Executive function following child stroke: the impact of lesion location

Predictors of neurocognitive outcome in pediatric ischemic and hemorrhagic stroke

This clinical study examined the impact of eight predictors (age at stroke, stroke type, lesion size, lesion location, time since stroke, neurologic severity, seizures post-stroke, and socioeconomic status) on neurocognitive functioning following pediatric stroke. Youth with a history of pediatric ischemic or hemorrhagic stroke (n = 92, ages six to 25) underwent neuropsychological testing and caregivers completed parent-report questionnaires. Hospital records were accessed for medical history. Spline regressions, likelihood ratios, one-way analysis of variance, Welch's t-tests, and simple linear regressions examined associations between predictors and neuropsychological outcome measures. Large lesions and lower socioeconomic status were associated with worse neurocognitive outcomes across most neurocognitive domains. Ischemic stroke was associated with worse outcome in attention and executive functioning compared to hemorrhagic stroke. Participants with seizures had more severe executive functioning impairments than participants without seizures. Youth with cortical-subcortical lesions scored lower on a few measures than youth with cortical or subcortical lesions. Neurologic severity predicted scores on few measures. No differences were found based on time since stroke, lesion laterality, or supra- versus infratentorial lesion. In conclusion, lesion size and socioeconomic status predict neurocognitive outcome following pediatric stroke. An improved understanding of predictors is valuable to clinicians who have responsibilities related to neuropsychological assessment and treatments for this population. Findings should inform clinical practice through enhanced appraisals of prognosis and the use of a biopsychosocial approach when conceptualizing neurocognitive outcome and setting up support services aimed at fostering optimal development for youth with stroke.

Predictors of externalizing behavior outcomes following pediatric stroke

Children who experience pediatric stroke are at higher risk for future behavioral problems in childhood. We examined the prevalence of parent reported externalizing behaviors and executive function problems in children following stroke and neurological predictors. This study included 210 children with pediatric ischemic stroke (mean age 9.18 years (SD = 3.95)). The parent form of the Behavioral Assessment System for Children-Second Edition (BASC-2) and Behavior Rating Inventory of Executive Function (BRIEF) were used to evaluate externalizing behavior and executive function. No externalizing behavior or executive function differences were found between perinatal (n = 94) or childhood (n = 116) stoke, except for the shift subscale which had higher T-scores among the perinatal group (M = 55.83) than childhood group (M = 50.40). When examined together, 10% of children had clinically elevated hyperactivity T-scores as opposed to the expected 2%. Parents endorsed higher ratings of concern on the behavior regulation and metacognition indices of the BRIEF. Externalizing behaviors were correlated moderately to strongly with executive functions (r = 0.42 to 0.74). When examining neurological and clinical predictors of externalizing behaviors, only female gender was predictive of increased hyperactivity (p = .004). However, there were no significant gender differences in diagnosis of attention deficit hyperactivity disorder (ADHD). In summary, in this cohort, children with perinatal and childhood stroke did not differ on parent reported externalizing behavior or executive function outcomes. However, compared to normative data, children with perinatal or childhood stroke are significantly more likely to experience clinically elevated levels of hyperactivity.

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.

20 years on: Confirmation of P. Anderson's (2002) paediatric model of executive functioning in a healthy adult sample

Executive Functioning (EF) is a construct that encompasses multiple interrelated higher order skills, however, conceptualising this nebulous construct remains challenging. This study aimed to confirm the validity of Anderson's (2002) paediatric model of EF in a healthy adult sample using congeneric modelling. Measures of EF were selected based on utility with adult populations giving rise to minor methodological differences from the original paper. Separate congeneric models were constructed using each of Anderson's constructs in order to isolate the sub-skills represented by each (Attentional Control-AC, Cognitive Flexibility-CF, Information Processing-IP, Goal Setting-GS), with a minimum of three tests per subskill. One hundred and thirty-three adults (42 males and 91 females) aged between 18 and 50 (M = 29.68, SD = 7.46) completed a cognitive test battery comprising 20 EF tests. AC revealed a good fitting model χ²(2) = 1.61, p = .447, RMSEA = 0.000, CFI = 1.000, after removing the non-significant indicator Map Search (p = .349), and BS-Bk as BS-Bk was required to covary with both BS-Fwd (M.I = 7.160, Par Change = .706), and TMT-A (M.I = 5.759, Par Change = -2.417). CF revealed a good fitting model χ²(8) = 2.90, p = .940, RMSEA = 0.000, CFI = 1.000 after covarying TSC-E and Stroop (M.I = 9.696, Par Change = .085). IP revealed a good fitting model χ²(4) = 1.15, p = .886, RMSEA = 0.000, CFI = 1.000 after covarying Animals total and FAS total (M.I. = 4.619, Par Change = 9.068). Lastly, GS indicated a good fitting model χ²(8) = 7.22, p = .513, RMSEA = 0.000, CFI = 1.000 after covarying TOH total time and PA (M.I = 4.25, Par Change = -77.868). Therefore, all four constructs were reliable and valid, and the utility of a parsimonious EF battery is suggested. Investigation of the inter-relationships between the constructs using regression techniques, de-emphasises the role of Attentional Control and argue instead for capacity bound skills.

