001) and showed significantly lower median pc-ASPECTS assessed using WB-CTP (CBF, cerebellar blood volume, mean transit time, time to drain; all with P<0.001) compared with MCE- patients, while median pc-ASPECTS on noncontrast CT and CTA was not significantly different (both P>0.05). Receiver operating characteristics analyses yielded the largest area under the curve values for the prediction of MCE development for CBF (0.979) and cerebellar blood volume deficit volumes (0.956) and pc-ASPECTS on CBF (0.935), whereas pc-ASPECTS on noncontrast CT (0.648) and CTA (0.684) had less diagnostic value. The optimal cutoff value for CBF deficit volume was 22 mL, yielding 100% sensitivity and 90% specificity for MCE classification. WB-CTP provides added diagnostic value for the early identification of patients at risk for MCE development in acute cerebellar stroke.

Monitored Anesthesia Care vs Intubation for Vertebrobasilar Stroke Endovascular Therapy

No consensus regarding the ideal sedation treatment for stroke endovascular therapy has been reached, and practices remain largely based on local protocols and clinician preferences. Most studies have focused on anterior circulation strokes; therefore, little is known regarding the optimal anesthesia type for vertebrobasilar occlusion strokes. To compare clinical and angiographic outcomes between monitored anesthesia care (MAC) and general anesthesia (GA) in patients presenting with vertebrobasilar occlusion strokes. Retrospective, matched, case-control study of consecutive vertebrobasilar occlusion strokes treated with endovascular therapy at 2 academic institutions. The study took place between September 2005 and September 2015 at University of Pittsburgh Medical Center Stroke Institute, Pittsburgh, Pennsylvania, and between September 2010 and September 2015 at the Marcus Stroke and Neuroscience Center at Grady Memorial Hospital, Atlanta, Georgia. Patients requiring emergent intubation prior to endovascular therapy were excluded. The remaining patients were categorized into (1) MAC and (2) elective intubation for the procedure (elective GA). Patients who converted from MAC to GA during the procedure were included in the MAC group. The 2 groups were matched for age, baseline National Institutes of Health Stroke Scale score, and glucose levels. Baseline characteristics and outcomes were compared. The primary outcome measure was the shift in the degree of disability among the 2 groups as measured by the modified Rankin scale at 90 days. A total of 215 patients underwent endovascular therapy for vertebrobasilar occlusion strokes during the study period. Thirty-nine patients were excluded owing to emergent pre-endovascular therapy intubation. Sixty-three patients had MAC (36%) and 113 patients had GA (64%). The conversion rate from MAC to GA was 13% (n = 8). After matching, 61 pairs of patients (n = 122) underwent primary analysis. The 2 groups were well balanced in terms of baseline characteristics. Median age was 69 years (interquartile range, 60-75 years) in the MAC group vs 67 years (interquartile range, 55.5-78.5 years) in the GA group (P = .83). Fifty-four percent of the patients in the MAC group were men vs 41% in the GA group (P = .44). When compared with the elective GA group, patients who underwent the procedure with MAC had similar rates of successful reperfusion, good clinical outcomes, hemorrhagic complications, and mortality. The modality of anesthesia was not associated with any significant changes in the modified Rankin scale score distribution (MAC: OR, 1.52; 95% CI, 0.80-2.90; P = .19). In endovascular therapy for acute posterior circulation stroke, MAC is feasible and appears to be as safe and effective as GA. Future clinical trials are warranted to confirm our findings.

Abstract TP14: Predictors of Good Outcome after Endovascular Therapy for Acute Posterior Circulation Stroke

Background and Purpose: Endovascular therapy (ET) is increasingly utilized in acute ischemic stroke treatment and is now considered the gold standard approach for select patient populations. Prior studies have demonstrated that eventual patient outcome depend on both patient specific factors as well as procedural considerations. However, these factors remain unclear for acute basilar artery occlusion stroke. We sought to determine prognostic factors of good outcome after ET for acute posterior circulation stroke Methods: We reviewed our prospectively collected endovascular databases at two tertiary care academic institutions for patients with acute posterior circulation strokes from September 2005 to September 2015. Baseline characteristics, procedural data and outcomes were evaluated. A good outcome was defined as a modified Rankin Scale score of 0 to 2 at 3 months. The association between clinical and procedural parameters and functional outcome was assessed. Results: A total of 214 qualified for the study. Smoking status, creatinine levels, baseline National Institutes of Health Stroke Scale score (NIHSS), anesthesia modality (conscious sedation vs general anesthesia), procedural length and reperfusion status were significantly associated with outcomes in the univariate analysis Multivariate logistic regression indicated that only smoking (odds ratio, 2.49; 95% confidence interval 1.16-5.36; P=0.019), low NIHSS (odds ratio, 0.92; 95% confidence interval 0.88-0.96; P&lt;0.001), and successful reperfusion (mTICI 2b-3) (odds ratio, 13.65; 95% confidence interval 1.71-108.76; P=0.014), were independent predictors of good outcomes. Conclusion: Our study suggests that baseline NIHSS, smoking and reperfusion status are independent predictors of good outcomes after ET for acute posterior circulation stroke.

