The TCD ultrasound, which is placed at the base of the patient's skull, measures the blood flow in the arteries. The more rapid the blood flow, the narrower the artery is, increasing the chance of developing a blood clot, which can eventually lead to a stroke.
The risk for stroke in people with sickle cell disease is greatest between the ages of two and 20 when the developing blood vessels are most susceptible to form plaques. Patients who are identified as high-risk for a stroke receive blood transfusions every three to four weeks to reduce their risk. Proper treatment can reduce the risk for stroke by approximately 90 percent.
Sickle cell disease is an inherited blood disorder that affects red blood cells. The red blood cells become sickle-shaped and have difficulty passing through small blood vessels. This can damage the wall of the artery, causing plaque to form and eventually narrowing blood flow.
"It's critical for children with sickle cell disease to have this test," says James Frey, director of St. Joseph's Hospital and Medical Center's Stroke Program. "Stroke is devastating, particularly when it impairs the quality of life for someone at such an early age."
The transcranial Doppler ultrasound has been used for nearly two decades to identify medical conditions in patients such as abnormal tears in the brain and cerebral vascular disease. It was recently discovered that the test also predicts stroke risk in children who have sickle cell disease.