By all accounts, Brendon Spear was a healthy newborn. But some subtly abnormal behavior made his mother, Jessica Spear, think twice.
"At two weeks, he couldn't turn his head to the right. At two months, he was clearly left-handed," Spear said. "He was walking at 13 months but was falling because he couldn't pick up his right foot. He would go in circles."
Spear, who lives in St. Louis, took Brendon for several examinations, and finally, when he was 19 months old, to a neurologist for a brain scan. She learned that Brendon had the neuromuscular disorder cerebral palsy -- due to a stroke he had suffered in the uterus.
"It was devastating because one, you never hear of stroke in children, and two, it took so long to get a diagnosis," Spear said.
"I thought, 'why the heck didn't someone tell me this long before now?' We would have had a diagnosis at six months and Brendon would not be denied the therapies he needed... I felt very isolated as a parent."
Although cases of pediatric stroke are rare, stroke occurs with two to four times more frequency in children and teenagers than was previously thought, according to a new study just published online in Stroke: Journal of the American Heart Association.
Prior estimates for rates of childhood stroke were between 0.54 and 1.2 cases per 100,000 children in the U.S. But analysis of 2.3 million children's hospital records in California by researchers at the University of California at San Francisco showed the rate of childhood stroke to be 2.4 cases per 100,000 children.
Researchers felt the higher rate of pediatric stroke was due to improper coding or typing errors in medical records.
"The number of times someone has said to me, 'We didn't think it was a stroke because it was a child,' is legend," said Dr. Ian Butler, director of the Division of Child and Adolescent Neurology at the University of Texas Medical School at Houston.
Vinette Harris said doctors were surprised when her 15-year-old son Paul Meikle, an avid athlete who played football, basketball and ran track, landed in the emergency room this summer with slurred speech and a drooping left eye.
"All the symptoms pointed to [stroke], even though he was young," Harris said. "The hospital didn't have a lot of experience in treatment options for children, so they offered us treatments they would give to adults. But they knew there was a risk."
Scans showed that Meikle, who also has an enlarged heart for which he has a pacemaker, had a blood clot lodged at the base of two veins on the right side of his brain, which was why his left eye was affected. He was treated with medications to break up the clot.
"After the medication... he felt he could move his arm -- which for me, it felt like watching my son walk again for the first time," Harris said. "That same evening, his mobility was completely restored... And now there are no physical remnants of the stroke."
Meikle made a full recovery. But children who suffer a stroke often live with the aftereffects for the rest of their lives. Such children are at increased risk for subsequent strokes as well as seizure disorders. In addition, developmental disorders, such as cerebral palsy, can impair their cognitive abilities and their motor function, requiring a lifetime of physical, occupational, or speech therapy.
"If you can get in there while these kids' brains are still plastic, you can still create [connections]," said Mary Kay Ballasiotes, of Evans, Ga., whose daughter Michelle had a stroke in utero during Ballasiotes' second trimester. "That's what's frustrating, when these babies are being diagnosed at 18 months or two years, you've lost all this time creating these new connections."
Michelle, 11, began occupational therapy at 6 months and continues to work with a therapist. She has not had another stroke since her birth but she does have cerebral palsy and wears an ankle brace to steady her leg muscles.
"Sometimes I wish I didn't have [the disorder] to see what it felt like not to have it, but I will never know any different," Michelle said. "Learning and remembering things is still hard for me and I run slow... I'm probably as good as I can get."
Many parents attribute their children's stroke diagnoses to their own observations which they must then urge doctors to pursue.
"Many times it is more difficult to identify strokes in children because they may not be cognitively developed enough to effectively communicate symptoms related to a stroke," said Dr. Edward Smith, a neurosurgeon at the Children's Hospital in Boston. "This may lead to a missed opportunity to diagnose a stroke."
But parents of children who have had strokes find the community of survivors and their families is larger than they expected, underscoring the UCSF study's findings that pediatric stroke occurs more frequently than expected.
Ballasiotes said she is part of a support group she founded for pediatric stroke survivors of over 80 families in the Chicago area.
Matt McDermott said he learned that several families in his Gardner, Mass., neighborhood had experience with pediatric stroke after he discovered that his daughter Kayelyn, now age 3, had had a stroke in utero.
"I couldn't name anyone with family members that this had happened to," said McDermott, whose daughter was diagnosed at six months. "Since Kayelyn was diagnosed, I know of three or four families in the area where we live who had the same thing happen to their children."
Dr. Lori Jordan, assistant professor of neurology and pediatrics at Johns Hopkins Children's Center, said that while "strokes in kids are rare, they are as common as brain tumors, which get a lot more [attention]... understanding the frequency and causes of stroke in kids should help target research that will prevent strokes and improve outcome."
Brendon, now four, receives regular physical therapy to strengthen and coordinate the muscles on his affected right side, but Spear still worries that his asymmetrical body might weaken to the point where he might need a hip or knee replacement when he is in his twenties.
Still, Spear said he has developed into a high functioning, talkative boy and his risk of having another stroke continues to decrease over time. The same is true of other children.
"They get frustrated but they don't let things stop them," Spear said. "They figure out a way to get what they want."
ABC News' Lauren Cox, Courtney Hutchison and Lara Salahi, and Med Page Today's Todd Neale contributed to this report.