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).

A 2002 report from the National Institute of Neurological Disorders and Stroke cited the critical importance of more childhood stroke studies. We present the incidence rate of pediatric stroke from a biethnic community-based project and calculate the population size required for future prospective studies of pediatric stroke.

Methods— This work is part of the Brain Attack Surveillance in Corpus Christi (BASIC) project. The community of 325 000 is located in southeast Texas and is composed of approximately equal numbers of Mexican Americans (MAs) and non-Hispanic whites (NHWs). Discharge diagnosis codes from all hospitals in the county were used to identify cases of childhood stroke (age >1 month and <20 years) in 2002 and 2003, and stroke cases were validated by source document review. On the basis of the incidence rates, the population size required to complete a case-control study to examine risk factors for pediatric stroke was calculated.

Results— Eight cases of pediatric stroke were identified, yielding an annual incidence rate of 4.3 per 100 000 (95% CI, 1.9 to 8.5). There were 5 cases of intracerebral hemorrhage, 1 subarachnoid hemorrhage, 1 ischemic stroke, and 1 transient ischemic attack. All of the events occurred in MAs. Depending on the prevalence of the risk factors of interest, future studies of pediatric stroke would have to draw from a population of up to 59 million children to complete a case-control study within 4 years.

Conclusions— Given the rarity of pediatric stroke, future studies will require multicenter efforts and possibly a national surveillance system.

Key Words: child • incidence • stroke

References
#  deVeber GA, MacGregor D, Curtis R, Mayank S. Neurologic outcome in survivors of childhood arterial ischemic stroke and sinovenous thrombosis. J Child Neurol.  2000; 15: 316–324.[Medline]
# Schoenberg BS, Mellinger JF, Schoenberg DG. Cerebrovascular disease in infants and children: a study of incidence, clinical features, and survival. Neurology. 1978; 28: 763–768.
# Fullerton HJ, Chetkovich DM, Wu YW, Smith WS, Johnston SC. Deaths from stroke in US children, 1979 to 1998. Neurology. 2002; 59: 34–39.

Full Text
Darin B. Zahuranec, MD; Devin L. Brown, MD; Lynda D. Lisabeth, PhD Lewis B. Morgenstern, MD

From the Stroke Program (D.B.Z., D.L.B., L.D.L., L.B.M.), University of Michigan Medical School, Ann Arbor; and Department of Epidemiology (L.B.M.), University of Michigan School of Public Health, Ann Arbor.

Correspondence to Lewis B. Morgenstern, MD, University of Michigan Medical School, 1500 E Medical Center Dr, TC 1920/0316, Ann Arbor, MI 48109-0316. E-mail .(JavaScript must be enabled to view this email address)