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The 2022 update of theCanadian Stroke Best Practice Recommendations (CSBPR) for Acute Stroke Management, 7thedition, is a comprehensive summary of current evidence-based recommendations, appropriate for use by an interdisciplinary team of healthcare providers and system planners caring for persons with an acute stroke or transient ischemic attack. These recommendations are a timely opportunity to reassess current processes to ensure efficient access to acute stroke diagnostics, treatments, and management strategies, proven to reduce mortality and morbidity. The topics covered include prehospital care, emergency department care, intravenous thrombolysis and endovascular thrombectomy (EVT), prevention and management of inhospital complications, vascular risk factor reduction, early rehabilitation, and end-of-life care. These recommendations pertain primarily to an acuteischemicvascular event. Notable changes in the 7thedition include recommendations pertaining the use of tenecteplase, thrombolysis as a bridging therapy prior to mechanical thrombectomy, dual antiplatelet therapy for stroke prevention,1the management of symptomatic intracerebral hemorrhage following thrombolysis, acute stroke imaging, care of patients undergoing EVT, medical assistance in dying, and virtual stroke care. An explicit effort was made to address sex and gender differences wherever possible. The theme of the 7thedition of the CSBPR is building connections to optimize individual outcomes, recognizing that many people who present with acute stroke often also have multiple comorbid conditions, are medically more complex, and require a coordinated interdisciplinary approach for optimal recovery. Additional materials to support timely implementation and quality monitoring of these recommendations are available atwww.strokebestpractices.ca.

The objective of this scoping review is to review the available information on objective performance metrics used during robotic neuroendovascular intervention procedures on humans.Robotic neuroendovascular intervention is defined as any endovascular procedure within the vasculature of the central nervous system with the assistance of a robotic system for diagnostic or therapeutic procedures. Robotic systems are described as a 2-component system consisting of a patient-side mechanical robot, and a separate operator control station. Robotic neuroendovascular intervention is a growing field and there is a need to establish objective performance metrics for furthering evidence-based reporting of the literature.This scoping review will consider all studies involving humans that utilize robotic neuroendovascular intervention. We will consider all types of studies, reports, and reviews as well as gray literature. Studies will be included if they describe the use of an objective performance metric during robotic neuroendovascular intervention. This review is not limited to a particular country or health care system, and will consider all study designs, regardless of their rigor or language.Utilizing a 3-step framework as a guide, we will perform a systematic search in Embase, Cochrane Library, and MEDLINE. Available literature from inception to the present will be considered. Studies will be independently screened according to the inclusion criteria by 2 reviewers based on title, abstract, and full text. Data will be extracted, sorted, and presented in both a narrative summary as well as table and diagram based on the objective of the scoping review.

Cerebral peri-aneurysmal edema (PE) is typically associated with giant partially-thrombosed aneurysms and less frequently with smaller aneurysms treated with endovascular embolization. An understanding of the pathophysiologic mechanism of PE is still limited. We report 3 cases of cerebral aneurysms associated with PE. We describe 2 cases of giant partially thrombosed aneurysms surrounded by vasogenic edema with apposition of an intramural and juxtamural thrombus. Our third case is a smaller aneurysm inciting vasogenic edema several years after coil embolization. Vessel-wall magnetic resonance imaging (MRI) showed avid wall enhancement and an enhancing thrombus embedded within the coils, reflecting inflammation of the aneurysm wall and proliferation of the vasa vasorum. Thrombosis within the aneurysmal sac and walls, both in native and treated aneurysms, may promote inflammatory changes and sustain the occurrence of PE. Vessel-wall MRI has a potential role in the evaluation process of this subgroup of aneurysms.

BackgroundNo randomized trial of intracranial aneurysm coiling has compared long-term efficacy of polymer-modified coils to bare metal coils (BMCs). We report 5-year results comparing Matrix2 coils to BMCs. The primary objective was to compare the rates of target aneurysm recurrence (TAR) at 12 months. Secondary objectives included angiographic outcomes at TAR or 12 months and TAR at 5 years.MethodsA total of 626 patients were randomized to BMCs or Matrix2 coils. Detailed methods and 1-year results have been published previously.ResultsOf 580 patients eligible for 5-year follow-up, 431 (74.3%) completed follow-up or reached TAR. Matrix2 coils were non-inferior to BMCs (P=0.8) but did not confer any benefit. Core lab reported post-treatment residual aneurysm filling (Raymond III) correlated with TAR (PConclusionsAfter 5 years Matrix2 coils were non-inferior to BMCs but no benefit was demonstrated. Post-treatment residual angiographic aneurysm filling (Raymond III) is strongly associated with TAR (P

