Publications by authors named "Michel Shamy"

69 Publications

Deferral of Consent: Recent Lessons From Canadian Acute Stroke Trials.

Stroke 2021 May 5:STROKEAHA121034655. Epub 2021 May 5.

Ottawa Hospital and Department of Medicine, University of Ottawa, Ontario, Canada. (M.S., D.D.).

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http://dx.doi.org/10.1161/STROKEAHA.121.034655DOI Listing
May 2021

Clinical Utility and Cost of Inpatient Transthoracic Echocardiography Following Acute Ischemic Stroke.

Neurohospitalist 2021 Jan 31;11(1):12-17. Epub 2020 Jul 31.

Department of Medicine (Neurology), Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada.

Background And Purpose: It is unclear whether it is clinically necessary or cost-effective to routinely obtain a transthoracic echocardiogram (TTE) during inpatient admission for ischemic stroke.

Methods: We assessed consecutive patients presenting with acute ischemic stroke at a comprehensive stroke center from 2015 to 2017 who underwent TTE. We assessed for findings on TTE that would warrant urgent intervention including cardiac thrombus, atrial myxoma, mitral stenosis, valve vegetation, valve dysfunction requiring surgery, and low ejection fraction. Subsequent changes in management included changes in anticoagulation, antibiotics, or valve surgery. We calculated in-hospital resource utilization and associated costs for inpatient TTE using individual direct cost details within a case-costing system.

Results: Of 695 patients admitted with acute ischemic stroke, 516 (74%) had a TTE and were included in our analysis. TTE findings were potentially clinically significant in 30 patients (5.8%) and changed management in 17 patients (3.3%). Inpatient admission was prolonged to expedite TTE in 24 patients, while TTE occurred after discharge in 76 patients. After correcting for the cost of TTE, the mean difference in cost to prolong an admission for TTE was $555.52 (USD), or $16 832 per change in management.

Conclusions: Given the low clinical utility of inpatient TTE after acute ischemic stroke and the costs associated with prolonging admission, discharge from hospital should not be delayed solely to obtain TTE.
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http://dx.doi.org/10.1177/1941874420946513DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8022191PMC
January 2021

Identifying sex-specific differences in the carotid revascularisation literature: findings from a scoping review.

Stroke Vasc Neurol 2021 Mar 29. Epub 2021 Mar 29.

School of Public Health, University of Alabama at Birmingham, Birmingham, Alabama, USA.

Objective: No systematic review of the literature has dedicated itself to looking at the management of symptomatic carotid stenosis in female patients. In this scoping review, we aimed to identify all randomised controlled trials (RCTs) that reported sex-specific outcomes for patients who underwent carotid revascularisation, and determine whether sufficient information is reported within these studies to assess short-term and long-term outcomes in female patients.

Design, Setting And Participants: We systematically searched Medline, Embase, Pubmed and Cochrane libraries for RCTs published between 1991 and 2020 that included female patients and compared either endarterectomy with stenting, or any revascularisation (endarterectomy or stenting) with medical therapy in patients with symptomatic high-grade (>50%) carotid stenosis.

Results: From 1537 references examined, 27 eligible studies were identified. Sex-specific outcomes were reported in 13 studies. Baseline patient characteristics of enrolled female patients were reported in 2 of those 13 studies. Common outcomes reported included stroke and death, however, there was significant heterogeneity in the reporting of both periprocedural and long-term outcomes. Sex-specific differences relating to the degree of stenosis and time from index event to treatment are largely limited to studies comparing endarterectomy to medical therapy. Adverse events were not reported by sex.

Conclusions: Only half of the previously published RCTs and systematic reviews report sex-specific outcomes. Detailed analyses on the results of carotid artery intervention for female patients with symptomatic stenosis are limited.
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http://dx.doi.org/10.1136/svn-2020-000744DOI Listing
March 2021

Association between insulin resistance and post-ischaemic stroke outcome in patients without diabetes: protocol for a systematic review and meta-analysis.

BMJ Open 2021 Mar 26;11(3):e044771. Epub 2021 Mar 26.

Neurology, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada.

Introduction: Insulin resistance is an independent risk factor for atherosclerosis, coronary artery disease and ischaemic stroke. Currently, insulin resistance is not usually included in post-stroke risk stratification. This systematic review and meta-analysis intends to determine if available scientific knowledge supports an association between insulin resistance and post-stroke outcomes in patients without diabetes.

Methods And Analysis: The authors will conduct a literature search in Medline, Embase, Web of Science and Cochrane Central. The review will include studies that assess the association between elevated insulin homeostasis model of insulin resistance (HOMA-IR) and post-stroke outcome (functional outcome and recurrent stroke). The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guidelines will be used. The primary outcome will be post-stroke functional outcome (Modified Rankin Scale), and the secondary outcome will be recurrent ischaemic stroke. Comparison of outcome will be made between highest and lowest HOMA-IR range (as defined in each article included in this systematic review). Risk of bias will be assessed qualitatively. Meta-analysis will be performed if sufficient homogeneity exists between studies. Heterogeneity of outcomes will be assessed by ².

Ethics And Dissemination: No human or animal subjects or samples were/will be used. The results will be published in a peer-reviewed journal, and will be disseminated at local and international neurology conferences.

Prospero Registration Number: CRD42020173608.
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http://dx.doi.org/10.1136/bmjopen-2020-044771DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8006852PMC
March 2021

Predicting long-term outcomes in acute intracerebral haemorrhage using delayed prognostication scores.

