title: Impact of posterior communicating artery on basilar artery steno-occlusive disease.
abstract: BACKGROUND
  Acute brainstem infarction with basilar artery (BA) occlusive disease is the most fatal type of all ischaemic strokes. This report investigates the prognostic impact of the posterior communicating artery (PcoA) and whether its anatomy is a safeguard or not.
  
  
  METHODS
  Consecutive patients who had acute brainstem infarction with at least 50% stenosis of BA upon CT angiography (CTA) were studied. The configuration of PcoA was divided into two groups upon CTA: "textbook" group (invisible PcoA with good P1 and P2 segment) and "fetal-variant of PcoA" group (only visible PcoA with absent P1 segment). Baseline demographics, radiological findings and stroke mechanisms were analysed. A multiple regression analysis was performed to predict clinical outcome at 30 days (modified Rankin disability Scale (mRS<or=2)).
  
  
  RESULTS
  Among all 95 patients, 58% (n = 55) had good prognoses (mRS<or=2). Interestingly, 44 patients (46.3%) had at least one fetal-variant PcoA (26 bilateral, 18 unilateral). By multiple logistic regression analysis, the atherosclerotic mechanism (OR 18.0; 95% CI 3.0 to 107.0) and presence of fetal-variant PcoA (OR 5.1; 95% CI 1.4 to 18.8) were independent predictors for good prognosis and initial NIH stroke scale score (OR 1.24 per one-point increase; 95% CI 1.1 to 1.4) for poor prognosis.
  
  
  CONCLUSIONS
  Fetal-variant PcoA appears to act as a safeguard against ischaemic insult in acute stroke victims involving the brainstem with BA occlusive disease. This result can be explained by the fact that patients with fetal-variant PcoA have a smaller area of posterior circulation and a possibility of retrograde filling into the upper brainstem through the fetal-variant PcoA.
authors.affiliation: Department of Neurology, School of Medicine, Ajou University, Suwon, Kyunggi, South Korea. dacda@hanmail.net
authors.forename: J M
authors.initials: JM
authors.lastname: Hong
authors.forename: J Y
authors.initials: JY
authors.lastname: Choi
authors.forename: J H
authors.initials: JH
authors.lastname: Lee
authors.forename: S W
authors.initials: SW
authors.lastname: Yong
authors.forename: O Y
authors.initials: OY
authors.lastname: Bang
authors.forename: I S
authors.initials: IS
authors.lastname: Joo
authors.forename: K
authors.initials: K
authors.lastname: Huh
mesh_terms: D000368:Aged; D020526:Brain Stem Infarctions / Q000473:pathology* / Q000503:physiopathology; D002941:Circle of Willis / Q000473:pathology* / Q000503:physiopathology; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D011379:Prognosis; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D014715:Vertebrobasilar Insufficiency / Q000473:pathology* / Q000503:physiopathology