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The use of flow diverting stents for wide based, intracranial aneurysms has become an invaluable treatment option. While intracranial hemorrhage and ischemic stroke from dislodged atherosclerotic emboli are common adverse events, the potential for delayed granulomatous inflammation from possible hydrophilic polymer emboli is rarely recognized. We present a unique case in which visible chipping of the pusher wire for stent placement was observed, followed by clinical and radiographic evidence suggestive of a delayed foreign body reaction to intracranial hydrophilic polymer emboli. A 55-year-old woman underwent placement of a Pipeline embolization device for a left-sided, broad-based aneurysm at the base of the internal carotid artery and posterior communicating artery. Two months later she developed right-sided focal neurological deficits. Imaging showed ipsilateral focal edema and enhancing lesions with contrast. Although not confirmed with biopsy and histopathology, clinical and radiographic evidence suggests that this patient probably experienced a delayed foreign body reaction to hydrophilic polymer emboli from compromised procedural equipment during flow diverting stent placement. Although previously described, this is the first instance to our knowledge in whichvisible chipping of the pusher wire was observed on a Pipeline embolization device. [ABSTRACT FROM AUTHOR]

Background Embolization has been proposed to reduce the size of the arteriovenous malformation (AVM) nidus in advance of radiosurgical treatment. Embolization followed by radiosurgery for brain AVMs, however, is controversial. Objective We assessed the impact of embolization on nidal size before radiosurgical treatment and evaluated cure rates and complications by using embolization followed by radiosurgery. Methods A retrospective review of our institutional AVM database identified 91 patients treated from 1995 to 2009 with embolization followed by radiosurgery. Pre- and postembolization AVM volumes were measured with angiography, and the modified radiation-based AVM scores (RBAS) also were calculated pre- and postembolization. RBAS determined from pre-embolization volumes were correlated with postradiosurgical obliteration. Results Median AVM volume declined from 18.8 mL (interquartile range, 10.2–32.2 mL) to 9.9 mL (3.1–19.2 mL) after embolization, P < 0.00003. Median RBAS scores decreased from 2.6 mL (1.8–3.9 mL) to 1.8 mL (1.0–2.8 mL), P < 0.00003. Two of 91 (2.2%) had new fixed deficits after embolization; however, no patient had new disabling deficits (modified Rankin Scale score >2). A total of 71 of 91 (79%) have had >3 years' follow-up, and 40 (56%) had complete obliteration, with 38 (53%) having excellent outcomes (complete obliteration without neurologic decline). Excellent outcome was seen in 90% of patients with modified RBAS score <1, 66% of patients with score 1–1.5, 50% patients with score 1.5–2, and 43% of patients with score >2. Conclusions These data suggest that embolization of brain AVMs can safely and effectively reduce the treatment volume before radiosurgery. Combined therapy with embolization and radiosurgery does not appear to adversely affect rates of excellent outcome. [ABSTRACT FROM AUTHOR]

Objective To understand how three commonly used measures of endovascular therapy correlate with clinical outcome and infarct growth. Methods Prospectively enrolled patients underwent baseline MRI and started endovascular therapy within 12 h of stroke onset. The final angiogram was given a primary arterial occlusive lesion (AOL) recanalization score (0-3), a Thrombolysis in Myocardial Infarction (TIMI) score (0-3) and a Thrombolysis in Cerebral Infarction (TICI) score (0-3). The scores were dichotomized into poor revascularization (AOL 0-2, TIMI 0-1 and TICI 0-2a) versus good revascularization (AOL 3, TIMI 2-3, TICI 2b-3). Patients were classified according to whether or not they had target mismatch (TMM). Good outcome was defined as a 90-day modified Rankin Scale score of 0-2. Results Endovascular treatment was attempted in 100. A good outcome was achieved in 57% of patients with a TICI score of 2b-3 and in 24% of patients with a TICI score of 0-2a (p=0.001). Patients with TIMI scores of 2-3 and an AOL score of 3 had lower rates of good outcome (44% and 47%, respectively), which were not significantly better than those with TIMI scores of 0-1 or AOL scores of 0-2. In patients with TMM, these rates of good outcome improved with all the scoring systems and were significantly better for TIMI and TICI scores. Patients with a TICI score of 2a had rates of good functional outcome and lesion growth which were not different from those with TICI scores of 0-1 but were significantly worse than those with TICI scores of 2b-3. Conclusions TIMI 2-3 and TICI 2b-3 reperfusion scores demonstrated improved outcome in patients with tissue mismatch with a small infarct core and a larger hypoperfused region but AOL scores did not. Patients with a TICI score of 2a had a poorer outcome and more lesion growth than those with TICI scores of 2b-3. [ABSTRACT FROM AUTHOR]

