title: Saccular intracranial aneurysm disease: distribution of site, size, and age suggests different etiologies for aneurysm formation and rupture in 316 familial and 1454 sporadic eastern Finnish patients.
abstract: OBJECTIVE
  Finnish saccular intracranial aneurysm (sIA) disease associates to 2q33, 8q11, and 9p21 loci and links to 19q13, Xp22, and kallikrein cluster in sIA families. Detailed phenotyping of familial and sporadic sIA disease is required for fine mapping of the Finnish sIA disease.
  
  
  METHODS
  Eastern Finland, which is particularly isolated genetically, is served by Kuopio University Hospital's Department of Neurosurgery. We studied the site and size distribution of unruptured and ruptured sIAs in correlation to age and sex in 316 familial and 1454 sporadic sIA patients on first admission from 1993 to 2007.
  
  
  RESULTS
  The familial and sporadic aneurysmic subarachnoid hemorrhage patients had slightly different median ages (46 vs 51 years in men; 50 vs 57 years in women), different proportion of males (50% vs 42%), equal median diameter of ruptured sIAs (7 mm vs 7 mm) with no correlation to age, and equally unruptured sIAs (30% vs 28%). The unruptured sIAs were most frequent at the middle cerebral artery (MCA) bifurcation (44% vs 39%) and the anterior communicating artery (12% vs 13%), in contrast to the ruptured sIAs at the anterior communicating artery (37% vs 29%) and MCA bifurcation (29% vs 29%). The size of unruptured sIAs increased by age in the sporadic group.
  
  
  CONCLUSIONS
  The MCA bifurcation was most prone to develop unruptured sIAs, suggesting that MCA branching during the embryonic period might be involved. The different site distribution of ruptured and unruptured sIAs suggests different etiologies for sIA formation and rupture. The lack of correlation of size and age at rupture (exposure to risk factors) suggests that the size at rupture is more dependent on hemodynamic stress.
authors.affiliation: Department of Neurosurgery, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Terhi
authors.initials: T
authors.lastname: Huttunen
authors.forename: Mikael
authors.initials: M
authors.lastname: von und zu Fraunberg
authors.forename: Juhana
authors.initials: J
authors.lastname: Frösen
authors.forename: Martin
authors.initials: M
authors.lastname: Lehecka
authors.forename: Gerard
authors.initials: G
authors.lastname: Tromp
authors.forename: Katariina
authors.initials: K
authors.lastname: Helin
authors.forename: Timo
authors.initials: T
authors.lastname: Koivisto
authors.forename: Jaakko
authors.initials: J
authors.lastname: Rinne
authors.forename: Antti
authors.initials: A
authors.lastname: Ronkainen
authors.forename: Juha
authors.initials: J
authors.lastname: Hernesniemi
authors.forename: Juha E
authors.initials: JE
authors.lastname: Jääskeläinen
mesh_terms: D000328:Adult; D000368:Aged; D000783:Aneurysm / Q000150:complications / Q000453:epidemiology* / Q000209:etiology*; D016208:Databases, Factual / Q000706:statistics & numerical data; D005192:Family Health; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications / Q000453:epidemiology* / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies