Intelligence after stroke in childhood: review of the literature and suggestions for future research

Implications of age at lesion onset for neuropsychological outcomes: A systematic review focusing on focal brain lesions

Theories of the relation between age at lesion onset and outcomes posit different views of the young brain: resilient and plastic (i.e., the so-called "Kennard Principle"), or vulnerable (i.e., the Early Vulnerability Hypothesis). There is support for both perspectives in previous research and questions about the "best" or "worst" times to sustain brain injury remain. Here, we present a systematic review investigating the influence of age at focal brain lesion onset on cognitive functioning. This systematic review identifies and qualitatively synthesizes empirical studies from 1985 to 2021 that investigated age at lesion onset as a variable of interest associated with neuropsychological outcomes. A total of 45 studies were identified from PubMed, PsycINFO, and CINAHL databases. Almost all studies indicated that brain injury earlier in the developmental period predicts worse cognitive outcomes when compared to onset either later in the developmental period or in adulthood. More specifically, the overwhelming majority of studies support an "earlier is worse" model for domains of intellect, processing speed, attention and working memory, visuospatial and perceptual skills, and learning and memory. Relatively more variability in outcomes exists for domains of language and executive functioning. Outcomes for all domains are influenced by various other age and injury variables (e.g., lesion size, lesion laterality, chronicity, a history of epilepsy). Continued interdisciplinary understanding and communication about the influence of age at lesion onset on neuropsychological outcomes will aid in promoting the best possible outcomes for patients.

Cognitive and Academic Outcomes Following Childhood Cortical Stroke

The majority of pediatric neuropsychological stroke research has focused on perinatal stroke outcomes given its relative frequency. Meanwhile, childhood-onset stroke is under-represented in the literature, resulting in limited knowledge about its neurocognitive sequelae. This retrospective study examined cognitive outcomes in children and youth (n = 27) with childhood arterial ischemic stroke (stroke occurring between 29 days and 18 years of life) isolated to the cortical region. Intellectual, academic, language, visual-perception, visual-motor integration, fine motor coordination, and executive function scores were examined relative to normative means. Results indicate that although these children are doing well in terms of general intellectual ability, they demonstrate lower scores on tasks of processing speed and fine motor coordination. Exploratory analysis also revealed that of the personal and neurologic factors examined, age at stroke was positively correlated with perceptual reasoning and fine motor control, age at assessment was negatively correlated with math calculation abilities, and maternal education was positively correlated with working memory and parent-reported behavioral regulation and impulse inhibition abilities. While neurologic variables were not predictive of cognitive neuropsychological outcomes, those with significant poorer performance had higher rates of medium/large, right-sided lesions with frontal lobe involvement. Our results highlight the overall resilience of the injured developing brain but also the vulnerability of specific cognitive skills within this unique population.

Pediatric Stroke: A Single-Center Experience

The aim of this study was to evaluate the clinical characteristics, risk factors, treatment, and outcomes of pediatric stroke cases. A total of 118 patients diagnosed with arterial ischemic stroke (AIS), hemorrhagic stroke, and sinovenous thrombosis (SVT) between January 2000 and December 2011 were included. Neonatal cases were excluded. Demographic and clinical findings were retrospectively examined from medical records. We identified 118 patients with stroke. The age of the patients ranged from 1 to 215 months (17.92 y), with a mean age of 5.19±5.25 years. AIS accounted for the majority of cases (n=69, 58.5%), and the major etiology was cardiac disease (17%). Hemorrhagic stroke accounted for 19.5% (n=23) of the cases, and late hemorrhagic disease of the newborn was the major etiology (43%, n=10). SVT accounted for 22% (n=26) of the cases, and the major etiology was otitis media-mastoiditis (27%, n=7). Hemiplegia and headache were the most frequent symptoms for AIS and SVT, respectively. Stroke is rare in children compared with adults; however, it is detected more frequently with better imaging techniques and increased awareness. We found that children with AIS presented more commonly with hemiplegia and children with SVT with headache and strabismus. We did not find an association between thrombophilia and stroke.

Language and cognitive outcomes after childhood stroke: Theoretical implications for hemispheric specialization

The purpose of this study was to investigate language and cognitive outcomes following severe childhood stroke, and the role of age at stroke according to lesion lateralization. We retrospectively included children consecutively admitted to a physical medicine and rehabilitation department between 1992 and 2015 following childhood stroke (age at stroke 1 month to15 years). Data collection included demographic and clinical information, results of cognitive assessments on the Wechsler Intelligence scales, detailed language assessments by speech and language therapists, and long-term academic outcome. Overall, 184 children (52% boys; mean age at assessment = 8.5 years, range .7-15.4 years) were hospitalized following ischemic (n = 79) or hemorrhagic (n = 105) stroke. After a median time since stroke of 4 months (n = 135), mean Full-Scale, Verbal, and Performance Intellectual Quotient (FSIQ, VIQ and PIQ) were 85 (SD = 19), 93 (SD = 22), and 85 (SD = 20), respectively. In language tests (n = 130) assessing lexical and syntactic expression and comprehension, 26%-53% of the children exhibited impairments (scores <2SD). After a median follow-up of 40 months, only 27% of the children were following a normal curriculum without adaptations or delay, and 27% were attending special education programs. School situation was strongly associated with language and FSIQ scores. Language and verbal IQ scores were significantly lower (p < .01) among patients with lesions in the left hemisphere as opposed to the right. After a left hemisphere lesion, language skills were not associated with age at stroke, but for right hemisphere lesions, language was more impaired among children who were younger at stroke onset. PIQ tended to correlate positively with age at stroke in left hemisphere lesions (poorer PIQ in early lesions) and negatively for right hemisphere lesions (poorer PIQ in late lesions). These findings, discussed in the light of the brain vulnerability and plasticity hypotheses, are in favor of a developmental view of hemispheric specialization.

Improving cognitive outcomes for pediatric stroke

PURPOSE OF REVIEW

The past 20 years have seen a 35% increase in prevalence of pediatric stroke. Contrary to widely held views, children do not recover better than adults. This review explores the impact of pediatric stroke on cognitive domains, including intellectual and executive functions, memory and behavior, and the influence of age, lesion characteristics, and comorbidities on outcome.

RECENT FINDINGS

Cognitive problems occur in up to half of ischemic and hemorrhagic stroke survivors. Single-center studies have shown intelligence quotient scores skewed to the lower end of the average range, with greater impairment in performance than verbal domains. Executive function, such as attention and processing speed are particularly vulnerable to the effects of pediatric stroke. Age at stroke, larger infarct size, cortical/subcortical lesion location, epilepsy, and comorbid physical deficits are associated with poorer cognitive outcomes.

SUMMARY

Cognitive impairment occurs relatively frequently following pediatric stroke but the nature, severity, and predictors of specific deficits are not well defined. Improving understanding of outcomes following pediatric stroke is a key priority for families but a paucity of data limits the ability to develop targeted disease, and age-specific pediatric rehabilitation strategies to optimize cognitive outcomes following pediatric stroke.

Moral Reasoning in Children with Focal Brain Insults to Frontotemporal Regions

Neuroscientific evidence indicates that human social functioning is supported by a distributed network of frontal and temporal brain regions that undergoes significant development during childhood and adolescence. Clinical studies of individuals with early brain insults (EBI) to frontotemporal regions suggest that such lesions may interfere with the maturation of sociocognitive skills and lead to increased sociobehavioural problems. However, little attention has focussed on the direct assessment of sociocognitive skills, such as moral reasoning, following focal EBI. In the present study, the performance of 15 patients with focal EBI (8–16 years) was compared to that of 15 demographically matched controls on basic neuropsychological measures (IQ and executive functions), sociocognitive tasks (moral reasoning, moral decision-making and empathy) and parent reports of sociobehavioural problems and social adaptive skills. Patients with focal EBI had significantly lower levels of moral reasoning maturity, moral decision-making, and empathy than their matched controls, but did not differ on more general measures of cognition. Their parents also reported increased sociobehavioural problems. These findings suggest that focal EBI to frontotemporal regions can result in reduced sociocognitive capacities, more specifically moral reasoning, and increased vulnerability to sociobehavioural problems.

Visuoperceptual sequelae in children with hemophilia and intracranial hemorrhage

BACKGROUND

The goal of this study was to examine the impact of focal brain injuries on the outcomes of visual perception and visuospatial abilities in Mexican children with hemophilia who have experienced intracranial hemorrhages.

METHODS

We assessed ten boys who had hemophilia with intracranial hemorrhage (HIC), six boys who had hemophilia without intracranial hemorrhage (HH), and ten boys without hemophilia (CTL). The Verbal (VIQ), Performance IQs (PIQ), and Full Scale IQs (FSIQ) from the Wechsler Intelligence Scale for Children-Mexican Revision, Visual Perception, and Visuospatial Abilities domains, which are from a neuropsychological assessment battery for Spanish-speaking children (ENI), were employed for our analysis.

RESULTS

The results showed that the HIC group performed in the low-average range on the PIQ and FSIQ, which was lower than the HH group. The HIC group showed low performance on visual perception tests, such as line orientation, fragmented objects, and overlapping figures, compared with their matched controls.

CONCLUSIONS

The results suggest that it is not the ability to recognize objects that is impaired in the HIC group, but the ability to identify objects under less favorable conditions. Our findings may have therapeutic and rehabilitative implications for the management of children with hemophilia and early focal brain lesions.

Central auditory processing outcome after stroke in children

OBJECTIVE

To investigate central auditory processing in children with unilateral stroke and to verify whether the hemisphere affected by the lesion influenced auditory competence.

METHOD

23 children (13 male) between 7 and 16 years old were evaluated through speech-in-noise tests (auditory closure); dichotic digit test and staggered spondaic word test (selective attention); pitch pattern and duration pattern sequence tests (temporal processing) and their results were compared with control children. Auditory competence was established according to the performance in auditory analysis ability.