Background DEFUSE 2 demonstrated that patients with magnetic resonance imaging mismatch had a favorable clinical response to tissue reperfusion assessed by magnetic resonance imaging. This study reports the endovascular results and correlates angiographic reperfusion with clinical and imaging outcomes. Methods Prospectively enrolled ischemic stroke patients underwent baseline magnetic resonance imaging and started endovascular therapy within 12 h of onset. Patients were classified as either target mismatch or no target mismatch using magnetic resonance imaging. The pre- and postprocedure angiogram was evaluated to determine thrombolysis in cerebral infarction scores. Favorable clinical response was determined at day 30, and good functional outcome was defined as a modified Rankin Scale 0-2 at day 90. Results One-hundred patients had attempted endovascular treatment. At procedure end, 23% were thrombolysis in cerebral infarction 0-1, 31% thrombolysis in cerebral infarction 2A, 28% thrombolysis in cerebral infarction 2B, and 18% thrombolysis in cerebral infarction 3. More favorable thrombolysis in cerebral infarction-reperfusion scores were associated with greater magnetic resonance imaging reperfusion (P < 0·001). thrombolysis in cerebral infarction scores correlated with 30-day favorable clinical response (P = 0·041) and 90-day modified Rankin Scale 0-2 (P = 0·008). These correlations were significant for target mismatch patients at 30 days (P = 0·034) and 90 days (P = 0·003). Infarct growth was strongly associated with poorer thrombolysis in cerebral infarction scores in target mismatch patients (P < 0·001). Patients with thrombolysis in cerebral infarctionnfarction 2A reperfusion had less magnetic resonance imaging reperfusion (P = 0·004) and poorer clinical outcome at 90 days (P = 0·01) compared with thrombolysis in cerebral infarction 2B-3 patients. Conclusion Thrombolysis in cerebral infarction reperfusion following endovascular therapy for ischemic stroke is highly correlated with magnetic resonance imaging reperfusion, infarct growth, and clinical outcome. [ABSTRACT FROM AUTHOR]

In recent years, the figurative face of politics in America often quite literally has become the face of a celebrity. This trend finds citizens in democratic society willing to yield up their political consciousness to media-created celebrities. Drawing on the theories of Michel Foucault and Jean Baudrillard, this article argues that the investiture of authority in celebrities represents a continuation of the trend by which social bodies operate as the site where relations of power are played out, and by which the media serve as a means in which real democracy has been replaced by a simulated one. Alongside grassroots participation, and in some cases leading it, society is incorporating a new language that deploys celebrities as chief vehicles for the simulation of political consent, thereby overcoming public apathy, and buttressing the existing political order. [ABSTRACT FROM AUTHOR]

This article addresses the problems that emerge when students in international studies courses approach the subject matter from the perspective of the first person plural. Whether in terms of “we,” “us,” or “our,” many college students choose to adopt a personal perspective in discussions of international affairs. While it is natural for students to base their analysis of international studies on their personal observations and experiences, this inclination to adopt a collective first person approach detracts from the scholarly neutrality toward which students of global studies should aspire. Furthermore, a first person plural approach to course subject matter creates the false impression among students that they are all in agreement over contentious issues of global interactions and the theories employed to study them. The article concludes with suggestions for remedying the “we” problem, and offers advice for instructors who have encountered it in their own classroom. [ABSTRACT FROM AUTHOR]

Focuses on prison metaphor for international politics. Relationships between prison metaphor and international relations; Implications on the pains of imprisonment; Evolution of prison life.

Background: After the occlusion of an internal carotid artery the principal source of collateral flow is through the arteries of the circle of Willis, but the size and patency of these arteries are quite variable. Study of the anatomy of the collateral pathways in patients with internal-carotid-artery occlusion with or without infarction in the watershed area of the deep white matter may identify patterns that afford protection from ischemic infarction. Methods: Using conventional magnetic resonance imaging and three-dimensional phase-contrast magnetic resonance angiography, we evaluated 29 consecutive patients (32 hemispheres at risk) with angiographically proved occlusion of the internal carotid artery. Four collateral pathways to the occluded vessel were evaluated: the proximal segment of the anterior cerebral artery, the posterior communicating artery, the ophthalmic artery, and leptomeningeal collateral vessels from the posterior cerebral artery. Results: Only features of the ipsilateral posterior communicating artery were related to the risk of watershed infarction. The presence of posterior communicating arteries measuring at least 1 mm in diameter was associated with the absence of watershed infarction (13 hemispheres, no infarcts; P<0.001). Conversely, there were 4 watershed infarcts in the 6 hemispheres with posterior communicating arteries measuring less than 1 mm in diameter and 10 infarcts in the 13 hemispheres with no detectable flow in the ipsilateral posterior communicating artery. Conclusions: A small (<1 mm in diameter) or absent ipsilateral posterior communicating artery is a risk factor for ischemic cerebral infarction in patients with internal-carotid-artery occlusion. (N Engl J Med 1994;330:1565-70.) [ABSTRACT FROM AUTHOR]

Background Cerebral vasospasm following subarachnoid hemorrhage (SAH) results in significant morbidity and mortality. Intra-arterial administration of calcium channel blockers or intracranial angioplasty may be performed when non-invasive medical management fails to prevent neurologic deterioration. Technical improvements in balloon catheters are expected to improve the success and safety of cerebral angioplasty. Objective To describe our initial experience with the new Scepter XC balloon catheter in cerebral vasospasm treatment following SAH. Design All patients who underwent cerebral angioplasty using the Scepter XC balloon for the treatment of medically refractory cerebral vasospasm after SAH were identified. Patient demographic information, procedural details, and outcome were obtained from electronic medical records. Results Five consecutive patients undergoing vasospasm treatment with cerebral angioplasty using the Scepter XC were identified. All treated patients had medically refractory vasospasm that was moderate or severe. Angioplasty of the supraclinoid internal carotid artery, the A1 and A2 segments of the anterior cerebral artery, the M1 and M2 segments of the middle cerebral artery, the V4 segment of the vertebral artery, and the basilar artery was performed. All angioplasty procedures were technically successful, and the degree of vasospasm improved significantly following angioplasty. There were no complications related to the cerebral angioplasty procedures. Conclusions The Scepter XC balloon catheter is safe and effective in the treatment of cerebral vasospasm following SAH. The excellent trackability and stability of the balloon catheter and the extra compliant design of the balloon represent technical advancements in the endovascular armamentarium in the treatment of cerebral vasospasm. [ABSTRACT FROM AUTHOR]

