Is It Time for a Large, Collaborative Study of Pediatric Stroke?

Childhood stroke, although rare, results in significant mortality and long-term morbidity. The lack of information about risk factors for childhood stroke recently led an expert panel from the National Institute of Neurological Disorders and Stroke to call for more studies addressing this important issue. Prospective, population-based studies, which reduce the possibility of referral bias, are an ideal way to study the impact of disease on a real-world population.

The Brain Attack Surveillance in Corpus Christi (BASIC) project is an ongoing stroke surveillance study in Nueces County, Texas. Our goal was to assess the feasibility of conducting community-based studies to assess risk factors for pediatric stroke. To this end, we calculated the incidence rate of childhood stroke and examined stroke type in this large biethnic community. On the basis of the stroke incidence rate and the estimated prevalence of various risk factors, we calculated the sample size required to investigate potential risk factors for childhood stroke in a hypothetical case-control study.

As a secondary goal, we sought to investigate ethnic differences in childhood stroke incidence rates in this population. Previous studies have suggested that gender and ethnicity may be independent risk factors for stroke in children, but this has not been well studied in Mexican Americans (MAs). Hispanics are the largest minority group in the United States, and MAs are the largest subgroup of Hispanics. Previous research has demonstrated differences in stroke incidence in adult MAs compared with non-Hispanic whites (NHWs).

There were 15 cases of childhood acute cerebrovascular events identified during the 2 years of the study using ICD-9 codes. There were 4 cases of subarachnoid hemorrhage (SAH), 3 cases of intracerebral hemorrhage (ICH), 3 cases of transient ischemic attack (TIA), 2 cases of ischemic stroke (IS), 2 cases of subdural hematoma, and 1 case of hypertensive encephalopathy. After review of the medical records, 7 cases were excluded as nonstroke. The 2 cases of subdural hematoma and 1 case of hypertensive encephalopathy were excluded because no other stroke diagnosis was found after chart review. Two of the cases of TIA were determined to be conversion disorders, and 1 case each of ICH and IS were remote events in children admitted for seizures. All validated cases were in MAs. Three of the cases coded as SAH were validated as ICH, for a total of 5 cases of ICH, 1 case of SAH, 1 IS, and 1 TIA.

The total 2000 population of Nueces County, Texas, for MA and NHW children <20 years of age was 92 418. Annual stroke incidence rate per 100 000 children was 4.3 (95% CI, 1.9 to 8.5). To provide comparison with other studies, the calculation was also repeated for children <16 years of age for a total of 4 cases and an annual overall incidence rate of 2.7 per 100 000 (95% CI, 0.7 to 7.0). Examining individual stroke subtypes, the rate of ICH was 2.7 per 100 000 (95% CI, 0.9 to 6.3), the rate of IS/TIA was 1.1 per 100 000 (95% CI, 0.1 to 3.9), and the rate of SAH was 0.5 per 100 000 (95% CI, 0.01 to 3.0 per 100 000).