Recanalization and Functional Outcome in Patients with Cervico-cephalic Arterial Dissections.

BACKGROUND: Cervico-cephalic arterial dissections (CeAD) are an important cause of stroke in young patients. This study aimed to determine the frequency and predictors of recanalization in spontaneous CeAD and to study the effect of recanalization on functional outcomes. METHODS: We identified patients presenting with acute ischemic stroke secondary to CeAD from the CT angiography (CTA) database of the Calgary Stroke Program. Dissections were diagnosed based on standard clinical and imaging findings. At the discretion of treating stroke Neurologists, the patients were either treated with single antiplatelet or dual antiplatelet or triple therapy. Follow-up imaging with CTA, magnetic resonance imaging, and DSA was completed, and a Modified Rankin scale (mRS) was performed to determine the outcome. RESULTS: Fifty-six patients with CeAdD were studied. Thirty-four patients (18 VAD; vertebral artery dissection and 16 CAD; carotid artery dissection) were followed up for recanalization. Complete recanalization was observed in 27 subjects; 13 patients with VAD recanalized in comparison to 14 with CAD (p = 0.40). All non-recanalized patients had hypertension. A good clinical outcome (mRS ≤ 2) was observed in 47 patients. Interestingly, the likelihood of a good neurological outcome was not influenced by recanalization status. There was no difference in clinical outcome for different sites in VAD, whereas patients with intracranial CAD had severe strokes (NIHSS > 21). CONCLUSIONS: CeAD has good recanalization rates and neurological outcomes, with recanalization seen even in vessels with initial complete occlusion. The presence of hypertension may influence recanalization. The efficacy of dual antiplatelets and heparin for early recanalization needs to be assessed in future clinical trials.

Association of Clinical, Imaging, and Thrombus Characteristics With Recanalization of Visible Intracranial Occlusion in Patients With Acute Ischemic Stroke.

Importance: Recanalization of intracranial thrombus is associated with improved clinical outcome in patients with acute ischemic stroke. The association of intravenous alteplase treatment and thrombus characteristics with recanalization over time is important for stroke triage and future trial design. Objective: To examine recanalization over time across a range of intracranial thrombus occlusion sites and clinical and imaging characteristics in patients with ischemic stroke treated with intravenous alteplase or not treated with alteplase. Design, Setting, and Participants: Multicenter prospective cohort study of 575 patients from 12 centers (in Canada, Spain, South Korea, the Czech Republic, and Turkey) with acute ischemic stroke and intracranial arterial occlusion demonstrated on computed tomographic angiography (CTA). Exposures: Demographics, clinical characteristics, time from alteplase to recanalization, and intracranial thrombus characteristics (location and permeability) defined on CTA. Main Outcomes and Measures: Recanalization on repeat CTA or on first angiographic acquisition of affected intracranial circulation obtained within 6 hours of baseline CTA, defined using the revised arterial occlusion scale (rAOL) (scores from 0 [primary occlusive lesion remains the same] to 3 [complete revascularization of primary occlusion]). Results: Among 575 patients (median age, 72 years [IQR, 63-80]; 51.5% men; median time from patient last known well to baseline CTA of 114 minutes [IQR, 74-180]), 275 patients (47.8%) received intravenous alteplase only, 195 (33.9%) received intravenous alteplase plus endovascular thrombectomy, 48 (8.3%) received endovascular thrombectomy alone, and 57 (9.9%) received conservative treatment. Median time from baseline CTA to recanalization assessment was 158 minutes (IQR, 79-268); median time from intravenous alteplase start to recanalization assessment was 132.5 minutes (IQR, 62-238). Successful recanalization occurred at an unadjusted rate of 27.3% (157/575) overall, including in 30.4% (143/470) of patients who received intravenous alteplase and 13.3% (14/105) who did not (difference, 17.1% [95% CI, 10.2%-25.8%]). Among patients receiving alteplase, the following factors were associated with recanalization: time from treatment start to recanalization assessment (OR, 1.28 for every 30-minute increase in time [95% CI, 1.18-1.38]), more distal thrombus location, eg, distal M1 middle cerebral artery (39/84 [46.4%]) vs internal carotid artery (10/92 [10.9%]) (OR, 5.61 [95% CI, 2.38-13.26]), and higher residual flow (thrombus permeability) grade, eg, hairline streak (30/45 [66.7%]) vs none (91/377 [24.1%]) (OR, 7.03 [95% CI, 3.32-14.87]). Conclusions and Relevance: In patients with acute ischemic stroke, more distal thrombus location, greater thrombus permeability, and longer time to recanalization assessment were associated with recanalization of arterial occlusion after administration of intravenous alteplase; among patients who did not receive alteplase, rates of arterial recanalization were low. These findings may help inform treatment and triage decisions in patients with acute ischemic stroke.