Stroke Vasc Neurol 2021 Mar 23. Epub 2021 Mar 23.

Department of Medicine, Division of Neurology, Stroke Program, Ottawa Hospital, Ottawa, Ontario, Canada.

Objective: The concept of the 'self-fulfilling prophecy' is well established in intracerebral haemorrhage (ICH). The ability to improve prognostication and prediction of long-term outcomes during the first days of hospitalisation is important in guiding conversations around goals of care. We previously demonstrated that incorporating delayed imaging into various prognostication scores for ICH improves the predictive accuracy of 90-day mortality. However, delayed prognostication scores have not been used to predict long-term functional outcomes beyond 90 days.

Design, Setting And Participants: We analysed data from the ICH Deferoxamine trial to see if delaying the use of prognostication scores to 96 hours after ICH onset will improve performance to predict outcomes at 180 days. 276 patients were included.

Interventions And Measurements: We calculated the original ICH score (oICH), modified-ICH score (MICH), max-ICH score and the FUNC score on presentation (baseline), and on day 4 (delayed). Outcomes assessed were mortality and poor functional outcome in survivors (defined as modified Rankin Scale of 4-5) at 180 days. We generated receiver operating characteristic curves, and measured the area under the curve values (AUC) for mortality and functional outcome. We compared baseline and delayed AUCs with non-parametric methods.

Results: At 180 days, 21 of 276 (7.6%) died. Out of the survivors, 54 of 255 had poor functional outcome (21.2%). The oICH, MICH and max-ICH performed significantly better at predicting 180-day mortality when calculated 4 days later compared with their baseline equivalents ((0.74 vs 0.83, p=0.005), (0.73 vs 0.80, p=0.036), (0.74 vs 0.83, p=0.008), respectively). The delayed calculation of these scores did not significantly improve our accuracy for predicting poor functional outcomes.

Conclusion: Delaying the calculation of prognostication scores in acute ICH until day 4 improved prediction of 6-month mortality but not functional outcomes.

Trial Registration Number: ClinicalTrials.gov Registry (NCT02175225).
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http://dx.doi.org/10.1136/svn-2020-000656DOI Listing
March 2021

Advanced consent for acute stroke trials.

Lancet Neurol 2021 03;20(3):170

Department of Medicine, Neurology, Ottawa, ON K1Y 4E9, Canada.

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http://dx.doi.org/10.1016/S1474-4422(21)00029-6DOI Listing
March 2021

Rationalisations for women-only randomised controlled trials in conditions that affect both sexes: a scoping review protocol.

BMJ Open 2021 02 16;11(2):e043370. Epub 2021 Feb 16.

Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada.

Introduction: Women have historically been under-represented in randomised controlled trials (RCTs), including many landmark RCTs that established standards of care. In light of this fact, some modern researchers are calling for replication of earlier landmark trials with women only. This approach is ethically concerning, in that it would require some enrolled women to be deprived of treatments that are currently considered standard of care.

Objective: In an attempt to better understand the justification of a women-only approach to designing clinical trials, this study looks to systematically categorise the number of women-only RCTs for conditions that affect both men and women and the reasons given within the medical and philosophical literatures to perform them.

Methodology: This scoping review of the literature will search, screen and select articles based on predetermined inclusion/exclusion criteria, after which a grounded theory approach will be used to synthesise the data. It is expected that there will be a variety of reasons given for why a women-only trial may be justified. Electronic databases that will be searched include MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, Cochrane Clinical Trials Register, Web of Science Proceedings, ClinicalTrials.gov, Philosopher's Index, Phil Papers, JSTOR, Periodicals Archive Online, Project MUSE and the National Reference Centre for Bioethics.

Significance: The scope of this study is to determine published rationales used to justify women-only randomised trials, both in the case of new trials and in the repetition of landmark trials.

Ethics And Dissemination: Research ethics board approval is not required for this study as there is no participant involvement. Results will be published as a stand-alone manuscript and will inform a larger project related to the ethics of a women-only RCT of carotid intervention for women with symptomatic high-grade carotid stenosis.
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http://dx.doi.org/10.1136/bmjopen-2020-043370DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7888323PMC
February 2021

Is This Contrast? Is This Blood? An Agreement Study on Post-thrombectomy Computed Tomography Scans.

Front Neurol 2020 22;11:593098. Epub 2020 Dec 22.

Ottawa Stroke Program, Department of Medicine (Neurology), University of Ottawa, Ottawa, ON, Canada.

Hemorrhagic transformation after acute ischemic stroke is a dreaded and severe complication of thrombolysis and thrombectomy. However, its detection on post-thrombectomy conventional non-contrast computed tomography (CT) scan can be complicated by the frequent (and sometimes concomitant) presence of contrast, resulting in changes in management. Our objective was to assess the inter- and intra-rater reliability for the detection of blood and/or contrast on day-1 post-thrombectomy CT scans. A total of 18 raters across 3 different specialties independently examined 30 post-thrombectomy CT scans selected from the Aspiration vs. STEnt-Retriever (ASTER) trial. They were asked to judge the presence of blood and contrast. Thirty days later, the same 18 raters again independently judged the 30 scans, in randomized order. Agreement was measured with Fleiss' and Cohen's statistics. Overall agreement on blood and/ or contrast presence was only fair, = 0.291 (95% CI = 0.273-0.309). There were 0 scans with consensus among the 18 readers on the presence of blood and/or contrast. However, intra-rater global agreement across all 18 physicians was relatively high, with a median kappa value of 0.675. This intra-rater consistency was seen across all specialties, regardless of level of training. Physician judgment for the presence of blood and/or contrast on day-1 post-thrombectomy non-contrast CT scan shows limited inter-observer reliability. Advanced imaging modalities may then be warranted for challenging clinical cases.
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http://dx.doi.org/10.3389/fneur.2020.593098DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7783397PMC
December 2020

Prevalence and the predictive performance of the dynamic CT-angiography spot sign in an observational cohort with intracerebral hemorrhage.

