KISSIMMEE, FLA—Stroke has a reputation for striking primarily older adults, but pediatric cases do occur. In a large, community-based sample, Zahuranec et al found a pediatric stroke incidence of 4.3 per 100,000. Nearly twice that incidence was reported by deVeber among infants. It has also been suggested that pediatric stroke rates are increasing.

Stroke can be just as devastating to children as to adults. Lynch and Han observed that more than half of pediatric stroke patients develop lifelong cognitive or motor deficits and that more than a third have recurrent stroke. The investigators recommended prospective studies to develop prevention and treatment strategies for pediatric stroke.

Much progress has been made in that area, ranging from validation of the NIH Stroke Scale modified for pediatric use (PedNIHSS) to the finding that some children with stroke may be eligible for treatment with tissue plasminogen activator (t-PA). These and other advances in pediatric stroke were discussed at the American Stroke Association’s 2006 International Stroke Conference.

PEDIATRIC STROKE OUTCOME PREDICTOR

"The pediatric modification of the NIH Stroke Scale is a valid and reproducible measure of acute stroke severity in children," reported principal study author Adam Kirton, MD, a Research/Clinical Stroke Fellow at the Hospital for Sick Children in Toronto. Dr. Kirton emphasized that a PedNIHSS score of 12 or greater predicted, with a high degree of specificity, poor stroke outcomes.

An interclass correlation coefficient of 0.98 indicated close agreement between retrospective and prospective PedNIHSS scores. Those scores were also well correlated with the Pediatric Stroke Outcome Measure (PSOM) findings obtained an average of 13.7 months after stroke presentation. PedNIHSS scores significantly predicted stroke outcomes as shown by an area under the curve of 0.72. The sensitivity and specificity of a PedNIHSS score of 12 or greater for poor neurologic outcomes were 50% and 93%, respectively. "Poor outcome is strongly predicted by a PedNIHSS score of 12 or greater but is not well excluded by lower scores," Dr. Kirton explained.

RESULTS OF CHILDHOOD CSVT

Dr. Moharir and colleagues performed a consecutive cohort study examining the extent and rate of recanalization, safety of anticoagulant therapy, and outcomes among 77 infants (excluding neonates), children, and adolescents diagnosed with CSVT during a 12.5-year period. Of these patients, who ranged in age from 35 days to 17 years, 71% received anticoagulants; therapy was administered for a median duration of 16 weeks in 85% of cases and was lifelong in 13%.

Among anticoagulant recipients, the major and minor bleeding rates were 5% and 3%, respectively. CSVT recurred in one child. The six-week and three-, six-, and 12-month rates of full recanalization were 20%, 38%, 57%, and 66%, respectively. During long-term follow-up, PSOM assessments showed no residual neurologic deficits in 61% of the study population. There were mild deficits in 14% and moderate or severe deficits in 19%. No association was observed between the extent of recanalization and neurologic outcomes.

PEDIATRIC ARTERIAL ISCHEMIC STROKE

"Half presented within the first six hours [after symptom onset]," said Dr. Ichord, Assistant Professor of Neurology and Pediatrics at the University of Pennsylvania in Philadelphia. However, the other half were taken for emergency care more than 24 hours after symptom onset, and delays of up to five days were reported. The median times from symptom onset to stroke-specific therapy (IV fluids and antithrombotics) and imaging confirmation of acute AIS were 23 and 36 hours, respectively.

The children’s neurologic symptoms included, primarily, hemiparesis, ataxic gait, chorea, and vertigo. "Neurologic deficits were associated with headache in four cases and seizures in two cases," Dr. Ichord said. Three of the children had known stroke risk factors, she noted.

RISK OF HEMORRHAGIC STROKE RECURRENCE

The authors analyzed data on all children presenting to the 16 hospitals in the Northern California Kaiser Permanente system with hemorrhagic stroke (intracerebral, subarachnoid, or intraventricular hemorrhage) during an 11-year period. Complete follow-up data were available for 100 such children.

Among those children, hemorrhagic stroke etiology was structural in 54%, trauma-related in 21%, and idiopathic in 17%; 8% had some "other" etiology. During a median follow-up period of 3.7 years, there were eight hemorrhagic stroke recurrences a median of 1.9 months after the initial event; two children had multiple recurrences.

Recurrence rates also varied by gender—16% for girls versus 3% for boys—but not by hemorrhagic stroke subtype. Multivariate analysis revealed a hazard ratio for stroke recurrence of 3.9 in girls. "The gender difference persisted when traumatic [hemorrhagic stroke] cases were excluded," Dr. Fullerton stated.

Although the risk of recurrent hemorrhagic stroke was greater in girls, another study by Dr. Fullerton’s group found that initial events were more likely to occur in boys. "This gender disparity is largely explained by an increased incidence of traumatic hemorrhages in boys," the authors said.

A different analysis of the same cohort revealed that hemorrhagic stroke etiology was most often structural, although trauma and cerebral aneurysm were also prominent etiologies. No etiology was identified in 16% of cases.

Overall, hemorrhagic stroke was 53% more likely to occur in boys. "Stratification revealed that boys have a threefold increased risk of traumatic hemorrhagic stroke but no significantly increased risk of spontaneous hemorrhagic stroke," the authors stated.

ELIGIBILITY FOR T-PA

By screening inpatient diagnostic codes, Dr. Khatri identified pediatric and adult stroke cases that occurred in the greater Cincinnati and northern Kentucky area during a two-year period. After the exclusion of premature infants and persons older than 18, the final study population consisted of 21 pediatric ischemic stroke patients whose ages ranged from less than 1 month to 17 years.

For 14 of these patients, the time between stroke occurrence and presentation for inpatient care was unknown. Four patients were brought to the hospital in three hours or less, and three patients presented more than three hours after stroke occurrence. The median estimated NIH Stroke Scale score was 5, with a range of 0 to 15. Potential eligibility for t-PA was determined according to the t-PA Stroke Study Group Guidelines.

Of the latter group, however, 11 patients would have been eligible had time not been a factor or if it could have been confirmed that they presented within three hours of stroke symptom onset, stated Dr. Khatri. Thus, with early presentation for treatment, t-PA eligibility rates in pediatric stroke would be 14% to 71%, Dr. Khatri concluded.

FINANCIAL BURDEN OF PEDIATRIC STROKE

The investigators obtained hospital admissions data in 2002 from the largest inpatient care database in the United States (the Nationwide Inpatient Survey). In the under-18 age-group, 817 ischemic strokes, 963 intracranial hemorrhages, and 256 subarachnoid hemorrhages were identified; the rates of each type of stroke were greater in males (61%, 58%, and 72%, respectively).

The average length of hospital stay was 8.1 days for ischemic stroke, 11 days for intracranial hemorrhage, and 7.8 days for subarachnoid hemorrhage. The estimated inflation-adjusted cost of hospitalization for each type of stroke was $45,900, $49,300, and $81,900, respectively. The rates of routine discharge and in-hospital mortality were 69% and 9.7% in the ischemic stroke group, 72.3% and 9.7% in the intracranial hemorrhage group, and 55.2% and 11.9% in the subarachnoid hemorrhage group.

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