EMBARGOED FOR RELEASE UNTIL 4 PM ET, May 10, 2004
Guideline Evaluates Use of Transcranial Doppler Ultrasound
ST. PAUL -
A new guideline developed by the American Academy of Neurology evaluates the use of transcranial Doppler ultrasonography (TCD) to determine when use of the test leads to better informed decisions by doctors and improved patient outcomes. A TCD is an ultrasound test that uses reflected sound waves to evaluate blood as it flows through the brain. TCD is mainly used to evaluate patients with cerebrovascular disease. The guideline, which is published in the May 11 issue of Neurology, the scientific journal of the American Academy of Neurology, was developed through expert review of all of the scientific evidence available on the use of TCD. “The guideline provides physicians with recommendations on how TCD may be used to evaluate the status of blood vessels inside the brain in patients with known or suspected cerebral vascular disease in diverse clinical settings,” said guideline co-author Michael A. Sloan, MD, of Rush University Medical Center in Chicago, Ill. The evidence showed that TCD provides valuable information in two situations: screening children age 2 to 16 with sickle cell disease for risk of stroke; and detecting and monitoring of vasospasms, or contractions of blood vessels, after subarachnoid hemorrhage, a type of stroke that occurs when a blood vessel on the brain’s surface ruptures and bleeds into the space around the brain. In other situations, TCD was found to provide important information, but the value of the test, compared to other tests, has not been determined. These include detection of cerebral circulatory arrest and brain death and monitoring of coronary artery bypass graft operations. In some situations, TCD does provide important information, but other tests are preferable. These include: detection of right-to-left cardiac shunts; and evaluation of extracranial internal carotid artery stenosis. Sloan also noted that more research is needed to determine the value of TCD in many of these areas.