Yan Deschaintre

Silent ischemic lesions in young adults with first stroke are associated with recurrent stroke

Objective: To determine the association between silent ischemic lesions (SILs) on baseline brain MRI and recurrent stroke in young adults with first-ever ischemic stroke. Methods: This was a single-center retrospective study of adult patients aged 18–50 years with first-ever ischemic stroke investigated by brain MRI between 2002 and 2009. Silent brain infarcts (SBIs) were defined as focal T2 hyperintensities ≥3 mm without corresponding focal symptoms, and leukoaraiosis was defined as focal, multifocal, or confluent hyperintensities on T2-weighted sequences. The primary outcome was recurrent stroke. A forward stepwise Cox regression model was used to determine whether SILs were independently associated with recurrent stroke. Results: A total of 271 eligible patients were identified in the database: 89 did not undergo MRI imaging and 12 patients had inadequate follow-up, leaving a study population of 170 patients. MRI demonstrated SILs in 48 of 170 (28.2) patients. No patients had isolated leukoaraiosis. Hypertension (p = 0.049), migraine with aura (p = 0.02), and cardiovascular disease (p = 0.04) were associated with SIL. Mean follow-up duration was 25 ± 7 months. Among patients with SILs, 11 of 48 (23%) had a recurrent stroke vs 8 of 122 (6.5%) patients without SIL (p = 0.003). After multivariate Cox regression, SILs remained independently associated with recurrent stroke (hazard ratio [HR] 3.2, 95% confidence interval [CI] 1.2−8.6, p = 0.02), as did the combination of SBIs and leukoaraiosis (HR 7.3, 95% CI 2.3−22.9, p = 0.003). Conclusions: In adults ≤50 years old with first-ever ischemic stroke, SILs are common and independently predict recurrent stroke.

Good is not Good Enough: The Benchmark Stroke Door-to-Needle Time Should be 30 Minutes.

Noreen Kamal, Oscar Benavente, Karl Boyle, Brian Buck, Ken Butcher, Leanne K. Casaubon,RobertCote,AndrewMDemchuk,YanDeschaintre,DarDowlatshahi,GordonJGubitz,GaryHunter,Tom Jeerakathil, Albert Jin, Eddy Lang, Sylvain Lanthier, Patrice Lindsay, Nancy Newcommon,Jennifer Mandzia, Colleen M. Norris, Wes Oczkowski, Celine Odier, Stephen Phillips,Alexandre Y Poppe, Gustavo Saposnik, Daniel Selchen, Ashfaq Shuaib, Frank Silver, Eric E Smith,Grant Stotts, Michael Suddes, Richard H. Swartz, Philip Teal, Tim Watson, Michael D. Hill

Application of calibrated fMRI in Alzheimer's disease

Calibrated fMRI based on arterial spin-labeling (ASL) and blood oxygen-dependent contrast (BOLD), combined with periods of hypercapnia and hyperoxia, can provide information on cerebrovascular reactivity (CVR), resting blood flow (CBF), oxygen extraction fraction (OEF), and resting oxidative metabolism (CMRO2). Vascular and metabolic integrity are believed to be affected in Alzheimers disease (AD), thus, the use of calibrated fMRI in AD may help understand the disease and monitor therapeutic responses in future clinical trials. In the present work, we applied a calibrated fMRI approach referred to as Quantitative O2 (QUO2) in a cohort of probable AD dementia and age-matched control participants. The resulting CBF, OEF and CMRO2 values fell within the range from previous studies using positron emission tomography (PET) with 15O labeling. Moreover, the typical parietotemporal pattern of hypoperfusion and hypometabolism in AD was observed, especially in the precuneus, a particularly vulnerable region. We detected no deficit in frontal CBF, nor in whole grey matter CVR, which supports the hypothesis that the effects observed were associated specifically with AD rather than generalized vascular disease. Some key pitfalls affecting both ASL and BOLD methods were encountered, such as prolonged arterial transit times (particularly in the occipital lobe), the presence of susceptibility artifacts obscuring medial temporal regions, and the challenges associated with the hypercapnic manipulation in AD patients and elderly participants. The present results are encouraging and demonstrate the promise of calibrated fMRI measurements as potential biomarkers in AD. Although CMRO2 can be imaged with 15O PET, the QUO2 method uses more widely available imaging infrastructure, avoids exposure to ionizing radiation, and integrates with other MRI-based measures of brain structure and function.