Medicine (Baltimore) 2020 Nov;99(47):e23278

Department of Medical Imaging, University of Ottawa and Ottawa Hospital Research Institute, Ottawa, Canada.

The CT-angiography (CTA) spot sign is a predictor of hematoma expansion (HE). We have previously reported on the use of dynamic CTA (dCTA) to detect spot sign, and to study its formation over the acquisition period. In this study, we report the frequency of dCTA spot sign in acute intracerebral hemorrhage, its sensitivity and specificity to predict HE, and explore the rate of contrast extravasation in relation to hematoma growth.We enrolled consecutive patients presenting with primary intracerebral hemorrhage within 4.5 hours. All patients underwent a dCTA protocol acquired over 60 seconds following contrast injection. We calculated frequency of the dCTA spot sign, predictive performance, and rate of contrast extravasation. We compared extravasation rates to the dichotomous definition of significant HE (defined as 6 mL or 33% growth).In 78 eligible patients, dCTA spot sign frequency was 44.9%. In 61 patients available for expansion analysis, sensitivity and specificity of dCTA spot sign was 65.4% and 62.9%, respectively. Contrast extravasation rate did not significantly predict HE (Odds Ratio 15.6 for each mL/min [95% confidence interval 0.30-820.25], P = .17). Correlation between extravasation rate and HE was low (r = 0.297, P= .11). Patients with significant HE had a higher rate of extravasation as compared to those without (0.12 mL/min vs 0.04 mL/min, P = .03).Dynamic CTA results in a higher frequency of spot sign positivity, but with modest sensitivity and specificity to predict expansion. Extravasation rate is likely related to HE, but a single measurement may be insufficient to predict the magnitude of expansion.
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http://dx.doi.org/10.1097/MD.0000000000023278DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7676581PMC
November 2020

Revised intracerebral hemorrhage expansion definitions: Relationship with care limitations.

Int J Stroke 2020 Nov 2:1747493020967255. Epub 2020 Nov 2.

Ottawa Stroke Program, Department of Medicine (Neurology), University of Ottawa and Ottawa Hospital Research Institute, Ottawa, ON, Canada.

Background: Hematoma expansion is an important therapeutic target in intracerebral hemorrhage. Recently proposed hematoma expansion definitions have not been validated, and no previous definition has accounted for withdrawal of care.

Aims: To externally validate revised definitions of hematoma expansion that incorporate intraventricular hemorrhage, and to test their validity in the context of withdrawal of care.

Methods: We analyzed data from the Antihypertensive Treatment of Acute Cerebral Hemorrhage II trial, comparing revised definitions of hematoma expansion incorporating intraventricular hemorrhage expansion to the conventional definition of "≥6 mL or ≥33%." Primary outcome was modified Rankin Scale of 4-6 at 90 days. We calculated the incidence, sensitivity, specificity, positive and negative predictive values, and statistic for all definitions of hematoma expansion. Definitions were compared using nonparametric methods. Secondary analyses were performed after removing patients with withdrawal of care.

Results: Primary analysis included 948 patients. Using the conventional definition, the sensitivity was 37.1% and specificity was 83.2% for the primary outcome. Sensitivity improved with all three revised definitions (53.3%, 48.7%, and 45.3%, respectively), with minimal change to specificity (78.4%, 80.5%, and 81.0%, respectively). The greatest improvement was seen with the definition "≥6 mL or ≥33% or any intraventricular hemorrhage," with increased -statistic from 60.2% to 65.9% ( < 0.001). Secondary analysis excluded 46 participants who experienced withdrawal of care. The revised definitions similarly outperformed the conventional definition in this population, with the greatest improvement in -statistic using "≥6 mL or ≥33% or any intraventricular hemorrhage" (58.1% vs. 64.1%,  < 0.001).

Conclusions: Revised hematoma expansion definitions incorporating intraventricular hemorrhage expansion outperformed conventional definitions for predicting poor outcome, even after accounting for care limitations.
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http://dx.doi.org/10.1177/1747493020967255DOI Listing
November 2020

Physician preparedness for resource allocation decisions under pandemic conditions: A cross-sectional survey of Canadian physicians, April 2020.

PLoS One 2020 22;15(10):e0238842. Epub 2020 Oct 22.

Department of Neurology, The Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.

Background: Under the pandemic conditions created by the novel coronavirus of 2019 (COVID-19), physicians have faced difficult choices allocating scarce resources, including but not limited to critical care beds and ventilators. Past experiences with severe acute respiratory syndrome (SARS) and current reports suggest that making these decisions carries a heavy emotional toll for physicians around the world. We sought to explore Canadian physicians' preparedness and attitudes regarding resource allocation decisions.

