Improving cognitive outcomes for pediatric stroke

The long-term negative impact of childhood stroke on language

Objectives

This study aims to investigate the long-term language outcome in children with unilateral childhood stroke in comparison to those with perinatal strokes and typically developing individuals and to explore the impact of lesion-specific modifiers.

Methods

We examined nine patients with childhood stroke, acquired between 0;2 and 16;1 years (CHILD; 3 female, median = 13.5 years, 6 left-sided), 23 patients with perinatal strokes (PERI; 11 female, median = 12.5 years, 16 left-sided), and 33 age-matched typically developing individuals (CONTROL; 15 female, median = 12.33 years). The language outcome was assessed using age-appropriate tasks of the Potsdam Illinois Test of Psycholinguistic Abilities (P-ITPA) or the Peabody Picture Vocabulary Test (PPVT). For group comparisons, study-specific language z-scores were calculated. Non-verbal intelligence was assessed using the Test of Non-verbal Intelligence (TONI-4), language lateralization with functional MRI, and lesion size with MRI-based volumetry.

Results

All four patients with childhood stroke who initially presented with aphasic symptoms recovered from aphasia. Patients with childhood stroke showed significantly lower language scores than those in the control group, but their scores were similar to those of the patients with perinatal stroke, after adjusting for general intelligence (ANCOVA, language z-score CHILD = -0.30, PERI = -0.38, CONTROL = 0.42). Among the patients with childhood stroke, none of the possible modifying factors, including lesion side, correlated significantly with the language outcome.

Conclusion

Childhood stroke, regardless of the affected hemisphere, can lead to chronic language deficits, even though affected children show a "full recovery." The rehabilitation of children and adolescents with childhood stroke should address language abilities, even after the usually quick resolution of clear aphasic symptoms.

The influential factors and non-pharmacological interventions of cognitive impairment in children with ischemic stroke

Background

The prevalence of pediatric ischemic stroke rose by 35% between 1990 and 2013. Affected patients can experience the gradual onset of cognitive impairment in the form of impaired language, memory, intelligence, attention, and processing speed, which affect 20-50% of these patients. Only few evidence-based treatments are available due to significant heterogeneity in age, pathological characteristics, and the combined epilepsy status of the affected children.

Methods

We searched the literature published by Web of Science, Scopus, and PubMed, which researched non-pharmacological rehabilitation interventions for cognitive impairment following pediatric ischemic stroke. The search period is from the establishment of the database to January 2022.

Results

The incidence of such impairment is influenced by patient age, pathological characteristics, combined epilepsy status, and environmental factors. Non-pharmacological treatments for cognitive impairment that have been explored to date mainly include exercise training, psychological intervention, neuromodulation strategies, computer-assisted cognitive training, brain-computer interfaces (BCI), virtual reality, music therapy, and acupuncture. In childhood stroke, the only interventions that can be retrieved are psychological intervention and neuromodulation strategies.

Conclusion

However, evidence regarding the efficacy of these interventions is relatively weak. In future studies, the active application of a variety of interventions to improve pediatric cognitive function will be necessary, and neuroimaging and electrophysiological measurement techniques will be of great value in this context. Larger multi-center prospective longitudinal studies are also required to offer more accurate evidence-based guidance for the treatment of patients with pediatric stroke.

Rehabilitation in Pediatric Stroke: Cognition and Behavior

Pediatric stroke is associated with a range of maladaptive cognitive and behavioral outcomes that often require targeted intervention. Despite increasing research on neuropsychological outcomes over the past decade, evidence for effective therapies and interventions for the most commonly reported cognitive and behavioral challenges is still limited. The most widely prescribed interventions address more overt deficits in sensorimotor and speech/language functions, yet interventions for higher-order cognitive, linguistic and behavioral deficits are notably less defined. Moreover, concepts of rehabilitation in adult stroke cannot be easily translated directly to pediatric populations because the effect of stroke and recovery in the developing brain takes a very different course than in the mature brain. In pediatric stroke, neuropsychological deficits often emerge gradually over time necessitating a long-term approach to intervention. Furthermore, family and school context often play a much larger role. The goal of this review is to describe cognitive and behavioral interventions for perinatal and childhood stroke, as motor rehabilitation is covered elsewhere in this issue. We also discuss cognitive aspects of current rehabilitative therapies and technology. Acknowledging the current limited state of stroke-specific rehabilitation research in children, findings from pediatric acquired brain injury intervention and use of transdiagnostic approaches lend important insights. Because there is limited support for single domain (cognitive) trainings and translation of research rehabilitation programs to clinical practice can be challenging, the value of holistic multidisciplinary approaches to improve everyday function in children and adolescents following stroke is emphasized.