Roadmap for the Assessment and Management of Outcomes in Pediatric Stroke

Neurological morbidity is common after pediatric stroke, with moderate to severe deficits that can significantly impact education and social function. Care and recovery occur in phases distinguished by the time interval after stroke onset. These phases include the hyperacute and acute periods in which the focus is on cerebral reperfusion and prevention of neurological deterioration, followed by the subacute and chronic phases in which the focus is on secondary stroke prevention and mitigation of disability through rehabilitation, adaptation, and reintegration into the community. In this article, a multidisciplinary group of pediatric stroke experts review the stages of recovery after pediatric stroke with an emphasis on critical assessment time points. Our goal is to encourage increased standardization of outcome assessment to facilitate future clinical trials comparing various treatment and intervention options and advance optimized care for children with stroke.

The impact of subcortical stroke-related aphasia on executive functions and working memory

Aphasia is a common post-stroke disorder characterized by impairments in speaking, listening, reading, and writing. Although cognitive impairments have been well studied in cortical aphasia, deficits associated with subcortical aphasia remain to be elucidated. The current study aimed to assess executive functions (EF) and working memory (WM) in patients with subcortical aphasia, and investigate the relationship between language abilities and cognition deficits. Participants of this research included patients with thalamus lesions (n = 9; mean age = 53.89 years) and healthy individuals (n = 9; mean age = 54.33 years). Assessment materials were the Mini-Mental State Examination (MMSE), Persian Western Aphasia Battery (P-WAB-1), digit span subtest of Adult Wechsler Test (WAIS-R), and Wisconsin Card Sorting Test (WCST). Obtained results revealed significant differences in all components of EF, as well as in WM forward and backward digit spans between patients and healthy individuals. However, investigating the relationship between MMSE and AQ scores and components of EF and WM revealed no significant difference. In conclusion, the findings of the present research indicated defects in cognitive functions, including WM and EF, in patients with subcortical stroke. Accordingly, it is crucial to provide optimal rehabilitation therapies for the improvement of language and cognitive problems upon subcortical aphasia.

[Formula: see text] Executive functions and psychosocial impairment in children following arterial ischemic stroke

This study examined the executive function (EF) of children with a history of arterial ischemic stroke (AIS) and preserved intellectual abilities, with reference to age at stroke onset, lesion characteristics, language, and motor functioning. In addition, the associations between EF and emotional and behavioral functioning were investigated. A battery of standardized neuropsychological tests was administered to children with previous AIS aged 7-12 in order to assess EF, including inhibition, working memory, cognitive flexibility, and attention. Parents rated questionnaires regarding real-life emotional and behavioral functioning. Finally, clinical and neuroradiological data were also gathered. Thirty patients were enrolled. Eight children fall in the lower end of the normative range or below in more than half of the EF measures, with working memory, inhibition and cognitive flexibility equally impaired, and attention relatively better preserved. Larger lesion size and language deficits were significantly associated with higher EF impairment. Emotional and behavioral functioning was lower in children with weaker EF. Children with a history of AIS, even those with preserved intellectual functioning, have a high risk of showing poor EF, mostly regardless of clinical features or functional impairment. EF difficulties are in turn associated with emotional and behavioral problems. Therefore, a standardized evaluation of EF in this population is mandatory as part of the follow-up, in order to ensure an early intervention and prevent related difficulties.

Visuospatial processing skills following unilateral arterial ischemic stroke in childhood

Due to the rare occurrence of childhood stroke, its impact on later cognitive functioning remains unclear. While it is often assumed that children recover better than adults, recent studies suggest that childhood stroke can negatively affect a wide range of cognitive domains, such as attention, language, and processing speed, among others. We examined the effect of unilateral stroke on children's visuoconstructive ability and visual memory. Seventeen children with left- or right-sided arterial ischemic stroke were tested using subtests of the Hamburg-Wechsler Intelligenztest für Kinder and the Rey-Osterrieth Complex Figure (ROCF). The ROCF was evaluated both quantitatively and qualitatively with the help of two separate scoring methods. We found that lesion laterality and age at stroke impacted childhood stroke patients' ability to recall certain elements of the figure. Regarding lesion laterality, left-sided stroke patients had more difficulties recalling internal details than right-sided stroke patients. In terms of age, patients with stroke onset before the age of 5 years remembered fewer structural elements than patients with stroke onset after the age of 5 years did. Moreover, the qualitative scoring method better differentiated between individuals and between groups than the more commonly used quantitative method. The results of this study not only highlight the importance of a qualitative assessment of the ROCF but could also aid clinicians in testing stroke patients more accurately and tailoring subsequent therapy to the patient's individual needs.