Canadian Stroke Best Practice Consensus Statement: Acute Stroke Management during pregnancy.

The Canadian Stroke Best Practice Consensus Statement Acute Stroke Management during Pregnancy is the second of a two-part series devoted to stroke in pregnancy. The first part focused on the unique aspects of secondary stroke prevention in a woman with a prior history of stroke who is, or is planning to become, pregnant. This document focuses on the management of a woman who experiences an acute stroke during pregnancy. This consensus statement was developed in recognition of the need for a specifically tailored approach to the management of this group of patients in the absence of any broad-based, stroke-specific guidelines or consensus statements, which do not exist currently. The foundation for the development of this document was the concept that maternal health is vital for fetal well-being; therefore, management decisions should be based first on the confluence of two clinical considerations: (a) decisions that would be made if the patient wasn't pregnant and (b) decisions that would be made if the patient hadn't had a stroke, then nuanced as needed. While empirical research in this area is limited, this consensus document is based on the best available literature and guided by expert consensus. Issues addressed in this document include initial emergency management, diagnostic imaging, acute stroke treatment, the management of hemorrhagic stroke, anesthetic management, post stroke management for women with a stroke in pregnancy, intrapartum considerations, and postpartum management. These statements are appropriate for healthcare professionals across all disciplines and system planners to ensure pregnant women who experience a stroke have timely access to both expert neurological and obstetric care.

Canadian stroke best practice consensus statement: Secondary stroke prevention during pregnancy.

The Canadian Stroke Best Practice Consensus Statement: Secondary Stroke Prevention during Pregnancy, is the first of a two-part series devoted to stroke in pregnancy. This document focuses on unique aspects of secondary stroke prevention in a woman with a prior history of stroke or transient ischemic attack who is, or is planning to become, pregnant. Although stroke is relatively rare in this cohort, several aspects of pregnancy can increase stroke risk during or immediately after pregnancy. The rationale for the development of this consensus statement is based on the premise that stroke in this group requires a specifically-tailored management approach. No other broad-based, stroke-specific guidelines or consensus statements exist currently. Underpinning the development of this document was the concept that maternal health is vital for fetal wellbeing; therefore, management decisions should be based on the confluence of two clinical considerations: (a) decisions that would be made if the patient was not pregnant and (b) decisions that would be made if the patient had not had a stroke. While empirical research in this area is limited, this consensus document is based on the best available literature and guided by expert consensus. Issues addressed in this document include general management considerations for secondary stroke prevention, the use of antithrombotics, blood pressure management, lipid management, diabetes care, and management for specific ischemic stroke etiologies in pregnancy. The focus is on maternal and fetal health while minimizing risks of a recurrent stroke, through counseling, monitoring, and the safety of select pharmacotherapy. These statements are appropriate for health care professionals across all disciplines.

Prehospital Management of Acute Stroke in Rural versus Urban Responders.

OBJECTIVE: Stroke guideline compliance of rural Canadian prehospital emergency medical services (EMS) care in acute stroke is unknown. In this quality assurance study, we sought to compare rural and urban care by prehospital EMS evaluation/management indicators from patients assessed at an urban Canadian stroke center. MATERIALS AND METHODS: One hundred adult patients were randomly selected from the stroke registry. Patients were transported through Rural EMS bypass protocols or urban EMS protocols (both bypass and direct) to our stroke center between January and December 2013. Patients were excluded if they were first evaluated at any other health center. Prehospital care was assessed using ten indicators for EMS evaluation/management, as recommended by acute stroke guidelines. RESULTS: Compliance with acute stroke EMS evaluation/management indicators were statistically similar for both groups, except administrating a prehospital diagnostic tool (rural 31.8 vs. urban 70.3%; P = 0.002). Unlike urban EMS, rural EMS did not routinely document scene time. CONCLUSION: Rural EMS responders' compliance to prehospital stroke evaluation/management was similar to urban EMS responders. Growth areas for both groups may be with prehospital stroke diagnostic tool utilization, whereas rural EMS responders may also improve with scene time documentation.