Developmental in nature, brain arteriovenous malformations (AVM) have the potential to affect whole brain organization. Here we investigated the impact of AVM on functional and structural brain organization using resting-state functional MRI (rsfMRI) and cortical thickness measures. We investigated brain functional organization and structure using rsfMRI in conjunction with cortical thickness analyses in 23 patients with cerebral arteriovenous malformations (AVMs) and 20 healthy control subjects. Healthy controls showed the expected anti-correlation between activity in the default mode network (DMN) and frontal areas that are part of the attentional control network. By contrast, patients demonstrated a disruption of this anti-correlation. Disruptions to this anti-correlation were even observed in a subgroup of patients with lesions remote from the main nodes of the DMN and were unrelated to differences in perfusion. Functional connectivity differences were accompanied by reduced cortical thickness in frontal attentional areas in patients compared to the controls. These results contribute to the discussion that AVMs affect whole brain networks and not simply the area surrounding the lesion.

Purpose Melanotic schwannoma (MS) was formerly known as a rare variant of schwannoma. The behavior of MS is unpredictable, with a tendency for recurrence and metastasis. The purpose of this study was to illustrate the imaging characteristics of these rare and misdiagnosed tumors. The prognosis of MS is discussed, along with the importance of follow-up exams to assess for recurrence and metastasis. Furthermore, we compare our results with those previously published on MS in order to have a better understanding of this rare entity. Methods Three MS cases were encountered between 2008 and 2015 at our institute. All available data were reviewed, including the clinical history, imaging findings, operative notes, and the histopathology results. A follow-up magnetic resonance imaging (MRI) scan was also reviewed up to 23 months post surgery to assess for recurrence. Results Three cases of MS are included: one in the brain and two in the spine. The brain lesion was in the occipital region. The spine lesions were thoracic intramedullary and sacral intradural. All cases were hypointense on T2-weighted imaging. Gross total resection was achieved for all lesions without adjuvant therapy. To date, the brain lesion recurred 15 months after surgery. Conclusions MS is a rare and distinct entity rather than a variant of schwannoma, and it poses both diagnostic and management dilemmas. Although MS has characteristic MRI features, including T1 and T2 shortening, the preoperative diagnosis is always challenging. Accurate diagnosis is crucial for management planning, including long-term follow-up exams to assess for recurrence and metastasis.

Objective Recently identified mutations of the axon guidance molecule receptor gene, DCC, present an opportunity to investigate, in living human brain, mechanisms affecting neural connectivity and the basis of mirror movements, involuntary contralateral responses that mirror voluntary unilateral actions. We hypothesized that haploinsufficient DCC+/- mutation carriers with mirror movements would exhibit decreased DCC mRNA expression, a functional ipsilateral corticospinal tract, greater "mirroring" motor representations, and reduced interhemispheric inhibition. DCC+/- mutation carriers without mirror movements might exhibit some of these features. Methods The participants (n = 52) included 13 DCC+/- mutation carriers with mirror movements, 7 DCC+/- mutation carriers without mirror movements, 13 relatives without the mutation or mirror movements, and 19 unrelated healthy volunteers. The multimodal approach comprised quantitative real time polymerase chain reaction, transcranial magnetic stimulation (TMS), functional magnetic resonance imaging (fMRI) under resting and task conditions, and measures of white matter integrity. Results Mirror movements were associated with reduced DCC mRNA expression, increased ipsilateral TMS-induced motor evoked potentials, increased fMRI responses in the mirroring M1 and cerebellum, and markedly reduced interhemispheric inhibition. The DCC+/- mutation, irrespective of mirror movements, was associated with reduced functional connectivity and white matter integrity. Interpretation Diverse connectivity abnormalities were identified in mutation carriers with and without mirror movements, but corticospinal effects and decreased peripheral DCC mRNA appeared driven by the mirror movement phenotype. ANN NEUROL 2019;85:433-442.

In order to evaluate the usefulness of presymptomatic MRI, we performed 3T brain MRI and Sanger gene sequencing in a proband with suspected but not confirmed CADASIL and her apparently asymptomatic father. The 35-year-old proband presented with migraine with visual aura. Brain MRI showed diffuse leukoencephalopathy, suggesting CADASIL. NOTCH3 gene sequencing (exons 3-6) was negative. Family history was unclear. The MRI study of the father documented severe, diffuse leukoencephalopathy, with involvement of the temporal poles and external capsules (not observed in the proband), and lacunar infarcts in the absence of cardiac disease or risk factors. The MRI findings were in favour of an autosomal dominant mode of transmission and reinforced the hypothesis of CADASIL. Full NOTCH3 gene sequencing uncovered a novel exon 8 mutation (c.1337G>A; p.Cys446Tyr) outside the most commonly mutated region of NOTCH3. The novel mutation leads to a typical MRI pattern but a variable overall phenotype. The study underlines the usefulness of combining full gene sequencing with familial MRI studies.