Neurological and Functional Outcomes after Pediatric Stroke

Pediatric stroke results in life-long morbidity for many patients, but the outcomes can vary depending on factors such as age of injury, or mechanism, size, and location of stroke. In this review, we summarize the current understanding of outcomes in different neurological domains (eg, motor, cognitive, language) for children with stroke of different mechanisms (ie, arterial ischemic stroke, cerebral sinus venous thrombosis, and hemorrhagic stroke), but with a focus on World Health Organization International Classification for Functioning, Disability, and Health (ICF-CY) framework for measuring health and disability for children and youth. We describe outcomes for the population as a whole and certain factors that may further refine prognostication.

Cognitive outcome is related to functional thalamo-cortical connectivity after pediatric stroke

The thalamus has complex connections with the cortex and is involved in various cognitive processes. Despite increasing interest in the thalamus and the underlying thalamo-cortical interaction, little is known about thalamo-cortical connections after pediatric arterial ischemic stroke. Therefore, the aim of this study was to investigate thalamo-cortical connections and their association with cognitive performance after arterial ischemic stroke.

Twenty patients in the chronic phase after pediatric arterial ischemic stroke (≥ 2 years after diagnosis, diagnosed <16 years; aged 5–23 years, mean 15.1 years) and twenty healthy controls matched for age and sex were examined in a cross-sectional study design. Cognitive performance (selective attention, inhibition, working memory, and cognitive flexibility) was evaluated using standardized neuropsychological tests. Resting-state functional magnetic resonance imaging was used to examine functional thalamo-cortical connectivity. Lesion masks were integrated in the preprocessing pipeline to ensure that structurally damaged voxels did not influence functional connectivity analyses.

Cognitive performance (selective attention, inhibition and working memory) was significantly reduced in patients compared to controls. Network analyses revealed significantly lower thalamo-cortical connectivity for the motor, auditory, visual, default mode network, salience, left/right executive and dorsal attention network in patients compared to controls. Interestingly, analyses revealed as well higher thalamo-cortical connectivity in some subdivisions of the thalamus for the default mode network (medial nuclei), motor (lateral nuclei), dorsal attention (anterior nuclei), and the left executive network (posterior nuclei) in patients compared to controls. Increased and decreased thalamo-cortical connectivity strength within the same networks was, however, found in different thalamic sub-divisions. Thus, alterations in thalamo-cortical connectivity strength after pediatric stroke seem to point in both directions, with stronger as well as weaker thalamo-cortical connectivity in patients compared to controls. Multivariate linear regression, with lesion size and age as covariates, revealed significant correlations between cognitive performance (selective attention, inhibition, and working memory) and the strength of thalamo-cortical connectivity in the motor, auditory, visual, default mode network, posterior default mode network, salience, left/right executive, and dorsal attention network after childhood stroke.

Our data suggest that the interaction between different sub-nuclei of the thalamus and several cortical networks relates to post-stroke cognition. The variability in cognitive outcomes after pediatric stroke might partly be explained by functional thalamo-cortical connectivity strength.

Impact of Age at Pediatric Stroke on Long-term Cognitive Outcome

Background and Objectives

To investigate the effect of age at pediatric arterial ischemic stroke on long-term cognitive outcome in order to identify patients particularly at risk for the development of long-term cognitive sequelae.

Methods

This cross-sectional study included patients in the chronic phase of stroke (>2 years after stroke) previously diagnosed with neonatal or childhood arterial ischemic stroke and a control group. Participants with active epilepsy, severe learning difficulties, or behavioral problems hindering the cognitive assessment were excluded. Several cognitive domains, including intelligence, executive functions (working memory, inhibition, and cognitive flexibility), processing speed, memory, letter fluency, and visual-motor skills were assessed with neuropsychological tests. Cognitive long-term outcome was compared across patients after neonatal stroke (stroke between 0 and 28 days of life), early childhood stroke (stroke between 29 days and <6 years), and late childhood stroke (stroke between ≥6 and <16 years).

Results

Fifty-two patients after neonatal or childhood arterial ischemic stroke (median age 15.3 years, interquartile range [IQR] 10.6–18.7) and 49 healthy controls (median age 13.6 years, IQR 9.8–17.2) met the inclusion criteria. Cognitive outcome was significantly worse in the pediatric stroke group compared to the control group. A nonlinear effect of age at stroke (irrespective of lesion size and lesion location) was found for cognitive flexibility, processing speed, and verbal learning with early childhood stroke (29 days to <6 years), showing significantly worse cognitive outcome compared to neonatal or late childhood stroke (p < 0.05, false discovery rate–corrected).

