title: Extracranial aneurysm of the posterior inferior cerebellar artery with an aberrant origination: case report.
abstract: OBJECTIVE
  Aneurysms of the extracranially originating posterior inferior cerebellar artery are very rare. An anatomic insight of its possible course and variations is necessary when confronting such extraordinary lesions.
  
  
  METHODS
  A 19-year-old man presented with the sudden onset of severe headaches. A physical examination was positive only for neck rigidity. Computed tomographic scans of the brain depicted intraventricular hemorrhage. TECHNIQUE AND INTERVENTION: Four-vessel brain digital subtraction angiography revealed an extracranial posterior inferior cerebellar artery arising extradurally from the right vertebral artery between the C1 and C2 vertebrae, bearing a saccular aneurysm in an upper cervical intradural location. An anterior inferior cerebellar artery-posterior inferior cerebellar artery variant was also found on the left side. Computed tomographic angiography failed to unmask the lesion. The aneurysm was clipped through a suboccipital craniectomy and C1 laminectomy.
  
  
  CONCLUSIONS
  The patient did well after surgery and was discharged from the hospital without neurological deficit. One can conclude that a comprehensive diagnostic approach oriented to the patient history and clinical data is mandatory to preclude such lesions evading the vigilant surgeon.
authors: Department of Neurosurgery, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran. tayebi_a77@yahoo.com
authors: Seyed Ali Fakhr
authors: SA
authors: Tabatabai
authors: Mehdi Zeinali
authors: MZ
authors: Zadeh
authors: Ali Tayebi
authors: AT
authors: Meybodi
authors: Mohammad
authors: M
authors: Hashemi
mesh_terms: D000328:Adult; D001158:Arteries / Q000002:abnormalities* / Q000601:surgery*; D002531:Cerebellum / Q000098:blood supply*; D006801:Humans; D002532:Intracranial Aneurysm / Q000209:etiology / Q000601:surgery*; D008297:Male; D019635:Neurosurgical Procedures / Q000379:methods*; D016896:Treatment Outcome; D014656:Vascular Surgical Procedures / Q000379:methods*