Time dependence of reliability of noncontrast computed tomography in comparison to computed tomography angiography source image in acute ischemic stroke.

There is no consensus on how the reliability and predictive ability of noncontrast computed tomography (NCCT) and computed tomography angiography source image (CTASI) change over time from acute ischemic stroke onset. We hypothesized that the reliability for detecting early ischemic changes (EIC) would be lower in early time periods and that changes identified on CTASI would be more reliable across examiners than changes identified on NCCT. To address this, we compared the relationships between CTASI, NCCT, and final infarct in patients with initial computed tomography (CT) imaging at different time points after stroke onset. Patients with acute ischemic stroke with proximal anterior circulation occlusions (internal carotid artery, middle carotid artery M1, proximal M2) from Calgary CT Angiography (CTA) database were studied. The cohort was categorized in four groups based on time from stroke onset to baseline NCCT/CTA: 0-90 mins (n = 69), 91-180 mins (n = 88), 181-360 mins (n = 46), and >360 mins (n = 58). Median scores of NCCT-Alberta Stroke Program Early CT Score (ASPECTS), CTASI ASPECTS, and follow-up ASPECTS among different time categories were compared. To determine reliability, a subsample of NCCT brain and CTASI were interpreted at separate sessions weeks apart by two neuroradiologists and two stroke neurologists in random order. Median and mean ASPECTS ratings on NCCT and CTASI were higher than final ASPECTS in each time category (P < 0·001 for all comparisons). CTASI ASPECTS was lower than NCCT ASPECTS in each time category, and differences were significant at 0-90 mins and 91-180 mins (P < 0·001). The least agreement among readers was in detection of EIC on NCCT brain in the ultra-early phase (<90 mins) [intraclass correlation coefficient (ICC) = 0·48. By contrast, there was excellent agreement on EIC on CTASI regardless of time period (ICC = 0·87-0·96). Using ASPECTS methodology, CTASI is more reliable than NCCT at predicting final infarct extent particularly in the early time windows.

Central nervous system imaging in diabetic cerebrovascular diseases and white matter hyperintensities.

Diabetes mellitus is an important vascular risk factor for cerebrovascular disease. This occurs through pathophysiologic changes to the microcirculation as arteriolosclerosis and to the macrocirculation as large artery atherosclerosis. Imaging techniques can provide detailed visualization of the cerebrovasculature using CT (computed tomography) angiography and MR (magnetic resonance) angiography. Newer techniques focused on advanced parenchymal imaging include CT perfusion, quantitative MRI, and diffusion tensor imaging; each identifies brain lesion burden due to diabetes mellitus. These imaging approaches have provided insights into the diabetes mellitus brain and cerebral circulation pathophysiology. Imaging has taught us that diabetics develop cerebral atrophy, silent infarcts, and white matter disease more rapidly than other patient populations. Longitudinal studies are needed to quantify the rate and extent of such structural brain and blood vessel changes and how they relate to cognitive decline. Diabetes prevention and treatment strategies will then be possible to slow the development of such changes.

Acute ischaemic stroke or transient ischaemic attack and the need for inpatient echocardiography.

OBJECTIVES: To determine the diagnostic yield of echocardiography and its utility in changing medical management; and to derive a risk score to guide its use in patients with in-hospital stroke or transient ischaemic attack (TIA). METHODS: We carried out a retrospective chart review from January 2009 to June 2010 of patients with acute ischaemic stroke or TIA who had undergone transthoracic echocardiography (TTE) or transoesophageal echocardiography (TOE). Clinical and imaging findings at baseline were noted and 'potential clinically relevant findings' identified on TTE and TOE. A multivariable logistic regression was used to identify predictors of potential clinically relevant findings on TTE or TOE and derive a risk score. RESULTS: Of 370 patients, 307 (83.0%) had TTE and 63 (17.0%) had additional TOE. Potential clinically relevant findings on echocardiography were noted in 28 (7.6%) patients. Change in medical management was noted in 19/307 (6.2%) patients on TTE and in 7/63 (11.1%) patients on TOE. Male sex (OR 3.05, 95% CI 1.19 to 7.84; p=0.021), abnormal admission ECG (OR 4.39, 95% CI 1.79 to 10.79; p=0.001), and embolic pattern imaging at baseline (OR 2.38, 95% CI 1.05 to 5.40; p=0.038) were independent predictors of findings on TTE or TOE. A risk score including these three variables had modest discrimination (c-statistic 0.69, 95% CI 0.59 to 0.80). CONCLUSIONS: Echocardiography detected potential clinically relevant findings in a minority of patients (7.6%), but these findings changed medical management 90.5% of the time. A risk score using sex, ECG abnormality, and embolic pattern imaging at baseline could help predict which patients are more likely to have these echo findings.