Methods: From April 3 to April 13, 2020, we conducted an 8-question online survey of physicians practicing in the region of Ottawa, Ontario, Canada, organized around 4 themes: physician preparedness for resource rationing, physician preparedness to offer palliative care, attitudes towards resource allocation policy, and approaches to resource allocation decision-making.

Results: We collected 219 responses, of which 165 were used for analysis. The majority (78%) of respondents felt "somewhat" or "a little prepared" to make resource allocation decisions, and 13% felt "not at all prepared." A majority of respondents (63%) expected the provision of palliative care to be "very" or "somewhat difficult." Most respondents (83%) either strongly or somewhat agreed that there should be policy to guide resource allocation. Physicians overwhelmingly agreed on certain factors that would be important in resource allocation, including whether patients were likely to survive, and whether they had dementia and other significant comorbidities. Respondents generally did not feel confident that they would have the social support they needed at the time of making resource allocation decisions.

Interpretation: This rapidly implemented survey suggests that a sample of Canadian physicians feel underprepared to make resource allocation decisions, and desire both more emotional support and clear, transparent, evidence-based policy.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0238842PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7580904PMC
November 2020

Advanced consent for participation in acute care randomised control trials: protocol for a scoping review.

BMJ Open 2020 10 16;10(10):e039172. Epub 2020 Oct 16.

Division of Neurology, Department of Medicine, The Ottawa Hospital, Ottawa, Ontario, Canada.

Introduction: Informed consent is essential to clinical research, though obtaining informed consent for participation in research for emergency conditions is challenging. Adapted consent methods include consent from a substitute-decision maker, deferral of consent and waiver of consent. A novel approach is to use advanced consent, where a potential participant provides consent in the present in the event that they become eligible for enrolment into a future study. This scoping review will map and synthesise the literature on the use of advanced consent for participation and enrolment in randomised control trials for emergency conditions.

Methods And Analysis: Guided by Arksey and O'Malley's scoping review methodology framework, we will search electronic databases (Medline, Embase, Web of Science and the Cochrane Register of Clinical Trials), the grey literature sources and reference lists of relevant studies. Eligible studies will include English language articles that discuss, examine or employ the use of advanced consent for enrolment in randomised control trials, specifically related to emergency conditions or emergency treatment. Diverse types of articles will be eligible for inclusion, including peer-reviewed qualitative and quantitative studies such as randomised control trials, observational studies, surveys, systematic reviews, as well as narrative reviews and ethics papers. Studies will be screened by two independent reviewers to determine eligibility for inclusion. Data on bibliographic information, study characteristics and methodology, and reported results, specifically author disposition, will be extracted and described using qualitative analysis.

Ethics And Dissemination: Formal ethics review is not required as primary data will not be collected. The findings of this study will be disseminated through a peer-reviewed publication. The findings of this study will help identify knowledge gaps that may guide areas for future research and may aid in the design of future clinical trials using advanced consent.
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http://dx.doi.org/10.1136/bmjopen-2020-039172DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7569993PMC
October 2020

Use of the ABC/2 Method to Select Patients for Thrombectomy After 6 Hours of Symptom Onset.

Neurology 2021 01 12;96(1):e10-e18. Epub 2020 Oct 12.

From the Interventional Neuroradiology Department (W.B., S.S., M.P., C.D.), Rothschild Foundation Hospital, Paris; Interventional Neuroradiology Department (C.D.), Gui de Chauliac Hospital, Montpellier; Neurology Department (J.C.), Saint-Antoine Hospital, Paris, France; and Department of Medicine, Division of Neurology (M.S., D.D., R.F.), and Department of Radiology (R.I.A., R.F.), The Ottawa Hospital, Ottawa Hospital Research Institute and University of Ottawa, Canada.

Objective: To determine whether the ABC/2 method could accurately and reliably measure infarct volume and guide thrombectomy decision in acute stroke cases presenting with late or unknown onset.

Methods: Four physicians who routinely use MRI for acute stroke imaging, blinded to the RAPID results, measured the diffusion-weighted imaging (DWI) infarct volume using the ABC/2 method. Measurements with ABC/2 (the index test) were compared with RAPID (the reference standard) to calculate sensitivity, specificity, and accuracy measures for various volume cutpoints. Thrombectomy decisions based on RAPID and raters' measurements using the criteria from the Diffusion-Weighted Imaging or Computerized Tomography Perfusion Assessment With Clinical Mismatch in the Triage of Wake-Up and Late-Presenting Strokes Undergoing Neurointervention With Trevo (DAWN) trial criteria were compared. Interrater and intrarater agreement was measured using kappa statistics.

Results: Accuracy with the ABC/2 method was greater than 80% for each rater and each volume cut point. Interrater and intrarater agreement was substantial to excellent for each volume cut point. Treatment decisions with ABC/2 volume estimations showed strong interrater and intrarater agreement, and led to similar thrombectomy decisions compared with RAPID in more than 85% of cases.

Conclusion: DWI infarct volume measurement using ABC/2 method shows strong accuracy and reliability and may be an acceptable alternative to RAPID software for the application of DAWN criteria for thrombectomy decision-making.
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http://dx.doi.org/10.1212/WNL.0000000000010999DOI Listing
January 2021

Diagnosis of Transient Ischemic Attack: Sex-Specific Differences From a Retrospective Cohort Study.

Stroke 2020 11 30;51(11):3371-3374. Epub 2020 Sep 30.

Neuroscience Program (S.G., C.Q.W., A.B., D.D., G.S., M.S.), Ottawa Hospital Research Institute, Ontario, Canada.

