Winter 2005

Researchers Study Dangers of Stroke in Children, Infants

When an adult presents with an acute hemiparesis, physicians are trained to immediately consider stroke as a possible cause. But even though stroke can be a serious problem in children and infants, it is often not diagnosed. "When kids present with hemiparesis, it is likely caused by something else, like migraine or a seizure, so the index of suspicion is lower" that the cause might be stroke, says UCSF pediatric neurologist Heather Fullerton, M.D.

More Common Than Thought

In recent years, researchers at UCSF and elsewhere have discovered that stroke in children and infants is much more common than previously recognized, and that the consequences of pediatric stroke are more serious than widely believed. Fullerton, one of the few neurologists in the United States who specialize in pediatric stroke, says that while there is a peak in stroke incidence around the time of birth and the first year of life, there is a second peak in the teenage years. And unlike adults, whose strokes are four times more likely to be ischemic rather than hemorrhagic, children suffer both types equally.

Causes of Stroke

The most common cause of hemorrhagic stroke in childhood is arteriovenous malformation, Fullerton says, although the teenage years can also bring exposure to the kind of trauma that can cause brain hemorrhage. Up to 25 percent of the time, the cause of the stroke is never discovered, Fullerton says.

Heather Fullerton, M.D.

Ischemic strokes in children may be caused by congenital heart disease, hematological disorders such as sickle-cell disease or lymphoma, vasculopathy associated with chicken pox, drug abuse, trauma in which blood vessels are torn, meningitis or endocarditis. Prothrombotic states, like factor V Leiden mutation, can lead to clotting and stroke when girls begin taking birth control pills, and can make any of the other causes of ischemia more severe. Because ischemic stroke may not be immediately recognized, treatment can be delayed. "Improving diagnosis of stroke in children is a matter of thinking along the lines that it might be stroke," Fullerton says. "MRI scans with diffusion-weighted imaging are a very sensitive way of diagnosing acute stroke."

Differences in Recovery

As children recover from stroke, there are other differences between pediatric and adult stroke that surface. "The general feeling is that children recover better, but the truth is that they simply recover differently," Fullerton says. "In some ways, they do recover better, but at the expense of other functions." For instance, she says, in a child with a stroke affecting the language areas in the dominant hemisphere of the brain, the child may be quicker to recover language, but does so at the expense of his or her motor skills when that part of the brain begins to be taken over by the language processing area. "The important thing is that these kids get adequate therapy and help in school," Fullerton says.

Neonatal Stroke

A number of researchers at UCSF are studying stroke in newborns and infants. Three years ago, research by UCSF pediatric neurologist Donna Ferriero, M.D., demonstrated that stroke among neonates and children is severely underrecognized. Although it was once thought that stroke among newborns is exceedingly rare, this and the more recent study showed that the risk of stroke in newborns is as high as the risk of large-vessel ischemic stroke in adults.

A more recent study by UCSF researchers reveals that four out of five newborns who experience intracerebral arterial infarction at the time of birth will later develop neurological disorders such as cerebral palsy, epilepsy or language delay. This study, headed by pediatric neurologist Yvonne Wu, M.D., in collaboration with Kaiser Permanente Division of Research, uncovered a higher rate of long-term neurological impairment than previously described. Past literature suggests that about half of infants with perinatal arterial infarction can expect a normal neurologic outcome.

The new numbers reported by Wu may be more accurate because this is the first study that includes all infants diagnosed within a large population. The researchers examined the records of almost 200,000 children born between 1997 and 2002. The overall rate of ischemic stroke in the newborn period was about one in 5,000 live births.

The most common adverse outcome following perinatal arterial stroke was cerebral palsy, which was found in 58 percent of survivors. Cerebral palsy was more likely to occur in infants who had a large stroke size and who sustained injury to the internal capsule or basal ganglia. The researchers also found that infants who had no symptoms at birth, but who were diagnosed with perinatal stroke months later, were also more likely to have cerebral palsy.

For more information, contact: Dr. Ferriero at (415) 502–5820, Dr. Fullerton at (415) 353–3681, Dr. Wu at (415) 353–3678.

Related Information

News Releases

Ferriero Elected to IOM
Donna M. Ferriero, M.D., chief of the Division of Child Neurology and professor of neurology and pediatrics, has recently been elected to the Institute of Medicine, along with five UCSF colleagues. The election brings to 69 the number of UCSF members in the institute.

Macy's Tree Lights Support UCSF Benioff Children's Hospital
UCSF Benioff Children's Hospital is the beneficiary of a fundraising effort centered around the Macy's holiday tree-lighting in San Francisco's Union Square. A $10 donation sponsors one of the thousands of lights on the 80-foot tree. Donations are being accepted through the end of the year at ucsfhealth.org/tree or by calling (888) 689-UCSF.