RESULTS

Was verified similar performance between groups in auditory closure ability and pronounced deficits in selective attention and temporal processing abilities. Most children with stroke showed an impaired auditory ability in a moderate degree.

CONCLUSION

Children with stroke showed deficits in auditory processing and the degree of impairment was not related to the hemisphere affected by the lesion.

Cognitive outcomes following arterial ischemic stroke in infants and children

This study sought to investigate cognitive outcomes following pediatric arterial ischemic stroke and explore predictors. Participants included 36 children with perinatal or childhood arterial ischemic stroke and a comparison group of 15 children with asthma. Outcomes included cognitive ability, executive functions, and neurological function (Pediatric Stroke Outcome Measure). Magnetic resonance imaging measured lesion location and volume. Mean cognitive scores were at the low end of the average range. Children with arterial ischemic stroke performed significantly below normative populations and significantly below the asthma group on inhibitory control (Cohen's d = .68). Both the Pediatric Stroke Outcome Measure and lesion volume were negatively correlated with cognitive outcome (Spearman r = -.01 to -.42 Pediatric Stroke Outcome Measure; r =-.14 to -.32 Volume). Following arterial ischemic stroke, children performed at the low end of the average range on measures of cognitive functioning. Cognitive outcomes depend on a variety of factors.

Functioning and disability after stroke in children: using the ICF-CY to classify health outcome and inform future clinical research priorities

AIM

The International Classification of Functioning Disability and Health, Child-Youth version (ICF-CY) provides a framework for describing and evaluating health, intervention outcomes, and needs assessment. It can, however, also serve as a system for classifying the focus of outcome studies and identification of gaps in current knowledge.

METHOD

The paediatric arterial ischaemic stroke (AIS) population was targeted. Multiple databases were systematically searched for AIS outcome studies focussing on functioning or disability. Findings were rated using the ICF-CY framework.

RESULTS

Twenty-eight studies were identified. Most were cross-sectional and age range at assessment varied widely. Sixty-seven different standardized measures were used, predominantly evaluating body functions. The most common domains of activity and participation reported were learning and applying knowledge, general tasks and demands, and self-care skills. Health-related quality of life was measured in nine papers. Environmental factors were rarely evaluated.

INTERPRETATION

AIS outcome studies addressing the relationship between body structures and functions (e.g. brain lesion characteristics, neurological examination findings) and activities, participation, and quality of life have emerged in recent years. Comparison of findings across studies is complicated by design and tool selection. The relationship between components of activity limitation and participation restriction is rarely explored.

Is executive function intact after pediatric intracranial hemorrhage? A sample of Mexican children with hemophilia

The goal of this study was to examine executive functioning outcomes in children with hemophilia who have suffered intracranial hemorrhage. We assessed 10 boys with hemophilia with intracranial hemorrhage; 6 boys with hemophilia without intracranial hemorrhage; and 10 healthy boys as controls. Intellectual functioning was assessed with subscales from the Wechsler Intelligence Scale for Children-Mexican Revision. Concept formation and reasoning, cognitive flexibility, and planning and organization domains from a neuropsychological assessment battery for Spanish-speaking children were employed for our analysis. Results indicated that children with intracranial hemorrhage demonstrated significant impairment on some measures of executive function compared with the control groups. All differences reflected poorer performance by the intracranial hemorrhage group. These results may reflect the impact of disruption to immature brain circuits and the deficiency of functional specificity within the immature brain. This is the only known study examining neuropsychological functioning in Mexican youth with hemophilia.

Cerebrovascular disorders in childhood

Cerebrovascular problems in childhood include diverse problems of vascular supply to the brain and occur with an overall frequency of from 5 to 8/100000 children/year. Signs and symptoms at manifestation are manifold. They depend not only on localization of the infarction but also on age at injury and specific risk factors. Acute arterial ischemic insult in neonates is oligosymptomatic (short-lasting seizures); hemiparesis is the most common symptom in children. Risk factors are multiple for both neonates and children, with more thromboembolic events in neonates and (infection-related) vasculopathies or cardiac problems in children. MRI (diffusion weighted) is the golden standard for diagnosis. In the absence of evidence for treatment in both groups, guidelines suggest use of platelet aggregation. There are some special indications for anticoagulation. Thrombolysis should be evaluated. Two-thirds of children and neonates face lifelong neurological and neuropsychological problems. Spinal artery ischemia presents with acute spinal symptoms, mostly paraplegia. Risk factors and prognosis are similar to cerebral insults. Sinus venous thromboses are significantly less common. Provoking factors in newborns are mainly neonatal problems, and in children infections, especially in the ENT region. For diagnosis the delta sign in CT is less sensitive than MR/MR venography. In the absence of any evidence, LMWH or heparinization for 3-6 months are recommended. Prognosis is better in children than in neonates. Deep vein thrombosis and/or young age worsen the outcome.