Background And Purpose: Research suggests that women and men may present with different transient ischemic attack (TIA) and stroke symptoms. We aimed to explore symptoms and features associated with a definite TIA/stroke diagnosis and whether those associations differed by sex.

Methods: We completed a retrospective cohort study of patients referred to The Ottawa Hospital Stroke Prevention Clinic in 2015. Exploratory multinomial logistic regression was used to evaluate candidate variables associated with diagnosis and patient sex. Backwards elimination of the interaction terms with a significance level for staying in the model of 0.25 was used to arrive at a more parsimonious model.

Results: Based on 1770 complete patient records, sex-specific differences were noted in TIA/stroke diagnosis based on features such as duration of event, suddenness of symptom onset, unilateral sensory loss, and pain.

Conclusions: This preliminary work identified sex-specific differences in the final diagnosis of TIA/stroke based on common presenting symptoms/features. More research is needed to understand if there are biases or sex-based differences in TIA/stroke manifestations and diagnosis.
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http://dx.doi.org/10.1161/STROKEAHA.120.031510DOI Listing
November 2020

Cohort Study of Features Used by Experts to Diagnose Transient Ischemic Attack.

Neurohospitalist 2020 Oct 17;10(4):245-249. Epub 2020 Mar 17.

Division of Neurology, The Ottawa Hospital, Ottawa, Ontario, Canada.

Background And Purpose: The diagnosis of transient ischemic attack (TIA) is largely dependent on a process of clinical decision-making that remains poorly characterized in the absence of a validated and accessible biomarker or imaging test. We performed a retrospective chart review to identify variables associated with a final neurologist diagnosis of TIA/stroke.

Methods: Records for all patients seen in The Ottawa Hospital's Stroke Prevention Clinic in 2015 were analyzed for patient and referral characteristics, features of the presenting neurological event, and final diagnosis by a stroke neurologist (classified as definite, possible, or definite not TIA/stroke). Multinomial logistic regression analysis with backward elimination was used to identify variables associated with the final diagnosis.

Results: Our inclusion criteria were met by 1894 patients. After backward elimination, 23 potentially important variables were identified, including monocular vision loss (odds ratio [OR]: 30.4, 95% confidence interval [CI]: 14.6-63.3), symptoms of sudden onset (OR: 28.3, 95% CI: 14.2-56.2), unilateral weakness affecting 2 or 3 of face, arm, or leg (OR: 17.7, 95% CI: 9.8-31.7), and homonymous hemianopia (OR: 16.6, 95% CI: 8.1-34.0).

Conclusions: Accurate diagnosis of TIA is essential to initiating appropriate secondary stroke prevention therapies. A focus on elements of the patient history most commonly associated with a final diagnosis of TIA/stroke may help to identify patients in greatest need of urgent SPC assessment and allow for the provision of effective and efficient stroke prevention services.
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http://dx.doi.org/10.1177/1941874420908485DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7495706PMC
October 2020

Prevalence of non-contrast CT abnormalities in adults with reversible cerebral vasoconstriction syndrome: protocol for a systematic review and meta-analysis.

BMJ Open 2020 09 21;10(9):e041776. Epub 2020 Sep 21.

Neurology, The Ottawa Hospital, Ottawa, Ontario, Canada.

Introduction: Reversible cerebral vasoconstriction syndrome (RCVS) is characterised by severe, recurrent thunderclap headaches (TCHs) and vasoconstriction of cerebral arteries that resolve within 3 months. Abnormalities on non-contrast CT (NCCT) such as ischaemic strokes, intracerebral haemorrhage and subarachnoid haemorrhages are frequently observed on brain imaging of patients with RCVS though their prevalence varies considerably between studies. The aim of this systematic review and meta-analysis is to estimate the prevalence of NCCT abnormalities seen on neuroimaging of adult patients with RCVS.

Methods And Analysis: We will search the Medline, Embase and the Cochrane Library databases for studies on the prevalence of NCCT abnormalities on neuroimaging of patients with RCVS. Search results will be screened for eligibility by title and abstract. Suitable studies will be fully reviewed and relevant data extracted using a data abstraction form. The studies will be assessed for methodological quality, risk of bias and heterogeneity. Prevalence estimates across studies will be pooled using a random-effects model and subgroup analysis will be performed to assess the impact of age, sex, publication year and study design on prevalence of vascular lesions. Sensitivity analysis will be used to investigate the robustness of the findings. This protocol has been devised using the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols 2015 checklist.

Ethics And Dissemination: Formal ethics is not required as primary data will not be collected. The findings of this study will be disseminated through a peer-reviewed publication and conference presentations.

Trial Registration Number: CRD42020190637.
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http://dx.doi.org/10.1136/bmjopen-2020-041776DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7507847PMC
September 2020

Recurrence of cervical artery dissection: protocol for a systematic review.

BMJ Open 2020 09 13;10(9):e037124. Epub 2020 Sep 13.

Neurology, The Ottawa Hospital, Ottawa, Ontario, Canada.

Introduction: Cervical artery dissection, including carotid and vertebral artery dissection, is an important cause of stroke in the young. Risk of developing cervical artery dissection has been associated with physical activity in various forms and has been presumed to be related to minor trauma and mechanical stretching of the cervical arteries. This systematic review will aim to synthesise data on the risk of recurrent cervical artery dissection after an initial dissection. This information may be applied to further understand the natural history of this disease, and potentially to help direct evidence-based discussions on safe return to activity after dissection.

