Article

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

Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, T’ai-pei, Taipei, Taiwan
European Neurology (Impact Factor: 1.36). 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
 · 
1,846 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND AND PURPOSE: Previous studies have described a correlation between variants of the circle of Willis and pathological findings, such as cerebrovascular diseases. Moreover, anatomic variations of the anterior cerebral artery (ACA) seem to correspond to the prevalence of aneurysms in the anterior communicating artery (ACoA). The aim of this study was to assess the prevalence of aneurysms in patients with anatomical/morphological variations of the circle of Willis. METHODS: We retrospectively analyzed 223 patients who underwent cerebral angiography between January 2002 and December 2010 for aneurysm of the ACoA. Diagnostic imaging was reviewed and statistically evaluated to detect circle of Willis anomalies, aneurysm size, and rupture. 204 patients with an unrelated diagnosis served as the control group. RESULTS: Variations of the A1 segment occurred significantly more frequently in the aneurysm group than in the control group. Mean aneurysm size in patients with grades I and III hypoplasia or aplasia was 6.58 mm whereas in patients with grade II hypoplasia it was 7.76 mm. CONCLUSIONS: We found that variations in the A1 segment of the ACAs are correlated with a higher prevalence of ACoA aneurysms compared with patients with a symmetric circle of Willis.
    Journal of Neurointerventional Surgery 04/2013; 6(3). DOI:10.1136/neurintsurg-2013-010669 · 2.50 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Strokes in tuberculous meningitis are important determinant of prognosis. Strokes are caused by tuberculosis-related vasculopathy. In this study, we aimed to demonstrate the value of computed tomography angiography. We also assessed value of angiographic findings in determining the prognosis. We included consecutive patients of tuberculous meningitis and prospectively followed them for 6 months. Computed tomography angiography was performed at inclusion. Follow-up angiography, after 6 months, was done in the patients, who had given consent. Angiographic findings were evaluated by experienced neuroradiologists. Initial computed tomography angiography revealed arterial narrowing or occlusion in 33 patients. In 30 patients the anterior cerebral circulation and in 9 patients posterior cerebral circulation was involved. Six (18.2%) patients had lesions in both the territories. The most frequently involved arteries were supraclinoid portion of the internal carotid artery, and proximal portions of the anterior cerebral and middle cerebral arteries. On univariate analysis, predictors of angiographic abnormalities were impaired vision (p = 0.019), hemiparesis (p = 0.002), hydrocephalous (p < 0.001), basal exudates (p < 0.001), meningeal enhancement (p = 0.026) and infarcts (p < 0.001). On multivariate analysis basal exudates was a significant predictor. Angiographic abnormalities were associated with insignificantly poorer prognosis. On follow-up angiograms, 3 patients showed resolution in vascular abnormalities. Two patients had developed new angiographic abnormalities. Arterial narrowing and occlusion is seen in majority of patients with tuberculous meningitis. Angiographic abnormalities may be associated with poor prognosis.
    The Journal of infection 03/2012; 64(6):565-72. DOI:10.1016/j.jinf.2012.03.015 · 4.13 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Aim. To investigate the morphology and variation of the circle of Willis (COW) in healthy Chinese male adults. Materials and Methods. We analyzed cerebral magnetic resonance angiography (MRA) images of 2,246 healthy subjects using typical magnetic resonance imaging (MRI) and MRA. 3D-time of flight (TOF) MRA method was applied to all subjects and the classification was therefore achieved according to the integrity level of COW and the developmental situation of vessels. Results. The overall incidence of COW integrity was 12.24%, with 7.57% nonvariation integral COW. The incidences of partial integrity and nonintegrity were 70.17% and 17.59%, respectively. The integrity rate of anterior circulation was 78.58%, with a close correlation with A1 segment of the anterior cerebral artery (ACA-A1) developmental condition. The developmental variation rate of ACA-A1 was 28.23% and the variation of the right side was higher than that of the left side. The nonintegrity rate of posterior circulation was 83.93% as the hypoplasia of P1 segment of the posterior cerebral artery (PCA-P1) with an incidence rate of 15.85% for PCA-P1 variation. Conclusions. The COW variation is a common phenomenon among the healthy subjects. MRA could enable reflecting the physiological morphology of COW in a comprehensive manner.
    BioMed Research International 01/2015; 2015:976340. DOI:10.1155/2015/976340 · 2.71 Impact Factor

Full-text (2 Sources)

Download
262 Downloads
Available from
Jun 3, 2014