Abstract WP53: The prognostic value of Posterior Circulation Acute Stroke Prognosis Early Ct Score (pcaspects) on CT perfusion in patients with basilar artery occlusion

Background: CT perfusion (CTP) increases diagnostic confidence in ischaemic stroke. Despite bone-related artefacts, CTP has been shown to improve diagnostic sensitivity compared to non contrast-CT (NCCT) and Computed Tomography Angiography source images (CTA-SI) in posterior circulation strokes. The posterior circulation Acute Stroke Prognosis Early CT score (pcASPECTS) on CTA-SI predicts clinical outcome in patients with basilar artery occlusion (BAO). We assessed the prognostic value of pcASPECTS on CTP in BAO patients. Methods: A retrospective analysis of consecutive patients with BAO diagnosed on CT angiography was performed. pcASPECTS was assessed as evident hypoattenuation on CTA-SI, focally reduced cerebral blood flow (CBF) or cerebral blood volume (CBV), focally increased time to peak of the residue function (Tmax) or mean transit time (MTT). Two investigators independently reviewed the images blinded to clinical outcome. Reliability was assessed with intraclass correlation coefficient (ICC). Good outcome was defined as modified Rankin Scale≤3 at 3 months. Results: We included 43 BAO patients with whole-brain CTP images. In receiver-operating-characteristic (ROC) analysis, the area-under-curve (AUC) was 0.79 (95% CI 0.6-0.9) for pcASPECTS on CBF, 0.77 (95% CI 0.6-0.9) on Tmax, 0.73 (95% CI 0.6-0.9) on MTT, 0.72 (95% CI 0.6-0.9) on CBV, 0.67 (95% CI 0.5-0.8) on CTA-SI. In logistic regression adjusted for age and clinical severity, pcASPECTS&lt;8 was associated with poor outcome on Tmax (OR 14.6, 95% CI 2.3-115; p=0.007) and CBF (OR 15.1, 95% CI 1.3-121; p=0.02). Although CTP AUC did not show higher accuracy in comparison with CTA-SI AUC (p=0.2), in logistic regression, CTA-SI pcASPECTS was not significantly associated with clinical outcome (OR 6.9, 95% CI 0.7-70; p=0.1, adjusted for age, NHSS). Higher pcASPECTS on CBF (OR 0.5 95%CI 0.2-0.9, p=0.04) and Tmax (OR 0.5 95% 0.3-0.9; p=0.02) were associated with lower mortality. Interrater reliability was good for CTP maps (ICC between 0.74 and 0.86 95% CI 0.6-0.9 versus 0.66 for CTA-SI 95% CI 0.4-0.8). Conclusions: The CTP pcASPECTS may identify BAO patients at higher risk of disability and mortality.

CT-angiography source images indicate less fatal outcome despite coma of patients in the Basilar Artery International Cooperation Study.

Background Coma is associated with poor outcome in patients with basilar artery occlusion. Aims We sought to assess whether the posterior circulation Acute Stroke Prognosis Early CT Score and the Pons-Midbrain Index applied to CT angiography source images predict the outcome of comatose patients in the Basilar Artery International Cooperation Study. Methods Basilar Artery International Cooperation Study was a prospective, observational registry of patients with acute basilar artery occlusion with 48 recruiting centers worldwide. We applied posterior circulation Acute Stroke Prognosis Early CT Score and Pons-Midbrain Index to CT angiography source images of Basilar Artery International Cooperation Study patients who presented with coma. We calculated adjusted risk ratios to assess the association of dichotomized posterior circulation Acute Stroke Prognosis Early CT Score (≥8 vs. <8) and Pons-Midbrain Index (<3 vs. ≥3) with mortality and favourable outcome (modified Rankin Scale score 0-3) at one month. Results Of 619 patients in the Basilar Artery International Cooperation Study registry, CT angiography source images were available for review in 158 patients. Among these, 78 patients (49%) presented with coma. Compared to non-comatose patients, comatose patients were more likely to die (risk ratios 2.34; CI 95% 1.56-3.52) and less likely to have a favourable outcome (risk ratios 0.44; CI 95% 0.24-0.80). Among comatose patients, a Pons-Midbrain Index < 3 was related to reduced mortality (adjusted RR 0.66; 95% CI 0.46-0.96), but not to favourable outcome (adjusted RR 1.19; 95% CI 0.39-3.62). Posterior circulation Acute Stroke Prognosis Early CT Score dichotomized at ≥ 8 vs. <8 was not significantly associated with death (adjusted RR 0.70; 95% CI 0.46-1.05). Conclusion In comatose patients with basilar artery occlusion, the extent of brainstem ischemia appears to be related to mortality but not to favourable outcome.