Methods And Analysis: A broad search of multiple electronic databases (Medline, Embase, Cochrane Central Register of Controlled Trials and Web of Science) will be conducted to identify studies published as of 13 November 2019, examining all-comers with cervical artery dissection observed over time. Studies will be screened by two independent reviewers in a two-level process to determine eligibility for inclusion. Data will be pooled from eligible articles and the main outcome of recurrent cervical artery dissection at 5 years will be determined using quantitative analysis.

Ethics And Dissemination: Ethics approval is not necessary as no primary data are being collected. The information will be disseminated in the form of a systematic review article which will be submitted to a peer-reviewed medical journal.

Prospero Registration Number: CRD42020166105.
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http://dx.doi.org/10.1136/bmjopen-2020-037124DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7488837PMC
September 2020

Decreased Stroke Presentation Rates at a Comprehensive Stroke Center during COVID-19.

Can J Neurol Sci 2021 Jan 3;48(1):118-121. Epub 2020 Sep 3.

Department of Medicine (Neurology), University of Ottawa Brain & Mind Institute and Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.

We reviewed stroke care delivery during the COVID-19 pandemic at our stroke center and provincial telestroke system. We counted referrals to our prevention clinic, code strokes, thrombolysis, endovascular thrombectomies, and activations of a provincial telestroke system from February to April of 2017-2020. In April 2020, there was 28% reduction in prevention clinic referrals, 32% reduction in code strokes, and 26% reduction in telestroke activations compared to prior years. Thrombolysis and endovascular thrombectomy rates remained constant. Fewer patients received stroke services across the spectrum from prevention, acute care to telestroke care in Ontario, Canada, during the COVID-19 pandemic.
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http://dx.doi.org/10.1017/cjn.2020.193DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7578633PMC
January 2021

Distribution and predictive performance of the temporal phase of dynamic spot sign appearance in acute intracerebral hemorrhage.

PLoS One 2020 6;15(8):e0236196. Epub 2020 Aug 6.

Department of Medicine, University of Ottawa, Ottawa, Canada.

Background: Dynamic CT angiography (dCTA) contrast extravasation, known as the "dynamic spot sign", can predict hematoma expansion (HE) in intracerebral hemorrhage (ICH). Recent reports suggest the phase of spot sign appearance is related to the magnitude of HE. We used dCTA to explore the association between the phase of spot sign appearance and HE, clinical outcome, and contrast extravasation rates.

Methods: We assessed consecutive patients who presented with primary ICH within 4.5 hours from symptom onset who underwent a standardized dCTA protocol and were spot sign positive. The independent variable was the phase of spot sign appearance. The primary outcome was significant HE (either 6 mL or 33% growth). Secondary outcomes included total absolute HE, mortality, and discharge mRS. Mann-Whitney U, Fisher's exact test, and logistic regression were used, as appropriate.

Results: Of the 35 patients with spot signs, 27/35 (77%) appeared in the arterial phase and 8/35 (23%) appeared in the venous phase. Thirty patients had follow-up CT scans. Significant HE was seen in 14/23 (60.87%) and 3/7 (42.86%) of arterial and venous cohorts, respectively (p = 0.67). The sensitivity and specificity in predicting significant HE were 82% and 31% for the arterial phase and 18% and 69% for the venous phase, respectively. There was a non-significant trend towards greater total HE, in-hospital mortality, and discharge mRS of 4-6 in the arterial spot sign cohort. Arterial spot signs demonstrated a higher median contrast extravasation rate (0.137 mL/min) compared to venous spot signs (0.109 mL/min).

Conclusion: Our exploratory analyses suggest that spot sign appearance in the arterial phase may be more likely associated with HE and poorer prognosis in ICH. This may be related to higher extravasation rates of arterial phase spot signs. However, further studies with larger sample sizes are warranted to confirm the findings.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0236196PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7410294PMC
October 2020

Natural history of recovery after intracerebral haemorrhage: a scoping review protocol.

BMJ Open 2020 08 4;10(8):e039460. Epub 2020 Aug 4.

Department of Medicine, University of Ottawa and Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.

Introduction: Clinical trials for intracerebral haemorrhage typically measure outcomes in the same way and at the same time points as trials for ischaemic stroke. However, there is growing evidence that the trajectory of recovery following intracerebral haemorrhage may differ significantly from that following ischaemic stroke. A better understanding of current approaches to outcome assessment is essential to ensure that future trials examining treatments for intracerebral haemorrhage are designed appropriately.

Objective: To determine when and how outcomes are measured in patients with intracerebral haemorrhage.

Methods And Analysis: With the assistance of an information specialist, we will conduct a scoping review by searching MEDLINE, Embase, Cochrane Central Register of Controlled Trials and Web of Science for prospective studies of adults with primary intracerebral haemorrhage and documented outcomes with specified times. Two reviewers will independently collect data on included studies pertaining to publication data, study population information, timing of outcome and details of the outcome measurement tools used. The extracted data will be used to demonstrate the type and timing of outcome measures.

Ethics And Dissemination: Primary data will not be collected therefore formal ethics is not required. The findings of this study will be disseminated through peer-reviewed publications and through presentation at academic conferences.
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http://dx.doi.org/10.1136/bmjopen-2020-039460DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7406024PMC
August 2020

Different meanings of equipoise and the four quadrants of uncertainty.

J Clin Epidemiol 2020 11 17;127:248-249. Epub 2020 Jul 17.