Stroke caused auditory attention deficits in children

OBJECTIVE

To verify the auditory selective attention in children with stroke.

METHODS

Dichotic tests of binaural separation (non-verbal and consonant-vowel) and binaural integration - digits and Staggered Spondaic Words Test (SSW) - were applied in 13 children (7 boys), from 7 to 16 years, with unilateral stroke confirmed by neurological examination and neuroimaging.

RESULTS

The attention performance showed significant differences in comparison to the control group in both kinds of tests. In the non-verbal test, identifications the ear opposite the lesion in the free recall stage was diminished and, in the following stages, a difficulty in directing attention was detected. In the consonant- vowel test, a modification in perceptual asymmetry and difficulty in focusing in the attended stages was found. In the digits and SSW tests, ipsilateral, contralateral and bilateral deficits were detected, depending on the characteristics of the lesions and demand of the task.

CONCLUSION

Stroke caused auditory attention deficits when dealing with simultaneous sources of auditory information.

The reorganized brain: how treatment strategies for stroke and amblyopia can inform our knowledge of plasticity throughout the lifespan

Neural plasticity plays a crucial role in human development. During development, neural networks are shaped by experience-dependent processes that selectively strengthen and prune connections so that those that remain match the environment and process it optimally. Over time, neural connections become more stable, forming widely distributed, interconnected networks involving balanced excitation and inhibition and structural stabilizers like myelin. It was long believed that the potential for organization or reorganization existed only during early development. However, the successful treatments for adults with stroke or amblyopia discussed in this issue suggest that the potential for significant reorganization persists well into adulthood. Thus, development can be thought of as the stabilization of connections to match the current environment but with considerable residual plasticity that can be revealed if there is a shift in the excitatory: inhibitory balance or the removal of the structural stabilizers.

Der Einfluss von Schlaganfällen im Kindes- und Jugendalter auf die kognitive Entwicklung

Schlaganfälle ereignen sich im Kindesalter nur selten, haben jedoch für betroffene Kinder große Auswirkungen auch auf kognitive Fähigkeiten. Die vorliegende Studie analysiert die Intelligenzleistung von 103 Kindern nach einem Schlaganfall im Versorgungsgebiet der Arteria cerebri media. Dabei zeigt sich, dass das Alter zum Zeitpunkt der Schädigung einen großen Einfluss auf das Leistungsniveau hat. Kinder mit perinatalen Schlaganfällen schneiden in den Intelligenztestskalen insgesamt am schlechtesten ab. Dabei weist eine antikonvulsive Medikation zur Epilepsiebehandlung einen zusätzlichen Effekt auf. Ereignet sich der Schlaganfall nach dem sechsten Lebensjahr, können lateralisierte Effekte sichtbar gemacht werden: nach linkshemisphärischen Infarkten zeigen sich Sprachleistungen reduziert, rechtshemisphärische Schlaganfälle wirken sich auf visuell-räumliche Leitungen aus. Die Ergebnisse weisen auf die Notwendigkeit langfristiger neuropsychologischer Begleitung der Kinder und Jugendlichen hin.

Challenges in the diagnosis and treatment of pediatric stroke

Stroke in children is rarely due to traditional stroke risk factors such as hypertension and diabetes. Rather, stroke in this patient group typically results from the simultaneous occurrence of multiple stroke risk factors, the presence of which necessitates a thorough evaluation to determine the cause of this disorder. Several challenges exist in the care of children with stroke. Of note, recognition of pediatric stroke onset by parents and caregivers is often delayed, highlighting the need for increased awareness of and education regarding this condition. Moreover, various neurological conditions resemble stroke in pediatric patients and a definite diagnosis of this disorder requires MRI; adding to the diagnostic challenge, young children may need to be sedated to undergo acute MRI. Perhaps the most significant challenge is the need for clinical research studies focusing on pediatric stroke treatment, so as to allow evidence-based treatment decision-making. A final challenge is the standardization of outcome assessment after stroke for a wide range of ages and developmental levels. In this Review, we examine recent findings and diagnostic issues pertaining to both arterial ischemic stroke and hemorrhagic stroke in children.

Executive function following child stroke: the impact of lesion location

Child stroke is a major cause of death in children, although limited information exists on neurobehavioral functioning of stroke survivors. Executive function (important for goal-directed behavior) is thought to be vulnerable to early insults such as stroke because of its widespread representation in the immature brain. This study investigated the impact of lesion location on executive skills. Twenty-eight children diagnosed with stroke at least 18 months before assessment were recruited. Lesion characteristics were coded from magnetic resonance imaging (MRI) scans. Neurobehavioral assessment focused on cognitive and everyday executive skills. Deficits were found in the context of overall normal intellectual functioning (M = 91.60; SD = 19.40). Generally, insults involving frontal and extra-frontal regions impacted equally on cognitive performance. Everyday deficits were marginally more prominent following frontal insult. Subcortical frontal lesions were associated with impairments in everyday executive skills. Results provide further support for the diffuse representation of executive function in the immature brain.

