Stroke in Children

Childhood Strokes Have Complex Causes
Patient Evaluations Should Seek Treatable Risk Factors

When children suffer strokes, physicians should look beyond the obvious causes to find risk factors that could be treated, say the authors of large British study of childhood stroke published November 15 in the on-line edition of the Annals of Neurology, the scientific journal of the American Neurological Association.

About half the children in the study of more than 200 stroke victims had some preexisting medical condition that predisposed them to stroke. However, a number of other risk factors were detected, including abnormalities of the cerebral arteries, infections such as chickenpox, and treatable conditions such as anemia due to iron deficiency.

“Our results confirm that rather than having a single cause, childhood stroke is a multifactorial process,” said lead author Vijeya Ganesan, M.D., a neurologist at the Institute of Child Health in London.

Childhood stroke is relatively rare, but it may be on the increase. In an unfortunate side effect of improved medical therapy, children with sickle cell disease, congenital heart disease, and other disorders now live longer, and thus are more likely to suffer strokes. However, the apparent increase in childhood stroke may also be due to improved recognition.

“Risk factors for stroke in children are very different from those in adults. They do not include atherosclerosis, hypertension, or life style issues,” said pediatric stroke expert Gabrielle deVeber, M.D., of the Hospital for Sick Children in Toronto, Canada.

The most common risk factors for childhood stroke include cardiac disease, iron deficiency anemia, and coagulation disorders. One impediment to understanding these and other potential risk factors–a necessary prelude to finding effective treatment and prevention strategies–has been the difficulty of gathering large enough study populations.

The British researchers reviewed the cases of 212 stroke patients (average age 5 years) who had been seen over 22 years at Great Ormond Street Hospital in London. In keeping with previous research, about half (97 patients; termed the “symptomatic” group) had previously been diagnosed with conditions ranging from congenital heart disease to sickle cell disease. Among the previously healthy group, 23 had recently suffered trauma to the head or neck and 68 had had chickenpox. These numbers were significantly greater than among the symptomatic patients.

Among all patients, abnormalities in the cerebral arteries were found in nearly 80% of cases. In addition, treatable risk factors such as anemia or elevated levels of the molecule homocysteine were found in many patients in both groups.

“In contrast to some previous studies, completely unexplained stroke was rare if patients were
evaluated in detail,” said Ganesan.

The practical implications of the study are that all children who suffer stroke should have comprehensive evaluations, even if the cause of the stroke is thought to be obvious, according to Ganesan.

“The study will help to sort out which risk factors are most common in children and should be investigated in patients following stroke. Future research will assess which treatments would help to prevent some or most of these risk factors,” said deVeber.