Discussion

Age at stroke is an important factor for poststroke recovery and modulates long-term cognitive outcome irrespective of lesion size and lesion location. Children after early childhood stroke are at particular risk for long-term alterations in cognitive functions.

Cerebral blood flow and cognitive outcome after pediatric stroke in the middle cerebral artery

Adaptive recovery of cerebral perfusion after pediatric arterial ischemic stroke (AIS) is sought to be crucial for sustainable rehabilitation of cognitive functions. We therefore examined cerebral blood flow (CBF) in the chronic stage after stroke and its association with cognitive outcome in patients after pediatric AIS. This cross-sectional study investigated CBF and cognitive functions in 14 patients (age 13.5 ± 4.4 years) after pediatric AIS in the middle cerebral artery (time since AIS was at least 2 years prior to assessment) when compared with 36 healthy controls (aged 13.8 ± 4.3 years). Cognitive functions were assessed with neuropsychological tests, CBF was measured with arterial spin labeled imaging in the anterior, middle, and posterior cerebral artery (ACA, MCA, PCA). Patients had significantly lower IQ scores and poorer cognitive functions compared to healthy controls (p < 0.026) but mean performance was within the normal range in all cognitive domains. Arterial spin labeled imaging revealed significantly lower CBF in the ipsilesional MCA and PCA in patients compared to healthy controls. Further, we found significantly higher interhemispheric perfusion imbalance in the MCA in patients compared to controls. Higher interhemispheric perfusion imbalance in the MCA was significantly associated with lower working memory performance. Our findings revealed that even years after a pediatric stroke in the MCA, reduced ipsilesional cerebral blood flow occurs in the MCA and PCA and that interhemispheric imbalance is associated with cognitive performance. Thus, our data suggest that cerebral hypoperfusion might underlie some of the variability observed in long-term outcome after pediatric stroke.

Relationship between motor abilities and executive functions in patients after pediatric stroke

Patients after pediatric stroke typically experience varying extent of motor and cognitive impairments. During rehabilitation, these impairments are often treated as separate entities. While there is a notion claiming that motor and cognitive functions are interrelated to some degree in healthy children, a minimal amount of evidence exists regarding this issue in patients after pediatric stroke. The purpose of this study was to investigate the association between motor abilities and executive functions in patients after pediatric arterial ischemic stroke. Twenty-seven patients (6 - 23 years) diagnosed with pediatric arterial ischemic stroke in the chronic phase (≥ 2 years after diagnosis, diagnosed < 16 years) and 49 healthy controls (6 - 26 years) were included in this study. Participants completed six tasks from standardized neuropsychological tests assessing the dimensions of executive functions, namely working memory, inhibition, and shifting. Additionally, we assessed hand strength and upper limb performance with two tasks each. In the patient group, the association between upper limb performance and executive functions was stronger than between hand strength and executive functions. Our results point toward the idea of a close interrelation between upper limb performance and executive functions. Training more complex and cognitively engaging motor abilities involving upper limb performance rather than basic motor abilities such as hand strength during a rehabilitation program may have the power to foster executive function development and vice versa in patients after stroke.

The clinical utility of the behavior rating inventory of executive function in preschool children with a history of perinatal stroke

The current study examined the utility of the Behavior Rating Inventory of Executive Function-Preschool Version (BRIEF-P) in capturing emerging deficits in executive function in preschool children with a history of perinatal stroke. Parents and teachers of 55 clinically referred preschool children (3-5 years of age) provided ratings using the BRIEF-P. Both parent (M = 56.02, p = .001) and teacher ratings (M = 58.61, p = .002) indicated significant scale elevations for working memory compared to the normative sample, albeit below the clinically elevated range. Parent and teacher ratings were low-to-moderately correlated (r = .05-.55). Greater deficits in working memory (r = -.58), inhibition (r = -.45), and planning/organization (r = -.51), as rated by teachers, were associated with lower intellectual functioning. Parents' ratings were not associated with intellectual functioning. Further, no neurological or personal characteristics were associated with ratings of executive function. The current study demonstrates children with a history of perinatal stroke are, on average, following a normal trajectory of executive function development according to BRIEF-P ratings. The needs for multi-informant ratings and performance-based measures to comprehensively assess executive functioning in preschoolers with a history of stroke are discussed.

[Formula: see text] Executive function following pediatric stroke. A systematic review

OBJECTIVE

Pediatric strokes are rare events that can lead to neuropsychological impairment or disability. While motor deficits are relatively easy to identify and investigate, cognitive outcomes after stroke are more complex to define. Many studies have focused on global cognitive outcomes, while only a few recent studies have focused on specific cognitive processes. The aims of the present review were to provide an overview of the effects of pediatric strokes on executive function and to investigate the relations between executive functioning and clinical factors.

