Research focusing on Child strokes

[Shogun]

The signs are subtle, silent and easy to miss. An infant may hold her bottle in just one hand, or gaze only to one side.

These are among the symptoms of stroke in babies and children -- a far more common occurrence than many parents and pediatricians realize, and one that is getting increased attention from researchers.

[color=dark red]Childhood stroke was once thought of as extraordinarily rare.[/color] But researchers now are finding that strokes in newborns, particularly, are nearly as common as strokes in the elderly, even though children share few of the same risk factors for stroke.

Stroke in infants and children up to age 18 occurs in one in 4,000 live births and seven in 100,000 children, [color=royal blue]making the disorder twice as frequent as pediatric brain tumors,[/color] according to Dr. Donna Ferreiro, chief of child neurology at University of California-San Francisco.

``The reason we're now becoming aware of it is technology,'' said Ferreiro, whose research on infant stroke was published recently in the journal Neurology. ``We're more capable of imaging (the brain) of a newborn. We can see what we couldn't see before.''

Physicians can even diagnose stroke in an unborn child, using sonograms, although these diagnoses are rare, Ferreiro said.

The causes of childhood stroke remain unclear. But doctors agree that early diagnosis and treatment is critical: Although only 6 percent of children die from stroke, according to some studies, more than two-thirds suffer lifelong, expensive-to-treat disabilities such as cerebral palsy, loss of vision or hearing, poor motor skills or speech problems.

``You're talking about a lifetime of impairment,'' Ferreiro said, noting that many children must receive extensive speech, physical and occupational therapy to overcome brain damage caused by stroke.

Fortunately, [color=royal blue]because children's developing brains are so malleable, such therapy can work near-miracles in restoring the damage, doctors[/color] say. Then, too, many childhood strokes are not as devastating as those that occur in the elderly, said Dr. Robert Maddox, chief of pediatrics at Kaiser-Santa Clara hospital.

Strokes occur when a small part of the brain is deprived of its blood supply, either because a clot has blocked a blood vessel or the vessel has burst open.

In adults, better-known symptoms of stroke include slurred speech, confusion and weakness on one side of the body.

But since newborns neither speak nor walk, the typical warning signs don't apply.

It may take months for parents to recognize that something is wrong with their children when they hold a bottle or toy in only one hand, develop ``handedness'' earlier than the typical 2 years of age or turn their heads only to one side, Ferreiro said.

For Beth Silver, it was her son Brook's refusal to use his left hand that was the tip-off. The San Rafael mother first noticed the behavior when her son was about 4 months old. Brook, it turns out, had experienced a fairly severe stroke on the right side of his brain just before or after his birth, Silver said.

``We were totally, totally surprised,'' Silver said of her son's stroke. ``People don't associate stroke with children, just with elderly people. But it's not as rare as people think.''

Brook, now 3 1/2, is plugging along but has a number of developmental delays, Silver said. A social, good-natured child who loves swimming, Brook can now walk but has trouble speaking complete sentences that anyone but his parents can understand. He attends a special school and receives seven hours of various kinds of speech and occupational therapy every week, Silver said.

``It's quite a challenge, a task you had not expected,'' Silver said. ``But Brook is an incredible child. He's a smiley, happy guy.''

Routine neurological screenings can also pick up early signs of stroke, particularly severe ones, said Kaiser's Maddox. Some affected babies will hold their breath or display other abnormal breathing patterns, while others will respond with only one side of their bodies to a ``startle test,'' which typically causes infants to throw out their arms and legs. Seizures have been noted in some babies with stroke.

A pediatrician may refer the child to a pediatric neurologist, who can order an MRI (magnetic resonance imaging) scan to conclusively diagnose a stroke.

Because infant and child stroke has been far less studied than stroke in the elderly, researchers aren't sure what causes it. There do not seem to be gender differences in child stroke, and one study found no differences between black and white infants.

Newborns certainly don't share some of the adult risk factors for stroke, such as heart disease or smoking. Scientists believe that stroke in children is linked to genetic factors, and are conducting studies of families of afflicted children to look for links. Some known risk factors include infection in the mother, blood clotting disorders, dehydration, drug exposure in utero, and problems with the mother's placenta, Ferreiro said.

Indeed, studies of children could help identify some of the biological and genetic, rather than environmental, triggers of stroke in the population in general, Ferreiro said.

[color=royal blue]For all the damage strokes can cause, children's brains are so plastic that various kinds of therapy can help re-establish neural pathways[/color], allowing children to walk, talk and generally lead normal lives. In some therapies, parents force children to use their stroke-afflicted limbs to strengthen them.

Child-safe medications for stroke, however, are more problematic. Physicians and researchers are trying to develop safe protocols for treating stroke in children. ``We can't use therapies designed for adults,'' Ferreiro said. ``We might cause more harm than good.''

While blood-thinning agents are routinely used in adults to prevent stroke, such treatment might harm an infant's developing brain. Doctors may try very low doses of baby aspirin for children, but ``treatment is all over the map,'' Ferreiro said. One promising treatment is ``low molecular weight'' heparin, a version of a common anti-clotting agent.

``If we can limit damage after a stroke, that would be great,'' Ferreiro said.