title: Controversies in epidemiology of intracranial aneurysms and SAH.
abstract: Rupture of an intracranial aneurysm is the most common cause of subarachnoid haemorrhage (SAH), which is a life-threatening acute cerebrovascular event that typically affects working-age people. The exact prevalence of unruptured intracranial aneurysms (UIAs) is unknown, but at least one in 20 to 30 adults is likely to carry an asymptomatic UIA. Approximately one quarter of these UIAs rupture in a lifetime. Complex methodological challenges in conducting studies of epidemiology and risk factors for UIAs and SAH might have led to conclusions being drawn on the basis of epidemiological data of variable quality. We believe that, as a result, misconceptions about UIAs and SAH may have arisen. In this Perspectives article, we discuss three possible misconceptions about the epidemiology of UIAs and SAH, and suggest how the quality of future research could be improved.
authors.affiliation: Department of Neurosurgery, University of Helsinki and Helsinki University Hospital, P.O. BOX 266, FI-00029 HUS, Finland.
authors.forename: Miikka
authors.initials: M
authors.lastname: Korja
authors.affiliation: Department of Public Health, University of Helsinki, P.O. BOX 41, FI-00014 Helsinki, Finland.
authors.forename: Jaakko
authors.initials: J
authors.lastname: Kaprio
mesh_terms: D000328:Adult; D017542:Aneurysm, Ruptured / Q000453:epidemiology* / Q000235:genetics; D015982:Bias; D035843:Biomedical Research; D003431:Cross-Cultural Comparison; D003430:Cross-Sectional Studies; D004200:Diseases in Twins / Q000453:epidemiology / Q000235:genetics; D005387:Finland; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D015994:Incidence; D002532:Intracranial Aneurysm / Q000453:epidemiology* / Q000235:genetics; D012307:Risk Factors; D013345:Subarachnoid Hemorrhage / Q000453:epidemiology* / Q000235:genetics