METHOD

Studies concerning executive functioning after pediatric stroke were identified using PsycInfo, PsycArticles and PubMed. A total of 142 studies were identified, and 22 met the inclusion criteria.

RESULTS

The review of the 22 studies included clearly indicates that childhood and perinatal strokes can affect executive function, and in particular inhibition. In contrast, the results concerning clinical factors related to EF outcomes are inconsistent.

DISCUSSION

Our results highlight the importance to assess EF following pediatric stroke. Early identification of difficulties in EF is crucial to provide adequate training to the children and to prevent the development of other correlated difficulties, such as behavioral problems or learning difficulties. Methodological issues regarding the heterogeneity of samples and measurement difficulties limit the conclusions that can be made about the clinical predictors of the outcomes. Studies are needed to better understand this aspect and to develop adequate EF interventions for children following stroke.

Robotic assessment of rapid motor decision making in children with perinatal stroke

Background

Activities of daily living frequently require children to make rapid decisions and execute desired motor actions while inhibiting unwanted actions. Children with hemiparetic cerebral palsy due to perinatal stroke may have deficits in executive functioning in addition to motor impairments. The objective of this study was to use a robotic object hit and avoid task to assess the ability of children with hemiparetic cerebral palsy to make rapid motor decisions.

Methods

Forty-five children with hemiparetic cerebral palsy due to perinatal stroke and 146 typically developing children (both groups ages 6–19 years) completed a robotic object hit and avoid task using the Kinarm Exoskeleton. Objects of different shapes fell from the top of the screen with increasing speed and frequency. Children were instructed to hit two specific target shapes with either hand, while avoiding six distractor shapes. The number of targets and distractors hit were compared between children with hemiparetic cerebral palsy and typically developing children, accounting for age effects. We also compared performance to a simpler object hit task where there were no distractors.

Results

We found that children with hemiparetic cerebral palsy hit a greater proportion of total distractors compared to typically developing children, demonstrating impairments in inhibitory control. Performance for all children improved with age. Children with hemiparetic cerebral palsy hit a greater percentage of targets with each arm on the more complex object hit and avoid task compared to the simpler object hit task, which was not found in typically developing children.

Conclusions

Children with hemiparetic cerebral palsy due to perinatal stroke demonstrated impairments in rapid motor decision making including inhibitory control, which can impede their ability to perform real-world tasks. Therapies that address both motor performance and executive functions are necessary to maximize function in children with hemiparetic cerebral palsy.

Ischemic sequelae and other vascular diseases

Although pediatric stroke is associated with higher survival rates compared with adult stroke, a substantial body of evidence indicates significant neuropsychologic morbidity in pediatric stroke survivors. Neuroplasticity does not guarantee good outcome in children. The general trends observed in the literature are reviewed as is the profile observed in common causes of pediatric stroke: congenital heart disease, moyamoya disease, and sickle cell disease. The neuropsychologic profile of pediatric stroke patients is heterogeneous due to the multiplicity of associated causes. Stroke in early infancy and large strokes are associated with cognitive impairment while more limited disorders, such as phasic deficit, are observed in childhood stroke. Executive dysfunction is common in pediatric stroke, but social interaction skills are usually preserved. Congenital heart disease and sickle cell disease are associated with global neuropsychologic dysfunction while cognition is usually preserved in moyamoya. Executive dysregulation is instead more frequently reported in this population. Further study of maladaptive processes after pediatric stroke will allow identification of predictors of functional and neuropsychologic outcomes and permit personalization of care.

Visuospatial Attention and Saccadic Inhibitory Control in Children With Cerebral Palsy

Cerebral palsy (CP) is a non-progressive syndrome due to a pre-, peri- or post-natal brain injury, which frequently involves an impairment of non-motor abilities. The aim of this article was to examine visuospatial attention and inhibitory control of prepotent motor responses in children with CP showing a normal IQ or mild cognitive impairment, measuring their performance in oculomotor tasks. Ten children (9–16-year-old) with spastic CP and 13 age-matched, typically developing children (TDC) participated in the study. Subjects performed a simple visually-guided saccade task and a cue-target task, in which they performed a saccade towards a peripheral target, after a non-informative visual cue was flashed 150 ms before the imperative target, either at the same (valid) or at a different (invalid) spatial position. Children with CP showed severe executive deficits in maintaining sustained attention and complying with task instructions. Furthermore, saccadic inhibitory control appeared to be significantly impaired in the presence of both stimulus-driven and goal-directed captures of attention. In fact, patients showed great difficulties in suppressing saccades not only to the cue stimuli but also to the always-present target placeholders, which represented powerful attentional attractors that had to be covertly attended throughout the task execution. Moreover, impairment did not affect in equal manner the whole visual field but showed a marked spatial selectivity in each individual subject. Saccade latencies in the cue-target task were faster in the valid than in the invalid condition in both child groups, indicating the preservation of low-level visuospatial attentive capabilities. Finally, this study provides evidence that these impairments of executive skills and in inhibitory control, following early brain injuries, manifest in childhood but recover to virtually normal level during adolescence.

