3,678 results match your criteria Circle of Willis


The Role of Hemodynamics through the Circle of Willis in the Development of Intracranial Aneurysm: A Systematic Review of Numerical Models.

J Pers Med 2022 Jun 20;12(6). Epub 2022 Jun 20.

Department of Neurosurgery, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands.

The role of regional hemodynamics in the intracranial aneurysmal formation, growth, and rupture has been widely discussed based on numerical models over the past decades. Variation of the circle of Willis (CoW), which results in hemodynamic changes, is associated with the aneurysmal formation and rupture. However, such correlation has not been further clarified yet. Read More

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Surpass Evolve Flow Diverter for the Treatment of Intracranial Aneurysm: A Systematic Review.

Brain Sci 2022 Jun 20;12(6). Epub 2022 Jun 20.

College of Medicine and Health Sciences, Khalifa University, Abu Dhabi P.O. Box 127788, United Arab Emirates.

Purpose: This systematic review aims to summarize the evidence investigating the effectiveness and safety of the Surpass Evolve-Flow Diverter (SE-FD) to treat brain aneurysms.

Method: We searched MEDLINE, EMBASE, CINAHL, Web of Science, and Cochrane Library from January 2019 to 29 March 2022. Terms related to the "intracranial aneurysm" and "surpass evolve flow diverter" concepts were used to search the databases; Medical Subject Headings (MeSH) and reference hand search were also utilized. Read More

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Moyamoya syndrome and stroke among pediatric sickle cell disease patients in Sudan: A cross-sectional study.

Ann Med Surg (Lond) 2022 Jun 21;78:103815. Epub 2022 May 21.

Ribat Neurospine Center, Ribat University Hospital, The National Ribat University, Khartoum, Sudan.

Background: Sickle cell disease (SCD) is autosomal recessive hemolytic anemia due to hemoglobinopathy commonly in Sub-Saharan Africa, and particularly in Sudan. The disease induces a pro-inflammatory cascade in the intimal layer that leads to hyperplasia and progressive stenosis in the major vessel of the circle of Willis. This is associated with the development of Moyamoya collaterals. Read More

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Endovascular treatment of patients with acute ischemic stroke and tandem occlusion due to internal carotid artery dissection: A multicenter experience.

Neuroradiol J 2022 Jun 14:19714009221108673. Epub 2022 Jun 14.

Diagnostic Imaging Unit, Department of Biomedicine and Prevention, 9318University of Rome Tor Vergata, Italy.

Background: The optimal management of patients with acute ischemic stroke (AIS) due to tandem occlusion (TO) and underlying carotid dissection (CD) remains unclear.

Objective: We present our multicenter-experience of endovascular treatment (EVT) approach used and outcomes for AIS patients with CD-related TO (CD-TO).

Methods: Consecutive AIS patients underwent EVT for CD-TO at five Italian Neuro-interventional Tertiary Stroke Centers were retrospectively identified. Read More

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Moyamoya syndrome presenting in an adult with Down syndrome: A case report with a literature review.

Radiol Case Rep 2022 Aug 4;17(8):2798-2801. Epub 2022 Jun 4.

Department of Neurology, Mohammed V Military Instruction Hospital, Rabat, Morocco.

Moyamoya disease is an unusual occlusive cerebrovascular condition commonly seen in children, marked by stenosis of the internal carotid artery and circle of Willis, causing, cerebral ischemia. Moyamoya syndrome is a Moyamoya-like arteriopathy with risk factors including autoimmune disorders, thyroid disease, sickle cell disease, or Down syndrome. Trisomy 21 is a genetic disorder consistent with specific physical and behavioral characteristics, with intellectual impairment. Read More

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Collateral Flow in Intracranial Atherosclerotic Disease.

Transl Stroke Res 2022 Jun 8. Epub 2022 Jun 8.

Department of Medicine and Therapeutics, The Chinese University of Hong Kong, The Prince of Wales Hospital, Hong Kong SAR, China.

Intracranial atherosclerotic disease (ICAD) is a major cause of ischemic stroke and transient ischemic attack (TIA) worldwide. The culprit of ICAD is frequently a high-grade intracranial atherosclerotic stenosis (ICAS) pertaining to the infarct territory, and by then, the ICAS is described as symptomatic. A high-grade ICAS may progressively limit cerebral perfusion downstream, demanding collateral compensation. Read More

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Changes in cerebral oxygenation during hemodialysis before and after carotid artery stenting.

Radiol Case Rep 2022 Aug 27;17(8):2589-2593. Epub 2022 May 27.

Division of Nephrology, First Department of Integrated Medicine, Saitama Medical Center, Jichi Medical University, Saitama, Japan.

