The impact of absent A1 segment on ischemic stroke characteristics and outcomes

Anatomical variations in posterior part of the circle of Willis and their associations with brain infarct in different vascular territories

Background

The relationship between anatomical variations in circle of Willis and brain infarction is controversial. The purpose of this study was to evaluate the relationship between anatomical variations in posterior portion of the circle of Willis assessed by MR angiography (MRA) and ischemic infarction in different brain territories.

Methods

This cross-sectional study was conducted on consecutive patients who underwent brain MRI and MRA for suspected cerebrovascular accident. The frequency of anatomical variations including persistent fetal origin of posterior cerebral artery (fPCA) and hypoplastic/aplastic posterior communicating artery (PCoA) and their association with infarction in different intracranial vascular territories was assessed.

Results

In total, 298 patients (155 male/143 female with mean age ± SD of 57 ± 15) were enrolled in the study and categorized into two groups with infarction (n = 142) and without infarction (n = 156). Sixty-three patients (21/1%) had fPCA and 231 (77.5%) had PCoA hypoplasia/aplasia. No significant correlation was identified between fPCA or PCoA hypoplasia/aplasia and presence of infarction. However, regarding the territories involved by infarction, the frequency of thalamus infarction was higher in subgroup with PCoA hypoplasia/aplasia, 17/101 (16.8%) compared to 1/41(2.4%) in the subgroup without ipsilateral PCoA hypoplasia/aplasia (p = 0.024). In two subgroups with and without ipsilateral fPCA variation, frequency of infarction in brain territories was not different significantly.

Conclusions

In patients with brain infarction, aplastic/hypoplastic ipsilateral PCoA is associated with higher incidence of thalamic territory infarction.

Circle of Willis anomalies in Turner syndrome: Absent A1 segment of the anterior cerebral artery

PURPOSE

Turner syndrome (TS) is the most common sex chromosome disorder in women and is associated with a higher than expected death rate secondary to cerebrovascular disease, including stroke. This study evaluates the cerebral vascular anatomy of individuals with TS.

METHODS

Twenty-one women with TS had brain magnetic resonance angiography (MRA). These MRAs were evaluated in a blinded manner with a control group of 25 men and 25 women who had MRA imaging for multiple indications including migraine headaches, psychiatric disorders, and seizures.

RESULTS

Twenty-nine percent of women with TS were missing an A1 segment of the anterior cerebral artery (ACA) compared to 0% in the control group (p < .001). There were no other significant differences in the circle of Willis (COW) in women with TS compared with the control group. A complete COW was found in 3 of 21 (14%) of women with TS and 12 of 47 (26%) controls (p = .36).

CONCLUSION

Women with TS have a significantly different intracranial vascular anatomy, specifically the absence of the A1 segment of the ACA when compared to male and female controls. More research in brain imaging in women with TS and stroke and other cerebrovascular diseases is needed to determine the clinical significance of this anomaly.

Magnetic resonance angiography of hypoplastic A1 segment of anterior cerebral artery at 3.0-Tesla in Andhra Pradesh population of India

Pre-communicating or A1 segment of anterior cerebral artery (A1ACA) hypoplasia can negotiate the anterior cerebral circulation. Not many studies have been examined the association of hypoplastic A1ACA and cerebral ischemic stroke (CIS). In this study the authors' want to accomplish the relationship between hypoplastic A1ACA and outcomes among the patients with CIS in Andhra Pradesh population of India. Retrospective review of prospectively identified 201 adult patients with CIS from 2015 to 2017 was achieved. Patients underwent 3.0T intracranial magnetic resonance angiography were compared with clinical and radiological aspects between male and female cases of A1ACA hypoplasia with associated variations in the circle of Willis. The obtained data was statistically analysed using SPSS software version 16.0 for Windows and P-value <0.05 was considered as significant. Chi-square test was applied to find out the association between the sex and incidence of hypoplastic A1ACA. Sixty-four of 201 patients with A1ACA hypoplasia with no aplastic cases were recorded. It was found to be more in males than females and common on right than left side. Frequent neurological indications such as headache, dizziness, visual instability, nausea, weakness of extremities and seizure were noted and most cases were associated with CIS. Hypoplastic A1ACA often associated with ischemia of terminal branches of ipsilateral ACA which is compromised by the blood flow via contralateral ACA. In this study, though the CIS is not directly related to hypoplastic A1ACA, any alterations in A1 segment is a considerable risk factor of stroke.

The association of the circle of Willis anomaly and risk of stroke in patients with carotid artery disease

Results

In this retrospective study, we analyzed 175 patients who presented at our outpatient stroke clinic between January, 2013 and June, 2015 with either unilateral symptomatic or asymptomatic carotid artery disease, and who had had CT angiography imaging performed. Demographic properties, carotid artery stenosis and the anomaly of the circle of Willis was recorded.

Conclusion

There was no statistically significant difference in patients with symptomatic and asymptomatic carotid artery disease in terms of the anomaly of the circle of Willis.