Long-term cognitive outcomes after pediatric stroke

This study assessed neurocognitive and neurologic outcomes of children with neonatal and childhood strokes. Twenty-one children with neonatal (mean age, 6.86 years) and 10 children with childhood (mean age, 8.21 years) strokes, identified via the Estonian Pediatric Stroke Database (1995-2006), participated. A developmental neuropsychologic assessment was used for neurocognitive outcomes, and the Paediatric Stroke Outcome Measure for neurologic outcomes. Neuromotor impairment was evident in 62% of children with neonatal strokes, and in 70% of children with childhood strokes. Compared with control subjects, children with strokes exhibited worse attention, language, memory, and sensorimotor functions. The sensorimotor domain comprised the most impaired neurocognitive area, whereas executive functions remained intact in both stroke groups. A well-preserved executive function may account for the normal range of intelligence in children with strokes. More severe impairment in neurocognitive skills was evident after neonatal strokes, and the visuospatial domain was more impaired than in children from the childhood group. Prognoses were worse after left hemisphere strokes associated with epilepsy. Our results on emerging neurocognitive deficits in several areas underline the importance of neuropsychologic testing and the follow-up of children with pediatric strokes.

Pediatric stroke: the importance of cerebral arteriopathy and vascular malformations

PURPOSE

Population-based estimates of the annual incidence of childhood stroke range from 2 to 13 per 100,000 person-years. More than half of children who have had a stroke have long-term neurological sequelae. The goal of this article is to review recent literature on both hemorrhagic and ischemic stroke in children with a focus on cerebral arteriopathy and vascular malformations as stroke risk factors. Additionally, we review diagnostic studies for childhood stroke, outcome data, and regional and geographic practice differences.

METHODS

PubMed was searched using the terms child, childhood, pediatric, stroke, ischemic, intracerebral hemorrhage, vasculopathy, and vascular malformation. Reference lists of these articles were reviewed for additional key publications. Preference was given to articles published since the year 2000; however, seminal articles in the field were also reviewed.

RESULTS

Pediatric stroke is a heterogeneous disorder and a major cause of morbidity in the pediatric population. Five-year recurrence risk is estimated to be 5-19%. Children with cerebrovascular abnormalities are at the highest risk of recurrence (66% at 5 years for ischemic stroke in one study). Furthermore, cerebral arteriopathy including arterial dissection may account for up to 80% of childhood stroke in otherwise healthy children.

CONCLUSION

In many cases, evaluation and treatment of pediatric stroke is not evidence-based, and regional and geographic variations in practice patterns exist. Ultimately multicenter cohort studies and dedicated pediatric clinical trials are essential to establish comprehensive evidence-based guidelines for pediatric stroke care.

Cerebrovascular complications in pediatric intensive care unit

Cerebrovascular complications are being frequently recognized in the pediatric intensive care unit in the recent few years. The epidemiology and risk factors for pediatric stroke are different from that of the adults. The incidence of ischemic stroke is almost slightly more than that of hemorrhagic stroke. The list of diagnostic causes is increasing with the availability of newer imaging modalities and laboratory tests. The diagnostic work up depends on the age of the child and the rapidity of presentation. Magnetic resonance imaging, computerized tomography and arteriography and venography are the mainstay of diagnosis and to differentiate between ischemic and hemorrhagic events. Very sophisticated molecular diagnostic tests are required in a very few patients. There are very few pediatric studies on the management of stroke. General supportive management is as important as the specific treatment. Most of the treatment guidelines and suggestions are extrapolated from the adult studies. Few guidelines are available for the use of anticoagulants and thrombolytic agents in pediatric patients. So, our objective was to review the available literature on the childhood stroke and to provide an insight into the subject for the pediatricians and critical care providers.

Paediatric arterial ischaemic stroke: functional outcome and risk factors

AIM

To study functional outcome in children aged 1 month to 18 years after paediatric arterial ischaemic stroke (PAIS) and to identify risk factors influencing their quality of life.

METHOD

In a consecutive series of 76 children (35 males 41 females, median age at diagnosis 2y 6mo, range 1mo-17y 2mo; median length of follow-up 2y 4mo, range [7mo-10y 6mo]) with PAIS diagnosed at the Erasmus Medical Centre Sophia Children's Hospital between 1997 and 2006, we collected clinical, biochemical, and radiological data prospectively. In 66 children surviving at least 1 year after PAIS, functional outcome could be evaluated with the World Health Organization's International Classification of Impairments, Disabilities and Handicaps.

RESULTS

Significant risk factors at presentation for a poor neurological outcome were young age, infarction in the right middle cerebral artery territory, and fever at presentation. Fifty-four % of children had severe neurological impairments at 12 months after PAIS, and at last follow-up more than half needed remedial teaching, special education, or institutionalization. Health-related quality of life (HRQOL) questionnaires showed a significantly lower HRQOL in all age groups. Children with a longer follow-up had a lower HRQOL in the cognitive functioning domain.

