title: Aneurysms from extracranial, extradurally originating posterior inferior cerebellar arteries: a rare case report.
abstract: BACKGROUND
  Aneurysms arising from the PICA are infrequent and those arising from an extracranially originating PICA in the extracranial intradural region are even rare. We report a case of bilaterally extracranial extradurally originating PICAs, each of which had an aneurysm, both being situated below the foramen magnum. This to the best of our knowledge is the first of its kind to be reported.
  
  
  METHODS
  A 35-year-old woman presented with giddiness and headache of 2-day duration. CT scan head revealed blood in the 4(th) ventricle. 4 vessel angiogram revealed bilateral extracranial, extradural origin of PICAs from the vertebral arteries between C1 and C2 vertebrae. Both PICAs were associated with a saccular aneurysm each, both of which were extracranial. She underwent a midline suboccipital craniectomy, C1 arch excision, and clipping of both aneurysms.
  
  
  CONCLUSIONS
  We report a very rare case of bilateral extracranial PICA aneurysms from an aberrantly originating PICA (ie, extracranial and extradural).
authors.affiliation: Department of Neurosurgery, National Institute of Mental Health and Neurosciences, Bangalore, India. dibhat@rediffmail.com
authors.forename: Dhananjaya Ishwar
authors.initials: DI
authors.lastname: Bhat
authors.forename: Sampath
authors.initials: S
authors.lastname: Somanna
authors.forename: Jerry
authors.initials: J
authors.lastname: Kovoor
authors.forename: B A
authors.initials: BA
authors.lastname: Chandramoul
mesh_terms: D000328:Adult; D020785:Central Nervous System Vascular Malformations / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D002531:Cerebellum / Q000098:blood supply; D002533:Cerebral Angiography; D001270:Cervical Atlas / Q000033:anatomy & histology / Q000601:surgery; D003399:Craniotomy / Q000379:methods; D004244:Dizziness / Q000209:etiology; D004824:Epidural Space / Q000033:anatomy & histology / Q000601:surgery; D005260:Female; D006261:Headache / Q000209:etiology; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D007796:Laminectomy / Q000379:methods; D019635:Neurosurgical Procedures / Q000379:methods*; D009777:Occipital Bone / Q000033:anatomy & histology / Q000601:surgery; D016896:Treatment Outcome; D014711:Vertebral Artery / Q000002:abnormalities* / Q000473:pathology* / Q000601:surgery; D014715:Vertebrobasilar Insufficiency / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology*