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Pongmoragot J.,St. Michaels Hospital | Saposnik G.,St. Michaels Hospital | Saposnik G.,Institute of Clinical Evaluative science | Saposnik G.,University of Toronto
Current Atherosclerosis Reports | Year: 2012

Cerebral venous thrombosis (CVT) is an uncommon cause of stroke with the incidence of 0.5 % from all strokes. The clinical presentation with cerebral hemorrhage constitutes a diagnostic challenge. Approximately one- third of CVT patients developed intracerebral hemorrhage (ICH). Associated factors include older age, female sex, acute onset (48 h), headache, decreased level of consciousness, seizure, elevated blood pressure and papilledema. MRI and MR venogram is the most recommend diagnostic modality in CVT. Anticoagulation therapy is the most commonly accepted treatment even in patients with ICH related CVT. Mechanical thrombectomy/thrombolysis may be considered in patients with neurological deterioration despite intensive medical treatment. Intracerebral hemorrhage in the context of CVT is usually associated with poorer outcomes compared to CVT without ICH. © Springer Science+Business Media, LLC 2012.

Cheng I.,Sunnybrook Health science Center | Kiss A.,Institute of Clinical Evaluative science | Lilge L.,University of Toronto
Wilderness and Environmental Medicine | Year: 2013

Objective To determine the level of UV radiation at extreme altitude and to assess the effect it has on the skin. Methods Fifteen expeditioners and 10 Sherpas were assessed during a climbing expedition on the north side of Mt Everest (8848 m). UV exposure measurement and diffuse skin reflectance spectrophotometry were performed at the beginning and end of the expedition. Results Over the course of the expedition, the expeditioners and Sherpas received a median dose of 93.6 (interquartile range [IQR], 61.0-102.8) and 102.5 (IQR, 72.2-117.8) minimal erythemal doses (MEDs) of UV radiation. The maximum dosage exceeded 106 ± 1.4 MEDs. Using reflectance spectrophotometry, expeditioner and Sherpa melanin-hemoglobin increased by 83.6% (IQR, -1.5 to 89.8%) and 24.7% (IQR, -22.4 to 61.5%) for exposed skin, respectively. The amount of subcutaneous lipid-water decreased by a factor of 196.6 (IQR, 52.1-308.4) and 46.7 (IQR, 1.8-1156.5), for expeditioners and Sherpas, respectively. Conclusions This expedition's participants received massive doses of UV radiation during their time at high altitude. In many individuals this was similar to the annual exposure of northern European office-workers (100 MEDs). Diffuse skin reflectance spectroscopy revealed considerable subcutaneous lipid loss, skin dehydration, and increased melanin in keeping with these levels of exposure. © 2013 Wilderness Medical Society.

Kirst M.,University of Toronto | Mecredy G.,University of Toronto | Mecredy G.,Institute of Clinical Evaluative science | Chaiton M.,University of Toronto
Canadian Journal of Public Health | Year: 2013

OBJECTIVES: Tobacco use co-morbidities, including co-occurring tobacco use, substance use and mental health problems, are a serious public health issue that has implications for treatment and policy. However, not enough is known about the prevalence of various types of tobacco use co-morbidities among the Canadian population. The purpose of this study was to increase understanding of the extent of this issue through an examination of prevalence and correlates of tobacco use co-morbidities in Canada. METHODS: We undertook a series of comprehensive secondary analyses of population survey data from the Canadian Community Health Survey (CCHS) and the Canadian Alcohol and Drug Monitoring Survey (CADUMS). Data were analyzed for 123,846 individuals from the CCHS and 13,581 individuals from the CADUMS. Substance use and mental health variables were compared by smoking status, with chi-square tests. Multivariate logistic regression models were fit to quantify the association between smoking, substance use and mental health issues, adjusting for age, sex, and family income. RESULTS: Prevalence of problematic alcohol and illicit drug use was significantly higher among current smokers than non-smokers. Co-morbid mental health problems were also elevated among current smokers, and co-morbidities varied by age and gender. While smokers of all ages and genders were more likely to report problematic substance use and poor mental health, the effect of smoking status was significantly larger among youth. CONCLUSION: Smoking in Canada is associated with problematic use of alcohol and illicit drugs, as well as co-morbid mental health problems. Youth tobacco use co-morbidities are at a concerning level, especially among young female smokers. More research on this issue in the Canadian context is needed, as well as the development of integrated interventions tailored to treat smokers with co-morbidities, particularly youth. © Canadian Public Health Association, 2013. All rights reserved.

Pongmoragot J.,University of Toronto | Parthasarathy S.,University of Toronto | Selchen D.,University of Toronto | Saposnik G.,University of Toronto | Saposnik G.,Institute of Clinical Evaluative science
Journal of Stroke and Cerebrovascular Diseases | Year: 2013

