Ultrasound Screening Prevents Stroke In Children With Sickle Cell Disease

Ruzanna Harutyunyan's picture

Screening with an ultrasound machine has proved highly successful in preventing stroke among children with sickle cell disease, by identifying children who are then preventively treated with blood transfusions. Over an eight-year period at The Children's Hospital of Philadelphia, researchers found that the technique, transcranial Doppler ultrasonography (TCD), along with regular transfusions for children found to be at high risk, reduced stroke to one-tenth of the incidence found before TCD was introduced.

"We studied the impact of using TCD starting in 1998, when the technique became routine at our hospital and many other centers," said Janet L. Kwiatkowski, M.D., a pediatric hematologist at The Children's Hospital of Philadelphia. Kwiatkowski presented her group's results at a press conference during the 50th annual meeting of the American Society of Hematology.

Childhood stroke has long been known to be a devastating complication of sickle cell disease, an inherited condition in which abnormal hemoglobin deforms red blood cells into sickle-shaped bodies that do not pass smoothly through blood vessels.


TCD is a noninvasive tool that uses ultrasound waves to measure the speed of blood flow in large vessels in the brain. An abnormally high speed is a marker of a narrowed vessel, and a sign of high risk for stroke.

After the multicenter Stroke Prevention Trial in Sickle Cell Anemia showed in 1998 the utility of TCD in detecting abnormal blood speeds and the benefit of transfusions in reducing stroke risk, the Sickle Cell Program at Children's Hospital began to routinely use TCD in screening sickle cell patients. "When we see an abnormal TCD result, we treat the child with preventive blood transfusions, given regularly every three to four weeks," said Kwiatkowski.

The current study compared the rate of stroke in children with sickle cell disease in the eight years before Children's Hospital began TCD screening with the eight years from 1998 to 2006. The researchers followed 475 children in the pre-TCD group and 530 children in the post-TCD group.

In reviewing patient records, the researchers measured overt strokes, other neurological events and indeterminate events -- those that could not be classified based on available information. In the pre-TCD group, there were 21 patients with overt stroke, three with other neurological events and two with indeterminate events. In contrast, the post-TCD group had two patients with overt stroke, six with other neurological events and one with an indeterminate event.

Overall, the incidence of overt stroke in the pre-TCD group was significantly higher compared to the post-TCD group -- an incidence of 0.67 per 100 patient years compared to 0.06 per 100 patient years. "The study confirmed that a program of TCD screening combined with regular transfusion therapy for children found to be at high risk of stroke is effective in preventing strokes," added Kwiatkowski.



Sickle Cell Anemia: A Rare And Deadly Form Of Blood Loss Sickle Cell Anemia (SCA) is an autosomal recessive genetic disorder, which means that one is born missing a chromosome, which is what shares DNA with another). And SCA causes chronic hemolytic anemia, which unlike anemia itself, actually destroys the red blood cells within a SCA patient, and not simply is depleted of such cells as is the case with anemia in general. SCA affects almost entirely the black population for reasons unclear as far as the race goes, but the disease is in fact due to a mutated gene assigned to regulate hemoglobin within red blood cells. The red blood cells (RBCs) take on a rigid and sickle shape in the bloodstream of those affected. SCA was first discovered around 1950, and researched as well afterwards. SCA typically presents itself in one’s childhood, as this anemia is rather ruthless in the damage it cause various areas of the human body The average life expectancy of A SCA patient is in the mid 40s presently. The low life expectancy is due to the multiple clinical consequences that occur due to SCA. The hemolysis that occurs causes excessive destruction of one’s red blood cells. As a result the spleen of the SCA patient becomes impaired due to the overload of red blood cells in now has to remove from the blood stream of the SCA victim. And the SCA victim has to rely on his own bone marrow to reproduce additional red blood cells destroyed because of this sequence of events. Approximately 70 thousand people are with SCA in the United States presently, and all experience this self destruction within them due to SCA. Symptoms that happen due to SCA include what is called a pain crisis, anemia, infections, spleen inflammation and damage, and infections due to decreased blood flow to various parts of the body. With SCA children, they are particularly at a high risk for both a stroke and lung disease as a result of this disorder. Treatment options for SCA include hydroxyurea, which is an anti-metabolite that has the ability to reduce the number of sickle cells present in a SCA patient as well as increases their hemoglobin levels- both of which are needed with the SCA patient. SCA patients report a deceased number of pain attacks on hdroxyurea as well. Blood transfusions occur at times with SCA patients- perhaps every few weeks. Pain management is needed for the SCA patient often at times. There is ongoing research regarding sickle cell anemia, and there is hope that better treatment options, if not a cure, will be created sooner rather than later. Because in this certain disease, anemia does not only mean one who is without blood. This anemia means the SCA victim is also without comfort, and often, without peace. Dan Abshear