Background: Moyamoya disease (MMD) is an idiopathic progressive arteriopathy affecting the proximal intracranial vasculature. To date only 4 case reports on intracranial angioplasty or stenting as treatment of this disease exist. We present 5 adult patients with MMD who failed angioplasty and/or stenting who remained symptomatic despite endovascular treatment or presented with recurrent symptoms and recurrence of stenosis/occlusion on angiography requiring subsequent extracranial-intracranial revascularization. Methods: Five adult MMD patients who underwent endovascular treatment with angioplasty or stenting were referred for further evaluation and treatment from outside hospitals. Data were collected from clinical referral notes and angiograms or reports. All patients underwent repeat 6-vessel cerebral angiography to assess the extent of disease and results of prior endovascular treatment. Results: Six endovascular procedures were performed in all 5 patients. Internal carotid artery (ICA) balloon angioplasty and Wingspan stenting was performed in 2 patients (3 arteries). One patient had ICA-M1 angioplasty without stenting. Two patients had M1 angioplasty and Wingspan stenting. All patients developed repeat transient ischemic attacks following treatment attributable to the vascular territories of endovascular treatment. Repeat endovascular treatment was performed in 3 patients at a mean of 4 months (range = 2-6). Two went on to a third endovascular treatment due to progression of disease in the angioplastied/stented vessel. The average time of symptom recurrence after initial endovascular therapy was 1.8 months (0-4 months). Follow-up angiography when referred to our institution demonstrated 70-90% instent restenosis of the stented vessel in 3 and occlusion in 1 patient. Due to persistence of symptoms cerebral revascularization was performed in all patients. Conclusion: MMD is a progressive angiopathy. Angioplasty and stenting may temporarily improve the cerebral blood flow and decrease cerebral ischemic events but do not appear to be durable nor provide long-term prevention against future ischemic events. Copyright © 2010 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Abstract: The capsular warning syndrome is a term used to describe recurrent stereotyped lacunar transient ischemic attacks (TIAs). This syndrome is associated with a high risk of developing a completed stroke. The presumed mechanism for this syndrome is angiopathy of a lenticulostriate artery. We describe the case of a 33-year-old man who presented with the capsular warning syndrome who was successfully treated with angioplasty. The patient''s capsular warning syndrome manifested as recurrent episodes of transient left hemiparesis. Symptoms recurred one to three times daily despite treatment with antithrombotics. Cerebral angiography demonstrated stenosis of the right middle cerebral artery (MCA) with decreased flow to a dominant lenticulostriate artery. Angioplasty of the right middle cerebral artery increased flow to the lenticulostriate artery and the TIAs resolved following the procedure. In select cases intracranial angioplasty, may be an effective treatment for patients with capsular warning syndrome. [Copyright &y& Elsevier]

Background: The natural history of unilateral moyamoya disease (MMD) in adult patients is not clearly described in the literature. We present a series of 18 patients with unilateral MMD and analyze the risk factors for progression to bilateral disease. Methods: A retrospective review of 157 MMD patients treated at Stanford University Medical Center from 1991 to 2005 identified 28 patients with unilateral MMD (defined as none, equivocal or mild involvement on the contralateral side). Results: Eigh teen patients (5 males and 13 females) were identified with unilateral MMD and angiographic follow-up of ≥5 months. Mean radiologic follow-up (± standard error of the mean) was 19.3 ± 3.4 months and mean clinical follow-up was 24.5 ± 3.7 months. Five patients had childhood onset MMD and 13 patients had adult onset disease. Angiographic progression from unilateral to bilateral disease was seen in 7 patients (38.9%) at a mean follow-up of 12.7 ± 2.4 months. Four of the 7 patients had significant clinical and radiologic progression requiring surgical intervention. Five of 7 patients that progressed had adult onset MMD. The presence of equivocal or mild stenotic changes of the contralateral anterior cerebral artery (ACA), middle cerebral artery (MCA) or internal carotid artery (ICA) was an important predictor of progression (p < 0.01); 6 of 8 patients (75%) with equivocal or mild contralateral disease progressed, whereas only 1 of 10 patients (10.0%) with no initial contralateral disease progressed to bilateral MMD. One patient had mild or equivocal MCA, ICA and ACA stenosis at the time of initial diagnosis and this patient progressed. Conclusions: Contralateral progression in the adult form occurs more commonly than previously reported. The presence of minor changes in the contralateral ACA, intracranial ICA and MCA is an important predictor of increased risk of progression. Patients with a completely normal angiogram on the contralateral side have a very low risk of progression. Copyright © 2006 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background and purpose: Arterial clot localization affects collateral flow to ischemic brain in patients with acute ischemic stroke due to large vessel occlusion (AIS‐LVO). We determined the association between vessel occlusion locations, tissue‐level collaterals (TLC), and venous outflow (VO) profiles and their impact on good functional outcomes. Methods: We conducted a multicenter retrospective cohort study of consecutive AIS‐LVO patients who underwent thrombectomy triage. Baseline computed tomographic angiography (CTA) was used to localize vessel occlusion, which was dichotomized into proximal vessel occlusion (PVO; internal carotid artery and proximal first segment of the middle cerebral artery [M1]) and distal vessel occlusion (DVO; distal M1 and M2), and to assess collateral scores. TLC were assessed on computed tomographic perfusion data using the hypoperfusion intensity ratio. VO was determined on baseline CTA by the cortical vein opacification score. Primary outcomes were favorable VO and TLC; secondary outcome was the modified Rankin Scale after 90 days. Results: A total of 649 patients met inclusion criteria. Of these, 376 patients (58%) had a PVO and 273 patients (42%) had a DVO. Multivariate ordinal logistic regression showed that DVO predicted favorable TLC (odds ratio [OR] = 1.77, 95% confidence interval [CI] = 1.24–2.52, p = 0.002) and favorable VO (OR = 7.2, 95% CI = 5.2–11.9, p < 0.001). DVO (OR = 3.4, 95% CI = 2.1–5.6, p < 0.001), favorable VO (OR = 6.4, 95% CI = 3.8–10.6, p < 0.001), and favorable TLC (OR = 3.2, 95% CI = 2–5.3, p < 0.001), but not CTA collaterals (OR = 1.07, 95% CI = 0.60–1.91, p = 0.813), were predictors of good functional outcome. Conclusions: DVO in AIS‐LVO patients correlates with favorable TLC and VO profiles, which are associated with good functional outcome. [ABSTRACT FROM AUTHOR]

