circle of Willis


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Noun1.circle of Willis - a ring of arteries at the base of the brain
arteria, arterial blood vessel, artery - a blood vessel that carries blood from the heart to the body
brain, encephalon - that part of the central nervous system that includes all the higher nervous centers; enclosed within the skull; continuous with the spinal cord
References in periodicals archive ?
The Circle of Willis was assessed for its completeness along with anatomical variations of anterior and posterior components of the circle.
This is important because the relative isolation of the MCA territory leaves the cerebral hemisphere ipsilateral to the absent ICA susceptible to injury, due to lack of collateral flow from the circle of Willis.
The anterior, middle, and posterior cerebral arteries that emanate from the circle of Willis may show varying degrees of stenosis or occlusion.
Incompleteness of circle of Willis is associated with a more frequent occurrence of neurological symptomatology or ischemic lesions of brain parenchyma in the operated patients with significant extracranial carotid stenosis
PCA arising from ICA represents foetal condition, variations in the sizes of the vessels of circle of Willis, variations in the ACoA Anatomy for surgeons," 1st Edu Vol 1 (head and neck) 32-40, Pub: medical book department of Harper & Brothers, New York, 1961.
In most cases, PTA and its variants have been found incidentally but can be associated with numerous anomalies in the cerebral vasculature, including arteriovenous malformation, aneurysms of the circle of Willis, carotid and vertebral artery agenesis, carotidcavernous fistula, and moyamoya disease [3, 7].
Moyamoya disease is a rare, progressive cerebrovascular disorder secondary to arterial obstruction at the proximal Circle of Willis arteries.
In a study of 170 people from three groups - a control group with no headaches, those who had migraine with aura, and those who had migraine without aura - the team found that an incomplete circle of Willis was more common in people with migraine with aura (73 percent) and migraine without aura (67 percent), compared to a headache-free control group (51 percent).
Background: The circle of Willis, present in the interpeduncular cistern at the base of the brain, is the major source of blood supply of the brain.
Researchers agree that the circle of Willis is one of the most important parts of the collateral circulatory system of the brain.
Methodology: The images of diffusion weighted imaging (DWI), DSC and ASL in 36 cases of TIA patients with unilateral MCA stenosis and 35 healthy volunteers were analyzed retrospectively to assess collateral flow in the circle of Willis, and to analyze the perfusion differences between ASL and DSC.