Circle Of Willis Variations Research Articles

The Relationship Between the Circle of Willis Variations and White Matter Hyperintensities in Different Migraine Subtypes

It is known that the Circle of Willis (CoW) variations and white matter hyperintensities (WMHs) are common in migraine. This retrospective study aims to investigate the relationship between the CoW variations and WMHs in migraine without aura (MWoA) (n=38) and migraine with aura (MWA) (n=40) patients. Demographic, clinical and radiological findings (the CoW variations and WMH burden) of the patients were recorded, and the relationship between the variables was evaluated in both groups. The overall incomplete COW, incomplete anterior or vertebrobasilar portion of the CoW, or the presence of fetal PCA showed no significant difference between the MWoA and MWA groups (p > 0.05). An incomplete posterior portion of the CoW was significantly higher in the MWA group than in the MWoA group (p = 0.034). In the WMA group, the visual aura was present in 72% of patients with the overall incomplete CoW; all of these were posterior portion variations of the CoW. When the WMH burden was compared, no significant difference was seen between the MWoA and MWA groups (p > 0.05). Among patients with the CoW variations in the MWoA group, the rate of patients without WMHs was significantly higher (p = 0.030). No significant difference was observed between the CoW variations and WMH burden in the MWA group (p > 0.05). In conclusion incomplete posterior portion of the CoW is common in MWA, and this variation is associated with visual aura but unrelated to WMH burden.

Circle of Willis variation and outcome after intra-arterial treatment

BackgroundIntra-arterial treatment (IAT) improves outcomes in acute ischaemic stroke. Presence of collaterals increases likelihood of good outcome. We investigated whether variations in the circle of Willis (CoW) and contributing carotid...

Detailed study of arterial variations in circle of Willis among migraine and non migrainous patients in Western Uttar Pradesh

Background: The human brain represents 2% of human body weight. It is supplied by two major arteries, paired internal carotid arteries and vertebral arteries. The arterial circle of Willis forms a polygonal anastomotic channel between two internal carotid artery and two vertebral arteries. The arterial circle is situated at the base of the brain in the interpeduncular fossa. Dr. Thomas Willis who first described the function of arterial anastomosis in 1966. Aim: To study the incidence of arterial variations in circle of willis among migraine patients of Western U.P. Methodology: Present study was conducted in the Department of Anatomy, Santosh Medical College Ghaziabad in collaboration with the Department of Radiodiagnosis, Rama Medical College & Hospital, Ghaziabad and from Dr. O.P Gupta Imaging Centre, Meerut. A total of 132 patients were scanned and 3D TOF sequence has been taken for MRA (BRAIN) examination.3D angiogram was reviewed for variation in brain. Results: The complete circle of Willis was absent among16.7% Migraine patients and 12.2% in non migrainous patients. The anterior communicating artery (A.com.) was absent in 26.7% migrainespatients and Anterior communicating artery were present in 73.3% in migrainous patients.

Relationship between Circle of Willis Variations and Cerebral or Cervical Arteries Stenosis Investigated by Computer Tomography Angiography and Multitask Convolutional Neural Network.

Circle of Willis (CoW) is the most critical collateral pathway that supports the redistribution of blood supply in the brain. The variation of CoW is closely correlated with cerebral hemodynamic and cerebral vessel-related diseases. But what is responsible for CoW variation remains unclear. Moreover, the visual evaluation for CoW variation is highly time-consuming. In the present study, based on the computer tomography angiography (CTA) dataset from 255 patients, the correlation between the CoW variations with age, gender, and cerebral or cervical artery stenosis was investigated. A multitask convolutional neural network (CNN) was used to segment cerebral arteries automatically. The results showed the prevalence of variation of the anterior communicating artery (Aco) was higher in the normal senior group than in the normal young group and in females than in males. The changes in the prevalence of variations of individual segments were not demonstrated in the population with stenosis of the afferent and efferent arteries, so the critical factors for variation are related to genetic or physiological factors rather than pathological lesions. Using the multitask CNN model, complete cerebral and cervical arteries could be segmented and reconstructed in 120 seconds, and an average Dice coefficient of 78.2% was achieved. The segmentation accuracy for precommunicating part of anterior cerebral artery and posterior cerebral artery, the posterior communicating arteries, and Aco in CoW was 100%, 99.2%, 94%, and 69%, respectively. Artificial intelligence (AI) can be considered as an adjunct tool for detecting the CoW, particularly related to reducing workload and improving the accuracy of the visual evaluation. The study will serve as a basis for the following research to determine an individual's risk of stroke with the aid of AI.