Background and Purpose: Patients with acute ischemic stroke due to a large vessel occlusion (AIS‐LVO) undergo emergent neuroimaging triage for thrombectomy treatment. MRI is often utilized for this evaluation, and cerebral magnetic resonance perfusion (MRP) imaging is used to identify the presence of the salvageable penumbra. To determine if dose reduction is feasible, we assessed whether a half‐dose reduction in gadobenate provided sufficient MRP quality in AIS‐LVO patients. Methods: A prospective observational study of all patients presenting to our neurovascular referral center with AIS‐LVO was performed. MRP was done with a half‐dose of gadolinium (0.1 ml/kg body weight) over a period of 10 months. MRP images were compared to a consecutive historical cohort of full‐dose gadolinium (0.2 ml/kg body weight) MRP studies and rated for image quality (poor, borderline, or good) that determined thrombectomy eligibility. Results: Fifty‐four half‐dose and 127 full‐dose patients were included. No differences in patient demographics or stroke presentation details were identified. MRP quality differed between half‐ and full‐dose scans (p < 0.001), which were rated as poor (40.7% vs. 6.3%), borderline (18.5% vs. 26.8%), and good quality (40.7% vs. 66.9%), respectively. MRP image quality was then dichotomized into poor and sufficient (borderline and good) quality groups; half‐dose studies were more likely to have poor quality compared to full‐dose studies (40.7% vs. 6.3%; p < 0.001). Conclusions: Half‐dose gadolinium administration for MRP in AIS‐LVO patients results in poor image quality in a substantial number of studies. MR cerebral perfusion performed with half‐dose gadolinium may adversely affect stroke patient triage for thrombectomy. [ABSTRACT FROM AUTHOR]

Ischemic lesion Net Water Uptake (NWU) quantifies cerebral edema formation and likely correlates with the microvascular perfusion status of patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO). We hypothesized that favorable tissue-level collaterals (TLC) predict less NWU and good functional outcomes. We performed a retrospective multicenter analysis of AIS-LVO patients who underwent thrombectomy triage. TLC were measured on cerebral perfusion studies using the hypoperfusion intensity ratio (HIR; volume ratio of brain tissue with [Tmax > 10 sec/Tmax > 6 sec]); favorable TLC were regarded as HIR ≤ 0.4. NWU was determined using a quantitative densitometry approach on follow-up CT. Primary outcome was NWU. Secondary outcome was a good functional outcome (modified Rankin Scale [mRS] 0–2). 580 patients met inclusion criteria. Favorable TLC (β: 4.23, SE: 0.65; p < 0.001) predicted smaller NWU after treatment. Favorable TLC (OR: 2.35, [95% CI: 1.31–4.21]; p < 0.001), and decreased NWU (OR: 0.75, [95% CI: 0.70–0.79]; p < 0.001) predicted good functional outcome, while controlling for age, glucose, CTA collaterals, baseline NIHSS and good vessel reperfusion status. We conclude that favorable TLC predict less ischemic lesion NWU after treatment in AIS-LVO patients. Favorable TLC and decreased NWU were independent predictors of good functional outcome. [ABSTRACT FROM AUTHOR]