A 68-year-old man received hemodialysis (HD) for the treatment of end-stage renal failure for 6 years. Five years prior to carotid artery stenting (CAS), a neck ultrasound performed to screen for carotid atherosclerosis revealed an asymptomatic right internal carotid artery stenosis. One month prior, the stenotic lesion progressed to 74% by cerebral angiography; therefore, CAS was performed. Read More

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Incomplete circle of Willis variants and stroke outcome.

Eur J Radiol 2022 Aug 30;153:110383. Epub 2022 May 30.

Brain Health Imaging Institute, Department of Radiology, Weill Cornell Medicine, New York, NY, USA.

Background: There is considerable variation in circle of Willis morphology among the general population, and these variations have been correlated with risk of aneurysms, cerebral ischemia, and other clinical events.

Purpose: To investigate the relationship between circle of Willis variants and stroke outcome.

Materials And Methods: We performed a retrospective study involving 297 patients from our institution's acute stroke academic registry. Read More

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Clinical Significance of Intracranial Aneurysms in Adult Moyamoya Disease.

World Neurosurg 2022 May 26. Epub 2022 May 26.

Department of Neurosurgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea.

Objective: We present the relationship between an aneurysm in adult moyamoya disease (MMD) patients and a future stroke event.

Methods: One hundred forty-seven aneurysms were found in 118 adult MMD patients. To find risk factors for future hemorrhagic and ischemic stroke, Kaplan-Meier and Cox-regression analyses were performed on clinical and radiologic factors. Read More

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Diagnostic Criteria for Moyamoya Disease - 2021 Revised Version.

Neurol Med Chir (Tokyo) 2022 May 25. Epub 2022 May 25.

Department of Neurosurgery, Kyoto University Graduate School of Medicine.

In this report, we, the Research Committee on Moyamoya Disease (Spontaneous Occlusion of the circle of Willis), describe in detail the changes in the new "Diagnostic Criteria 2021" for moyamoya disease and its scientific basis to make it widely known to the world. The revised criteria cover all aspects of the disease, including a definition of the disease concept, diagnostic imaging, and the concept of quasi-moyamoya disease (moyamoya syndrome). Read More

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Chronic Cognitive and Cerebrovascular Function Following Mild Traumatic Brain Injury in Rats.

J Neurotrauma 2022 May 20. Epub 2022 May 20.

Phoenix VA Health Care System, 19969, Phoenix, Arizona, United States.

Severe traumatic brain injury (TBI) results in cognitive dysfunction in part due to vascular perturbations. In contrast, the long-term vasculo-cognitive pathophysiology of mild TBI (mTBI) remains unknown. We evaluated mTBI effects on chronic cognitive and cerebrovascular function and assessed their interrelationships. Read More

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The Association between Migraine and Fetal-Type Posterior Cerebral Artery in Patients with Ischemic Stroke.

Cerebrovasc Dis 2022 May 13:1-7. Epub 2022 May 13.

Department of Neurology, Jinling Hospital, The First School of Clinical Medicine, Southern Medical University, Nanjing, China.

Objective: The aim of the study was to determine if migraine is associated with fetal-type posterior cerebral artery (PCA) in patients with ischemic stroke.

Method: In this cross-sectional study, patients with acute ischemic stroke were enrolled from two hospitals. The history of migraine headache was evaluated during a face-to-face interview. Read More

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Asymmetry in cerebral perfusion from circle of Willis arterial variations in normal population.

Neuroradiol J 2022 May 4:19714009221098366. Epub 2022 May 4.

Department of Radiodiagnosis and Imaging, 29751PGIMER, Chandigarh, India.

Background: Angiographic and cadaveric studies have evidenced variations in the circle of Willis (CoW). Age-related changes in cerebral hemodynamics may be attributable to vascular variations.

Objectives: The objective is to assess interdependence of completeness of CoW with age using non-invasive MRA and cerebral perfusion using arterial spin labeling (ASL). Read More

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Endovascular coiling of recurrent trapped pseudoaneurysm of petrous ICA across the distal barrier: When the other way round is the only way around!

Neuroradiol J 2022 May 2:19714009221096835. Epub 2022 May 2.

Department of Radiodiagnosis, (Division of Neuroradiology), 29751Post Graduate Institute of Medical Education and Research, Chandigarh, India.

Background: The pseudoaneurysms of the internal carotid artery (ICA) at the skull base form a unique subset of craniofacial pseudoaneurysms with varied diagnostic and therapeutic challenges. Recurrence in a surgically treated pseudoaneurysm may become a nightmare due to very limited number of open and endovascular options.

