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Objective Chorioamnionitis is associated with increased risk for cerebral palsy (CP) in term infants. A functional polymorphism in the interleukin-6 (IL-6) gene has been implicated in newborn brain injury. We studied whether the IL-6 -174 G/C polymorphism confers increased risk for CP in term infants. Methods This population-based case–control study included 334,333 live-born infants born at ≥36 weeks gestation within Kaiser Permanente Medical Care Program from 1991 to 2002. Case patients (n = 250) were identified from electronic records and confirmed by chart review, and comprised all infants with spastic or dyskinetic CP not caused by developmental abnormalities who had a neonatal blood specimen available for study. Control patients (n = 305) were randomly selected from the study population. Results Compared with genotype GG, the less common CC genotype was associated with increased risk for overall CP (odds ratio [OR], 2.6; 95% confidence interval [CI], 1.5–4.6), quadriparetic CP (OR, 4.1; 95% CI, 1.8–9.3), and hemiparetic CP (OR, 2.7; 95% CI, 1.3–5.7), after controlling for race. The C allele conferred increased risk for CP in both recessive and additive genetic models. In multivariate analysis controlling for race, independent risk factors for CP included CC genotype compared with GG (OR, 2.4; 95% CI, 1.3–4.4), clinical chorioamnionitis (OR, 4.6; 95% CI, 2.1–10.4), maternal age ≥ 35 (OR, 2.6; 95% CI, 1.6–4.1), and male sex (OR, 1.6; 95% CI, 1.1–2.4). Interpretation Our data suggest that a functional polymorphism in the IL-6 gene is a risk factor for CP among term and near-term infants. Ann Neurol 2009;66:663–670

Some infants with perinatal arterial ischemic stroke (PAS) experience development of cerebral palsy (CP), epilepsy, and cognitive impairment, whereas others have a normal outcome. Previous prognostic studies rarely have included all diagnosed cases of PAS within a population. Among 199,176 infants born within Kaiser Permanente from 1997 to 2002, we electronically identified head imaging reports and physician diagnoses suggesting stroke. The diagnosis of PAS was confirmed by review of brain imaging and medical records. Presentation of PAS was considered delayed if symptoms were only noted after 28 days. Outcomes were determined by chart review. Of 40 infants with PAS, 36 were observed over 12 months. Abnormal outcomes included CP (58%), epilepsy (39%), language delay (25%), and behavioral abnormalities (22%). A delayed presentation was associated with increased risk for CP (relative risk [RR], 2.2; 95% confidence interval [CI], 1.2-4.2). Radiological predictors of CP included large stroke size (RR, 2.0; 95% CI, 1.2-3.2) and injury to Broca's area (RR, 2.5; 95% CI, 1.3-5.0), internal capsule (RR, 2.2; 95% CI, 1.1-4.4), Wernicke's area (RR, 2.0; 95% CI, 1.1-3.8), or basal ganglia (RR, 1.9; 95% CI, 1.1-3.3). Among infants with PAS, specific radiological findings and a lack of symptoms in the newborn period are associated with increased risk for CP.

The cause of intraventricular hemorrhage in term neonates is poorly understood. Among 29 neonates of at least 36 weeks' gestation with intraventricular hemorrhage, 9 (31%) had cerebral sinovenous thrombosis. Of the 26 neonates who underwent computed tomography or magnetic resonance studies, those with thalamic hemorrhage were more likely to have sinovenous thrombosis than those without thalamic involvement (4/5 vs 5/21, p = 0.03). Term neonates with intraventricular hemorrhage should undergo neuroimaging to evaluate the presence of sinovenous thrombosis. Ann Neurol 2003