False-Negative Initial Magnetic Resonance Imaging in Acute Posterior Circulation Stroke: A Case Report Describing Locked in Syndrome

SESSION TITLE: Student/Resident Case Report Poster - Critical Care II SESSION TYPE: Student/Resident Case Report Poster PRESENTED ON: Tuesday, October 25, 2016 at 01:30 PM - 02:30 PM INTRODUCTION: As identification of acute stroke is greatly dependent on neuroimaging, negative CT and MRI in the context of focal neurological deficits demands heightened awareness of technology limitations. It has been described in the literature that posterior circulation strokes may not be readily seen on MRI for up to 24 hours. We present a case of Locked in Syndrome whose initial presentation was bilateral lower extremity weakness and dysarthria with negative MRI findings. CASE PRESENTATION: Patient is a 49 yo male with past medical history significant for HTN, DM, CHF, presenting with two days of dysarthria and bilateral lower extremity weakness resulting in a fall on day of admission. On physical exam, cranial nerves two through twelve were intact, cerebellar signs negative, sensory was intact bilaterally upper and lower extremities. Patient was admitted for stroke work up with an NIHSS of 5. CT brain and MRI showed no acute pathology. Over the next 4 days, patient developed worsening flaccid quadraplegia with bulbar symptoms. Repeat MRI on day 5 of admission showed bilateral basilar pontine infarcts on diffusion weighted imaging (DWI) not previously seen. NIHSS progressed to 12 and on day five, patient required intubation for airway protection. Exam at this time included quadraplegia and complete anarthria, with preservation of eye movement. After an extended period in the critical care unit, patient was discharged to a rehabilitation center. DISCUSSION: Imaging on presentation, localizes the foci of infarction in a vast majority of patients. It is important to remember that while DWI has become synonymous with the acute inpatient management of stroke, reported sensitivity in ischemic stroke ranges from 90 to 98% depending on stroke location and timing of the study. False negative diffusion weighted imaging is especially prevalent in patients with posterior circulation and lacunar strokes. In our case, initial imaging findings obfuscated the diagnosis. Only after clinical deterioration and repeat neuroimaging was the diagnosis made. CONCLUSIONS: Considering the high morbidity and mortality of disease, a physician’s index of suspicion for posterior circulation or hyper-acute infarctions should be raised in patients with a correlating clinical exam and negative initial neuroimaging findings. There is evidence in the literature that clinical examination may be more sensitive than MRI in detecting posterior circulation strokes. Because natural infarct evolution is to be expected, repeat neuroimaging may be necessary. Reference #1: Ay H, et al. Normal diffusion-weighted MRI during stroke-like deficits. Neurology. 1999 Reference #2: Oppenheim C, et al. False-negative diffusion-weighted MR findings in acute ischemic stroke. AJNR Am J Neuroradiol. 2000 Reference #3: Chalela JA, et al. Magnetic resonance imaging and computed tomography in emergency assessment of patients with suspected acute stroke: a prospective comparison. Lancet. 2007 DISCLOSURE: The following authors have nothing to disclose: Christian Castaneda, Michael Lerario No Product/Research Disclosure Information

Computed Tomography Perfusion Improves Diagnostic Accuracy in Acute Posterior Circulation Stroke

Background and Purpose: Computed tomography perfusion (CTP) has a high diagnostic value in the detection of acute ischemic stroke in the anterior circulation. However, the diagnostic value in suspected posterior circulation (PC) stroke is uncertain, and whole brain volume perfusion is not yet in widespread use. We therefore studied the additional value of whole brain volume perfusion to non-contrast CT (NCCT) and CT angiography source images (CTA-SI) for infarct detection in patients with suspected acute ischemic PC stroke. Methods: This is a retrospective review of patients with suspected stroke in the PC in a database of our stroke center (n = 3,011) who underwent NCCT, CTA and CTP within 9 h after stroke onset and CT or MRI on follow-up. Images were evaluated for signs and pc-ASPECTS locations of ischemia. Three imaging models - A (NCCT), B (NCCT + CTA-SI) and C (NCCT + CTA-SI + CTP) - were compared with regard to the misclassification rate relative to gold standard (infarction in follow-up imaging) using the McNemar's test. Results: Of 3,011 stroke patients, 267 patients had a suspected stroke in the PC and 188 patients (70.4%) evidenced a PC infarct on follow-up imaging. The sensitivity of Model C (76.6%) was higher compared with that of Model A (21.3%) and Model B (43.6%). CTP detected significantly more ischemic lesions, especially in the cerebellum, posterior cerebral artery territory and thalami. Conclusions: Our findings in a large cohort of consecutive patients show that CTP detects significantly more ischemic strokes in the PC than CTA and NCCT alone.

