Original ArticleLong-Term Cognitive Outcomes After Pediatric Stroke
Introduction
Stroke in children has long been considered a rare and benign occurrence. Sensitive neuroimaging techniques and increasing knowledge on the subject have contributed to a rising awareness of strokes in children during the last few decades [1]. A cerebrovascular event occurring from birth to age 28 days is termed “neonatal,” whereas an event occurring between ages 29 days and 18 years is termed “childhood” stroke. The incidence of childhood stroke from population-based studies is estimated at 2.1-13.0 per 100,000 children per year [2], [3], [4], [5], [6], [7]. The Estonian Pediatric Stroke Study reported an incidence of childhood stroke at 2.73/100,000 persons per year [7], and a much higher incidence of perinatal stroke, at 63/100,000 [8].
The results of outcome studies indicate a high rate of lifelong morbidity. Ten percent of children die, 20% experience another stroke, and 70% manifest seizures or other neurologic deficits [1], [9], [10]. Children with early focal brain lesions are thought to be less vulnerable to emerging cognitive deficits, but this hypothesis is largely based on reports of good motor and language outcomes [11], [12]. Our previous studies demonstrated impairment in many cortical functions during later childhood in children with early-onset hemiparesis [13], [14], [15]. Moreover, subtle delays or difficulties may gradually develop into significant problems [1], [10], [11], [15]. Muter et al. [16] found that performance intelligence quotients, but not verbal intelligence quotients, are lowered in hemiplegic children with perinatal stroke compared with control subejcts. Ricci et al. [17] and Hetherington et al. [18] found normal range intelligence quotients at an early school age in children surviving a perinatal arterial ischemic stroke. However, Westmacott et al. [19] suggested that children with unilateral neonatal strokes, and particularly boys, are at increased risk for emerging deficits in higher-level cognitive skills during school years. At the same time, large-scale prospective studies of different functional domains are rare, and the results of outcome studies are difficult to generalize because of differences in sampling and assessment methods and the length of follow-up periods [1].
The present study was designed to examine a number of different neurocognitive skills, and to measure neurocognitive outcomes, in a sample of children with pediatric strokes. This study aimed to: (1) examine long-term neurologic outcomes after neonatal and childhood stroke; (2) examine neurocognitive outcomes and the most impaired cognitive functions in children with neonatal and childhood strokes; and (3) investigate the correlation between neurocognitive abilities and clinical features.
Section snippets
Patients and Study Groups
Patients were identified via the Estonian Pediatric Stroke Database during an epidemiologic study (1995-2006). This study was approved by the Medical Research Ethics Committee of Tartu University. Informed consent was obtained from the parents of patients for participation in the study. Signs of cerebrovascular events were categorized according to the International Pediatric Stroke Study [20]. Children were considered for participation if:
- (1)
They had a documented ischemic or hemorrhagic neonatal
Neurologic Outcomes
In the neonatal stroke group, neuromotor development according to Paediatric Stroke Outcome Measure score was not impaired in 9.5% of patients. Outcomes were good in 28.6% of patients, and moderately or severely impaired in 62% of patients (Table 2). In the childhood stroke group, motor outcomes were good in 30% of the children, and moderately impaired in 70% of the children.
Effects of Pediatric Stroke on Different Cognitive Domains
Because age at testing significantly influenced the results in all subtests, it was treated as a covariate. Subtest mean
Discussion
This longitudinal study examined neurocognitive outcomes in children with neonatal and childhood strokes. To the best of our knowledge, it is the first to use data from a prospective population-based database to focus on neurocognitive outcomes in children with neonatal and childhood stroke. Strokes affect the cortical and subcortical regions, where the sensorimotor systems are represented. Several studies reported on the prevalence of motor impairment and hemiparesis, which occurs in 30-60% of
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