Department of Medicine, University of California, Davis, CA, USA.

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http://dx.doi.org/10.1016/j.jclinepi.2020.07.010DOI Listing
November 2020

Variability Predictors of Vasospasm in Subarachnoid Hemorrhage: A Feasibility Study.

Can J Neurol Sci 2021 Mar 20;48(2):226-232. Epub 2020 Jul 20.

Department of Medicine, The Ottawa Hospital and University of Ottawa, Ottawa, ON, Canada.

Background: Mean cerebral blood flow velocity (mean-CBFV) obtained from Transcranial Doppler (TCD) poorly predicts cerebral vasospasm in patients with aneurysmal subarachnoid hemorrhage (aSAH). Variability descriptors of mean-CBFV obtained during extended TCD recordings may improve this prediction. We assessed the feasibility of generating reliable linear and non-linear descriptors of mean-CBFV variability using extended recordings in aSAH patients and in healthy controls. We also explored which of those metrics might have the ability to discriminate between aSAH patients and healthy controls, and among patients who would go on to develop vasospasm and those who would not.

Methods: Bilateral mean-CBFV, blood pressure, and heart rate were continuously recorded for 40 minutes in aSAH patients (n = 8) within the first 5 days after ictus, in age-matched healthy controls (n = 8) and in additional young controls (n = 8). We obtained linear [standard deviation, coefficient of variations, and the very-low (0.003-0.040 Hz), low (0.040-0.150 Hz), and high-frequency (0.15-0.4 Hz) power spectra] and non-linear (Fractality, deterministic Chaos analyses) variability metrics.

Results: We successfully obtained TCD recordings from patients and healthy controls and calculated the desired metrics of mean-CBFV variability. Differences were appreciable between aSAH patients and healthy controls, as well as between aSAH patients who later developed vasospasm and those who did not.

Conclusions: A 40-minute TCD recording provides reliable variability metrics in aSAH patients and healthy controls. Future studies are required to determine if mean-CBFV variability metrics remain stable over time, and whether they may serve to identify patients who are at greatest risk of developing cerebral vasospasm after aSAH.
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http://dx.doi.org/10.1017/cjn.2020.157DOI Listing
March 2021

A Delayed Modified ICH Score Outperforms Baseline Scoring in Acute Intracerebral Hemorrhage.

Neurohospitalist 2020 Jul 30;10(3):217-220. Epub 2019 Dec 30.

Ottawa Stroke Program, Division of Neurology, Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada.

The Modified Intracerebral Hemorrhage (MICH) score is a simple tool created to provide prognostication in basal ganglia hemorrhages. Current prognostic scores, including the MICH, are based on the assessment of baseline patient characteristics, failing to account for significant developments, such as intraventricular extension and clinical deterioration, which may occur over the first 72 hours. We propose to validate the MICH in all hemorrhage locations and hypothesize that its calculation at 72 hours will outperform its baseline counterpart with respect to predicting mortality and functional outcome. We performed a retrospective analysis of collated data from the Virtual International Stroke Trials Archive database. Primary outcome was 90-day mortality. Secondary outcome was poor outcome (modified Rankin Scale 4-6) at 90 days. Receiver operating characteristic curves were generated looking at the predictive ability of the MICH score for mortality and poor outcome, at baseline and at 72 hours. Competing curves were assessed with nonparametric methods. A total of 226 patients were included, with a 90-day mortality of 22.5%. The MICH scores calculated at 72 hours were more predictive of mortality than at baseline (area under the curve [AUC]: 0.89 [95% confidence interval [CI]: 0.83-0.94] vs 0.78 [95% CI: 0.70-0.85]), < .01. The MICH scores at 72 hours similarly better predicted functional outcome (AUC: 0.78 [95% CI: 0.72-0.84] vs AUC: 0.72 [95% CI: 0.66-0.78]), = .047. The MICH score has positive prognostic value for mortality and poor functional outcome in all hemorrhage locations. Delaying its calculation resulted in higher predictive values for both and suggests that delaying discussions around withdrawal of care may result in more accurate prognostication in acute intracerebral hemorrhage.
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http://dx.doi.org/10.1177/1941874419896715DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7271617PMC
July 2020

Clinical Reasoning: Recurrent strokes secondary to unknown vasculopathy.

Neurology 2020 06 15;94(22):e2396-e2401. Epub 2020 May 15.

From the Divisions of Neurology (R.L., N.N., M.S., G.S., D.B.) and Hematology (J.M.), Department of Medicine, and Division of Hematopathology, Department of Pathology and Laboratory Medicine, Ottawa and Eastern Ontario Regional Laboratory Association (R.P.), The Ottawa Hospital, Canada.

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http://dx.doi.org/10.1212/WNL.0000000000009534DOI Listing
June 2020

Early Dabigatran Treatment After Transient Ischemic Attack and Minor Ischemic Stroke Does Not Result in Hemorrhagic Transformation.

Can J Neurol Sci 2020 09 28;47(5):604-611. Epub 2020 Apr 28.

Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.

Objectives: The optimal timing of anticoagulation after ischemic stroke in atrial fibrillation (AF) patients is unknown. Our aim was to demonstrate the feasibility and safety of initiating dabigatran therapy within 14 days of transient ischemic attack (TIA) or minor stroke in AF patients.