A previously healthy 48-year-old female presented to the emergency department with a 2-week history of low back pain, progressive lower extremities weakness, and right leg numbness. There were no bowel or bladder dysfunction symptoms. Spine magnetic resonance imaging (MRI) showed an intradural cystic lesion dorsal to the spinal cord at the level of L1 measuring 1.6 × 2.1 × 4.1 cm, which was T1 hypointense and T2 hyperintense, with a small soft tissue component and no gadolinium enhancement (Figure 1). A small lipomatous component was also noted. There were no associated vertebral anomalies. The patient underwent a T12-L2 laminectomy and cyst resection, which was subtotal due to the cyst adherence to the conus medullaris. Histopathology showed characteristic features of a neurenteric cyst, with respiratory-type epithelium in the cyst wall (Figure 2). Eight months later, follow-up MRI showed no evidence of recurrence. The patient reported improved sensation in the lower extremities; however, there was some residual weakness predominantly in the proximal hip flexors bilaterally.

Assessment of collateral circulation in ischemic stroke, which can identify patients for the most appropriate treatment strategies, is currently conducted with visual inspection by a radiologist. Yet numerous studies have shown that visual inspection suffers from inter and intra-rater variability. We present an automatic evaluation of collaterals using radiomic features and machine learning based on the ASPECTS scoring terminology with non-contrast computed tomography (NCCT). The method includes ASPECTS regions identification, extraction of radiomic features, and classification of collateral scores with support vector machines (SVM). Experiments are performed on a dataset of 64 ischemic stroke patients to classify collateral circulation as good, intermediate, or poor and yield an overall area under the curve (AUC) of 0.86 with an average sensitivity of 80.33% and specificity of 79.33%. Thus, we show the feasibility of using automatic evaluation of collateral circulation using NCCT when compared to the ASPECTS score by radiologists using 4D CT angiography as ground truth.

The 2018 update of the Canadian Stroke Best Practice Recommendations for Acute Stroke Management, 6th edition, is a comprehensive summary of current evidence-based recommendations, appropriate for use by healthcare providers and system planners caring for persons with very recent symptoms of acute stroke or transient ischemic attack. The recommendations are intended for use by a interdisciplinary team of clinicians across a wide range of settings and highlight key elements involved in prehospital and Emergency Department care, acute treatments for ischemic stroke, and acute inpatient care. The most notable changes included in this 6th edition are the renaming of the module and its integration of the formerly separate modules on prehospital and emergency care and acute inpatient stroke care. The new module, Acute Stroke Management: Prehospital, Emergency Department, and Acute Inpatient Stroke Care is now a single, comprehensive module addressing the most important aspects of acute stroke care delivery. Other notable changes include the removal of two sections related to the emergency management of intracerebral hemorrhage and subarachnoid hemorrhage. These topics are covered in a new, dedicated module, to be released later this year. The most significant recommendation updates are for neuroimaging; the extension of the time window for endovascular thrombectomy treatment out to 24 h; considerations for treating a highly selected group of people with stroke of unknown time of onset; and recommendations for dual antiplatelet therapy for a limited duration after acute minor ischemic stroke and transient ischemic attack. This module also emphasizes the need for increased public and healthcare provider’s recognition of the signs of stroke and immediate actions to take; the important expanding role of paramedics and all emergency medical services personnel; arriving at a stroke-enabled Emergency Department without delay; and launching local healthcare institution code stroke protocols. Revisions have also been made to the recommendations for the triage and assessment of risk of recurrent stroke after transient ischemic attack/minor stroke and suggested urgency levels for investigations and initiation of management strategies. The goal of this updated guideline is to optimize stroke care across Canada, by reducing practice variations and reducing the gap between current knowledge and clinical practice.