The Features of the Circle of Willis and Cerebral Aneurysm in Patients with Cerebral Aneurysms through Films of Multi- slice Computed Tomography

This paper studies the features of the circle of Willis and cerebral aneurysm in patients with cerebral aneurysms through films of Multi-slice Computed Tomography (MSCT) at the Department of Radiology, Bach Mai Hospital, from March 2017 to March 2018. The study results show that female/male ratio was 2.37: 1; the number of patients with only one aneurysm accounted for 90.68%; Saccular aneurysm was more common than lozenge-shaped aneurysm; the rate of aneurysm ruptures was 82.35%; the bulge was mainly distributed in the carotid artery (94.6%). The very small bulge (less than 3mm) and the small bulge (3-7mm) were most common and accounted for 33.33% and 49.62%, respectively. The variations of the circle of Willis were very diverse and complex, including 13 forms, four of which were the circle of Willis anterior part variants and nine transformations were the circle of Willis posterior variants. Abnormalities (aplasia, hypoplasia) of the anterior communicating arterial were 8.48% and abnormalities of the posterior communicating arterial were 82.6%. The paper concludes that the abnormal anatomical variations in the circle of Willis can facilitate the early diagnosis and treatment of cerebral aneurysm disease.
 Keywords
 Circle of Willis, cerebral aneurysm, MSCT.
 References
 [1] C.S. Hee, L.J. Ye, R.K. Hwa, et al. Diagnosis of Cerebral Aneurysm Via Magnetic Resonance Angiography Screening: Emphasis on Legal Responsibility Increases False Positive Rate, Neurointervention 13(1) (2018) 48-53. [2] T.A. Tuan, Research the value of the diagnosis of cerebral aneurysm by 64 slices computer tomography, Graduate thesis in resident doctor, Hanoi Medical University, 2008 (in Vietnamese).[3] M.W. Son, J.W. Park, K.J. Park, et al, Prognostic Factors of Clinical Outcome after Aneurysmal Clipping in the Aged Patients with Unruptured Intracranial Aneurysm, Journal of Neurointensive Care 3(1) (2020) 20-25. [4] H.M. Tu, N.X. Khoa, Study on the anatomical changes of the cerebral arteries on the MSCT 64 imaging, Thesis Master of Medicine, Hanoi Medical University, 2012 (in Vietnamese).[5] Z. Molnar, W. Thomas (1621-1675), the founder of clinical neuroscience, Nat Rev Neurosci 5(4) (2004) 329-335. [6] Q. Li, J. Li, F. Lv, et al., A multidetector CT angiography study of variations in the circle of Willis in a Chinese population, J Clin Neurosci. 18(3) (2011) 379–383.[7] A. Karatas, G. Coban, C. Cinar, et al., Assessment of the Circle of Willis with Cranial Tomography Angiography, ed Sci Monit. 21 (2015) 2647–2652, [8] S.A. Gunnel, M.S. Farooqui, R.N. Wabale, Anatomical variations of the circulus arteriosus in cadaveric human brains, Neurol Res Int.: 687281, http://doi.org/10.1155/2014/687281, indexed in Pubmed: 24891951 (2014).[9] I.Ö. Yeniçeri, Circle of Willis variations and artery diameter measurements in the Turkish population, Via Medica 76 (3) (2017) 420–425.

Circle of Willis Variation: Implications for Aneurysm, Atherosclerosis, and Stroke

Arterial variations within the Circle of Willis, especially hypoplastic arteries, are linked to intracranial aneurysm, atherosclerosis, and stroke; therefore, the study of Circle of Willis variants are of clinical importance. In a sample of 116 cadavers, the arteries comprising the Circle of Willis were directly observed and assessed for hypoplasia, hyperplasia, aplasia, duplication, triplication, and plexiform structure. A total of 53 different arterial patterns of the Circle of Willis were identified. The most common vascular pattern was one with no noteworthy variation of the arteries, which occurred in 34.48% (40:116) of the sample. The second most common pattern was a right hyperplastic posterior communicating artery, with concomitant right hypoplastic P1 and right hyperplastic P2 vessels which occurred in 3.45% (4:116) of cadavers. The most common variation of an individual artery, regardless of concomitant variations, was a hyperplastic right posterior communicating artery, which occurred in 19.8% (23:116) of the sample. Similarly, a right hyperplastic P2, right hyperplastic posterior communicating artery, left hypoplastic P1, and left hyperplastic posterior communicating artery each occurred in 18.1% (21:116) of cadavers. A duplicated anterior communicating artery was observed in 12.9% (15:116) of cadavers. Aplasia was only observed in the posterior communicating artery (left‐sided: 7.8%; 9:116, right‐sided: 6.0%; 7:116). The results of this study provide a clearer understanding of the variant vascular patterns of the Circle of Willis that create predisposition for aneurysm, atherosclerosis, and stroke.Support or Funding InformationWest Virginia University, Oman Medical College and West Liberty UniversityThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Circle of Willis variations in migraine patients with ischemic stroke.

