BACKGROUND AND PURPOSE Current transcranial Doppler criteria for vasospasm after aneurysmal subarachnoid hemorrhage are not age specific. We analyzed the effect of age on cerebral blood flow velocity changes after subarachnoid hemorrhage and constructed an age-adjusted predictive model of cerebral blood flow velocity in subarachnoid hemorrhage patients. METHODS We identified patients with ane...

background: nitric oxide synthase (nos) activity is increased during hypertension and cerebral ischemia. nos inactivation reduces stroke-induced cerebral injuries, but little is known about its role in blood-brain barrier (bbb) disruption and cerebral edema formation during stroke in acute hypertension. here, we investigated the role of nos inhibition in progression of edema formation and bbb d...

Background and Purpose: Ischemic episodes distal to an internal carotid artery occlusion are common. We undertook this study to look for evidence of transhemispheric passage of embolic material in this patient category as a mechanism for embolic events. Methods: Seven symptomatic patients with unilateral internal carotid artery occlusion and contralateral stenosis were examined by transcranial ...

We report an attempt to obtain images of the basal cerebral arteries and to measure the quantitative flow velocity in these arteries from outside the skull via the color Doppler imaging method. In 25 healthy volunteers, 22-41 years old, the transducer was positioned just superior to the zygomatic arch and anterior to the external ear canal. The absolute flow velocity was calculated by dividing ...

Although the augmentation of central hemodynamics during human sexual intercourse is well established, dynamic changes in human regional cerebral blood flow have not been reported. Noninvasive transcranial Doppler ultrasonography has been well validated and allows direct, continuous measurement of phasic blood velocity in the human middle cerebral artery (a linear index of regional cerebral blo...

In the search for a more reproducible focal ischemic stroke model in the rat, we systematically interrupted blood flow to the right middle cerebral artery territory by ligating the right middle cerebral artery, and the right and left common carotid arteries in succession. Using a laser-Doppler flowmeter, we found that the relative surface blood flow in cerebral cortex supplied by the right midd...

BACKGROUND Caffeine is present in a variety of beverages and food and is widely consumed. In a previous study of patients recovering from an acute ischaemic stroke using transcranial Doppler ultrasound we demonstrated a fall in middle cerebral artery blood velocity of 12% following ingestion of 250 mg caffeine. The aim of this study was to investigate if this velocity change reflected a change ...

PURPOSE To characterize cerebral hemodynamics in patients immediately before microsurgical resection of moderate to large arteriovenous malformations during isoflurane anesthesia. METHODS In angiographically defined arteriovenous malformation feeding and nonfeeding arteries, transcranial Doppler studies were performed in 25 surgeries on 22 patients. The mean blood flow velocity and pulsatilit...

INTRODUCTION Transcranial Doppler is an effective diagnostic tool to detect sickle cell children at risk for stroke. METHODS We conducted a cross-sectional descriptive study of Malagasy children aged between 24 months and 15 years (group 1: 57 sickle cell diseases, group 2: 43 controls) to assess the cerebral artery velocimetry in the patient population. Transcranial doppler ultrasound with a...

BACKGROUND Environmental factors interfere on sickle cell anaemia (SCA). Transcanial Doppler (TCD) is important to evaluate cerebrovascular disease. OBJECTIVE To evaluate brain haemodynamic profile of children with SCA in Sergipe. METHODS Cross sectional study (group1: SCA patients aged 3-18; group2: age and sex matched healthy individuals). Baseline brain flow was evaluated. RESULTS Grou...