PURPOSE To determine the accuracy of transcranial Doppler (TCD) ultrasound for evaluation of collateral supply through the circle of Willis in patients with internal carotid artery (ICA) occlusion. METHODS The evaluation of the collateral pathways through the circle of Willis with TCD ultrasound and with cerebral angiography was compared in 40 patients (30 men, 10 women; mean age, 55 +/- 9 ye...

Direct endovascular access to the anterior cerebral artery (ACA) with a guidewire and catheter is not always possible. A C-shaped guidewire advanced as a loop into the middle cerebral artery and then withdrawn to advance the guidewire into the ACA is a way to gain endovascular access to the ACA when the direct approach is unsuccessful.

To further define the sensory projections to the circle of Willis, we measured concentrations of immunoreactive substance P in pial arteries of cats following either bilateral removal of the C1-3 dorsal root ganglia (six cats) or bilateral removal of the trigeminal ganglia (three cats). Removal of the dorsal root ganglia decreased concentrations of the tachykinin substance P in the vertebral ar...

· Posterior Circulation Two vertebral arteries originate from the first part of the subclavian arteries. These join intra-cranially to form the basilar artery and supply the posterior cerebral circulation. This is the main blood supply to the brain stem, cerebellum and posterior cerebrum. · Anterior Circulation Both internal carotid arteries arise from the carotid bifurcation in the neck. Intra...

BACKGROUND AND PURPOSE In childhood-onset moyamoya disease, the angiographic disease process of stenoocclusive lesions is progressive, and cerebral infarctions often develop as a result of ischemia. Our purpose was to determine how the severity of stenoocclusive lesions in the anterior and posterior circulations affects the distribution of cerebral infarction in patients with childhood-onset mo...