BACKGROUND AND PURPOSE: The safety and efficacy of endovascular therapy for large-artery stroke in the extended time window is not yet well-established. We performed a subgroup analysis on subjects enrolled within an extended time window in the Endovascular Treatment for Small Core and Proximal Occlusion Ischemic Stroke (ESCAPE) trial. MATERIALS AND METHODS: Fifty-nine of 315 subjects (33 in the intervention group and 26 in the control group) were randomized in the ESCAPE trial between 5.5 and 12 hours after last seen healthy (likely to have groin puncture administered 6 hours after that). Treatment effect sizes for all relevant outcomes (90-day mRS shift, mRS 0–2, mRS 0–1, and 24-hour NIHSS scores and intracerebral hemorrhage) were reported using unadjusted and adjusted analyses. RESULTS: There was no evidence of treatment heterogeneity between subjects in the early and late windows. Treatment effect favoring intervention was seen across all clinical outcomes in the extended time window (absolute risk difference of 19.3% for mRS 0–2 at 90 days). There were more asymptomatic intracerebral hemorrhage events within the intervention arm (48.5% versus 11.5%, P = .004) but no difference in symptomatic intracerebral hemorrhage. CONCLUSIONS: Patients with an extended time window could potentially benefit from endovascular treatment. Ongoing randomized controlled trials using imaging to identify late presenters with favorable brain physiology will help cement the paradigm of using time windows to select the population for acute imaging and imaging to select individual patients for therapy.

OBJECTIVE Large internal carotid artery aneurysms can cause remodeling of the sphenoid bone with subsequent hemorrhage into the sinus. No reports have demonstrated small unruptured lesions causing similar bone remodeling. The purpose of this study was to demonstrate our experience with small unruptured paraophthalmic aneurysms causing sphenoid bone remodeling, specifically when the optimal aneurysm inflow angle is present. METHODS We searched our database for computed tomography angiography studies of small paraophthalmic aneurysms and assessed adjacent sphenoid bone remodeling and inflow angle. RESULTS We found that aneurysms causing sphenoid remodeling represent 19.51% of all small paraophthalmic aneurysms at our institution and that the average inflow angle for these aneurysms was 94.38 degrees, significantly greater than for those not causing remodeling. CONCLUSIONS Our findings add support to using computed tomography angiography in the follow-up of aneurysms to assess surrounding bone changes and to the development of a more evidence-based approach in the management of small paraophthalmic aneurysms, which currently may be managed conservatively.

Intracranial dissecting aneurysms have been frequently reported to present with fairly challenging and time-variable imaging findings that can be mostly explained by the pathological mechanisms that underline the dissection. We present two cases of spontaneous dissecting aneurysm of the supraclinoid ICA, both clinically presenting with SAH, but characterized by different progression of clinical symptoms and imaging. However, in both cases an outpouch and a mild fusiform dilation of the supraclinoid ICA was present in the initial CTA performed after the occurrence of symptoms. These findings were well depicted by the MPR reformats performed retrospectively. We postulate that this finding may represent the point of initial transmural dissection and we recommend that careful analysis of the CTA MRP reformatted images should be performed in order to detect this finding promptly.

IntroductionStents reduce the rate of angiographic recurrence of intracranial aneurysms. The newest stent for intracranial use is the Low-profile Visible Intraluminal Support device (LVIS Jr).ObjectiveTo assess the efficacy of the new stent in a multicenter retrospective registry.Materials and methodCenters across Canada using LVIS Jr were contacted and asked to participate in a retrospective registry of consecutive patients treated with LVIS Jr for intracranial aneurysms between January 2013 and July 2015.ResultsA total of 102 patients, with saccular aneurysms in 100 patients (72 women; age range 21–78 years; mean 56.0 years; median 57.5 years) were treated with a LVIS Jr stent. The mean maximum diameter of the dome and neck of the aneurysm and dome to neck ratios were 8.3 mm±7.7 mm, 4.4 mm±1.9 mm, and 1.86±1.22, respectively. Angiographic complications arose in 23 patients, clinical complications in 9 patients, and only 3% of permanent neurological deficits occurred. Death occurred in 1 patient, unrelated to the stent. The ruptured status of the aneurysms (OR=3.29; p=0.046) and use of LVIS Jr for bailout (OR=2.54; p=0.053) showed a trend towards significant association with higher angiographic complications. At the last available follow-up, 68 class I, 20 class II, and 12 class III results were seen.ConclusionsThe LVIS Jr stent is a safe and effective device for stent-assisted coiling, with 3% permanent neurological complications. Stent-assisted coiling continues to be technically challenging in cases of ruptured aneurysms and bailout situations.