Introduction: Dural arteriovenous fistulae (DAVF) are vascular lesions with arteriovenous shunting that may be treated with surgical obliteration or endovascular embolization. Some DAVF, such as anterior cranial fossa DAVF (AC-DAVF) derive their arterial supply from ophthalmic artery branches in nearly all cases, and trans-arterial embolization carries a risk of vision loss. We determined the efficacy and safety of trans-ophthalmic artery embolization of DAVF. Materials and methods: We performed a retrospective cohort study of all patients with DAVF treated by trans-ophthalmic artery embolization from 2012 to 2020. Primary outcome was angiographic cure of the DAVF. Secondary outcomes included vision loss, visual impairment, orbital cranial nerve injury, stroke, modified Rankin Scale at 90-days, and mortality. Results: 12 patients met inclusion criteria (9 males; 3 females). 10 patients had AC-DAVF. Patient age was 59.7 ± 9.5 (mean ± SD) years. Patients presented with intracranial hemorrhage (4 patients), headache (4 patients), amaurosis fugax (1 patients), or were incidentally discovered (2 patients). DAVF Cognard grades were: II (1 patient), III (6 patients), and IV (5 patients). DAVF were embolized with Onyx (10 patients), nBCA glue (1 patient), and a combination of coils and Onyx (1 patient). DAVF cure was achieved in 11 patients (92%). No patients experienced vision loss, death, or permanent disability. One patient experienced a minor complication of blurry vision attributed to posterior ischemic optic neuropathy. 90-day mRS was 0 (10 patients) and 1 (2 patients). Conclusions: Trans-ophthalmic artery embolization is an effective and safe treatment for DAVF. [ABSTRACT FROM AUTHOR]

Background: The role of Alberta Stroke Program Early CT Score (ASPECTS) for thrombectomy patient selection and prognostication in late time windows is unknown. Aims: We compared baseline ASPECTS and core infarction determined by CT perfusion (CTP) as predictors of clinical outcome in the Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke 3 (DEFUSE) 3 trial. Methods: We included all DEFUSE 3 patients with baseline non-contrast CT and CTP imaging. ASPECTS and core infarction were determined by the DEFUSE 3 core laboratory. Primary outcome was functional independence (modified Rankin Scale (mRS) ≤2). Secondary outcomes included ordinal mRS shift at 90 days and final core infarction volume. Results: Of the 142 patients, 85 patients (60%) had ASPECTS 8–10 and 57 (40%) had ASPECTS 5–7. Thirty-one patients (36%) with ASPECTS 8–10 and 11 patients (19%) with ASPECTS 5–7 were functionally independent at 90 days (p = 0.03). In the primary and secondary logistic regression analysis, there was no difference in ordinal mRS shift (p = 0.98) or functional independence (mRS ≤ 2; p = 0.36) at 90 days between ASPECTS 8–10 and ASPECTS 5–7 patients. Similarly, primary and secondary logistic regression analyses found no difference in ordinal mRS shift (p = 1.0) or functional independence (mRS ≤ 2; p = 0.87) at 90 days between patients with baseline small core (< 50 ml) versus medium core (50–70 ml). Conclusions: Higher ASPECTS (8–10) correlated with functional independence at 90 days in the DEFUSE trial. ASPECTS and core infarction volume did not modify the thrombectomy treatment effect, which indicates that patients with a target mismatch profile on perfusion imaging should undergo thrombectomy regardless of ASPECTS or core infarction volume in late time windows. [ABSTRACT FROM AUTHOR]

AHA guidelines recommend use of perfusion imaging for patient selection in the 6–24 h window. Recently, the safety of gadolinium-based contrast agents for MR perfusion imaging has been questioned based on findings that gadolinium accumulates in brain tissue. Regulatory bodies have recommended to limit the use of gadolinium-based contrast agents where possible. Focusing specifically on the time to maximum of the tissue residue function (Tmax) parameter, used in DAWN and DEFUSE 3, we hypothesized that half-dose scans would yield a similar Tmax delay pattern to full-dose scans. We prospectively recruited 10 acute ischemic stroke patients imaged with two perfusion scans at their follow-up visit, one with a standard dose gadolinium followed by a half-dose injection a median of 7 min apart. The brain was parcellated into a grid of 3 × 3 regions and the mean of the difference in Tmax between the 3 × 3 regions on the half- and full-dose Tmax maps was 0.1 s (iqr 0.38 s). The fraction of brain tissue that differed by no more than ±1 s was 93.7%. In patients with normal or modest Tmax delays, half-dose gadolinium appears to provide comparable Tmax measurements to those of full-dose scans. [ABSTRACT FROM AUTHOR]

We previously demonstrated that in the DEFUSE 3 trial, the union of the baseline core and the 24-h Tmax > 6 s perfusion lesion predicts the infarct volume at 24 h. Presently, we assessed if collateral robustness measured by the hypoperfusion intensity ratio (HIR) and cerebral blood volume (CBV) index accounts for the variance in these predictions. DEFUSE 3 patients underwent MRI/CT perfusion imaging at baseline and 24 h post-randomization. We compared baseline and follow-up HIR and CBV index across subgroups stratified by differences between predicted and observed 24-h infarct volumes. Of 123 eligible patients, 34 with 24-h infarcts larger than predicted had less favorable collaterals at baseline (HIR 0.43 vs. 0.32, p = 0.006; CBV Index 0.78 vs. 0.85, p = 0.001) and 24 h (HIR 0.56 vs. 0.07, p = 0.004; CBV Index 0.47 vs. 0.73, p = 0.006) compared to 71 patients with more accurate infarct volume prediction. Eighteen patients with 24-h infarcts smaller than predicted had similar baseline collateral scores but more favorable 24-h CBV indices (0.81 vs. 0.73, p = 0.040). Overall, patients with 24-h infarcts larger than predicted had evidence of less favorable baseline collaterals that fail within 24 h, while patients with 24-h infarcts smaller than predicted typically had favorable collaterals that persisted for 24 h. [ABSTRACT FROM AUTHOR]