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.

Parameters of diffusional kurtosis imaging for the diagnosis of acute cerebral infarction in different brain regions

Diffusional kurtosis imaging (DKI) is a new type diffusion-weighted sequence which measures the non-Gaussianity of water diffusion. The present study aimed to investigate whether the parameters of DKI could distinguish between differences in water molecule diffusion in various brain regions under the conditions of acute infarction and to identify the optimal DKI parameter for locating ischemic lesions in each brain region. A total of 28 patients with acute ischemic stroke in different brain regions were recruited for the present study. The relative values of DKI parameters were selected as major assessment indices, and the homogeneity of background image and contrast of adjacent structures were used as minor assessment indices. According to the brain region involved in three DKI parametric maps, including mean kurtosis (MK), axial kurtosis (Ka) and radial kurtosis (Kr), 112 groups of regions of interest were outlined in the following regions: Corpus callosum (n=17); corona radiata (n=26); thalamus (n=21); subcortical white matter (n=24); and cerebral cortex (n=24). For ischemic lesions in the corpus callosum and corona radiata, significant increases in relative Ka were detected, as compared with the other parameters (P<0.05). For ischemic lesions in the thalamus, subcortical white matter and cerebral cortices, an increase in the three parameters was detected, however this difference was not significant. Minor assessment indices demonstrated that Ka lacked tissue contrast and the background of Kr was heterogeneous; thus, MK was the superior assessment parameter for ischemic lesions in these regions. In conclusion, Ka is better suited for the diagnosis of acute ischemic lesions in highly anisotropic brain regions, such as the corpus callosum and corona radiate. MK may be appropriate for the lesions in low anisotropic or isotropic brain regions, such as the thalamus, subcortical white matter and cerebral cortices.

[Formula: see text]Working memory outcomes following unilateral arterial ischemic stroke in childhood

There is a dearth of research examining working memory (WM) following pediatric arterial ischemic stroke (AIS). This study assesses the WM patterns of 32 children, aged 6 to 14 years, with a history of unilateral AIS and 32 controls using a paradigm based on Baddeley and Hitch's multi-component WM model. The results indicate compromised WM in children with AIS relative to controls and parent reports confirm higher rates of dysfunction. Supplementary analyses of impairment confirm higher rates in children with AIS, ranging from 31.25% to 38.70% on performance-based measures and 50.00% on parent reports, compared to 0.00% to 21.88% on performance-based measures in controls and 15.63% on parent reports. Continual follow-up is recommended given that a subset of children with stroke appear to be at risk for WM impairment. Moreover, the subtle nature of WM challenges experienced by many children who have experienced a stroke increases the likelihood that WM impairment could go undetected. The long-term trajectories of WM in the pediatric stroke population remains unknown and future studies are needed to track changes in WM functioning over time.

Environmental Contributions to Social and Mental Health Outcomes Following Pediatric Stroke

Mental health and social outcomes following acquired brain injury (ABI) in children are often considered to be due to brain insult, but other factors, such as environment, may also play a role. We assessed mental health and social function in children with chronic illness, with and without stroke (a form of ABI), and typically developing (TD) controls to examine environmental influences on these outcomes. We recruited 36 children diagnosed with stroke, 15 with chronic asthma, and 43 TD controls. Children and parents completed questionnaires rating child mental health and social function and distal and proximal environment. TD children had significantly less internalizing and social problems than stroke and asthma groups, and engaged in more social activities than children with stroke. Poorer parent mental health predicted more internalizing and social problems and lower social participation. Family dysfunction was associated with internalizing problems. Lower parent education contributed to children's social function. Children with chronic illness are at elevated risk of poorer mental health and social function. Addition of brain insult leads to poorer social participation. Quality of home environment contributes to children's outcomes, suggesting that supporting parent and family function provides an opportunity to optimize child mental health and social outcomes.

Social competence following pediatric stroke: contributions of brain insult and family environment

Limited information is available regarding predictors of psychosocial difficulties in children following stroke. This study aimed to (i) compare social competence of children with arterial ischemic stroke (AIS) to those with chronic illness and healthy controls and (ii) investigate the contribution of stroke pathology, neurological outcome and environment. Thirty-six children with AIS > 12 months prior to recruitment were compared with children with chronic illness (asthma) (n = 15) and healthy controls (n = 43). Children underwent intellectual assessment, and children and parents completed questionnaires to assess social competence. Children with AIS underwent MRI scan and neurological evaluation. Child AIS was associated with poorer social adjustment and participation, and children with AIS were rated as having more social problems than controls. Lesion volume was not associated with social outcome, but subcortical stroke was linked to reduced social participation and younger stroke onset predicted better social interaction and higher self-esteem. Family function was the sole predictor of social adjustment. Findings highlight the risk of social impairment following pediatric stroke, with both stroke and environmental factors influencing children's social competence in the chronic stages of recovery. They indicate the potential for intervention targeting support at the family level.