Ophthalmic masquerades of the atherosclerotic carotids.

Patients with carotid atherosclerosis can present with ophthalmic symptoms. These symptoms and signs can be due to retinal emboli, hypoperfusion of the retina and choroid, opening up of collateral channels, or chronic hypoperfusion of the globe (ocular ischemic syndrome). These pathological mechanisms can produce many interesting signs and a careful history can bring out important past symptoms pointing toward the carotid as the source of the patient's presenting symptom. Such patients are at high risk for an ischemic stroke, especially in the subsequent few days following their first acute symptom. It is important for clinicians to be familiar with these ophthalmic symptoms and signs caused by carotid atherosclerosis for making an early diagnosis and to take appropriate measures to prevent a stroke. This review elaborates the clinical features, importance, and implications of various ophthalmic symptoms and signs resulting from atherosclerotic carotid artery disease.

Stroke- on- Awakening: Safety of CT-CTA Based Selection for Reperfusion Therapy.

BACKGROUND: We studied the safety of use of acute reperfusion therapies in patients with stroke- on- awakening using a computed tomographic angiography (Cta) based large vessel occlusion-good scan paradigm in clinical routine. METHODS: the Cta database of the Calgary stroke program was reviewed for the period January 2003-March 2010. patients with stroke-on-awakening with large artery occlusions on Cta, who received conservative, iV thrombolytic and/or endovascular treatment at discretion of the attending stroke neurologist were analyzed. time of onset was defined by the time last seen or known to be normal. Baseline non-contrast Ct scan (nCCt) alberta Stroke program early Ct Score (aSpeCtS) > 7 was considered a good scan. hemorrhage was defined on follow-up brain imaging using eCaSS 3 criteria. independence (mrS≤2) at three months was considered a good clinical outcome. Standard descriptive statistics and multivariable analysis were done. RESULTS: among 532 patients with large artery occlusions, 70 patients with stroke-on-awakening (13.1%) were identified. the median age was 69.5 (iQr 24) and 41 (58.6%) were female; 41 (58.6%) received anti-platelets only and 29 (41.4%) received thrombolytic treatment [iV-12 (17.1%), iV/ia-12 (17.1%) and ia-5(7.1%)]. unadjusted analysis showed that baseline nCCt aSpeCtS ≤ 7 (p=0.002) and higher nihSS scores (p=0.018) were associated with worse outcomes. there were no ph2 hemorrhages in the iV thrombolytic or endovascular treated group. functional outcome was not different by treatment. CONCLUSION: When carefully selected using Ct ­Cta, by a good scan (aSpeCtS > 7) occlusion paradigm, acute reperfusion therapies in patients with stroke-on-awakening can be performed safely in clinical routine.

Measurement of length of hyperdense MCA sign in acute ischemic stroke predicts disappearance after IV tPA.

BACKGROUND: We sought to assess the hypothesis that length and volumes of middle cerebral artery (MCA) thrombus were associated with disappearance of the hyperdense middle cerebral artery sign (HMCAS) in acute ischemic stroke. METHODS: This is a retrospective cohort study of acute ischemic stroke patients with MCA occlusion admitted to the University Hospital in Canada. The length and volumes of the HMCAS was measured on the plain CT by placing CTA images (CTA source images or MIP images) side-by-side. RESULTS: Seventy-six patients with acute stroke having HMCAS on noncontrast CT (NCCT) with M1 MCA occlusion confirmed by CT angiography or digital subtraction angiography and received tPA. The treatments received were: IV tPA 41(53.9%) and endovascular treatment ± IV tPA 35 (46.1%). In the IV tPA group, the rate of disappearance varied depending on the baseline HMCAS length. Short length HMCAS (<10 mm) disappeared in 6/7 (85.7%) (P < .001). Medium length HMCAS (10-20 mm) disappeared in 9/24 (37.5%). No cases of long length HMCAS (>20 mm) disappeared (0/10) (P = .05). Rate of disappearance of HMCAS was found to be volume dependent (P < .002). CONCLUSION: HMCAS length >10 mm infrequently disappears with IV tPA suggesting a potential need for ancillary therapy in this group.

