Topical review Cerebral venous sinus thrombosis risk factors Mohammad Saadatnia, Farzad Fatehi à , Keivan Basiri, Seyed Ali Mousavi, and Gilda Kinani Mehr Cerebral venous sinus thrombosis is an uncommon disease marked by clotting of blood in cerebral venous, or dural sinuses, and, in rare cases, cortical veins. It is a rare but potentially fatal cause of acute neurological deterioration previously related to otomastoid, orbit, and central face cuta- neous infections. After the advent of antibiotics, it is more often related to neoplasm, pregnancy, puerperium, systemic diseases, dehydration, intracranial tumors, oral contracep- tives, and coagulopathies are the most common causes, but in 30% of cases no underlying etiology can be identified. It has been found in association with fibrous thyroiditis, jugular thrombosis after catheterization, or idiopathic jugular vein stenosis. Other factors include surgery, head trauma, arterio- venous malformations, infection, paraneoplastic, and autoim- mune disease. This article presents a comprehensive review of cerebral venous sinus thrombosis etiologies. Key words: cerebral infarction, countries, epidemiology, hemocoagulation, MRI, stroke Introduction Cerebral venous sinus thrombosis (CVST) is an uncommon disease representing roughly 1% of all strokes, marked by clotting of blood in cerebral venous or dural sinuses, and in rare cases, cortical veins. The first detailed account of CVST appeared in 1825, in France, which was attributed to systemic malignancy. So far, CVST has involved an autopsy diagnosis; however, with the advent of magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) and enhanced clinical awareness, it can now be reliably diagnosed throughout life (1, 2). In the past, CVST was attributed to otomastoid, orbital, and central face infections, but after the introduction of antibiotics, it is more often related to neoplasm (3, 4), pregnancy (4, 5), puerperium (4, 5), systemic diseases, dehydration, intracranial tumors (4), oral contraceptives (OCPs) (4, 5), and coagulopathies (4, 6), even though in 30% of cases, no underlying etiology could be identified (7). There is only limited literature and very few comprehensive reviews covering causes of CVST. Methods We searched the MEDLINE and EMBASE databases for all articles (in all languages), published in peer-reviewed journals between January 1965 and January 2009, for evidence relevant to the presence of etiologies for CVST. We included case controls, cohorts, case series studies, and case reports. Moreover, we looked for the reference lists from the articles identified by the search, as well as key review articles, to identify additional articles. The focus was on etiologies and causes, and less on other aspects like symptoms, diagnosis, and management. Descriptions of the selected studies Our search included the MESH headings intracranial venous thrombosis, intracranial sinus thrombosis, sinus thromboph- lebitis, venous sinus thrombosis, and also risk factor, etiology, and cause. A total of 402 articles were obtained; 142 articles included risk factor, etiology, and cause (23 original articles, 91 case reports, 26 case series studies, and two meta-analyses). The list of articles, the first author, and the year of publication are presented in Table 1. One (0Á70%) article was published between 1965 and 1974, eight (5Á63%) articles between 1975 and 1984, 29 (20Á42%) articles between 1985 and 1994, 34 (23Á94%) articles between 1995 and 2000, and 70 (49Á31%) articles from 2001 through to the present time (January 2009). Provided that we consider the year 1985 as the cut point year for the introduction and usage of MRI, we see that from 142 included articles, only nine (6Á34%) articles had been pub- Correspondence: Farzad Fatehi à , Neurology Department, Isfahan Neurosciences Research Center and Isfahan Medical Education Research Center, Isfahan University of Medical Sciences, Isfahan, Iran. Tel: 198- 9133186330; e-mails: fatehi@edc.mui.ac.ir; farzad_fatehi@yahoo.com Neurology Department, Isfahan University of Medical Sciences, Isfahan, Iran & 2009 The Authors. & 2009 World Stroke Organization International Journal of Stroke Vol 4, April 2009, 111–123 111