June 09, 2010
It's well worth the risk of surgery to correct moyamoya disease in children, says pediatric neurosurgeon Edward Ahn.
One morning, a 15-year-old girl stumbled down the stairs of her family’s Baltimore home, walked crookedly to the couch and lay down. When her father asked her what was wrong, she did not reply. He assumed his daughter was “faking it” to get out of going to school. Only later that evening, when she was unable to move one side of her body or speak properly, did he realize that something was seriously wrong.
The girl had had a stroke.
Although the teenager recovered, “the father felt terrible,” says pediatric neurologist and stroke specialist Lori Jordan, who treated the girl after she was taken to Hopkins Children’s. “He just kept saying that he didn’t know that kids could have strokes.”
Jordan, who has heard that misconception all too often, tries to correct it by speaking about pediatric stroke at medical conferences for groups of paramedics, nurses and physicians. Pediatric stroke, she says, is at least as common as brain tumors in children. At least three out of every 100,000 children have a stroke each year, and in newborns the rate is about one out of 4,000.
“Parents see symptoms that they would recognize as stroke in adults, but they don’t in children,” says Jordan. On average, a child who has had a stroke is not presented for medical care for about 20 hours. Doctors, too, often miss the diagnosis. In an Australian study, children who had experienced a stroke were diagnosed on average 10 hours after being admitted to the hospital.
The sooner a child is brought to the hospital, the sooner doctors can provide the special care that will help protect the brain and avert a subsequent stroke, says Jordan, who co-directs the Johns Hopkins Pediatric Stroke and Neurovascular Center. The center’s team of neurologists, neurosurgeons, interventional neuroradiologists, hematologists, cardiologists and intensive care physicians diagnose and treat about 100 pediatric stroke patients each year. They have extensive experience treating patients with sickle cell disease and heart disease, two of the most common underlying causes of pediatric stroke.
In addition, the center specializes in a surgical procedure for patients who have moyamoya disease. Affecting only about one in a million people, moyamoya stems from blocked arteries at the base of the brain. These children naturally progress to have repeated strokes, says pediatric neurosurgeon Edward Ahn. In operating on children with moyamoya disease, Ahn isolates the superficial temporal artery from the scalp and grafts it onto the brain’s cortex. The procedure, he explains, stimulates the growth of healthy new vessels that can deliver blood to the afflicted brain region. The surgery itself poses a risk of stroke, notes Ahn. But that risk – about 4 percent – is significantly less than the almost inevitable chance of stroke that children with moyamoya disease face otherwise.
Still, despite all the medical care available for pediatric stroke patients, scientists have a lot to learn about the condition, says Jordan. She and her colleagues are involved in several multicenter studies of pediatric stroke, including one aimed at determining the causes of hemorrhagic stroke and another focused on improving methods for monitoring brain function. They are also planning to participate in multicenter studies looking at the role that infection and inflammation may play in pediatric stroke. Soon they'll examine the use of clot-busting drugs in young stroke patients.
In the field of neurology, says Jordan, “pediatric stroke research is exploding.”
For more information, call 410-955-4259. Also, see the American Heart Association’s guidelines on managing stroke in infants and children.