Tuberculomas Mimicking Posterior-Circulation Stroke

Dear Editor, Posterior-circulation stroke is of grave concern to any physician versed with the mortality and morbidity associated with the condition. Various nonvascular neurological and nonneurological conditions may mimic posterior-circulation stroke. We report a 29-year-old male with no prior comorbidities who presented to the emergency room of a tertiary-care hospital in northern India with sudden-onset alteration in consciousness following severe vertigo with multiple episodes of vomiting and gait imbalance. Detailed history-taking revealed the presence of pain in the nape of the neck and low-grade fever for the previous 10 days and a history of chiropractic neck manipulation for the previous 7 days. The possibility of acute posterior-circulation stroke following vertebral artery dissection was considered, and a computed tomography (CT) scan of the head was performed on an emergency basis. The CT scan revealed a large hypodensity in the midbrain, pons, and cerebellum (Fig. 1A). However, CT angiography of the neck and the intracranial vessels did not show any evidence of vertebral artery dissection. Routine hemogram, biochemistry, and chest X-ray findings were normal. The possibility of an alternative diagnosis was considered, based specifically on the history of preceding fever and the normal CT angiography findings. Magnetic resonance imaging (MRI) of the brain revealed multiple ring enhanced lesions in the cerebellum with significant surrounding perilesional edema (Fig. 1B and C). Cerebral spinal fluid (CSF) analysis showed a total count of 250 cells/mm3, predominantly lymphocytes, with proteins 90 at mg/dL and sugar at 35 mg/dL. Cryptococcal antigen, acid fast bacilli stain, and fungal smear findings were negative in the CSF. The blood sugar level was 121 mg/dL. The possibility of multiple infratentorial tuberculomas was considered, and the patient was started on antitubercular therapy with steroids. The patient was completely asymptomatic after 6 months of treatment. Fig. 1 A: Contrast enhanced CT head showing hypodensity of pons and cerebellum. B and C: Shows multiple ring enhancing lesions in cerebellum on contrast enhanced, T1 weighted MRI brain. Posterior-circulation stroke is associated with grave mortality and morbidity statistics.1 A population-based case-control study2 found that chiropractic manipulation was positively correlated with vertebrobasilar accidents, specifically in subjects aged <45 years. There are abundant data in the Western literature that have increased public concern about the safety of chiropractic manipulation, but the situation is different in developing countries. Various nonvascular neurological and nonneurological conditions may mimic posterior-circulation stroke, including acute peripheral vestibular dysfunction, acute intracranial hemorrhage, subarachnoid hemorrhage, basilar migraine, hypoglycemia, central pontine myelinosis, postinfectious disorders, tumors, and many toxic and metabolic disturbances.3 Although chronic infectious and inflammatory disorders may also simulate this condition, a hyperacute presentation should always be addressed immediately. Tuberculosis is a imitator. In 1961, Sievers4 termed tuberculosis as the second great imitator after syphilis, based on his observations in the Indian population of southwestern United States suffering from tuberculosis. Tuberculomas of the brain account for 20–30% of lesions occupying the intracranial space in India, and multiple such lesions are present in 15–30% cases.5 Tuberculomas can affect any part of brain, but those with an infratentorial origin are rare. There are isolated cases of brainstem or cerebellar tuberculomas reported in the literature. Though uncommon, infratentorial tuberculomas can be life-threatening.6 Gadolinium-enhanced MRI of the brain is a more sensitive modality for detecting tuberculomas. A retrospective analysis after performing brain MRI in the present patient produced consistent findings. While CT can be performed in most centers, it is not the diagnostic modality of choice, specifically when considering infratentorial lesions. Though clinically hyperacute presentations always warrant consideration of a vascular event, it must be remembered that tuberculosis is a great mimic, and can present with hyperacute presentations as described in the present case.

Posterior Circulation Acute Stroke Prognosis Early Computed Tomography Score Using Hypointense Vessels on Susceptibility Weighted Imaging Independently Predicts Outcome in Patients with Basilar Artery Occlusion.