Combined full-dose IV and endovascular thrombolysis in acute ischaemic stroke.

BACKGROUND: There is an increasing trend to treating proximal vessel occlusions with intravenous-inter-arterial (IV-IA) thrombolysis. The best dose of IV tissue plasminogen activator (tPA) remains undetermined. We compared the combination of full-dose IV recombinant tissue plasminogen activator (rtPA) and IA thrombolytic therapy to IA therapy. METHODS: Between 2002 and 2009, we reviewed our computed tomographic angiography database for patients who received full-dose intravenous rtPA and endovascular therapy or endovascular therapy alone for acute ischaemic stroke treatment. Details of demographics, risk factors, endovascular procedure, and symptomatic intracranial haemorrhage were noted. Modified Rankin Scale ≤2 at three-months was used as good outcome. Recanalization was defined as Thrombolysis in Myocardial Ischaemia 2-3 flow on angiography. RESULTS: Among 157 patients, 104 patients received IV-IA treatment and 53 patients underwent direct IA therapy. There was a higher recanalization rate with IV-IA therapy compared with IA alone (71% vs. 60%, P < 0·21) which was driven by early recanalization after IV rtPA. Mortality and independent outcome were comparable between the two groups. Symptomatic intracranial haemorrhage occurred in 8% of patients (12% in the IA group, 7% in the IV-IA group) but was more frequent as the intensity of intervention increased from device alone to thrombolytic drug alone to device plus thrombolytic drug(s). Recanalization was a strong predictor of reduced mortality risk ratio (RR) 0·48 confidence interval95 0·27-0·84) and favourable outcome (RR 2·14 confidence interval95 1·3-3·5). CONCLUSIONS: Combined IV-IA therapy with full-dose intravenous rtPA was safe and results in good recanalization rates without excess symptomatic intracranial haemorrhage. Testing of full-dose IV tPA followed by endovascular treatment in the IMS3 trial is justified.

Malignant emboli on transcranial Doppler during carotid stenting predict postprocedure diffusion-weighted imaging lesions.

BACKGROUND AND PURPOSE: Carotid angioplasty and stenting (CAS) has a higher incidence of periprocedural stroke compared with endarterectomy. Identifying CAS steps with the highest likelihood of embolization may have important implications. We evaluated CAS safety by correlating the findings of procedural transcranial Doppler with postprocedure diffusion-weighted imaging (DWI) lesions. METHODS: In this prospective study, transcranial Doppler monitoring was performed during CAS procedures, which were divided into 11 steps. Embolic signals on transcranial Doppler were counted and classified based on the relative energy index of microembolic signals into microemboli ≤ 1 or malignant macroemboli >1. Poststenting MRI was performed in all cases. A negative binomial regression model was used to evaluate the predictive value of transcranial Doppler emboli for new DWI lesions. RESULTS: Thirty subjects were enrolled. Seven of 30 subjects (23.3%) were asymptomatic. The median embolic signal count was 212.5 (108 microemboli and 80 malignant macroemboli). Stent deployment phase showed the highest median embolic signals count at 58, followed by protection device deployment at 30 (P=0.0006). Twenty-four of 30 (80%) had new DWI lesions on post-CAS MRI. The median DWI count was 4 (interquartile range 7). Two of 30 (6.7%) had new or worsening clinical deficits post-CAS. For every malignant embolus, the expected count of DWI lesions increases by 1% ( 95% confidence interval, 0%-2%; P=0.032). CONCLUSIONS: We observed a high incidence of embolic signals during CAS procedure, especially, when devices were deployed. Most subjects developed new DWI lesions, but only 6.7% had deficits. Malignant macroemboli predicted new DWI lesions.

High rate of magnetic resonance imaging stroke recurrence in cryptogenic transient ischemic attack and minor stroke patients.

