Prevalence and risk of rupture of intracranial aneurysms: a systematic review. Stroke. 1998;29:251 256. 51. Lin N, Cahill KS, Frerichs KU, Friedlander RM, Claus EB. Treatment of ruptured and unruptured cerebral aneurysms in the USA: a paradigm shift. J Neurointerv Surg. 2012;4:182 189. 52. Ghods AJ, Lopes D, Chen M. Gender differences in cerebral aneurysm location. Front Neurol. 2012;3:78. 53. Vlak MH, Rinkel GJ, Greebe P, van der Bom JG,AlgraA. Trigger factors for rupture of intracranial aneurysms in relation to patient and aneurysm characteristics. J Neurol. 2012;259:1298 1302. 54. Kim YW, Neal D, Hoh BL. Cerebral aneurysms in pregnancy and deliv- ery: pregnancy and delivery do not increase the risk of aneurysm rupture. Neurosurgery. 2013;72:143 149. 55. Schievink WI. Intracranial aneurysms [published correction appears in N Engl J Med. 1997;336:1267]. N Engl J Med. 1997;336:28 40. 56. Mhurchu CN, Anderson C, Jamrozik K, Hankey G, Dunbabin D; Australasian Cooperative Research on Subarachnoid Hemorrhage Study (ACROSS) Group. Hormonal factors and risk of aneurysmal subarach- noid hemorrhage: an international population-based, case-control study. Stroke. 2001;32:606 612. 57. Schiller JS, Lucas JW, Ward BW, Peregoy JA. Summary health statistics for U.S. adults: National Health Interview Survey, 2010. Vital Health Stat 10. 2012;(252):1 207. 58. Centers for Disease Control and Prevention (CDC). Prevalence of stroke United States, 2006 2010. MMWR Morb Mortal Wkly Rep. 2012;61:379 382. 59. Murphy SL, Xu JQ, Kochanek KD. Deaths: final data for 2010. National Vital Statistics Report. Vol 61, No 4. Hyattsville, MD: National Center for Health Statistics; 2013. 60. Centers for Disease Control and Prevention (CDC). Ten great public health achievements: United States, 1900 1999. MMWR Morb Mortal Wkly Rep. 1999;48:241 243. 61. Towfighi A, Ovbiagele B, Saver JL. 