Background— The Endovascular Treatment for Small Core and Proximal Occlusion Ischemic Stroke (ESCAPE) trial used innovative imaging and aggressive target time metrics to demonstrate the benefit of endovascular treatment in patients with acute ischemic stroke. We analyze the impact of time on clinical outcome and the effect of patient, hospital, and health system characteristics on workflow within the trial. Methods and Results— Relationship between outcome (modified Rankin Scale) and interval times was modeled by using logistic regression. Association between time intervals (stroke onset to arrival in endovascular-capable hospital, to qualifying computed tomography, to groin puncture, and to reperfusion) and patient, hospital, and health system characteristics were modeled by using negative binomial regression. Every 30-minute increase in computed tomography-to-reperfusion time reduced the probability of achieving a functionally independent outcome (90-day modified Rankin Scale 0–2) by 8.3% ( P =0.006). Symptom onset-to-imaging time was not associated with outcome ( P >0.05). Onset-to-endovascular hospital arrival time was 42% (34 minutes) longer among patients receiving intravenous alteplase at the referring hospital (drip and ship) versus direct transfer (mothership). Computed tomography-to-groin puncture time was 15% (8 minutes) shorter among patients presenting during work hours versus off hours, 41% (24 minutes) shorter in drip-ship patients versus mothership, and 43% (22 minutes) longer when general anesthesia was administered. The use of a balloon guide catheter during endovascular procedures shortened puncture-to-reperfusion time by 21% (8 minutes). Conclusions— Imaging-to-reperfusion time is a significant predictor of outcome in the ESCAPE trial. Inefficiencies in triaging, off-hour presentation, intravenous alteplase administration, use of general anesthesia, and endovascular techniques offer major opportunities for improvement in workflow. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT01778335.

IntroductionThe SILK flow diverter (SFD) is used for the treatment of complex intracranial aneurysms. Small case series have been reported in the literature but few studies with a large number of patients have been published. We present our experience with the SFD for the treatment of intracranial aneurysms in Canada.MethodsCenters across Canada using SFDs were contacted to fill out a case report form for patients treated with an SFD in their center. Individual centers were responsible for approval from their ethics committee. Image analysis was performed by individual operators. The case report forms were collected and the final analysis was performed.ResultsA total of 92 patients were treated with SFDs in eight centers in Canada between January 2009 and August 2013. The aneurysms were located in the posterior circulation in 16 patients and in the anterior circulation in 76 patients. Most aneurysms (75%) were saccular in shape; 22% were fusiform and 3% were blister aneurysms. The size of the aneurysms varied from 2 to 60 mm with the neck varying from 2 to 60 mm. Perioperative morbidity and mortality were 8.7% and 2.2%, respectively. At the last available follow-up, 83.1% of the aneurysms were either completely or near-completely occluded. The rate of complications was higher for fusiform aneurysms (pConclusionsThe SFD appears to be an important tool for the treatment of complex intracranial aneurysms. Treatment outcomes and complication rates remain a problem, but should be considered in the context of available alternative interventions. Ongoing analysis of flow-diverting stents for radiographic and clinical performance is required.

Among patients with a proximal vessel occlusion in the anterior circulation, 60 to 80% of patients die within 90 days after stroke onset or do not regain functional independence despite alteplase treatment. We evaluated rapid endovascular treatment in addition to standard care in patients with acute ischemic stroke with a small infarct core, a proximal intracranial arterial occlusion, and moderate-to-good collateral circulation. Methods We randomly assigned participants to receive standard care (control group) or standard care plus endovascular treatment with the use of available thrombectomy devices (intervention group). Patients with a proximal intracranial occlusion in the anterior circulation were included up to 12 hours after symptom onset. Patients with a large infarct core or poor collateral circulation on computed tomography (CT) and CT angiography were excluded. Workflow times were measured against predetermined targets. The primary outcome was the score on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]) at 90 days. A proportional odds model was used to calculate the common odds ratio as a measure of the likelihood that the intervention would lead to lower scores on the modified Rankin scale than would control care (shift analysis). Results The trial was stopped early because of efficacy. At 22 centers worldwide, 316 participants were enrolled, of whom 238 received intravenous alteplase (120 in the intervention group and 118 in the control group). In the intervention group, the median time from study CT of the head to first reperfusion was 84 minutes. The rate of functional independence (90-day modified Rankin score of 0 to 2) was increased with the intervention (53.0%, vs. 29.3% in the control group; P

ESCAPE is a prospective, multicenter, randomized clinical trial that will enroll subjects with the following main inclusion criteria: less than 12 h from symptom onset, age > 18, baseline NIHSS >5, ASPECTS score of >5 and CTA evidence of carotid T/L or M1 segment MCA occlusion, and at least moderate collaterals by CTA. The trial will determine if endovascular treatment will result in higher rates of favorable outcome compared with standard medical therapy alone. Patient populations that are eligible include those receiving IV tPA, tPA ineligible and unwitnessed onset or wake up strokes with 12 h of last seen normal. The primary end-point, based on intention-to-treat criteria is the distribution of modified Rankin Scale scores at 90 days assessed using a proportional odds model. The projected maximum sample size is 500 subjects. Randomization is stratified under a minimization process using age, gender, baseline NIHSS, baseline ASPECTS (8–10 vs. 6–7), IV tPA treatment and occlusion location (ICA vs. MCA) as covariates. The study will have one formal interim analysis after 300 subjects have been accrued. Secondary end-points at 90 days include the following: mRS 0–1; mRS 0–2; Barthel 95–100, EuroQOL and a cognitive battery. Safety outcomes are symptomatic ICH, major bleeding, contrast nephropathy, total radiation dose, malignant MCA infarction, hemicraniectomy and mortality at 90 days.