Determinants of cognitive outcomes of perinatal and childhood stroke: A review

Our understanding of cognitive and behavioral outcomes of perinatal and childhood stroke is rapidly evolving. A current understanding of cognitive outcomes following pediatric stroke can inform prognosis and direct interventions and our understanding of plasticity in the developing brain. However, our understanding of these outcomes has been hampered by the notable heterogeneity that exists amongst the pediatric stroke population, as the influences of various demographic, cognitive, neurological, etiological, and psychosocial variables preclude broad generalizations about outcomes in any one cognitive domain. We therefore aimed to conduct a detailed overview of the published literature regarding the effects of age at stroke, time since stroke, sex, etiology, lesion characteristics (i.e., location, laterality, volume), neurologic impairment, and seizures on cognitive outcomes following pediatric stroke. A key theme arising from this review is the importance of interactive effects among variables on cognitive outcomes following pediatric stroke. Interactions particularly of note include the following: (a) age at Stroke x Lesion Location; (b) Lesion Characteristics (i.e., volume, location) x Neurologic Impairment; (c) Lesion Volume x Time Since Stroke; (d) Sex x Lesion Laterality; and (e) Seizures x Time Since Stroke. Further, it appears that these relationships do not always apply uniformly across cognitive domains but, rather, are contingent upon the cognitive ability in question. Implications for future research directions are discussed.

Costs of pediatric stroke care in the United States: a systematic and contemporary review

A substantial literature exists regarding cost-of-care outcomes in adult stroke, however less is known about pediatric stroke. The objective of this review of the literature was to examine studies of costs associated with pediatric stroke care. Six studies reporting data from individuals who experienced a pediatric stroke were included in the review. Cost data (charges and payments) were generally limited to one year and ranged from approximately US$15,000-140,000 depending upon stroke type. Pediatric stroke is linked to substantial costs but studies primarily emphasize the direct cost of care during the first year post-stroke onset. However, since many pediatric stroke survivors experience normal lifespans, they can also accumulate a significantly greater long term cost of care than strokes that occur in adulthood. Future studies are needed to examine long term direct costs, short and long term indirect costs and other economic outcomes in this population.

Age, sex, and performance influence the visuospatial working memory network in childhood

This study describes the influence of age, sex, and working memory (WM) performance on the visuospatial WM network. Thirty-nine healthy children (7-12 years) completed a dot location functional magnetic resonance imaging (fMRI) task. Percent signal change measured the intensity and laterality indices measured the asymmetry of activation in frontal and parietal brain regions. Old children showed greater intensity of activation in parietal regions than young children but no differences in lateralization were observed. Intensity of activation was similar across sex and WM performance groups. Girls and high WM performers showed more right-sided lateralization of parietal regions than boys and low WM performers.

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.

Executive function in children and adolescents with unilateral cerebral palsy

AIM

The aim of this study was to compare executive function in children with left- and right-sided unilateral cerebral palsy (CP) and typically developing children.

METHOD

There was a cross-sectional cohort of 46 children with unilateral CP (24 right-side, 22 left-side; 25 males, 21 females; mean age 11y 1mo, SD 2y 5mo) and 20 typically developing children (nine males, 11 females; mean age 10y 10mo, SD 2y 4mo). Four cognitive domains of executive function were assessed: attentional control, cognitive flexibility, goal setting, and information processing. Subtests from the Delis-Kaplan Executive Function System, the Test of Everyday Attention for Children, the Rey-Osterrieth Complex figure, and the Wechsler Intelligence Scale for Children - Fourth Edition were utilized. Between-group differences (right unilateral CP, left unilateral CP, and typically developing children) were examined using analyses of covariance.

RESULTS

Children with CP performed significantly more poorly than typically developing children on all executive function measures (aggregate executive function: F(1,63)=31.16; p<0.001; η(2) =0.33). There were no significant differences between children with left and right unilateral CP, except in the case of inhibition/switching total errors, with children with left unilateral CP making fewer errors than children with right unilateral CP (F(1,39)=4.14; p=0.049; η(2) =0.1).

INTERPRETATION

Children and adolescents with unilateral CP experience difficulties across multiple executive function domains compared with typically developing children, irrespective of the side of hemiplegia. This finding supports an early vulnerability model of early brain injury and has implications for intervention for children with CP.

