Children's Health: Strokes during infancy have lasting effects

Canadian researchers are shedding new light on what happens to children after they suffer a stroke during the early weeks of life.

Robyn Westmacott, a neuropsychologist in the children's stroke program at Toronto's Hospital for Sick Children, says strokes occurring in the first four weeks of life are more common than most people think, striking one in 2,500 to one in 4,000 live births. While the survival rate is high, little is known about the effects of stroke on childhood learning ability.

"Parents of these kids always come to us and ask: 'What will my child be like when he's older? Is he going to be able to learn like the other kids? Is he going to be able to make friends? Will he graduate? Become independent?' " Westmacott says. "Understanding long-term outcomes in these kids is very important for families, and it helps them plan for the future and develop realistic expectations."

In an earlier study, Westmacott and her colleagues examined infants and toddlers who had survived a neonatal stroke. In the one-year-olds, they found very subtle weaknesses in early movement skills. In the two-year-olds, there were subtle signs of mental difficulties in tasks such as matching shapes.

More recently, the researchers have followed 34 children to preschool and school age. In the preschool years, there were no significant differences in overall IQ or reasoning skills between children who had had strokes and normal children.

"However, when we followed them up in the school years, the results were very different." In this age group, the stroke survivors scored significantly lower on IQ, verbal comprehension, reasoning, memory and mental processing speed.

"Following neonatal stroke, cognitive deficits seem to become more pronounced in the school age years," Westmacott says. "Children seem to grow into their deficits over time. We can't assume that if they're doing well at two years of age they're necessarily going to continue doing well. We need to follow them up over the long term and have long-term educational interventions."

She adds that some children who have a neonatal stroke do not show signs of significant cognitive problems. "We'd like to know why these kids are doing well, and why other children seem to start to show these deficits."