A case of aneurysm of the extra-cranial section of the internal carotid artery extending to the base of the skull is described. Treatment comprised proximal vessel ligation, the tolerance of the patient's cerebral circulation to this procedure first being assessed by measuring the back pressure across the circle of Willis after temporary carotid artery occlusion. The value of this technique is ...

The case is reported of a 7-year-old Czech boy with an obliterating disorder of the large intracranial arteries with formation of an extensive collateral network of blood vessels of the `rete mirabile' type. It is analogous to cases described under the names `abnormal cerebrovascular network', `occlusion of the circle of Willis', or the `moyamoya disease' by Japanese authors.

Human immunodeficiency virus (HIV)-associated cerebral aneurysmal arteriopathy is described in the pediatric medical literature and features diffuse fusiform aneurysms of the arteries of the circle of Willis. We present the first report (to our knowledge) of this disease entity in an adult, a 29-year-old woman with acquired immunodeficiency syndrome who presented with subarachnoid hemorrhage.

BACKGROUND AND PURPOSE The presence of collaterals is associated with a reduced risk of stroke and transient ischemic attack in patients with steno-occlusive carotid artery disease. Although metabolic syndrome negatively impacts collateral status, it is unclear whether and to what extent type 2 diabetes mellitus affects cerebral collateral flow regulation during hypoperfusion. METHODS We exam...

Neuropathological changes associated with Alzheimer's disease (AD) such as amyloidplaques, cerebral amyloid angiopathy, and related pathologies are reproduced in APP23 transgenic mice overexpressing amyloid precursor protein (APP) with the Swedish mutation. Magnetic resonance angiography (MRA) was applied to probe, in vivo, the cerebral arterial hemodynamics of these mice. Flow voids were detec...

Many cases of spontaneous occlusion of the circle of Willis (moyamoya disease) have been reported in Japan, but the worldwide distribution is unclear. The total number of cases in each country reported in the literature and complications were evaluated. A total of 1063 cases have occurred worldwide excluding Japan. Cases were observed most frequently in Asia and in people of non-Caucasian origin.

BACKGROUND AND PURPOSE We sought to investigate whether preoperative volume flow in the internal carotid arteries (ICAs), the basilar artery (BA), and the middle cerebral arteries (MCAs) and collateral flow via the circle of Willis differ between patients who do and patients who do not develop cerebral ischemia during clamping of the carotid artery in carotid endarterectomy (CEA). METHODS Qua...

A computational fluid dynamics (CFD) approach is presented to model the blood flow through the human circulatory system under altered gravity conditions. Models required for CFD simulation relevant to major hemodynamic issues are introduced such as non-Newtonian flow models governed by red blood cells, a model for arterial wall motion due to fluid-wall interactions, a vascular bed model for out...

Power-based transcranial color-coded sonography and contrast-enhanced transcranial color-coded sonography are ultrasonographic techniques that allow improved visualization of vascular structures. The present study was designed to investigate and compare the diagnostic capacity and applicability of both methods in the assessment of intracranial vessels of the circle of Willis (33 patients) and t...

BACKGROUND AND PURPOSE We sought to investigate the relation between collateral flow via different pathways and hemodynamic parameters measured by dynamic susceptibility contrast-enhanced MRI in patients with severe carotid artery disease. METHODS Dynamic susceptibility contrast-enhanced MRI was performed in 66 patients and 33 control subjects. Patients had severe stenosis (>70%, n=12), unila...