PurposeAppearance of hypointense vessels on susceptibility weighted imaging (SWI) has been reported to correlate with outcome in patients with ischemia of the anterior circulation. This study investigates the correlation between the appearance of hypointense vessels on SWI after recanalization therapy and outcome in patients with basilar artery occlusion.MethodsPatients with basilar artery occlusion who were treated with endovascular recanalization or intravenous alteplase and received an MRI including SWI after therapy were retrieved from the hospital database for retrospective analysis. Posterior circulation Acute Stroke Prognosis Early Computed Tomography Score (pcASPECTS) was calculated based on regions displaying hypointense vessels on SWI and compared to lesions on diffusion weighted imaging (DWI). Subsequently, SWI based pcASPECTS was correlated with outcome determined with modified Rankin Scale (mRS), categorized as favorable outcome (mRS 0-2) or unfavorable outcome (3-6).ResultsTwenty-two MRI of patients with basilar artery occlusion were analyzed. In seven out of eight areas of the pcASPECTS hypointense vessels on SWI were significantly correlated to areas of restricted diffusion on DWI. In univariate analysis median pcASPECTS on SWI was significantly higher in patients with favorable outcome (7.5 vs. 5, p=0.02). In a multivariate analysis pcASPECTS on SWI was an independent predictor of favorable outcome (OR 2.02; CI [1.02;3,99]; p=0.04).ConclusionpcASPECTS based on hypointense vessels on SWI after therapy predicts outcome in patients with basilar artery occlusion and might potentially be used as an additional imaging biomarker in the management of patients with stroke in the posterior circulation. This needs to be confirmed in larger prospective clinical trials.

Are physicians more vigilant in recognizing acute Posterior Circulation Stroke symptoms? - Experience of a Tele-stroke Network. (S21.007)

Are physicians more vigilant in recognizing acute Posterior Circulation Stroke symptoms? - Experience of a Tele-stroke Network. (S21.007)

Abstract NS26: Pre-hospital Stroke Evaluation Using Expanded Stroke Screening Tools

Background and Purpose: The Cincinnati Pre-Hospital Stroke scale is a quick and accurate method for identifying stroke in the EMS setting. In 1999, Kothari et. al. demonstrated that the Cincinnati Pre-Hospital Stroke Scale (CPSS) identified 87% of acute anterior circulation strokes. We hypothesize that adding additional criteria from the NIH Stroke Scale to the CPSS will increase EMS providers’ ability to recognize stroke syndromes beyond anterior circulation strokes in the EMS setting. In Iowa, current EMS protocols use the CPSS for field stroke examinations as a minimum standard. The addition of additional elements from the NIH Stroke Scale that specifically evaluate posterior circulation should improve stroke recognition in the field. The Miami Emergency Neurological Deficit exam (MEND) specifically meets these criteria: it is based on the CPSS, and adds elements of the NIHSS that evaluate posterior circulation. This should allow EMS providers to triage and transport more patients to a primary stroke center. Methods: A retrospective chart review was done within a 22 month period at a Joint Commission Certified Primary Stroke Center. Only patients with confirmed diagnosis of stroke were included; TIA and all other diagnoses were excluded. Patient symptoms were listed and the exam criteria for both the CPSS and MEND were applied. The vascular distribution of stroke for each patient was evaluated to confirm results. Results: 732 patients presented in the 22 month period. 468 (64%) were identified using CPSS criteria.644 (88%) were identified using MEND criteria. This results in an increase of 176 (24%) patients who would have been recognized as experiencing an acute stroke using the MEND exam. Conclusion: Use of an expanded stroke exam by EMS providers will result in a higher recognition rate for anterior and posterior circulation acute stroke.

Symptomatic intracranial haemorrhage after thrombolysis with adjuvant anticoagulation in basilar artery occlusion.

Our aim was to determine factors associated with symptomatic intracranial haemorrhage (sICH) in basilar artery occlusion patients treated with intravenous thrombolysis (IVT) and adjuvant anticoagulant therapy. A registry of 176 consecutive patients with angiography-proven basilar artery occlusion who received IVT with alteplase and heparin between 1995 to 2013 was assessed. Post-treatment sICH was evaluated with the European Cooperative Acute Stroke Study II criteria. Unfavourable outcome was defined as a modified Rankin Scale score of 3-6 at 3months. Twenty-four patients developed sICH (13.6%, sICH+), all of whom had unfavourable outcome and only two (8.3%) sICH+ patients survived. On admission, sICH+ patients more frequently had extensive ischaemic changes defined as posterior circulation Acute Stroke Prognosis Early CT Score (PC-ASPECTS) < 8 (50% vs. 27% in sICH-, P=0.031) and lower platelet counts (183 vs. 218 E9/l; P=0.011). They also had higher systolic blood pressure (SBP) (median 160 vs. 147mmHg, P=0.034) immediately after IVT. In multivariable regression analysis, lower platelet values [odds ratio (OR) 0.99, 95% confidence interval (CI) 0.97-0.996; P=0.006], PC-ASPECTS < 8 on admission (OR 3.6, 95% CI 1.3-10.3; P=0.017) and higher SBP after treatment (OR 1.03, 95% CI 1.01-1.05; P=0.017) were independently associated with sICH. Ninety per cent of the sICHs occurred within 48h from IVT/anticoagulation treatment. No differences in activated partial thrompoplastin times prior to or after the treatment were observed between sICH+ and sICH- patients. The risk of sICH was largely determined by extension of ischaemic changes on admission computed tomography. Clinically relevantly, also higher post-thrombolytic SBP as described earlier and lower perithrombolytic platelet counts do increase the risk, a finding requiring confirmation in other patient series.