Bilateral infarction of the medial medulla (MMI) is rare. Limited information is available on clinical characteristics, etiology, and prognosis. High-resolution neuroimaging has a major role in elucidating the underlying stroke mechanism. The aim of this systematic review was to analyze the clinical presentations, stroke mechanisms, and outcomes in patients with bilateral MMI. We performed a systematic review of the literature from 1992-2011 that reported on clinical presentations, stroke mechanism, and/or outcomes in patients with magnetic resonance imaging-proven bilateral MMI. Medline, EMBASE, and Web of Science Scholars Portal were searched without language restriction. Two reviewers independently assessed identified studies to determine eligibility, validity, and quality. The primary outcome was inpatient mortality; a secondary outcome was case fatality at 12 months. We identified 138 articles from Medline, EMBASE, and Scholars Portal including the MeSH terms "brainstem infarction," "medulla," and "bilateral." Twenty-nine articles met our inclusion criteria, including a total of 38 cases with bilateral MMI, and included in our study. These 38 patients had a mean age of 62.2 years and were predominately male (74.2%). The most common clinical presentations were motor weakness in 78.4%, dysarthria in 48.6%, and hypoglossal palsy in 40.5%. The most common vascular pathology was vertebral artery atherosclerosis, in 38.5%. The clinical outcome was poor (mortality, 23.8%; dependency, 61.9%). Bilateral medial medullary infarction is a rare stroke syndrome. Clinical presentations were mostly rostral medullary lesions. Large-artery atherosclerosis and branch disease were the most common stroke mechanisms. The clinical outcome was usually poor. © 2013 by National Stroke Association.

Henry D.A.,Institute of Clinical Evaluative science
Cochrane database of systematic reviews (Online) | Year: 2011

Concerns regarding the safety of transfused blood have led to the development of a range of interventions to minimise blood loss during major surgery. Anti-fibrinolytic drugs are widely used, particularly in cardiac surgery, and previous reviews have found them to be effective in reducing blood loss, the need for transfusion, and the need for re-operation due to continued or recurrent bleeding. In the last few years questions have been raised regarding the comparative performance of the drugs. The safety of the most popular agent, aprotinin, has been challenged, and it was withdrawn from world markets in May 2008 because of concerns that it increased the risk of cardiovascular complications and death. To assess the comparative effects of the anti-fibrinolytic drugs aprotinin, tranexamic acid (TXA), and epsilon aminocaproic acid (EACA) on blood loss during surgery, the need for red blood cell (RBC) transfusion, and adverse events, particularly vascular occlusion, renal dysfunction, and death. We searched: the Cochrane Injuries Group's Specialised Register (July 2010), Cochrane Central Register of Controlled Trials (The Cochrane Library 2010, Issue 3), MEDLINE (Ovid SP) 1950 to July 2010, EMBASE (Ovid SP) 1980 to July 2010. References in identified trials and review articles were checked and trial authors were contacted to identify any additional studies. The searches were last updated in July 2010. Randomised controlled trials (RCTs) of anti-fibrinolytic drugs in adults scheduled for non-urgent surgery. Eligible trials compared anti-fibrinolytic drugs with placebo (or no treatment), or with each other. Two authors independently assessed trial quality and extracted data. This review summarises data from 252 RCTs that recruited over 25,000 participants. Data from the head-to-head trials suggest an advantage of aprotinin over the lysine analogues TXA and EACA in terms of reducing perioperative blood loss, but the differences were small. Compared to control, aprotinin reduced the probability of requiring RBC transfusion by a relative 34% (relative risk [RR] 0.66, 95% confidence interval [CI] 0.60 to 0.72). The RR for RBC transfusion with TXA was 0.61 (95% CI 0.53 to 0.70) and was 0.81 (95% CI 0.67 to 0.99) with EACA. When the pooled estimates from the head-to-head trials of the two lysine analogues were combined and compared to aprotinin alone, aprotinin appeared more effective in reducing the need for RBC transfusion (RR 0.90; 95% CI 0.81 to 0.99).Aprotinin reduced the need for re-operation due to bleeding by a relative 54% (RR 0.46, 95% CI 0.34 to 0.62). This translates into an absolute risk reduction of 2% and a number needed-to-treat (NNT) of 50 (95% CI 33 to 100). A similar trend was seen with EACA (RR 0.32, 95% CI 0.11 to 0.99) but not TXA (RR 0.80, 95% CI 0.55 to 1.17). The blood transfusion data were heterogeneous and funnel plots indicate that trials of aprotinin and the lysine analogues may be subject to publication bias.When compared with no treatment aprotinin did not increase the risk of myocardial infarction (RR 0.87, 95% CI 0.69 to 1.11), stroke (RR 0.82, 95% CI 0.44 to 1.52), renal dysfunction (RR 1.10, 95% CI 0.79 to 1.54) or overall mortality (RR 0.81, 95% CI 0.63 to 1.06). Similar trends were seen with the lysine analogues, but data were sparse. These data conflict with the results of recently published non-randomised studies, which found increased risk of cardiovascular complications and death with aprotinin. There are concerns about the adequacy of reporting of uncommon events in the small clinical trials included in this review.When aprotinin was compared directly with either, or both, of the two lysine analogues it resulted in a significant increase in the risk of death (RR 1.39, 95% CI 1.02, 1.89), and a non-significant increase in the risk of myocardial infarction (RR 1.11 95% CI 0.82, 1.50). Most of the data contributing to this added risk came from a single study - the BART trial (2008). Anti-fibrinolytic drugs provide worthwhile reductions in blood loss and the receipt of allogeneic red cell transfusion. Aprotinin appears to be slightly more effective than the lysine analogues in reducing blood loss and the receipt of blood transfusion. However, head to head comparisons show a lower risk of death with lysine analogues when compared with aprotinin. The lysine analogues are effective in reducing blood loss during and after surgery, and appear to be free of serious adverse effects.

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