INTERPRETATION

Our study shows significant morbidity and mortality and a reduced HRQOL after PAIS depending on age, fever at presentation, and infarction in the right middle cerebral artery territory.

Paediatric stroke: the need for interdisciplinary models of care

Stroke is an important cause of mortality and long-term morbidity in children. The aetiology of stroke in childhood differs from that of adults, with vasculopathies and congenital heart disease being the most commonly identified risk factors. Recognition and diagnosis are often delayed, limiting access to acute medical interventions such as thrombolysis. Optimal management of stroke in children is still not known and existing guidelines are at the level of expert consensus. Interdisciplinary childhood stroke programmes are required to meet the needs of this population and to contribute to the development of evidence-based therapies.

Arterial ischemic stroke in children--recent advances

Childhood stroke syndromes are an important cause of mortality and morbidity. This paper focuses on the recent advances in arterial ischaemic stroke beyond the neonatal period. Vascular risk factors are identified in the majority of children and guide both acute and longer term treatments, as well as determining prognosis. Contrary to popular belief many children have residual impairments encompassing a wide range of domains. National and international collaborations are facilitating an increase in the understanding of childhood stroke and have the eventual aim of conducting trials of potential therapeutic interventions.

Brain lesions and IQ: recovery versus decline depends on age of onset

A growing literature suggests that early lesions are associated with poorer IQ outcome. Those studies covered a restricted age range in pediatric populations only and did not control for important moderator variables. The present investigation studied IQ change in brain-lesioned children and adults (age 0 to 84 years). Altogether, 725 cases with a documented unilateral focal lesion were gathered from hospital charts and from published cases in the literature, including 240 with repeated IQ testing. Multiple regression analyses isolated the contribution of age at lesion onset to IQ change. Important mediator variables included were lesion side, site, volume, etiology, and so on. An early lesion was significantly associated with poorer postlesion IQ in time and with decline of IQ in time. Later onset lesions were associated with better postlesion IQ and recovery in time. The so-called Kennard principle is refuted, with regard to IQ.

Neuropsychologic outcomes in a case series of twins discordant for perinatal stroke

Perinatal stroke may affect cognitive development, but few studies have addressed the details of cognitive function after perinatal stroke. The present study was designed to compare the neuropsychologic features of five sets of twins discordant for perinatal stroke. All of the affected children had unilateral middle cerebral artery infarction (two left, three right); four of the five infarcts were large-branch, affecting the entire M1 territory. Three of the five affected children had comorbid epilepsy. Measures of intelligence, memory, language, attention, executive function, visual-motor integration, and fine motor skills were administered to children at a median age of 5 years (range, 5-8 years). Relative to their unaffected co-twins, the twins with perinatal stroke exhibited lower levels of full scale (p=0.005), verbal (p=0.006), and nonverbal (p=0.005) intelligence. Children with perinatal stroke also showed significant deficits on tests of verbal memory (p=0.041), receptive language (p=0.011), verbal fluency (p=0.019), and visual attention (p=0.011), compared with their unaffected co-twins. Twin gestation may be a risk factor for poor cognitive outcome after perinatal stroke. Large infarct size and comorbid epilepsy may have contributed to some of the poor cognitive outcomes in this cohort.

Early cognitive outcome after neonatal stroke

The purpose of this study was to assess the cognitive development of 27 children with nonhemorrhagic neonatal stroke (occurring within the first 28 days of life). The cognitive evaluation consisted of the Bayley Scales of Infant Development, administered at 12 and/or 24 months poststroke. Compared with the normative sample, children with neonatal stroke obtained significantly lower scores on the Bayley Psychomotor Development Index at 12 months poststroke and on the Bayley Mental and Psychomotor Development Indices at 24 months poststroke. Outcome did not differ based on stroke type or laterality of infarct. However, there was a trend toward higher scores on the Bayley Psychomotor Development Index at 24 months in the left hemisphere group compared to the right hemisphere group. Overall, children with neonatal stroke evidenced significant impairment within the first 2 years poststroke. Further research is required to confirm whether cognitive impairments in these children resolve, remain in the low-average range, or increase with development as more complex skills are learned.

Ischemic stroke in children with critical illness: a poor prognostic sign

A consecutive case series of 55 children (0-17 years old) with arterial ischemic stroke is reported. Twenty of these children were critically ill at the time their stroke occurred. Mortality among these 20 children was 40%, compared with 3% in non-critically ill children with arterial ischemic stroke; overall mortality in this case series was 16%. Mortality resulted primarily from the underlying illness. Prognosis after stroke is markedly worsened in children with premorbid critical illness.