Background: Acute ischemic stroke patients with a large-vessel occlusion but mild symptoms (NIHSS ≤ 6) pose a treatment dilemma between medical management and endovascular thrombectomy. Aims: To evaluate the differences in clinical outcomes of endovascular thrombectomy-eligible patients with target-mismatch perfusion profiles who undergo either medical management or endovascular thrombectomy. Methods: Forty-seven patients with acute ischemic stroke due to large-vessel occlusion, NIHSS ≤ 6, and a target-mismatch perfusion imaging profile were included. Patients underwent medical management or endovascular thrombectomy following treating neurointerventionalist and neurologist consensus. The primary outcome measure was NIHSS shift. Secondary outcome measures were symptomatic intracranial hemorrhage, in-hospital mortality, and 90-day mRS scores. The primary intention-to-treat and as-treated analyses were compared to determine the impact of crossover patient allocation on study outcome measures. Results: Forty-seven patients were included. Thirty underwent medical management (64%) and 17 underwent endovascular thrombectomy (36%). Three medical management patients underwent endovascular thrombectomy due to early clinical deterioration. Presentation NIHSS (P = 0.82), NIHSS shift (P = 0.62), and 90-day functional independence (mRS 0–2; P = 0.25) were similar between groups. Endovascular thrombectomy patients demonstrated an increased overall rate of intracranial hemorrhage (35.3% vs. 10.0%; P = 0.04), but symptomatic intracranial hemorrhage was similar between groups (P = 0.25). In-hospital mortality was similar between groups (P = 0.46), though all two deaths in the medical management group occurred among crossover patients. Endovascular thrombectomy patients demonstrated a longer length of stay (7.6 ± 7.2 vs. 4.3 ± 3.9 days; P = 0.04) and a higher frequency of unfavorable discharge to a skilled-nursing facility (P = 0.03) rather than home (P = 0.05). Conclusions: Endovascular thrombectomy may pose an unfavorable risk-benefit profile over medical management for endovascular thrombectomy-eligible acute ischemic stroke patients with mild symptoms, which warrants a randomized trial in this subpopulation. [ABSTRACT FROM AUTHOR]

Background Endovascular treated cerebral aneurysms have a greater recurrence rate compared with microsurgical clip ligation. Despite recent endovascular advances, microsurgical clip ligation might be the treatment of choice for certain previously endovascular treated recurrent aneurysms. We report on our single-center experience with 76 previously coiled and/or stent-coiled aneurysms. Objective To analyze the surgical and radiologic outcome after clipping of previous endovascular treated recurrent cerebral aneurysms. Methods Patients were retrospectively identified. Demographic data, aneurysm size, location, perioperative coil extraction, occlusion rate, and complication rate were recorded. Patients were divided into a previously coiled-only group (COG) and a previously stent-assisted coiled group (SAC). Results Seventy-five patients with 76 aneurysms were included. Sixty-nine patients were included in the COG, 7 patients in the SAC group. Complete or acceptable near-complete occlusion was obtained in 95% of patients in the COG and 57% in the SAC group. Two patients in the COG (2.9%) died postoperatively of a major stroke. One patient died of rehemorrhage after wrapping of an aneurysm. Minor complications occurred in 8.7%. In the SAC group, the mortality was 0%, with 1 major stroke (14.2%), 1 minor stroke (14.2%), and 1 cranial nerve palsy (14.2%). Intraoperative coil extraction and previous stent-assisted coiling were significant predictors of complication rate (P = 0.025 and P = 0.0036 respectively). Previous stent-assisted coiling was a significant predictor of incomplete occlusion (P = 0.036). Conclusions Microsurgical clipping of previously endovascular treated recurrent aneurysms is an effective treatment with high obliteration rates. Previously stent-assisted coiling and intraoperative coil extraction are predictors of worse outcome and incomplete occlusion. [ABSTRACT FROM AUTHOR]

Background Subarachnoid hemorrhage (SAH) secondary to rupture of a blister aneurysm (BA) results in high morbidity and mortality. Endovascular treatment with the pipeline embolization device (PED) has been described as a new treatment strategy for these lesions. We present the first reported case of PED retraction and foreshortening after treatment of a ruptured internal carotid artery (ICA) BA. Case description A middle-aged patient presented with SAH secondary to ICA BA rupture. The patient was treated with telescoping PED placement across the BA. After 5 days from treatment, the patient developed a new SAH due to re-rupture of the BA. Digital subtraction angiography revealed an increase in caliber of the supraclinoid ICA with associated retraction and foreshortening of the PED that resulted in aneurysm uncovering and growth. Conclusions PED should be oversized during ruptured BA treatment to prevent device retraction and aneurysm regrowth. Frequent imaging follow up after BA treatment with PED is warranted to ensure aneurysm occlusion. [ABSTRACT FROM AUTHOR]

Rationale: Early reperfusion in patients experiencing acute ischemic stroke is effective in patients with large vessel occlusion. No randomized data are available regarding the safety and efficacy of endovascular therapy beyond 6 h from symptom onset. Aim: The aim of the study is to demonstrate that, among patients with large vessel anterior circulation occlusion who have a favorable imaging profile on computed tomography perfusion or magnetic resonance imaging, endovascular therapy with a Food and Drug Administration 510 K-cleared mechanical thrombectomy device reduces the degree of disability three months post stroke. Design: The study is a prospective, randomized, multicenter, phase III, adaptive, blinded endpoint, controlled trial. A maximum of 476 patients will be randomized and treated between 6 and 16 h of symptom onset. Procedures: Patients undergo imaging with computed tomography perfusion or magnetic resonance diffusion/perfusion, and automated software (RAPID) determines if the Target Mismatch Profile is present. Patients who meet both clinical and imaging selection criteria are randomized 1:1 to endovascular therapy plus medical management or medical management alone. The individual endovascular therapist chooses the specific device (or devices) employed. Study outcomes: The primary endpoint is the distribution of scores on the modified Rankin Scale at day 90. The secondary endpoint is the proportion of patients with modified Rankin Scale 0-2 at day 90 (indicating functional independence). Analysis: Statistical analysis for the primary endpoint will be conducted using a normal approximation of the Wilcoxon-Mann-Whitney test (the generalized likelihood ratio test). [ABSTRACT FROM AUTHOR]