Introduction Existing stroke literature demonstrates that rapid recanalization of vessels improves long-term prognosis after acute ischemic stroke. However, further optimization of the speed of the thrombectomy procedure, used to recanalize a blocked vessel, is limited by our minimal knowledge of the clot dimensions pre-procedure. Knowing the clot dimensions would allow planning of the thrombectomy procedure with the appropriate size and length of stent retriever, and determination of the correct site of the stent deployment ensuring total coverage of the clot by the stent retriever. Methods We performed a feasibility study to assess if multiphase computed tomography angiography (mCTA) can be used to estimate clot length by comparing CTA imaging data with imaging data obtained from conventional digital subtraction angiography (DSA). A retrospective chart review was performed of patients with clots in the proximal middle cerebral artery and adequate collateral circulation, who underwent both mCTA and DSA. Results Clot length was not significantly different on 3D mCTA versus mCTA MIPs, nor was it significantly different on MIP mCTA versus DSA. Pathological evidence also supported our ability to measure clot length on mCTA. Conclusions We suggest that mCTA is a reliable and valid measure of clot length in acute ischemic stroke patients.

Background and Purpose— In the ESCAPE trial (Endovascular Treatment for Small Core and Anterior Circulation Proximal Occlusion with Emphasis on Minimizing CT to Recanalization Times), patients with large vessel occlusions and small infarct cores identified with computed tomography (CT)/CT angiography were randomized to endovascular therapy or standard of care. CT perfusion (CTP) was obtained in some cases but was not used to select patients. We tested the hypothesis that patients with penumbral CTP patterns have higher rates of good clinical outcome. Methods— All CTP data acquired in ESCAPE patients were analyzed centrally using a semiautomated perfusion threshold-based approach. A penumbral pattern was defined as an infarct core 15 mL, and a total hypoperfused volume:core volume ratio of >1.8. The primary outcome was good functional outcome at 90 days (modified Rankin Scale score, 0–2). Results— CTP was acquired in 138 of 316 ESCAPE patients. Penumbral patterns were present in 116 of 128 (90.6%) of patients with interpretable CTP data. The rate of good functional outcome in penumbral pattern patients (53 of 114; 46%) was higher than that in nonpenumbral patients (2 of 12; 17%; P =0.041). In penumbral patients, endovascular therapy increased the likelihood of a good clinical outcome (34 of 58; 57%) compared with those in the control group (19 of 58; 33%; odds ratio, 2.68; 95% confidence interval, 1.25–5.76; P =0.011). Only 3 of 12 nonpenumbral patients were randomized to the endovascular group, preventing an analysis of treatment effect. Conclusions— The majority of patients with CTP imaging in the ESCAPE trial had penumbral patterns, which were associated with better outcomes overall. Patients with penumbra treated with endovascular therapy had the greatest odds of good functional outcome. Nonpenumbral patients were much less likely to achieve good outcomes.

Stroke is the second leading cause of disability worldwide. Thrombectomy has been shown to offer fast and efficient reperfusion with high recanalization rates and thus improved patient outcomes. One of the most important indicators to identify patients amenable to thrombectomy is evidence of good collateral circulation. Currently, methods for evaluating collateral circulation are generally limited to visual inspection with potentially high inter- and intra-rater variability. In this work, we present an automatic technique to evaluate collateral circulation. This is achieved via low-rank decomposition of the target subject’s 4D CT angiography, and using principal component analysis (PCA) and support vector machines (SVMs) to automatically generate a collateral circulation score. With the proposed automatic score evaluation technique, we have achieved an overall scoring accuracy of 82.2% to identify patients with poor, intermediate, and good/normal collateral circulation.

We describe a case of brain cortical reorganization after embolization of a large right temporal arteriovenous malformation. A comprehensive imaging protocol, including functional magnetic resonance imaging (fMRI), cortical thickness analysis and 320-row computed tomography (CT) perfusion was used to provide information on brain plasticity and potential steal phenomenon. A 25-year-old man known for a right temporal grade V Spetzler-Martin classification arteriovenous malformation (AVM) presented with left progressive hemiparesis. He underwent functional 3T magnetic resonance imaging (fMRI), cortical thickness analysis, and CT perfusion (CT 320 row, Aquilion ONE, Toshiba, Tokyo, Japan) before and after endovascular treatment. The results were compared to look for modifications in brain perfusion and organization. An improvement in the left hemiparesis and a reorganization of motor function were observed after endovascular treatment. Modifications in the angioarchitecture and perfusion of an extensive AVM may be accompanied by a functional and structural reorganization of the brain. The location in the so-called eloquent regions may not be sufficient to explain the wide spectrum of symptoms that these patients can present. A more comprehensive approach considering a global involvement of the brain in patients with large AVMs is suggested to achieve the best treatment strategy and to stage treatment in incurable AVMs.

