Anterior cerebral artery A1 segment hypoplasia may contribute to A1 hypoplasia syndrome.

Department of Neurology, Tao-Yuan General Hospital, Tao-Yuan City, Taiwan, ROC.
European Neurology (Impact Factor: 1.5). 02/2007; 57(4):208-11. DOI: 10.1159/000099160
Source: PubMed

ABSTRACT Anterior cerebral artery A1 segment hypoplasia is an uncommon fetal variant of the circle of Willis. The frequency of this congenital variation is 1-13% as derived from angiograms and autopsy reports. Impaired collateral blood flow through the circle of Willis is a recognized risk factor for ischemic stroke. The A1 segment of the anterior cerebral artery is a principal supplier of anterior collateral blood flow. The aim of our study was to determine whether A1 segment hypoplasia may be responsible for acute ischemic stroke. We consecutively examined 280 acute ischemic stroke patients (aged 66.9 +/- 14.2 years). Cerebral magnetic resonance angiography was performed within 72 h of ischemic stroke onset. The overall incidence of A1 variation in our experimental group was 15.0% (n = 42, agenesis/hypoplasia = 18/24), which was statistically higher than in the control group (n = 12). The majority (n = 30, 71.42%) had ipsilateral striatal lacunar infarctions. Based on our results, A1 agenesis/hypoplasia appears to be a risk factor contributing to ischemic stroke, especially to strokes in arteries penetrating the striatal area.

1 Bookmark
  • [Show abstract] [Hide abstract]
    ABSTRACT: Various cerebral pathological changes have been reported to cause leukoaraiosis (LA). We hypothesized that circle of Willis (CoW) anomalies may contribute to LA in severe carotid artery stenosis victims through impaired cerebral autoregulation. We conducted a retrospective review on cerebral magnetic resonance (MR) patterns in patients with severe symptomatic carotid artery stenosis and compared white matter lesion (WML) load between subjects with and without complete CoW. LA on fluid attenuation inversion recovery (FLAIR) MR images at the levels of the centrum semiovale and frontal horns in both cerebral hemispheres were scored in 106 patients with unilateral carotid artery stenosis (64 men and 42 women; mean age 68.7 ± 9.2 years, range 44-82). Subjects were divided into groups of complete and incomplete CoW according to cerebral MR angiography. Differences in the LA scores between the groups of complete and incomplete CoW were further analyzed. Compared with those with incomplete configuration of the CoW, subjects with a complete CoW demonstrated a decreased WML load at the level of the centrum semiovale (2.78 ± 1.17 vs. 5.62 ± 2.12, p = 0.02) and frontal horns (2.21 ± 0.79 vs. 4.22 ± 1.83, p = 0.01). Our results support the importance of a complete CoW since it may protect from WML in case of carotid stenosis.
    European Neurology 08/2011; 66(3):136-44. · 1.50 Impact Factor
  • Source
    Circulation 07/2011; 124(3):360-2. · 15.20 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Limited data exist to guide patient selection for preventive treatment of unruptured cerebral aneurysms. Cerebral aneurysms have been associated with circle of Willis anomalies but whether this association is also related to aneurysm rupture is not known. The occurrence of cerebral aneurysm rupture when a circle of Willis anomaly was present or absent was compared. Patients admitted over a 2 year period with a diagnosis of a cerebral aneurysm and an anterior communicating artery (ACoA) or posterior communicating artery (PCoA) aneurysm were included in the analysis. Brain vascular imaging was reviewed for aneurysm size, morphology and presence of circle of Willis anomaly. Relevant medical history and demographics were obtained from the medical records. Of the 113 patients with ACoA or PCoA aneurysms, 85 (75.2%) cases were ruptured. There were 49 (43.4%) PCoA aneurysms and 64 (56.6%) ACoA aneurysms. Mean aneurysm size was 5.65 mm (SD 3.31). A circle of Willis anomaly was identified in 46 (40.7%) of all patients. Circle of Willis anomalies were present in 38 (46.9%) ruptured aneurysm cases and eight (29.6%) unruptured aneurysm cases. Multivariate analysis revealed a higher risk of aneurysm rupture when a circle of Willis anomaly was present (p=0.0245, OR 3.72 (CI 1.18 to 11.66)). This series shows that circle of Willis anomalies are more commonly found in ruptured as opposed to unruptured cerebral aneurysms of the anterior and posterior communicating arteries. The presence of a circle of Willis anomaly may be an important characteristic for selecting patients for preventive aneurysm treatment.
    Journal of neurointerventional surgery 01/2012; 4(1):22-6. · 1.38 Impact Factor

Full-text (2 Sources)

Available from
Jun 3, 2014