Schlaganfälle im Kindes- und Jugendalter

Zusammenfassung. Schlaganfälle im Kindes- und Jugendalter gehören zu den seltenen Erkrankungen des Kindesalters. Die neurologischen Beeinträchtigungen verursachen sehr unterschiedliche neuropsychologische Defizite. Art und das Ausmaß der kognitiven Beeinträchtigungen hängen wesentlich vom Alter der Kinder zum Zeitpunkt des Schlaganfalls und von der Lokalisation der Schädigung ab. Eine neuropsychologisch orientierte Diagnostik kann wertvolle Ansatzpunkte zur Therapie der kognitiven Defizite sowie der schulbezogenen Lernstörungen liefern. Dabei spielen Aufmerksamkeits- und Gedächtnisstörungen auch bei der Beurteilung der allgemeinen Intelligenz von Kindern mit einem Schlaganfall eine zentrale Rolle. Therapeutische Bemühungen erfordern aufgrund der Vielschichtigkeit von Beeinträchtigungen nach einem Schlaganfall im Kindes- und Jugendalter einen multidisziplinären Ansatz.

Physiological correlates of intellectual function in children with sickle cell disease: hypoxaemia, hyperaemia and brain infarction

Lowered intelligence relative to controls is evident by mid-childhood in children with sickle cell disease. There is consensus that brain infarct contributes to this deficit, but the subtle lowering of IQ in children with normal MRI scans might be accounted for by chronic systemic complications leading to insufficient oxygen delivery to the brain. We investigated the relationship between daytime oxyhaemoglobin saturation (SpO2), cerebral blood flow velocity (CBFV) and intellectual function (IQ) using path-analysis in 30 adolescents with sickle cell disease (mean age 17.4 years, SD 4.2). Initial analyses revealed that the association between SpO2 and Full Scale IQ (FSIQ) was fully mediated by increased CBFV, whereby SpO2 was negatively correlated with CBFV and CBFV was negatively correlated with FSIQ, i.e. decreases in oxygen saturation are associated with increases in velocity, and increased velocity is associated with lowered IQ scores. The mediated relationship suggests that lowered IQ may be a function of abnormal oxygen delivery to the brain. Further analyses showed that the association between CBFV and IQ was significant for verbal but not for performance IQ. The pathophysiology characteristic of SCD can interfere with brain function and constrain intellectual development, even in the absence of an infarct. This supports the hypothesis that lowered intellectual function is partly explained by chronic hypoxia, and has wider implications for our understanding of SCD pathophysiology.

Hypoxic adaptation during development: relation to pattern of neurological presentation and cognitive disability

Children with acute hypoxic-ischaemic events (e.g. stroke) and chronic neurological conditions associated with hypoxia frequently present to paediatric neurologists. Failure to adapt to hypoxia may be a common pathophysiological pathway linking a number of other conditions of childhood with cognitive deficit. There is evidence that congenital cardiac disease, asthma and sleep disordered breathing, for example, are associated with cognitive deficit, but little is known about the mechanism and whether there is any structural change. This review describes what is known about how the brain reacts and adapts to hypoxia, focusing on epilepsy and sickle cell disease (SCD). We prospectively recorded overnight oxyhaemoglobin saturation (SpO2) in 18 children with intractable epilepsy, six of whom were currently or recently in minor status (MS). Children with MS were more likely to have an abnormal sleep study defined as either mean baseline SpO2 <94% or >4 dips of >4% in SpO2/hour (p = .04). In our series of prospectively followed patients with SCD who subsequently developed acute neurological symptoms and signs, mean overnight SpO2 was lower in those with cerebrovascular disease on magnetic resonance angiography (Mann-Whitney, p = .01). Acute, intermittent and chronic hypoxia may have detrimental effects on the brain, the clinical manifestations perhaps depending on rapidity of presentation and prior exposure.

Stroke in Childhood

BACKGROUND

Childhood stroke is increasingly recognized as an important cause of morbidity and mortality. Risk factors for stroke in childhood are different than those traditionally seen in adults.

REVIEW SUMMARY

This review summarizes, in brief, the epidemiology, risk factors, evaluation, treatment, outcome, and recurrence risk of children with arterial ischemic stroke (AIS). Areas of controversy and those that require further study are highlighted. Tables summarizing important points of the history, physical examination, and diagnostic evaluation of AIS are provided.

CONCLUSIONS

Children with stroke should be carefully evaluated for risk factors and possible etiology of stroke. At the present time, treatment is based upon extrapolation from the adult literature and expert opinion, as no evidence-based guidelines exist, except in sickle cell anemia. International, multicenter trials are beginning and should provide some answers over the next few years.

Aphasia owing to subcortical brain infarcts in childhood

The aim of this study was to further define the clinical features of subcortical aphasia in children with deep brain infarcts and to define the sequelae associated with childhood strokes. We retrospectively studied nine children with left subcortical brain infarcts who presented with acquired language disorder and underwent language investigations based on standardized tests. Stroke in these patients involved the left internal capsule, lenticular or thalamic nuclei, or a combination of these. Early aphasic manifestations following the deep cerebral infarcts affected language expression. These included mutism, nonfluent speech, word finding difficulties, and phonemic and semantic paraphasia. Speech comprehension was generally more preserved. All patients subsequently improved, although variably; sequelae such as dysfluency, word finding difficulties, and written language learning impairment could be detected through standardized tests in six of them (all younger than 6 years at the time of the infarct). Two of the three remaining patients (both older than 6 years at the time of the infarct) had a full recovery. Our study confirms the concept of childhood subcortical aphasia, depicts the linguistic profile in these patients, and sustains the indication of systematic formal language assessment during the follow-up of all children with subcortical infarct involving the dominant hemisphere.