BACKGROUND AND PURPOSE: AD is one of the few leading causes of death without a disease-modifying drug; however, hopeful agents are in various phases of development. MR imaging abnormalities, collectively referred to as amyloid-related imaging abnormalities, have been reported for several agents that target cerebral Aβ burden. ARIA includes ARIA-E, parenchymal or sulcal hyperintensities on FLAIR indicative of parenchymal edema or sulcal effusions, and ARIA-H, hypointense regions on gradient recalled-echo/T2* indicative of hemosiderin deposition. This report describes imaging characteristics of ARIA-E and ARIA-H identified during studies of bapineuzumab, a humanized monoclonal antibody against Aβ. MATERIALS AND METHODS: Two neuroradiologists with knowledge of imaging changes reflective of ARIA reviewed MR imaging scans from 210 bapineuzumab-treated patients derived from 3 phase 2 studies. Each central reader interpreted the studies independently, and discrepancies were resolved by consensus. The inter-reader κ was 0.76, with 94% agreement between neuroradiologists regarding the presence or absence of ARIA-E in individual patients. RESULTS: Thirty-six patients were identified with incident ARIA-E (17.1%, 36/210) and 26 with incident ARIA-H (12.4%, 26/210); of those with incident ARIA-H, 24 had incident microhemorrhages and 2 had incident large superficial hemosiderin deposits. CONCLUSIONS: In 49% of cases of ARIA-E, there was the associated appearance of ARIA-H. In treated patients without ARIA-E, the risk for incident blood products was 4%. This association between ARIA-E and ARIA-H may suggest a common pathophysiologic mechanism. Familiarity with ARIA should permit radiologists and clinicians to recognize and communicate ARIA findings more reliably for optimal patient management.

A computed tomography study of the remains of a Ptolemaic male mummy from Thebes (RM2718; 350-60 BCE), one of three ancient Egyptian human mummies curated at McGill University's Redpath Museum, demonstrates the packing of a large interproximal carious lesion with a protective linen barrier. The dental packing described here is unique among ancient Egyptian mummies studied to date, and represents one of only a few recorded dental interventions in ancient Egypt. Such a finding lends further support for the existence of a group of dental specialists practicing interventional medicine in ancient Egypt. While the physical evidence, to date for other interventions, may be scarce, the findings presented here should underline the need to continue to look for evidence of dental packing as well as other therapeutic dental interventions in the ancient world.

We present a case of a preterm boy (born at 35 weeks of pregnancy) who was delivered urgently by a caesarean section due to placental abruption. The baby was found to have a tense fontanelle leading to imaging that showed a 5.5 cm right intraventricular mass centred in the atrium, hydrocephalus and extensive surrounding vasogenic oedema. The mass was avidly enhancing with a few large associated vessels suggesting high vascularity. The condition of the baby was acutely deteriorating. He had multiple seizures followed by persistent low level of consciousness in the third day of life. His clinical decline prompted decision to proceed with surgical resection and preoperative embolization. A large single feeder (the right posterolateral choroidal artery) was embolized leading to near complete obliteration of the tumour blush. Embolization likely facilitated subsequent surgery the next day. This is based on an estimated blood loss of 250 ml in this 3 kg baby without haemodynamic instability. Gross total resection was achieved with a single surgery and the diagnosis was choroid plexus papilloma. Utilization of this combined approach in this preterm baby had led to survival in this potentially curable disease.

Background: The acquisition of a new 320-row multidetector computed tomography angiography (CTA) scanner at the Montreal Neurological Institute and Hospital has provided higher quality imaging with less radiation exposure and shorter time of acquisition. However, its reliability has not been fully proven in critical vascular lesions when it comes to replacing a more invasive examination such as cerebral angiography. We wished to validate the accuracy of this equipment to investigate four common indications for patients to undergo conventional digital subtraction angiography: subarachnoid hemorrhage, vasospasm, unusual intracerebral hemorrhage, and unruptured aneurysm. Methods: Radiological reports and relevant imaging from 82 consecutive subjects who underwent a 320-row multidetector CTA followed by cerebral angiography from February 2010 to February 2014 were retrospectively analysed. A total of 102 cerebrovascular anomalies were found. Reports from both imaging modalities were compared to determine the diagnostic accuracy of CTA. Results: The overall sensitivity and specificity of 320-row multidetector CTA for detecting cerebrovascular abnormalities were, respectively, 97.60% and 63.20%. Similar results were obtained for all four categories of clinical indications. Conclusion: Results obtained from CTA were consistent with those obtained on digital subtraction angiography regardless of the vascular pathology. To our knowledge, this study is the first validating the accuracy of 320-row CTA in diagnosing critical cerebrovascular lesions.

