title: Infratentorial arteriovenous malformation associated with persistent primitive hypoglossal artery.
abstract: BACKGROUND
  We report a case of infratentorial arteriovenous malformation (AVM) associated with persistent primitive hypoglossal artery (PPHA). To our knowledge, this is the second reported case of these combined anomalies in the English literature. We discuss the embryological relationship between these two congenital vascular anomalies.
  
  
  METHODS
  An 18-year-old girl, who suddenly developed severe headache and vomiting followed by loss of consciousness, was admitted to our hospital. A computed tomography scan showed intracerebellar hemorrhage with obstructive hydrocephalus. Digital subtraction angiography revealed an AVM in the left cerebellar hemisphere and an ipsilateral PPHA. After the intracranial pressure was stabilized, the AVM was surgically removed. AVMs develop during the 4(th) to 8(th) week of embryonic life. In contrast, carotid-basilar anastomoses (CBAs) including primitive hypoglossal arteries appear and close spontaneously by the 6(th) week of embryonic life. Thus, AVMs precede CBAs, and a large amount of blood flows into the adjoining AVM via ipsilateral CBAs. As a result, spontaneous closure of a CBA may be disturbed.
  
  
  CONCLUSIONS
  We speculate that coexistence of infratentorial AVMs and ipsilateral CBAs is not incidental but inevitable.
authors.affiliation: Department of Neurosurgery, Kuki General Hospital, 418-1 Kamihayami Kuki, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kageyama
authors.affiliation: Department of Neurosurgery, Kuki General Hospital, 418-1 Kamihayami Kuki, Japan.
authors.forename: Terushige
authors.initials: T
authors.lastname: Toyooka
authors.affiliation: Department of Neurosurgery, National Defense Medical College, Namiki 3-2, Tokorozawa, Saitama, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Osada
authors.affiliation: Department of Neurosurgery, Kuki General Hospital, 418-1 Kamihayami Kuki, Japan.
authors.forename: Nobusuke
authors.initials: N
authors.lastname: Tsuzuki
keywords: Arteriovenous malformation; carotid-basilar anastomosis; persistent primitive hypoglossal artery; posterior fossa