Self-perception and behavioural outcomes of early acquired brain injury

Acquired brain injury (ABI) occurs commonly in young children. Despite this, the psychosocial implications of ABI in young children are not established, with little understood about the impacts on self-perception and self-esteem. In this study we investigated self-perception, self-esteem and behaviour of children with early ABI. Children with an ABI (n = 47) before six years were compared to 17 typically developing controls (TDCs) matched on demographics. Children were aged 6-12 years and completed the Harter Self-Perception Profile. One parent completed the Child Behavior Checklist. No differences for self-perception and self-esteem were found between the groups. Parents of children with an early ABI reported more internalizing and externalizing behaviours. Children with more externalizing behaviour and social skill problems had more negative self-perceptions. Interaction effects were seen between socioeconomic status (SES) and child self-perception and behaviour. Specifically, children from families of higher SES had a more positive perception of their appearance and children from lower SES backgrounds had more externalizing behaviours and social problems. The study suggests that the relationship between ABI and self-perception and self-esteem is complicated and that children with behavioural problems have lowered feelings of competence. SES has an important role in self-perception and behavioural outcomes.

Targeting the Erk1/2 and autophagy signaling easily improved the neurobalst differentiation and cognitive function after young transient forebrain ischemia compared to old gerbils

The hippocampal neurogenesis occurs constitutively throughout adulthood in mammalian species, but declines with age. In this study, we overtly found that the neuroblast proliferation and differentiation in the subgranular zone and the maturation into fully functional and integrated neurons in the granule-cell layer in young gerbils following cerebral ischemia/reperfusion was much more than those in old gerbils. The neurological function and cognitive and memory-function rehabilitation in the young gerbils improved faster than those in the old one. These results demonstrated that, during long term after cerebral ischemia/reperfusion, the ability of neurogenesis and recovery of nerve function in young animals were significantly higher than that in the old animals. We found that, after 14- and 28-day cerebral ischemia/reperfusion, the phosphorylation of MEK1/2, ERK1/2, p90RSK, and MSK1/2 protein levels in the hippocampus of young gerbils was significantly much higher than that of old gerbils. The levels of autophagy-related proteins, including Beclin-1, Atg3, Atg5, and LC3 in the hippocampus were effectively maintained and elevated at 28 days after cerebral ischemia/reperfusion in the young gerbils compared with those in the old gerbils. These results indicated that an increase or maintenance of the phosphorylation of ERK1/2 signal pathway and autophagy-related proteins was closely associated with the neuroblast proliferation and differentiation and the process of maturation into neurons. Further, we proved that neuroblast proliferation and differentiation in the dentate gyrus and cognitive function were significantly reversed in young cerebral ischemic gerbils by administering the ERK inhibitor (U0126) and autophagy inhibitor (3MA). In brief, following experimental young ischemic stroke, the long-term promotion of the neurogenesis in the young gerbil’s hippocampal dentate gyrus by upregulating the phosphorylation of ERK signaling pathway and maintaining autophagy-related protein levels, it overtly improved the neurological function and cognitive and memory function.

