title: A case of angiographically occult, distal small anterior inferior cerebellar artery aneurysm.
abstract: BACKGROUND
  A small aneurysm at an unusual location, such as a distal anterior inferior cerebellar artery (AICA) aneurysm, may conceal as a computed tomography angiography (CTA) and digital subtraction angiography (DSA)-occult aneurysm.
  
  
  METHODS
  We herein present the case of a patient suffering from a subarachnoid hemorrhage (SAH) with two aneurysms in which the AICA aneurysm was negative by CTA and DSA. CTA demonstrated a right anterior choroidal artery aneurysm, which was revealed to be an unruptured aneurysm after surgical exploration. A small distal AICA aneurysm was detected by 3D rotational angiography (3DRA). The patient fully recovered except for left-side hearing loss four months after the second operation.
  
  
  CONCLUSIONS
  We recommend a meticulous diagnosis by 3DRA in patients with SAH in which the distribution is not coincident with a typical aneurysmal location.
authors.affiliation: Department of Neurosurgery, Kinki University, Faculty of Medicine, Osaka, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Kubota
authors.affiliation: Department of Neurosurgery, Kinki University, Faculty of Medicine, Osaka, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Sanada
authors.affiliation: Department of Neurosurgery, Kinki University, Faculty of Medicine, Osaka, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Nagatsuka
authors.affiliation: Department of Neurosurgery, Kinki University, Faculty of Medicine, Osaka, Japan.
authors.forename: Amami
authors.initials: A
authors.lastname: Kato
keywords: 3D computed tomography angiography; 3D rotational angiography; Distal anterior inferior cerebellar aneurysm; diagnosis; subarachnoid hemorrhage