Neuropsychological and neurobehavioral outcome following childhood arterial ischemic stroke: attention deficits, emotional dysregulation, and executive dysfunction

OBJECTIVES

To investigate neuropsychological and neurobehavioral outcome in children with arterial ischemic stroke (AIS).

BACKGROUND

Childhood stroke can have consequences on motor, cognitive, and behavioral development. We present a cross-sectional study of neuropsychological and neurobehavioral outcome at least one year poststroke in a uniquely homogeneous sample of children who had experienced AIS.

METHOD

Forty-nine children with AIS aged 6 to 18 years were recruited from a specialist clinic. Neuropsychological measures of intelligence, reading comprehension, attention, and executive function were administered. A triangulation of data collection included questionnaires completed by the children, their parents, and teachers, rating behavior, executive functions, and emotions.

KEY FINDINGS

Focal neuropsychological vulnerabilities in attention (response inhibition and dual attention) and executive function were found, beyond general intellectual functioning, irrespective of hemispheric side of stroke. Difficulties with emotional and behavioral regulation were also found. Consistent with an "early plasticity" hypothesis, earlier age of stroke was associated with better performance on measures of executive function.

CONCLUSIONS

A significant proportion of children poststroke are at long-term risk of difficulties with emotional regulation, executive function, and attention. Data also suggest that executive functions are represented in widespread networks in the developing brain and are vulnerable to unilateral injury.

Executive functioning in children with unilateral cerebral palsy: protocol for a cross-sectional study

INTRODUCTION

Early brain injury, as found in children with unilateral cerebral palsy (CP), may cause deficits in higher-order cognitive tasks known as executive functions (EF). EF has been conceptualised as comprised of four distinct yet inter-related components: (1) attentional control, (2) cognitive flexibility, (3) goal setting and (4) information processing. The aim of this study was to examine EF in children with unilateral CP and compare their performance with a typically developing reference group (TDC). The potential laterality effects of unilateral CP on EF will be explored, as will the relationship between the cognitive measures of EF, behavioural manifestations of EF, psychological functioning and clinical features of unilateral CP.

METHODS AND ANALYSIS

This cross-sectional study aims to recruit a total of 42 children with unilateral CP (21 right unilateral CP and 21 left unilateral CP) and 21 TDC aged between 8 and 16 years. Clinical severity will be described for gross motor function and manual ability. Outcomes for cognitive EF measureswill include subtests from the Wechsler Intelligence Scale for Children-Fourth Edition, Delis-Kaplan Executive Function System, Rey Complex Figure Test and the Test of Everyday Attention for Children. Behavioural manifestations of EF will be assessed using the Behaviour Rating Inventory of Executive Function, Parent and Teacher versions. Psychological functioning will be examined using the Strengths and Difficulties Questionnaire. Between-groups differences will be examined in a series of one-way analyses of covariance and followed up using linear comparisons. An overall composite of cognitive EF measures will be created. Bivariate correlations between the EF composite and psychological measures will be calculated.

ETHICS AND DISSEMINATION

This protocol describes a study that, to our knowledge, is the first to examine multiple components of EF using a cohort of children with unilateral CP. Exploration of potential laterality effects of EF among children with a congenital, unilateral brain injury is also novel. Possible relationships between EF and psychological functioning will also be investigated. Ethics have been obtained through the University of Queensland School of Psychology Ethics Committee and the Queensland Children's Health Services Human Research Ethics Committee. Results will be disseminated in peer reviewed publications and presentations at national and international conferences. This study is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12611000263998).

Ecological assessment of cognitive functions in children with acquired brain injury: a systematic review

BACKGROUND

Childhood acquired brain injury (ABI) often leads to impairment in cognitive functioning, resulting in disabilities in both the home and school environment. Assessing the impact of these cognitive deficits in everyday life using traditional neuropsychological tests has been challenging. This study systematically reviewed ecological measures of cognitive abilities available for children with ABI.

METHOD

Eight databases were searched (until October 2011) for scales: (1) focused on ecological assessment of cognitive functioning; (2) with published data in an ABI population; (3) applicable to children up to 17;11 years of age; and (4) in English. The title and abstract of all papers were reviewed independently by two reviewers.

RESULTS

Database searches yielded a total of 12 504 references, of which 17 scales met the inclusion criteria for the review, focusing on executive functions (n = 9), memory (n = 3), general cognitive abilities (n = 2), visuo-spatial skills (n = 2) and attention (n = 1). Four tasks used observation of actual performance in a natural environment, five were proxy-reports and six were functional paper and pencil type tasks, performed in an office.

CONCLUSION

Overall, few measures were found; eight were still experimental tasks which did not provide norms. Executive functions were better represented in ecological assessment, with relatively more standardized scales available.