Short-term intellectual outcome after arterial ischemic stroke and sinovenous thrombosis in childhood and infancy

Arterial ischemic stroke is approximately four times more prevalent than sinovenous thrombosis and has been associated with a worse neurologic outcome than sinovenous thrombosis; however, no data are available comparing intellectual outcome after pediatric arterial ischemic stroke and sinovenous thrombosis. We report the short-term intellectual outcome (mean 5.8 months since stroke) in a sample of 72 children, 47 with arterial ischemic stroke, and 25 with sinovenous thrombosis. Intellectual outcome measures were the Full-Scale IQ of the age-appropriate Wechsler intelligence test for older children and the Mental Developmental Index of the Bayley Scales of Infant Development for younger children. Stroke type did not directly influence intellectual outcome. Intellectual outcome was in the normal range whether the children had suffered an arterial ischemic stroke or a sinovenous thrombosis.

A matched lesion analysis of childhood versus adult-onset brain injury due to unilateral stroke: another perspective on neural plasticity and recovery of social functioning

BACKGROUND

The literature on neuroplasticity lacks a direct comparison of chronic neuropsychological and social outcomes following brain damage acquired in childhood versus adulthood, when lesions are matched across adults and children for size and location.

METHODS

We paired adults and children with similar unilateral stroke lesions and then compared chronic neuropsychological and social outcomes. Quantitative comparisons were conducted, as well as qualitative analyses of each subject pair, focusing on specific domains of cognitive impairment and changes in social functioning.

RESULTS

We found that learning and memory impairments were most common in both children and adults. Left hemisphere-lesioned children were normal on speech/language ratings, whereas their adult counterparts were borderline impaired. Impairments in social functioning were highly associated with hemispheric side of damage in adults, but not in children: Specifically, adults with right hemisphere lesions developed social defects much more frequently than adults with left hemisphere lesions, whereas this asymmetry was not evident in the children. Most importantly, though, was the overarching finding of a high degree of similarity between chronic neuropsychological and social function outcomes in adults and children with similarly located brain lesions due to unilateral stroke.

CONCLUSIONS

On balance, the findings suggest that lesion location and size are prepotent factors determining neuropsychological and social recovery from stroke.

Thrombosis during infancy and childhood: what we know and what we do not know

Despite underlying illnesses, children have a greater chance to survive and are expected to live 6 to 8 decades following an episode of venous or arterial thrombosis. The disproportionate benefits of preventing thrombosis and its sequelae in pediatric patients are evident. Therefore, it is necessary to develop appropriate strategies for diagnosis and management of thromboembolic events in children and to understand their acute and long-term effects. There still are many unanswered questions and clinical trials are being designed to help study these important issues.

The clinical outcomes of neonatal and childhood stroke: review of the literature and implications for future research

A detailed assessment of clinical outcomes after ischemic stroke in childhood is necessary to evaluate prognostic factors. Previous studies are difficult to compare because of differences in test instruments, study design, heterogeneity of cohorts and number of included cases. Depending on neurodevelopmental assessment methods, major and subtle/minor disabilities, especially in infants, may not have been detected. Most outcome studies reveal only limited information about behavioral changes and quality of life in children with ischemic stroke. Thus the assumption that children make a better recovery from stroke than adults due to the immature brain's capacity to reorganize function is not evidence-based. We systematically review the current literature with regard to the neurological and psychosocial development of affected children as well as their quality of life. Implications for future research strategies follow the review to encourage further clinical study of the neurobehavioral trajectory of childhood stroke.

Effect of side of lesion on neuropsychological performance in childhood stroke

The purpose of the current study was to examine the effect of side of lesion on neuropsychological performance in childhood stroke. While laterality effects have been shown fairly consistently in adults who have experienced stroke, results from studies on children who have experienced childhood stroke are not as clear. Numerous methodological differences between previous studies on laterality effects in childhood stroke make it difficult to draw overall conclusions regarding laterality findings. The current study aimed to study a single group of children who experienced stroke in childhood across a number of cognitive domains. The participants were 13 children/adolescents with left hemisphere lesions and 16 children/adolescents with right hemisphere lesions, with a range of onset from prenatal to 13 years. All participants were administered a broad battery of neuropsychological tests including tests of intelligence, achievement, language skills, visuospatial skills, memory, and executive functioning. No significant differences were found between the groups on any of the measures and the calculated effect sizes were small for all but one of the measures examined. These results have implications for a greater understanding of the ability of the young brain to reorganize after childhood stroke.