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Transcranial Doppler evaluates cerebral hemodynamics in patients with brain injury and is a useful technical tool in diagnosing cerebral circulatory arrest, usually present in the brain-dead patient. This Latin American Consensus was formed by a group of 26 physicians experienced in the use of transcranial Doppler in the context of brain death. The purpose of this agreement was to make recommendations regarding the indications, technique, and interpretation of the study of transcranial ultrasonography in patients with a clinical diagnosis of brain death or in the patient whose clinical diagnosis presents difficulties; a working group was formed to enable further knowledge and to strengthen ties between Latin American physicians working on the same topic. A review of the literature, concepts, and experiences were exchanged in two meetings and via the Internet. Questions about pathophysiology, equipment, techniques, findings, common problems, and the interpretation of transcranial Doppler in the context of brain death were answered. The basic consensus statements are the following: cerebral circulatory arrest is the final stage in the evolution of progressive intracranial hypertension, which is visualized with transcranial Doppler as a ?pattern of cerebral circulatory arrest?. The following are accepted as the standard of cerebral circulatory arrest: reverberant pattern, systolic spikes, and absence of previously demonstrated flow. Ultrasonography should be used - in acceptable hemodynamic conditions - in the anterior circulation bilaterally (middle cerebral artery) and in the posterior (basilar artery) territory. If no ultrasonographic images are found in any or all of these vessels, their proximal arteries are acceptable to be studied to look for a a pattern of cerebral circulatory arrest. [ABSTRACT FROM AUTHOR]

Introduction: The intracranial Atherosclerosis disease represents a frequent cause of ischemic stroke in which the study with transcranial Doppler constitutes an important tool for the diagnosis. Case report: Male of 39 years old referred to consultation with a history of stroke of uncertain cause. The rmagnetic resonance image demonstrated a left striatum-capsular infarction. The transcranial Doppler showed a focal increase of the flow rates compatible with a stenosis in the proximal segment of left middle cerebral artery that was demonstrated later in the computed tomography angiography. This case don't have another embolic source (arterial or cardiac) and have some vascular risk factors (hypertension, and increase of serum triglycerides). Five month later the changes in the flow blood velocity persisted in transcranial Doppler ultrasound. Conclusions: In this case, the transcranial Doppler and Transcranial Color Doppler Sonography allowed a reliable diagnosis of intracraneal stenosis. The persistence of hemodynamic changes and the exclusion of other causes of intracranial stenosis suggest the atherosclerotic cause. [ABSTRACT FROM AUTHOR]