Late Emergence of Cognitive Deficits After Unilateral Neonatal Stroke

Abstract

Neonatal arterial ischemic stroke (AIS) affects a surprisingly large number of children each year, yet little is known about the long-term neuropsychological implications. Using age-appropriate Wechsler scales of intellectual ability, this longitudinal study examined 26 children with a history of acutely diagnosed unilateral neonatal AIS as preschoolers (3 years 6 months to 5 years 11 months) and again as grade-school students (6 years 1 month to 12 years 5 months), and contrasted performance with the normative sample of the test. As preschoolers, patients' performance did not differ from the normative sample for Full Scale IQ, Verbal IQ, or Performance IQ, and there were no significant differences associated with infarct laterality. As school-age children, performance was significantly lower than the normative sample for Full Scale IQ Working Memory and Processing Speed, but not for Verbal IQ or Performance IQ. Contrasts between Time 1 and Time 2 revealed a significant decline in Full Scale IQ, which reflected emerging deficits in nonverbal reasoning, working memory, and processing speed. Individual subject analyses revealed that 69% of the children showed significant declines in 1 or more IQ index measures. We found no significant differences in cognitive performance associated with lesion laterality, though males performed more poorly than females on several cognitive measures at Time 2. These findings suggest that children with unilateral neonatal stroke, particularly males, are at increased risk for emerging deficits in higher-level cognitive skills during the school years. Continued follow-up of these children is needed, even those with no apparent deficits as toddlers or preschoolers.