BACKGROUND AND PURPOSE: Cryptogenic stroke is common in patients with transient ischemic attack (TIA) and minor stroke. It is likely that the imaging recurrence risk is higher than the clinical recurrence rate. We sought to determine the rate of clinical and radiographic stroke recurrence in a population of cryptogenic TIA and minor stroke. METHODS: Patients with TIA/minor stroke (National Institutes of Health Stroke Scale score≤3) were prospectively enrolled and imaged within 24 hours of symptom onset as part of 2 cohorts. Patients were assessed at 3 months to document any clinical recurrence and underwent repeat magnetic resonance imaging (MRI) at either 30 or 90 days. Stroke mechanism was categorized as cryptogenic after standard etiologic work-up was completed and was negative. Follow-up MRI was assessed for any new lesions in comparison with baseline imaging. RESULTS: Three hundred thirty-three of 693 (48%) patients had cryptogenic stroke. Of these cryptogenic patients, 207 (62%) had follow-up imaging. At 30-day MRI follow-up, 6.6% (5/76) had new lesions (3 in a remote arterial territory). At 90-day MRI follow-up, 14.5% (19/131) had new lesions (9 in a remote arterial territory). Clinical recurrent stroke was seen in 1.2% (4/333) of patients within 90 days. CONCLUSIONS: Cryptogenic etiology is common in a TIA/minor stroke population. This population shows a high rate of silent radiographic recurrence, suggesting active disease. Use of MRI as a surrogate marker of disease activity is 1 potential way of assessing efficacy of new treatments in this population with reduced sample size.

Thrombolytic therapy for acute ischaemic stroke: what can we do to improve outcomes?

Constant efforts are being made in the stroke community to aim for maximum benefit from thrombolytic therapy since the approval of intravenous recombinant tissue plasminogen activator (rt-PA; alteplase) for the management of acute ischaemic stroke. However, fear of symptomatic haemorrhage secondary to thrombolytic therapy has been a major concern for treating physicians. Certain imaging and clinical variables may help guide the clinician towards better treatment decision making. Aggressive management of some predictive variables that have been shown to be surrogate outcome measures has been related to better clinical outcomes. Achieving faster, safer and complete recanalization with evolving endovascular techniques is routinely practiced to achieve better clinical outcomes. Selection of an 'ideal candidate' for thrombolysis can maximize functional outcomes in these patients. Although speed and safety are the key factors in acute management of stroke patients, there must also be a systematic and organized pattern to assist the stroke physician in making decisions to select the 'ideal candidate' for treatment to maximize results.

Routine CT angiography in acute stroke does not delay thrombolytic therapy.

INTRODUCTION: Lack of additional utility over non-contract computed tomography (NCCT) in decision making and delay in door to needle time are arguments used against routine computed tomographic angiography (CTA) use in acute ischemic stroke management. We compare interval times during a CTA based acute ischemic stroke protocol with an earlier non-CTA based protocol at our center. METHODS: We reviewed 850 stroke thrombolysis patients in a university hospital in Canada from April 1996 to December 2009. Time to treatment was divided into the following interval times: onset-to-door, door-to-needle and onset-to-needle. Patients were categorized into: Group 1 (April 1996-Dec 2002) (Non-contrast CT Scan based thrombolysis) n=297, Group 2 (Jan 2004-Dec 2009) (CTA based thrombolysis) n=504. The period from Jan to Dec 2003 (n=49) was considered a washout period as we had started the CTA protocol that year. Interval times were compared between the two groups. RESULTS: Interval times in Group 1 and Group 2 were: median onset-to-door times in Group 1 [55 minutes (IQR 48),] and Group 2 [61 minutes (IQR 57)] (p=0.019); median door-to-needle times in Group 1 [67 minutes(IQR 43)] and Group 2 [62.5 minutes (IQR 52)] (p=0.519); median onset-to-needle times in Group 1 (139 minute (IQR 73)] and Group 2 (141.5 min (IQR 109.5) (p=0.468). In multivariable linear regression analysis, age and onset-to-door time influenced the door-to-needle time. For every decade of age, door-to-needle times were 5.4 minutes faster. CONCLUSIONS: CTA based thrombolytic approach for acute ischemic stroke does not significantly delay thrombolysis in routine clinical practice.