OBJECTIVE Computed tomography perfusion (CTP) has become a mainstay in acute stroke management. The aim of this study was to investigate the occurrence of an unreported phenomenon of a paradoxically decreased mean transit time (MTT) in the cerebral area of ischemia. METHODS In this retrospective study, patients with an acute anterior circulation ischemic stroke were selected. Computed tomography perfusion diffusion maps of all patients were reviewed by 2 blinded and experienced neuroradiologists. RESULTS A total of 31 patients were included in the study. Eighteen subjects (58%) had a paradoxical MTT perfusion map, whereas only 13 (42%) had an expected CTP profile. No significant associations between the paradoxical MTT perfusion and the size of the infarct, the side of the occlusion, or the age of the patients were observed. However, a trend in collateral circulation status and paradoxical MTT was noted. CONCLUSIONS A paradoxical MTT response is a frequent finding in CTP analysis of patients with acute stroke. Its presence is not associated to the location or size of the affected cerebral territory and could be related to the presence of collateral circulation.

Background and Purpose— The goal of reperfusion therapy in acute ischemic stroke is to limit brain infarction. The objective of this study was to investigate whether the beneficial effect of endovascular treatment on functional outcome could be explained by a reduction in post-treatment infarct volume. Methods— The Endovascular Treatment for Small Core and Anterior Circulation Proximal Occlusion With Emphasis on Minimizing CT to Recanalization Times (ESCAPE) trial was a multicenter randomized open-label trial with blinded outcome evaluation. Among 315 enrolled subjects (endovascular treatment n=165; control n=150), 314 subject’s infarct volumes at 24 to 48 hours on magnetic resonance imaging (n=254) or computed tomography (n=60) were measured. Post-treatment infarct volumes were compared by treatment assignment and recanalization/reperfusion status. Appropriate statistical models were used to assess relationship between baseline clinical and imaging variables, post-treatment infarct volume, and functional status at 90 days (modified Rankin Scale). Results— Median post-treatment infarct volume in all subjects was 21 mL (interquartile range =65 mL), in the intervention arm, 15.5 mL (interquartile range =41.5 mL), and in the control arm, 33.5 mL (interquartile range =84 mL; P P P P P P >0.05). Post-treatment infarct volume ( P P Conclusions— These results support the primary results of the ESCAPE trial and show that the biological underpinning of the success of endovascular therapy is a reduction in infarct volume. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT01778335.

Background and Purpose: The goal of reperfusion therapy in acute ischemic stroke is to limit the extension of the ischemic core. The objectives of the present study were to assess the relationship between endovascular treatment and final infarct volume. Methods and Results: ESCAPE is a multicenter prospective randomized open-label trial with blinded outcome evaluation that enrolled 315 patients (endovascular treatment n=165; control n=150). Of these, 314 patient infarct volumes at 24 hours on CT or MRI were measured blinded to clinical data. Because infarct volumes were non-normally distributed, final infarct volumes were analysed by quartiles. Final infarct volumes were compared by treatment assignment and recanalization/reperfusion status measured by 2-8h CT angiogram in the control group and by formal angiography in the intervention arm. Results: Median final infarct volume among all study participants was 21 mL (IQR: 7 to 72). Median final infarct volume in endovascular treatment arm at 15.5 mL (IQR: 5 to 46.5) was significantly lower than median final infarct volume in control arm 33.5 mL (IQR: 11 to 95; P=0.0004). Small infarcts, defined as 1st quartile of infarct volumes were more common in the endovascular group compared to control (relative risk [RR] 1.5, CI95 1.02-2.3). Successful recanalization and reperfusion was highly associated with small infarcts (RR 2.2, CI95 1.4-3.4). The proportion of large hemispheric stroke (defined as an infarct volume in the 4th quartile) was much less frequent in the endovascular treatment arm (RR 0.6, CI95 0.3-0.8). Conclusions: This analysis supports the primary results of ESCAPE trial as endovascular treatment was associated with significantly smaller final infarct volumes. Recanalization/reperfusion was associated with smaller final infarct volume.