Recognition of posterior circulation stroke.

Better identification and triage of acute posterior circulation (PC) stroke patients is needed as the PC ischemic stroke (IS) patients may be allowed longer thrombolysis window than anterior circulation (AC) IS patients and PC patients with hemorrhagic stroke (ICH) may require care in a neurosurgical unit possibly remote from stroke unit. Consecutive stroke patients treated at a tertiary center with thrombolysis (100% for IS) and/or comprehensive stroke unit care. Altogether, 1641 patients had AC (75%) and 553 PC strokes. The PC-IS patients were younger (65 vs 70), had less often prior hypertension (51 vs 61%), and were twice more often on warfarin. They presented 3.5 times more often with seizure, vomited five times more often, had headache twice as often, and required intubation 2 to 3 times more often despite equal NIHSS (9 vs 8) or GCS (15 both) scores with AC-IS patients. Among PC patients, IS (n = 190) associated with younger age, prior atrial fibrillation (AF) in 25% and dyslipidemia in ~40%. One-third of PC-ICH patients (n = 363) had headache and vomited at the onset. PC-ICH patients had BP median of 177/92 mmHg and blood glucose 7.4 mmol/l on ER arrival. Warfarin use was twice as common in PC-ICH. Despite being of typical age for multiple cardiovascular conditions the PC-ICH patients less often have a previous history of AF or dyslipidemia than IS patients do. The vomiting PC-ICH patient with hypertensive BP values often has headache and a red flag for hemorrhage is warfarin treatment.

Diagnostic and Prognostic Impact of pc-ASPECTS Applied to Perfusion CT in the Basilar Artery International Cooperation Study.

The posterior circulation Acute Stroke Prognosis Early CT Score (pc-APECTS) applied to CT angiography source images (CTA-SI) predicts the functional outcome of patients in the Basilar Artery International Cooperation Study (BASICS). We assessed the diagnostic and prognostic impact of pc-ASPECTS applied to perfusion CT (CTP) in the BASICS registry population. We applied pc-ASPECTS to CTA-SI and cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) parameter maps of BASICS patients with CTA and CTP studies performed. Hypoattenuation on CTA-SI, relative reduction in CBV or CBF, or relative increase in MTT were rated as abnormal. CTA and CTP were available in 27/592 BASICS patients (4.6%). The proportion of patients with any perfusion abnormality was highest for MTT (93%; 95% confidence interval [CI], 76%-99%), compared with 78% (58%-91%) for CTA-SI and CBF, and 46% (27%-67%) for CBV (P < .001). All 3 patients with a CBV pc-ASPECTS < 8 compared to 6/23 patients with a CBV pc-ASPECTS ≥ 8 had died at 1 month (RR 3.8; 95% CI, 1.9-7.6). CTP was performed in a minority of the BASICS registry population. Perfusion disturbances in the posterior circulation were most pronounced on MTT parameter maps. CBV pc-ASPECTS < 8 may indicate patients with high case fatality.

Craniectomy in Acute Ischemic Stroke

Anterior and posterior circulation acute ischemic stroke carries significant morbidity and mortality as a result of malignant cerebral edema. Decompressive craniectomy has evolved as a viable neurosurgical intervention in the armamentarium of treatment options for this life-threatening edema. In this review, we highlight the history of craniectomy for stroke and discuss recent data relevant to its efficacy in modern neurosurgical practice.

Outcomes of Endovascular Mechanical Thrombectomy and Intravenous Tissue Plasminogen Activator for the Treatment of Vertebrobasilar Stroke