Report: We report a rare case of recurrent pseudoaneurysm of petrous ICA, which presented with massive epistaxis following an initial successful occlusion by surgical trapping of the parent arterial segment with surgical clip. Read More

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Risk Factors of Impaired Perfusion in Patients With Symptomatic Internal Carotid Artery Steno-Occlusive Disease.

Front Neurol 2022 14;13:801413. Epub 2022 Apr 14.

Jinzhou Medical University General Hospital of Northern Theatre Command Postgraduate Training Base, Shenyang, China.

Objective: To quantitatively evaluate the impaired perfusion status of patients with symptomatic internal carotid artery (ICA) steno-occlusive disease and to explore the risk factors of impaired perfusion with computed tomography perfusion (CTP).

Methods: The clinical and imaging data of 187 patients with ICA steno-occlusive disease were retrospectively analyzed. The ICA stenosis rate was divided into Grades I-IV (70-79%; 80-89%; 90-99%; 100%), and the circle of Willis was classified as four types (types I-IV). Read More

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A Retrospective Study of 320 Patients Treated with Carotid Artery Stenting at 4 General Hospitals in Zhejiang Province to Establish a Risk Score for Cerebral Hypoperfusion Syndrome.

Med Sci Monit 2022 Apr 25;28:e935697. Epub 2022 Apr 25.

Department of Neurosurgery, Hangzhou Third People's Hospital, Hangzhou, Zhejiang, China (mainland).

BACKGROUND Cerebral hypoperfusion syndrome (CHS) includes a spectrum of clinical symptoms, ranging from focal neurologic deficit to intracerebral hemorrhage. CHS was initially described as a complication of carotid endarterectomy but also occurs following carotid artery stenting. This retrospective study included 320 patients treated with carotid artery stenting at 4 general hospitals in Zhejiang Province between June 2019 and June 2021 and aimed to establish a risk score for CHS. Read More

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Risk for Additional Infarction in Emergency Carotid Artery Endarterectomy in Thrombectomy Acute Stroke Patients.

Vasc Endovascular Surg 2022 Apr 23:15385744221095669. Epub 2022 Apr 23.

Department of Neuroradiology, University Hospital, 569121RWTH Aachen University, Aachen, Germany.

Thromboembolic occlusion of the middle cerebral artery with tandem occlusion of the internal carotid artery is a life-threatening condition with unfavorable neurological outcome. We perform emergency carotid endarterectomy in the same anesthesia session as thrombectomy in our angiography suite whenever needed despite the absence of electrophysiological neuromonitoring. We evaluated 47 thrombectomy patients with emergency CEA in our clinic between June 2013 and November 2020. Read More

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Emergency extra-intracranial bypass surgery in a patient with neurologic deficit after an accident in carotid occlusive test: A case report.

Int J Surg Case Rep 2022 May 12;94:107071. Epub 2022 Apr 12.

Global Brainsurgery Initiative, Washington, DC, USA; Neurosurgery at Lehigh Valley Health Network, Allentown, PA, USA. Electronic address:

Objective: BTO is the procedure performed to assess the collateral circulation within the Willis circle in a giant ICA aneurysm. An ICA occlusion after BTO is very rare. We present a case of an internal carotid artery occlusion as a complication of BTO that required urgent revascularization surgery. Read More

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Bilateral Giant Familial Carotid Body Tumors With Concomitant Skull-Base Paraganglioma and Facial Nerve Palsy.

Tex Heart Inst J 2022 03;49(2)

Division of Cardiothoracic Surgery, National Cardiothoracic Center of Excellence, University of Nigeria Teaching Hospital, Ituku-Ozalla, Enugu, Nigeria.

Carotid body tumors, rare neck paragangliomas arising from the common carotid artery bifurcation, can be classified as sporadic, hyperplastic, or familial. The familial type is often bilateral and associated with germline mutation of the mitochondrial enzyme succinate dehydrogenase. We report the rare case of a 42-year-old man who presented with bilateral giant familial carotid body tumors associated with a concomitant skull-base paraganglioma, left-sided facial nerve palsy, and an incomplete circle of Willis. Read More

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The "Hand as Foot" teaching method in Brain Willis circle anatomy.

Asian J Surg 2022 Apr 14. Epub 2022 Apr 14.

Department of Neurosurgery, Binzhou Medical University Hospital, No. 661 Huanghe 2nd Road, Binzhou, Shandong, 256603, China. Electronic address:

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Flow control in the middle cerebral artery during thrombectomy: the effect of anatomy, catheter size and tip location.

J Neurointerv Surg 2022 Apr 12. Epub 2022 Apr 12.

