title: Ruptured aneurysm at the cortical segment of the distal posterior inferior cerebellar artery associated with hemodynamic stress after basilar artery occlusion.
abstract: BACKGROUND
  A distal posterior inferior cerebellar artery (PICA)de novoaneurysm at the cortical segment after atherosclerotic basilar artery occlusion is extremely rare. Here, we report the case of a ruptured distal PICAde novoaneurysm 8 years after basilar artery occlusion.
  
  
  METHODS
  A 75-year-old man experienced sudden disturbance of consciousness; computed tomography demonstrated cerebellar and subarachnoid hemorrhage due to a ruptured distal PICA aneurysm. Neck clipping of the aneurysm prevented re-rupture initially, and superficial temporal artery-superior cerebellar artery (STA-SCA) bypass was performed 3 months after admission. Postoperative angiography confirmed patency of the bypass, and the patient was discharged without any new neurological deficits.
  
  
  CONCLUSIONS
  This report describes a case ofde novodevelopment of a saccular distal PICA aneurysm after atherosclerotic basilar artery occlusion. We believe that increased hemodynamic stress at the PICA might have contributed to the occurrence and rupture of the aneurysm. STA-SCA bypass, introduced in the territory of the cerebellar hemisphere, reduces hemodynamic stress, which would prevent the occurrence ofde novoaneurysm and recurrent bleeding.
authors.affiliation: Department of Neurosurgery, Nara Medical University, Nara, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Marutani
authors.affiliation: Department of Neurosurgery, Nara Medical University, Nara, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Nakagawa
authors.affiliation: Department of Neurosurgery, Nara Medical University, Nara, Japan.
authors.forename: Hun Soo
authors.initials: HS
authors.lastname: Park
authors.affiliation: Department of Neurosurgery, Nara Medical University, Nara, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Tamura
authors.affiliation: Department of Neurosurgery, Nara Medical University, Nara, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Motoyama
authors.affiliation: Department of Neurosurgery, Nara Medical University, Nara, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakase
keywords: Distal posterior inferior cerebellar artery aneurysm; hemodynamic stress; neck clipping; superficial temporal artery-superior cerebellar artery bypass