Background and PurposeAggressive treatment of posterior-circulation occlusions is important due to the high rates of morbidity and mortality associated with these infarctions. A large administrative database was evaluated to determine the outcomes of mechanical thrombectomy and intravenous tissue plasminogen activator (IV-tPA) for the treatment of posterior-circulation (vertebrobasilar) strokes. Outcomes were compared across age groups.MethodsThe United States Nationwide Inpatient Sample was used to evaluate the outcomes of patients treated for posterior-circulation acute ischemic stroke between 2006 and 2010. Patients who underwent endovascular mechanical thrombectomy and IV-tPA were selected. Primary outcomes were discharge status and mortality; secondary outcomes were length of stay, rate of intracranial hemorrhage, tracheostomy, and percutaneous endoscopic gastrostomy/jejunostomy tube placement. Outcomes were grouped according to age (i.e., <50, 50-64, and ≥65 years). Chi-squared test and Student's t-test were used for comparisons of categorical and continuous variables, respectively.ResultsDuring 2006-2010 there were 36,675 patients who had discharge International Classification of Diseases (9th edition) codes indicating posterior-circulation strokes. Of these, 631 (1.7%) underwent mechanical thrombectomy and 1554 (4.2%) underwent IV-tPA. The in-hospital mortality rate for mechanical thrombectomy patients was significantly lower for those aged <50 years than for those aged 50-64 years (30.4% versus 47.4%, p<0.01) and those aged ≥65 years (30.4% versus 43.0%, p≤0.01). Age had no effect on the in-hospital mortality for IV-tPA patients, with an incidence of 22.7% for patients aged <50 years, compared to 25.4% for patients aged 50-64 years (p=0.46) and 23.0% for patients aged ≥65 years (p=0.92).ConclusionsPatients requiring IV-tPA and/or mechanical thrombectomy for the treatment of posterior-circulation strokes suffer from high mortality rates. Increased age is associated with significantly higher mortality rates among posterior-circulation stroke patients who require mechanical thrombectomy.

Thrombolysis of basilar artery occlusion: Impact of baseline ischemia and time

To evaluate the impact of extensive baseline ischemic changes on functional outcome after thrombolysis of basilar artery occlusion (BAO), and to study the effect of time to treatment in the absence of such findings. We prospectively evaluated 184 consecutive patients with angiography-proven BAO. The majority of patients received intravenous alteplase and concomitant full-dose heparin. Extensive baseline ischemia was defined as posterior circulation Acute Stroke Prognosis Early CT score (pc-ASPECTS) < 8. Onset-to-treatment time (OTT) was evaluated both as a continuous and as a categorical variable (0-6 hours, 6-12 hours, 12-24 hours, and 24-48 hours). Successful recanalization means thrombolysis in myocardial infarction (TIMI) = 2 to 3. Symptomatic intracranial hemorrhage (sICH) was evaluated with National Institute of Neurological Disorders and Stroke, European Cooperative Acute Stroke Study II, and Safe Implementation of Thrombolysis in Stroke criteria. Poor 3-month outcome was defined as modified Rankin Scale score of 3 to 6. The majority (96%) of patients with baseline pc-ASPECTS < 8 had poor 3-month outcome, and a similar number (94%) was observed in those of them with confirmed recanalization (51.5%). In contrast, half of the patients with pc-ASPECTS ≥ 8 and successful recanalization (73.2%) achieved good outcome. In these patients, OTT was associated with poor outcome neither as a continuous nor as a categorical variable. Factors independently associated with poor outcome were greater age and baseline National Institutes of Health Stroke Scale, lack of recanalization, history of atrial fibrillation, and sICH. In the model including the whole cohort (patients with any pc-ASPECTS), pc-ASPECTS < 8 was independently associated with poor outcome (odds ratio = 5.83, 95% confidence interval = 1.09-31.07). In the absence of extensive baseline ischemia, recanalization of BAO up to 48 hours was seldom futile and produced good outcomes in 50% of patients, which was independent of time to treatment.

Endovascular Treatment Outcomes in Acute Posterior Circulation Stroke Patients Undergoing Mechanical Thrombolysis with Penumbra System: A Single Center Experience (P05.270)

Objective: To assess outcome of endovascular mechanical thrombolysis with Penumbra system in patients with posterior circulation acute ischemic strokes (AIS). Background Posterior circulation large vessel ischemic strokes are known for poor prognosis. Recent advances in endovascular therapy have shown improved clinical outcome in patients who present with posterior circulation ischemic stroke. Limited data exist regarding use of penumbra system to treat posterior circulation strokes. Design/Methods: Retrospective chart review was performed in 150 consecutive patients who underwent endovascular treatments AIS at our institution between 2008 and 2011. We included those with posterior circulation AIS (n=17) with mean age 63.7±12.3 years, 6 females, 11 males. Of these patients, 52.9% (n=9) underwent Penumbra system intervention along with other endovascular treatment modalities (MERCI and/or Penumbra and/or angioplasty and stenting) and/or chemical thrombolysis (intra-arterial tPA). 11% (n=1) had posterior cerebral artery and 89% (n=8) had basilar artery strokes. Comorbidities include 89% (n=8) hypertension, 33% (n=3) diabetes mellitus, 78% (n=7) dyslipidemia, 67% (n=6) coronary artery disease, and 33% (n=3) with atrial fibrillation. Primary outcome measures were rate of partial to complete recanalization (TIMI 2-3 post-intervention), discharge NIHSS, discharge modified Rankin Scale (mRS), symptomatic intracerebral hemorrhage (SICH) (ECASS criteria), hemicraniectomy, and all cause mortality. Results: Rates of partial to complete recanalization were 88.9% (n=8). Of those with survival, mean discharge NIHSS were 9±9 points. 0% (n=0) patients had SICH, although 11% (n=1) had asymptomatic hemorrhage on CT post-intervention (PH1). 11% (n=1) underwent suboccipital hemicraniectomy. At time of discharge, 11% (n=1) had mRS Conclusions: In patients undergoing endovascular treatment modalities in posterior circulation stroke, those with Penumbra system intervention had good revascularization rates. Additional data with larger sample size is needed to better evaluate outcomes of penumbra system in posterior circulation strokes. Disclosure: Dr. Shams has nothing to disclose. Dr. Sharma has nothing to disclose. Dr. Jung has nothing to disclose. Dr. Blackham has nothing to disclose.

Treatment of Acute Ischemic Stroke With Clot Retrieval Devices

Mechanical clot retrieval is increasingly used for flow-restoration and thrombectomy in acute embolic stroke. Emerging as a treatment option in addition to intravenous or intra-arterial thrombolysis, it is currently being further developed and investigated as a potential first-line and stand-alone treatment. The ability to rapidly restore flow and effectively retrieve clots from large intracranial arteries is reflected by angiographic data and preliminary clinical results. This article reviews the principles and technical aspects of this new technique, its emergence from the spectrum of intravenous and endovascular stroke treatment, and summarizes the first clinical results for acute ischemic anterior and posterior circulation stroke. Clot retrieval devices are a very promising option for treatment of acute ischemic stroke in the setting of large vessel occlusion. However, there currently exists a reported discrepancy between excellent recanalization rates and less satisfactory clinical outcomes. This problem urgently needs to be addressed in a prospective randomized fashion and improvements of treatment be recognized and implemented before clot retrieval can be considered an established form of acute stroke treatment.

Abstract 3708: Safety and Efficacy of Antiplatelet Monotherapy (clopidogrel) in Stent Assisted Elective Coil Embolization of Cerebral Aneurysms

BACKGROUND AND PURPOSE: Thromboembolic events are the most common complication seen in elective coil embolization of cerebral aneurysms. Previous studies have shown that administration of oral clopidogrel and/or aspirin may lower the thromboembolic complication rate but little data exists regarding clinical outcome with the use of antiplatelet monotherapy in stent assisted elective aneurysm coil embolization. Objectives: To assess the safety and efficacy of antiplatelet monotherapy (clopidogrel) in elective stent assisted coil embolization of cerebral aneurysms MATERIALS AND METHODS: Retrospective chart review was performed in 94 consecutive patients who underwent endovascular treatments for elective coil embolization of cerebral aneurysms between 2008-2010. Thirty patients were included in this study who met the inclusion criteria of stent assisted coil embolization. All these patients received 75mg clopidogrel for one week prior to the procedure. Clopidogrel was continued post procedure for six to eight weeks. Primary outcome measure was peri-procedure and post-procedure symptomatic thromboembolic complications. RESULTS The study included 23 females and 7 males with mean age 52.6 years.Twenty (66.7%) patients had anterior circulation aneurysms and 10 (33.3%) patients had posterior circulation aneurysms. Twenty (66.7%) patients were treated with Neuroform, 9 (30%) patients with Enterprise stent and 1 (3.3%) patient was treated with both Neuroform and Enterprise stent assisted coil embolization. One (3.3%) patient had an iatrogenic flow limiting vertebral artery dissection during embolization of vertebrobasilar artery aneurysm with no clinical deficit. The patient’s vertebral artery dissection was treated with 2 Wingspan stents and 1 Medtronic driver stents. Symptomatic thromboembolic complication was seen in 1 patient (3.3%) at discharge. The patient had a giant basilar tip aneurysm which was treated with stent assisted coil embolization. Postprocedure the patient had a right facial palsy with gaze deviation. The MRI was consistent with acute posterior circulation stroke. The patient was discharged home with a modified Rankin Scale &lt;2. Follow up at six to eight weeks post procedure clinical data was available for 21 patients (73.3%). No delayed thromboembolic complication was observed in these patients at follow up visit. CONCLUSION: Oral clopidogrel is safe and efficacious as an antiplatelet monotherapy during elective stent assisted coil embolization. Further multicenter prospective trials are warranted to evaluate safety and efficacy of clopidogrel as a monotherapy for elective stent assisted coil embolization.