Patients And Methods: A prospective, multi-center registry (NCT02415855) in patients with AF treated with dabigatran within 14 days of acute ischemic stroke/TIA (National Institutes of Health Stroke Scale (NIHSS) ≤ 3) onset. Baseline and follow-up computed tomography (CT) scans were assessed for hemorrhagic transformation (HT) and graded by using European Cooperative Acute Stroke Study criteria.

Results: One hundred and one patients, with a mean age of 72.4 ± 11.5 years, were enrolled. Median infarct volume was 0 ml. Median time from index event onset to dabigatran initiation was 2 days, and median baseline NIHSS was 1. Pre-treatment HT was present in seven patients. No patients developed symptomatic HT. On the day 7 CT scan, HT was present in six patients (one progressing from baseline hemorrhagic infarction type 1). Infarct volume was a predictor of incident HT (odds ratio = 1.063 [1.020-1.107], p < 0.003). All six (100%) patients with new/progressive HT were functionally independent (modified Rankin Scale (mRS) = 0-2) at 30 days, which was similar to those without HT (90%, p = 0.422). Recurrent ischemic events occurred within 30 days in four patients, two of which were associated with severe disability and death (mRS 5 and 6, respectively).

Conclusion: Early dabigatran treatment did not precipitate symptomatic HT after minor stroke. Asymptomatic HT was associated with larger baseline infarct volumes. Early recurrent ischemic events may be clinically more important.
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http://dx.doi.org/10.1017/cjn.2020.84DOI Listing
September 2020

"It's About How Hard You Can Get Hit and Keep Moving Forward": How to Survive Rejection and Get Your Research Published.

Stroke 2020 05 9;51(5):e74-e77. Epub 2020 Apr 9.

From the Division of Neurology, Department of Medicine, Ottawa Hospital Research Institute and University of Ottawa, Ontario, Canada.

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http://dx.doi.org/10.1161/STROKEAHA.119.028857DOI Listing
May 2020

Evaluating Hematoma Expansion Scores in Acute Spontaneous Intracerebral Hemorrhage: A Systematic Scoping Review.

Stroke 2020 04 22;51(4):1305-1308. Epub 2020 Jan 22.

From the Division of Neurology (V.Y., M.M., M.S., D.D.), University of Ottawa, Ontario, Canada.

Background and Purpose- In acute spontaneous intracerebral hemorrhage, multiple hematoma expansion scores have been proposed for use in clinical trial environments. We performed a systematic scoping review to identify all existing hematoma expansion scores and describe their development, validation, and relative performance. Methods- Two reviewers searched MEDLINE, PUBMED, EMBASE, and CENTRAL (Cochrane Central Register of Controlled Trials) for studies that derived or validated a hematoma expansion prediction score in adults presenting with spontaneous intracerebral hemorrhage. A descriptive analysis of the extracted data was performed, focusing on score development techniques and predictive capabilities. Results- Of the 14 434 records retrieved, 15 studies met inclusion criteria and 10 prediction scores were identified. Validation analysis using independent samples was performed in 9 studies on 5 scores. All derivation studies reported high performance with C statistics ranging from 0.72 to 0.93. In validation, the C-statistic range was broader with studies reporting 0.62 to 0.77. For every score, the risk of expansion increased with each point increase, although patients with high scores were rare. Conclusions- At present, 10 hematoma expansion scores have been developed, of which 5 have been externally validated. Real-world performance in validation studies was lower than performance in derivation studies. Data from the current literature are insufficient to support a meaningful meta-analysis.
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http://dx.doi.org/10.1161/STROKEAHA.119.028574DOI Listing
April 2020

Overcoming Neurophobia With the Help of Peruvian Talking Bears.

JAMA Neurol 2020 03;77(3):291-292

Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.

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http://dx.doi.org/10.1001/jamaneurol.2019.4668DOI Listing
March 2020

Normal Systolic Blood Pressure at Presentation With Acute Ischemic Stroke Predicts Cardioembolic Etiology.

J Am Heart Assoc 2020 01 4;9(1):e014399. Epub 2020 Jan 4.

Department of Medicine (Neurology) Ottawa Hospital Research Institute & University of Ottawa Canada.

Background Early insight into the possible etiology of ischemic stroke allows for early initiation of mechanism-specific secondary stroke prevention. Initial systolic blood pressure during acute ischemic stroke may relate to stroke etiology. We sought to determine whether normotension at presentation with acute ischemic stroke predicts cardioembolic etiology. Methods and Results All patients presenting with acute ischemic stroke within 12 hours of symptom onset at a comprehensive stroke center from January 2015 to December 2017 were assessed. Normotension was defined as systolic blood pressure ≤130 mm Hg. The primary exposure was blood pressure on arrival at the hospital, and the primary outcome was cardioembolic etiology. Multivariable regression with stepwise selection was used to adjust for relevant covariates. We included 683 patients in our analysis, 303 (44%) of whom were diagnosed with cardioembolic etiology at 6 months. The probability of cardioembolic etiology was inversely associated with systolic blood pressure, and initial systolic blood pressure was significantly associated with cardioembolic etiology (odds ratio: 1.15; 95% CI, 1.05 to 1.26). Normotension was associated with 2.62-fold increased odds of cardioembolic etiology (95% CI, 1.46 to 4.72). Conclusions Normotension at presentation with acute ischemic stroke strongly predicts cardioembolic etiology. These patients may especially benefit from early and prolonged cardiac investigations.
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http://dx.doi.org/10.1161/JAHA.119.014399DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6988141PMC
January 2020