Appropriate Use of Antithrombotic Medication in Canadian Patients With Nonvalvular Atrial Fibrillation

This national chart audit of 7,019 patients with nonvalvular atrial fibrillation (AF) from 735 primary care physician practices sought to examine the management of Canadian patients with AF through an evidence-based, guideline-recommended approach. The appropriate use of oral anticoagulants (OACs) in this patient population and the potential factors guiding OAC choice were examined. Suboptimal dosing was seen. In patients on warfarin, 30.9% had not achieved a time in therapeutic range (TTR) in excess of 65% and, despite current Canadian guideline recommendations, were continued on warfarin rather than one of the novel OACs. In patients who received no antithrombotic therapy, 65.5% met criteria for treatment with an OAC. In addition, 62.8% of patients who were treated with acetylsalicylic acid monotherapy met guideline criteria for the use of an OAC. In those patients treated with an OAC, 24.8% were not on the recommended dose based on the product monograph or, if on warfarin, had a TTR <65%. Of the patients on novel OACs (NOACs), 7.4% of patients were underdosed, whereas overdosing was seen in 4.3%. Factors that may have contributed to dosing outside recommendations included underestimation of stroke risk, overestimation of bleed risk, compliance concerns, and lack of provincial reimbursement. In conclusion, significant correctable gaps remain in optimal treatment for stroke prevention in AF.

Proper name anomia in poststroke aphasics: evidence from a multiple-case study

We aimed to characterize difficulties in famous face naming in three poststroke aphasic patients with a lesion limited to the left mid-posterior temporal language regions, sparing the anterior temporal lobe. The patients did not present semantic deficits specific to known people. Nonetheless, they showed difficulties naming famous buildings in addition to famous faces, but they were comparable to healthy controls in generating proper names. Our results support the critical role of the mid-posterior temporal language regions in the lexical retrieval of proper names, namely from pictorial stimuli, in absence of semantic impairments.

Short- and Long-Term Reduction of Door-to-Needle Time in Thrombolysis for Acute Stroke

BACKGROUND More timely administration of tissue plasminogen activator (alteplase) for patients with acute ischemic stroke yields greater clinical benefits. We implemented door-to-needle (DTN) time reduction strategies at our center and evaluated their short- and long-term effects on in-hospital treatment delays and clinical outcomes. METHODS Strategies, including stroke team prenotification, direct computed tomography transfer, not routinely waiting for laboratory results and alteplase delivery on the computed tomography table, were implemented in June 2013. We included all thrombolysed patients admitted directly to our hospital between January 2012 and March 2015. In-hospital delays and symptomatic intracerebral hemorrhage rates were compared between patients pre- and postmodification, and the latter period was divided into early (first 6 months) and late (beyond 6 months) phases to assess the durability of our modifications. RESULTS Forty-eight individuals were treated premodification compared with 58 postmodification. The median DTN time was reduced from 75 to 46 minutes (p<0.0001). The median DTN time in the early and late postmodification phases was not significantly different (41 vs 46 minutes, p=0.4085). There was no significant difference in rates of symptomatic intracerebral hemorrhage (4.2 vs 1.7%, p=0.361) or stroke mimics (2.1 ves 5.2%, p=0.625) Conclusions: We were able to decrease our DTN time for acute stroke thrombolysis by implementing relatively simple modifications and these improvements persisted over time.

A randomized pragmatic care trial on endovascular acute stroke interventions (EASI): criticisms, responses, and ethics of integrating research and clinical care

BackgroundThe Endovascular Acute Stroke Intervention (EASI) trial was conceived as a pragmatic care trial, designed to integrate trial methods with clinical practice. Reporting the EASI experience was met with objections and criticisms during peer review concerning both scientific and ethical issues. Our goal is to discuss these criticisms in order to promote the pragmatic approach of care trials in outcome-based medical care.MethodsThe comments and criticisms of 11 reviewers from 5 journals were collected and analyzed. The EASI protocol was also compared to the protocols of seven thrombectomy trials using the pragmatic-explanatory continuum indicator summary (PRECIS).ResultsMain criticisms of EASI concerned selection criteria that were judged to be too vague and too inclusive, brain and vascular imaging methods that were not sufficiently prescribed by protocol, lack of blinding of outcome assessment, and lack of power. EASI was at the pragmatic end of the spectrum of thrombectomy trials.ConclusionThe pragmatic care trial methodology is not currently well-established. More work needs to be done to integrate scientific methods and ethical care in the best medical interest of current patients.