ObjectivesMigraine is a risk factor for stroke, which might be explained by a higher prevalence in anatomical variants in the circle of Willis (CoW). Here, we compared the presence of CoW variants in patients with stroke with and without migraine.Materials and MethodsParticipants were recruited from the prospective Dutch acute Stroke Study. All participants underwent CT angiography on admission. Lifetime migraine history was assessed with a screening questionnaire and confirmed by an interview based on International Classification of Headache Disorders criteria. The CoW was assessed for incompleteness/hypoplasia (any segment <1 mm), for anterior cerebral artery asymmetry (difference > 1/3), and for posterior communicating artery (Pcom) dominance (Pcom–P1 difference > 1/3). Odds ratios with adjustments for age and sex (aOR) were calculated with logistic regression.ResultsWe included 646 participants with stroke, of whom 52 had a history of migraine. Of these, 45 (87%) had an incomplete or hypoplastic CoW versus 506 (85%) of the 594 participants without migraine (aOR: 1.47; 95% CI: 0.63–3.44). There were no differences between participants with and without migraine in variations of the anterior or posterior CoW, anterior cerebral artery asymmetry (aOR: 0.86; 95% CI: 0.43–1.74), or Pcom dominance (aOR: 0.64; 95% CI: 0.32–1.30). There were no differences in CoW variations between migraine patients with or without aura.ConclusionWe found no significant difference in the completeness of the CoW in acute stroke patients with migraine compared to those without.

Circle of Willis variations and artery diameter measurements in the Turkish population.

The aim of this study was to evaluate the frequency of circle of Willis (COW) variations and the measurements of the COW vessel diameters in the Turkish population. The patient population for this single-centre, retrospective study was formed of patients who had brain magnetic resonance angiography (MRA). A total of 384 subjects were included in the study. The three-dimensional time-of-flight (TOF) technique was used for MRA imaging to evaluate the anatomy of the COW. Variations in the COW were recorded. The diameters of the critical arteries of the COW were measured. Adult configuration of the COW was determined in 326 (85%) cases, foetal configuration in 50 (13%) cases and transitional configuration in 8 (2%) cases. The COW was normal in 328 (85.4%). In the remaining 56 (14.6%) cases, agenesis was determined in 62 vessels. The mean calibrations of the vessels were measured as 2.85 mm in the basilar artery, 4.24 mm in the right internal carotid artery (ICA), 4.32 mm in the left ICA, 1.58 mm in the right A1, 1.64 mm in the left A1, 2.13 mm in the right M1, 2.10 mm in the left M1, 1.80 mm in the right P1, 1.88 mm in the left P1, 1.12 mm in the right posterior communicating artery, and 1.12 mm in the left posterior communicating artery. Circle of Willis variations may show geographic and ethnic differences. Knowledge of the frequency and types of variation in the population is important for neurosurgeons and in radiological interventional procedures as a guide for entry and in respect of collateral which could develop later.

A multitude of variations in the configuration of the circle of Willis: an autopsy study.

The circle of Willis (CW) is an anastomotic system of arteries located at the base of the brain. The aim of the study was to evaluate the anatomic configuration of the CW in the Polish population and to compare results with previously conducted research. Brains were obtained from 100 recently deceased human adults, and the diameters of cerebral vessels were measured using a slide caliper. Cerebral vessels were observed, paying attention to their origin, diameter, typical configuration and variations. Twenty-seven percent of cases presented the typical literature pattern. The remaining 73% of all cases were atypical; in 16% the CW was incomplete and in 57% complete. Atypical findings involved the posterior communicating artery (PcomA), 62%; anterior communicating artery (AcomA), 22%; anterior cerebral artery (ACA), 14%; posterior cerebral artery (PCA), 8%. The most common variations were bilateral hypoplastic PcomAs (27% of cases) and unilateral hypoplastic PcomAs (19% of cases). Only 9 of the 22 types of CW variations classified previously in the literature were observed, and 26 variations (36 cases) in our study were labeled as 'other' type. Mean diameter values for typical CW patterns were internal carotid artery=3.6mm, ACA=2.3mm, AcomA=1.9mm, PCA=2.2mm and PcomA=1.4mm. Circle of Willis variations have a large impact on clinical practice. This study shows many rare variations that should be taken into consideration to avoid any unexpected complications during surgical procedures involving cerebral vessels.