Department of Diagnostic and Interventional Neuroradiology, University Hospital Aachen, Aachen, Nordrhein-Westfalen, Germany

Background: Catheter size, location and circle of Willis anatomy impact the flow conditions during interventional stroke therapy. The aim of the study was to systematically investigate the influence of these factors on flow control in the middle cerebral artery by means of a computational model based on 100 patients with stroke who received endovascular treatment.

Methods: The dimensions of the cervical and intracranial cerebral arteries of 100 patients who received endovascular mechanical thrombectomy for acute ischemic stroke were measured and a three-dimensional model of the circle of Willis was created based on these data. Read More

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Neck dissection with carotid artery resection after insertion of a protective endovascular covered stent for recurrent head and neck cancer: a case report.

Int Cancer Conf J 2022 Apr 1;11(2):119-123. Epub 2022 Feb 1.

Department of Head and Neck Surgery, Miyagi Cancer Center, 47-1 Nodayama, Medeshima-Shiode, Natori, Miyagi 981-1293 Japan.

Head and neck cancer involving the carotid artery is usually unresectable. Such involvement often leads to exposure of the carotid artery and the risk of its blow-out. Carotid covered stent placement may be effective in preventing carotid blow-out; however, thus far, there are few published reports of this procedure. Read More

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Age-related changes in the completeness of the circle of Willis in children.

Childs Nerv Syst 2022 Jun 8;38(6):1181-1184. Epub 2022 Apr 8.

Neuroradiology, Children's Hospital Colorado, Aurora, USA.

Purpose: The circle of Willis is a circulatory anastomosis that supplies blood to the brain. If any of the bridging segments are hypoplastic or absent, the capacity for collateral flow in the setting of large vessel occlusion may be decreased. Outside of the neonatal period, the prevalence of a complete circle of Willis (CoW) in the pediatric population has not been well described. Read More

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Evolution of Extracranial Internal Carotid Artery Disease in Children With Sickle Cell Anemia.

Stroke 2022 Apr 7:101161STROKEAHA121037980. Epub 2022 Apr 7.

Referral Center for Sickle Cell Disease, Department of Pediatric Imaging, Robert-Debre Hospital, AP-HP, Nord, Paris University, France. (S.V., C.O., I.C., S.B., A.K., A.N., H.O., A.T., A.S., N.B., M.E., M.A.).

Background: Cerebral arteriopathy in patients with sickle cell anemia mainly affects the intracranial anterior circulation. However, the extracranial internal carotid artery (eICA) can also be stenosed and responsible for ischemic lesions. In children with sickle cell anemia, we perform routine annual Doppler ultrasound assessment of the eICA and magnetic resonance imaging with 3-dimensional time-of-flight magnetic resonance angiography of the Willis circle and neck arteries in those with abnormal velocity. Read More

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Atheromatosis of the brain-supplying arteries: Circle of Willis, basilar, vertebral and their branches.

Ann Anat 2022 Aug 1;243:151941. Epub 2022 Apr 1.

Department of Anatomy and Embryology, School of Medicine, Complutense University of Madrid, Madrid, Spain.

Purpose: Atherosclerotic plaques in the brain-supplying arteries are slowly-developing alterations of vascular structures that can lead to neurological impairment due to stenosis and insufficient oxygenation of eloquent brain areas. The aim of this study is to provide detailed demographic information related to the incidence of atherosclerotic plaques in the cerebral arteries.

Material And Methods: Forty-eight circles of Willis (21 men, 21 women, mean age: 70. Read More

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Endovascular treatment of ischemic stroke due to isolated internal carotid artery occlusion: ETIS registry data analysis.

J Neurol 2022 Mar 31. Epub 2022 Mar 31.

Department of Neurology, CHRU Gui de Chauliac, University Hospital of Montpellier, 80 Avenue Augustin Fliche, 34295, Montpellier, France.

Background: The best treatment for acute ischemic stroke (AIS) due to isolated cervical internal carotid artery occlusion (CICAO) (i.e., without associated occlusion of the circle of Willis) is still unknown. Read More

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Embryology of the anterior communicating artery complex: implications on possible adult variants.

Surg Radiol Anat 2022 May 31;44(5):737-748. Epub 2022 Mar 31.

Department of Neurosurgery, Regional Hospital of Lugano, Neurocenter of the Southern Switzerland, Via Tesserete 46, CH-6903, Lugano, Switzerland.

The anterior cerebral artery (ACA) and the anterior communicating artery (AComA) are important arteries of the telencephalon and are prominent location for cerebral aneurysms. Their embryological development is closely linked, and explains the possible variants seen in adults. In this paper, we present details related to the development of these two arteries, focusing on some variants such as the infra-optic course of the ACA, the unpaired ACA, and the persistent primitive olfactory artery. Read More

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