Objective: To assess the utility of computed tomographic (CT) perfusion for selection of patients for endovascular therapy up to 18 hours after symptom onset.Methods: We conducted a multicenter cohort study of consecutive acute stroke patients scheduled to undergo endovascular therapy within 90 minutes after a baseline CT perfusion. Patients were classified as "target mismatch" if they had a small ischemic core and a large penumbra on their baseline CT perfusion. Reperfusion was defined as >50% reduction in critical hypoperfusion between the baseline CT perfusion and the 36-hour follow-up magnetic resonance imaging.Results: Of the 201 patients enrolled, 190 patients with an adequate baseline CT perfusion study who underwent angiography were included (mean age = 66 years, median NIH Stroke Scale [NIHSS] = 16, median time from symptom onset to endovascular therapy = 5.2 hours). Rate of reperfusion was 89%. In patients with target mismatch (n = 131), reperfusion was associated with higher odds of favorable clinical response, defined as an improvement of ≥8 points on the NIHSS (83% vs 44%; p = 0.002, adjusted odds ratio [OR] = 6.6, 95% confidence interval [CI] = 2.1-20.9). This association did not differ between patients treated within 6 hours (OR = 6.4, 95% CI = 1.5-27.8) and those treated > 6 hours after symptom onset (OR = 13.7, 95% CI = 1.4-140).Interpretation: The robust association between endovascular reperfusion and good outcome among patients with the CT perfusion target mismatch profile treated up to 18 hours after symptom onset supports a randomized trial of endovascular therapy in this patient population. Ann Neurol 2017;81:849-856. [ABSTRACT FROM AUTHOR]

Background Platelet function testing is controversia and not well studied in patients with neurovascular disease. Objective To evaluate the performance of thromboelastography (TEG) as a platelet function test in neurovascular patients treated with the Pipeline embolization device (PED). Methods A prospective protocol was instituted for platelet function testing in patients undergoing repair of intracranial aneurysms with the PED. All patients received dual antiplatelet therapy (DAT) and their response to both P2Y12 inhibitors and aspirin was quantified with TEG. Each patient's DAT induction strategy was tailored based on the percentage ADP-induced and percentage arachidonic acid-induced platelet inhibition reported by TEG. Data collected included clinical presentation, aneurysm characteristics, treatment details, and periprocedural events. Patients were followed up clinically and/or angiographically at 30 days, 6 months, and 1 year. Results Thirty-four PED procedures were performed on 31 patients. TEG results altered the DAT strategy in 35% of patients. Technical success with the Pipeline placement was 100%. Two patients had minor strokes and five had transient ischemic attacks (TIAs). There have been no hemorrhagic complications. No patient had permanent neurologic deficits. Six of eight (75%) of patients with thromboembolic/TIA events were ADP-induced hyporesponders by TEG. Our 6- and 12-month angiographic occlusion rates were 78.9% and 89.5%, respectively. The 19 major branches covered by the PED that were assessed by follow-up imaging have all remained patent. Conclusions Platelet function testing with TEG altered our DAT induction strategy in a significant number of cases. No hemorrhagic or disabling thromboembolic complications were seen in this series. Future studies should compare methods of platelet function testing and, possibly, no platelet function testing in neurovascular patients undergoing flow diversion and/or stent-assisted treatment of intracranial aneurysms. [ABSTRACT FROM AUTHOR]

Background Reperfusion is associated with good functional outcome after stroke. However, minimal data are available regarding the effect of reperfusion on clinical outcome and infarct growth in patients with distal MCA branch occlusions. Aim The aim of this study was to evaluate this association and to determine the impact of the perfusion-diffusion mismatch. Methods Individual patient data from three stroke studies ( EPITHET, DEFUSE and DEFUSE 2) with baseline MRI profiles and reperfusion status were pooled. Patients were included if they had a single cortical perfusion lesion on their baseline MRI that was consistent with a distal MCA branch occlusion. Good functional outcome was defined as a score of 0-2 on the modified Rankin Scale at day 90 and infarct growth was defined as change in lesion volume between the baseline DWI and the final T2/ FLAIR. Results Thirty patients met inclusion criteria. Eighteen (60%) had a good functional outcome and twenty (67%) had reperfusion. Reperfusion was not associated with good functional outcome in the overall cohort ( OR: 1·0, 95% CI 0·2-4·7) and also not in the subset of patients with a PWI-DWI mismatch ( n = 17; OR: 0·7, 95% CI 0·1-5·5). Median infarct growth was modest and not significantly different between patients with (0 ml) and without reperfusion (6 ml); P = 0·2. Conclusions The overall high rate of good outcomes in patients with distal MCA perfusion lesions might obscure a potential benefit from reperfusion in this population. A larger pooled analysis evaluating the effect of reperfusion in patients with distal MCA branch occlusions is warranted as confirmation of our results could have implications for the design of future stroke trials. [ABSTRACT FROM AUTHOR]

