Global epidemiology and patterns of cerebral venous thrombosis: a systematic review and meta-analysis protocol

Introduction Venous thrombosis can affect all veins in the body including cerebral veins, where it causes cerebral venous thrombosis (CVT). CVT is an aetiology of stroke, particularly in children and young adults. Its clinical features vary widely according to the occluded vessel. Data concerning the epidemiology of CVT are scant. This protocol for a systematic review and meta-analysis aims to critically synthesise data concerning prevalence, incidence, risk factors, anatomical patterns, diagnostic and therapeutic delays, and mortality rate of CVT in the global population. Methods and analysis MEDLINE, EMBASE and ISI Web of Science databases will be searched for relevant abstracts of studies published between 1 January 1990 and 31 October 2017, without language restriction. After the screening of abstracts, study selection, data extraction and assessment of risk of bias, we will assess studies individually for heterogeneity. Random effects metaanalysis will then be used to pool studies judged to be clinically homogenous. Funnel plot analysis and Egger's test will be used to detect publication bias. Results will be presented according to economic level of the various countries (high-income vs low/middle-income countries). Ethics and dissemination Since the current study will be based on published data, ethical approval is not required. This review is expected to provide relevant data to help in evaluating the global burden of CVT. The final report of this study will be published in a peer-reviewed journal.