ASSA14-12-18 Effects of intracoronary diltiazem and sodium nitroprusside on no-reflow phenomenon after percutaneous coronary intervention in patients with acute coronary syndrome

<h3>Introduction and purpose</h3> Current methods to risk stratify patients with unruptured cerebral aneurysms are based on limited natural history data. Circle of Willis variations are thought to contribute to aneurysm development via hemodynamic changes, including increased blood flow. The impact of circle of Willis anomalies on risk of aneurysm rupture is not known. We hypothesized that a circle of Willis anomaly is more commonly seen in ruptured cerebral aneurysms. Our aim was to compare the frequency of circle of Willis anomalies that contribute to increased flow between ruptured and unruptured cerebral aneurysms. <h3>Methods</h3> Over a 2 year period, we identified all patients with an ICD-9 diagnosis code for subarachnoid hemorrhage or non-ruptured cerebral aneurysm admitted to a single urban tertiary care institution. Only patients with anterior communicating artery (ACoA) or posterior communicating artery (PCoA) aneurysms were included in the analysis. Demographic and clinical information was abstracted from patient charts. Catheter cerebral angiograms for all patients were independently reviewed on a picture archiving and communications system (PACS) for aneurysm location and morphology. A submillimeter measurement tool was used on magnified images for measurements of vessel diameter and aneurysm size. Circle of Willis anomalies of the ACoA group were defined as hypoplasia (diameter ≤50% of the dominant A1) or absence of the contralateral A1 segment of the anterior cerebral artery. A circle of Willis anomaly in the PCoA group was defined as the presence of a fetal origin posterior cerebral artery (PCoA diameter greater than the P1 segment of the ipsilateral posterior cerebral artery). χ² test, Student9s t test and multivariate logistic regression analyses were performed to evaluate the association between circle of Willis anomalies and ruptured aneurysms. <h3>Results</h3> During 2008 and 2009, of the 587 patients with ruptured and unruptured cerebral aneurysms, 113 had either an ACoA or PCoA aneurysm and were included in the analysis. Mean age was 57.5 years, 83 (73.5%) patients were female and 85 (75.2%) cases were ruptured aneurysms. Hypertension was present in 77 (68.1%) patients and 70 (61.9%) patients were smokers. There were 49 (43.4%) PCoA aneurysms and 64 (56.6%) ACoA aneurysms. Aneurysm shape was non-spherical in 74 (65.5%) cases. Mean aneurysm size was 5.65 mm (SD 3.31) and mean vessel diameter within anomaly groups was 2.31 mm (SD 0.39) and 1.96 mm (SD 0.52) for the dominant A1 and PCoA, respectively. A circle of Willis anomaly was identified in 46 (40.7%) of all patients. Multivariate regression 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)). <h3>Conclusions</h3> This series suggests that aneurysms associated with a circle of Willis anomaly have an increased risk of rupture compared with aneurysms associated with a normal circle of Willis. Circle of Willis anomalies may increase the risk of aneurysm rupture through hemodynamic changes involving increased flow. Physiologic characterization of blood flow associated with circle of Willis anomalies is warranted. Future studies could establish circle of Willis anomalies as an important determinant in patient selection for preventative aneurysm treatment.

Thalamic Stroke: Precursors and Outcomes for Ten Patients

Objective: The purpose of this study was to examine susceptibility factors in thalamic stroke, as well as outcomes in order to identify rehabilitation needs.Methods: Ten patients with thalamic stroke were interviewed and administered the Audio Recorded Cognitive Screen. Magnetic resonance imaging (MRI) scans were examined to determine location and size of the lesion, as well as basilar artery size and anatomical variances in the circle of Willis.Results: Risk factors such as high cholesterol, high blood pressure and pre-existing heart conditions were identified. Circle of Willis variations were found in 6 of the 10 participants, with MR angiography indicating that the posterior communication artery was absent or failed to join the posterior cerebral artery. Basilar artery diameter measurements were no larger than normal. All participants reported post-stroke changes, including decreased coordination and mobility, poor balance, reduced energy, memory deficits and mood changes. Participants’ overall scores on cognitive tests were significantly lower than age-matched norms. Performance on the test domains of memory, fluency, language and attention were all significantly below age norms.Conclusions: The variability of outcome measures demonstrates the difficulty of defining patterns of relationship between risk factors and severity of functional sequelae in thalamic stroke.

E-020 Circle of Willis anomalies are associated with ruptured cerebral aneurysms

Introduction and purposeCurrent methods to risk stratify patients with unruptured cerebral aneurysms are based on limited natural history data. Circle of Willis variations are thought to contribute to aneurysm development...

Circle of Willis variation in a complex stroke presentation: a case report

BackgroundThe impact of circle of Willis anatomical variation upon the presentation of stroke is probably underrecognised.Case presentationA 63-year-old right-handed woman developed a left hemiparesis and right leg weakness sequentially following a road traffic accident (RTA). Despite initial concern about the possibility of cervical spinal cord injury, the final diagnosis was bilateral artery-to-artery embolic cerebral infarction with dominant right internal carotid artery.ConclusionThe case illustrates the complex presentation of stroke as a pseudo-cervical cord lesion and the impact of circle of Willis anatomical variation upon the expression of large vessel cerebrovascular disease.