Summary: Background: Whether endovascular stroke treatment improves clinical outcomes is unclear because of the paucity of data from randomised placebo-controlled trials. We aimed to establish whether MRI can be used to identify patients who are most likely to benefit from endovascular reperfusion. Methods: In this prospective cohort study we consecutively enrolled patients scheduled to have endovascular treatment within 12 h of onset of stroke at eight centres in the USA and one in Austria. Aided by an automated image analysis computer program, investigators interpreted a baseline MRI scan taken before treatment to establish whether the patient had an MRI profile (target mismatch) that suggested salvageable tissue was present. Reperfusion was assessed on an early follow-up MRI scan (within 12 h of the revascularisation procedure) and defined as a more than 50% reduction in the volume of the lesion from baseline on perfusion-weighted MRI. The primary outcome was favourable clinical response, defined as an improvement of 8 or more on the National Institutes of Health Stroke Scale between baseline and day 30 or a score of 0–1 at day 30. The secondary clinical endpoint was good functional outcome, defined as a modified Rankin scale score of 2 or less at day 90. Analyses were adjusted for imbalances in baseline predictors of outcome. Investigators assessing outcomes were masked to baseline data. Findings: 138 patients were enrolled. 110 patients had catheter angiography and of these 104 had an MRI profile and 99 could be assessed for reperfusion. 46 of 78 (59%) patients with target mismatch and 12 of 21 (57%) patients without target mismatch had reperfusion after endovascular treatment. The adjusted odds ratio (OR) for favourable clinical response associated with reperfusion was 8·8 (95% CI 2·7–29·0) in the target mismatch group and 0·2 (0·0–1·6) in the no target mismatch group (p=0·003 for difference between ORs). Reperfusion was associated with increased good functional outcome at 90 days (OR 4·0, 95% CI 1·3–12·2) in the target mismatch group, but not in the no target mismatch group (1·9, 0·2–18·7). Interpretation: Target mismatch patients who had early reperfusion after endovascular stroke treatment had more favourable clinical outcomes. No association between reperfusion and favourable outcomes was present in patients without target mismatch. Our data suggest that a randomised controlled trial of endovascular treatment for patients with the target mismatch profile is warranted. Funding: National Institute for Neurological Disorders and Stroke. [Copyright &y& Elsevier]

Intracranial vertebral artery (VA) dissection has three clinical presentations: ischemia, hemorrhage, and mass effect. Imaging findings of intracranial VA dissections vary according to clinical presentation. Irregular stenosis or occlusion of the VA is the most common finding in patients with posterior fossa infarction, whereas a dissecting aneurysm is the main feature in those with acute subarachnoid hemorrhage. A chronic, giant, dissecting aneurysm can cause mass effect on the brain stem or cranial nerves, as well as distal embolism. Magnetic resonance imaging is useful for detection of intramural hematomas and intimal flaps, both of which are diagnostic of VA dissection. Multidetector computed tomography angiography is increasingly used for diagnosis of VA dissection. Catheter angiography is still beneficial for evaluation of precise endoluminal morphology of the dissection before surgical or endovascular intervention. Endovascular treatment is now considered a major therapeutic option for patients with a ruptured dissecting aneurysm or a chronic dissecting aneurysm. Anticoagulation therapy is currently considered the initial treatment of choice in patients with posterior circulation ischemic symptoms. Endovascular treatment, such as stent-assisted angioplasty or coil occlusion at the dissection site, can be performed in selected patients with posterior fossa ischemic symptoms. [ABSTRACT FROM AUTHOR]

Background Patients who have successful reperfusion following endovascular therapy for acute ischemic stroke have improved clinical outcomes. We sought to determine if the chance of successful reperfusion differs among hospitals, and if hospital site is an independent predictor of reperfusion. Methods Nine hospitals recruited patients in the Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution Study 2 (DEFUSE 2), a prospective cohort study of endovascular stroke treatment conducted between 2008 and 2011. Patients were included for analysis if they had a baseline Thrombolysis in Cerebral Infarction (TICI) score of 0 or 1. Successful reperfusion was defined as a TICI reperfusion score of 2b or 3 at completion of the procedure. Collaterals were assessed using the Collateral Flow Grading System and were dichotomized as poor (0-2) or good (3-4). The association between hospital site and successful reperfusion was first assessed in an unadjusted analysis and subsequently in a multivariate analysis that adjusted for predictors of successful reperfusion. Results 36 of 89 patients (40%) achieved successful reperfusion. The rate of reperfusion varied from 0% to 77% among hospitals in the univariate analysis (χ2 p<0.001) but hospital site did not remain as an independent predictor of reperfusion in multivariate analysis (p=0.81) after adjustment for the presence of good collaterals (p<0.01) and use of the Merci retriever ( p<0.05). Conclusions Reperfusion rates vary among hospitals, which may be related to differences in treatment protocols and patient characteristics. Additional studies are needed to identify all of the factors that underlie this variability as this could lead to strategies that reduce interhospital variability in reperfusion rates and improve clinical outcomes. [ABSTRACT FROM AUTHOR]

A correction to the article "Optimal Definition for PWI/DWI Mismatch in Acute Ischemic Stroke Patients" that was published in a 2008 issue of the "Journal of Cerebral Blood Flow & Metabolism" is presented.