Non-verbal Intelligence in Unilateral Perinatal Stroke Patients With and Without Epilepsies

Background: The risk factors for impaired cognitive development after unilateral perinatal stroke are poorly understood. Non-verbal intelligence seems to be at particular risk, since language can shift to the right hemisphere and may thereby reduce the capacity of the right hemisphere for its originary functions. Pharmaco-refractory epilepsies, a frequent complication of perinatal strokes, often lead to impaired intelligence. Yet, the role of well-controlled epilepsies is less well-understood. Here, we investigated whether well-controlled epilepsies, motor impairment, lesion size, lesion side, and lateralization of language functions influence non-verbal functions. Methods: We recruited 8 patients with well-controlled epilepsies (9-26 years), 15 patients without epilepsies (8-23 years), and 23 healthy controls (8-27 years). All underwent the Test of Non-verbal Intelligence, a motor-independent test, which excludes biased results due to motor impairment. Language lateralization was determined with functional MRI, lesion size with MRI-based volumetry, and hand motor impairment with the Jebson-Taylor Hand Function-Test. Results: Patients with epilepsies showed significantly impaired non-verbal intelligence [Md = 89.5, interquartile range (IQR) = 13.5] compared with controls (Md = 103, IQR = 17). In contrast, patients without epilepsies (Md = 97, IQR = 15.0) performed within the range of typically developing children. A multiple regression analysis revealed only epilepsy as a significant risk factor for impaired non-verbal functions. Conclusion: In patients with unilateral perinatal strokes without epilepsies, the neuroplastic potential of one healthy hemisphere is able to support the development of normal non-verbal cognitive abilities, regardless of lesion size, lesion side, or language lateralization. In contrast, epilepsy substantially reduces this neuroplastic potential; even seizure-free patients exhibit below-average non-verbal cognitive functions.

Intensive treadmill training promotes cognitive recovery after cerebral ischemia-reperfusion in juvenile rats

Rehabilitation training is routine for children who experience stroke, but its protective mechanism remains unclear. To study the effect of treadmill training intensity on hippocampal synaptic plasticity after cerebral ischemia, a model of middle cerebral artery occlusion (MCAO)/reperfusion was established in young rats to simulate childhood ischemic stroke. The rats were randomly allocated into five groups: sham operation, MCAO, low-intensity exercise and MCAO (5 m/min), medium-intensity exercise and MCAO (10 m/min), and high-intensity exercise and MCAO (15 m/min). Intervention was continued for 14 days, and a series of experimental tests were conducted. After MCAO, the juvenile rats exhibited a series of morphological and functional alterations, including changes in their neurobehavior and cerebral infarct volumes. Compared with control rats, MCAO rats had a longer escape latency and crossed fewer platforms in the water maze test and exhibited decreased hippocampal neuron density and Synapsin I and PSD95 expression. Furthermore, MCAO rats exhibited synapse morphology changes and abnormal serum levels of lactic acid and corticosterone. Treadmill training effectively reduced the neurobehavioral scores and cerebral infarction volumes, with medium-intensity training showing the best effect. Treadmill training shortened the escape latency, increased the number of platform crossings, and improved the spatial cognitive abilities of the rats, with the medium intensity training having the best effect on spatial learning/memory efficiency. Treadmill training increased the neuron density in the hippocampus, with the medium-intensity training resulting in the highest density. Treadmill training had a positive effect on the expression of Synapsin I and PSD95, with the medium-intensity training showing the strongest effect. Treadmill training improved the sub-microstructure synapse morphology, with the medium-intensity training demonstrating the best effect. Treadmill training increased the plasma levels of lactic acid and corticosterone, with the high-intensity training having the most obvious effect. Treadmill training can provide neuroprotection by promoting hippocampal synaptic plasticity, with medium-intensity training showing the most optimal effects.

[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.

Cognitive resilience following paediatric stroke: Biological and environmental predictors

Little is known about resilience after paediatric stroke (PS), or the factors that contribute to better outcomes. Rather, research emphasis has been on impairment, measured through cross-sectional or retrospective designs, often heavily weighted to children presenting for clinical or rehabilitation follow-up. Implementing a resilience framework, this study aimed to investigate cognitive recovery post-stroke and factors that contribute to cognitive resilience at 12 months following PS. In a single site, prospective, longitudinal study (baseline, 1, 6, 12 months post-stroke), 61 children (55.7% male) aged 0-18 years, with a diagnosis of acute arterial ischemic stroke were recruited. Neurological status, lesion and child characteristics were collected at diagnosis. Cognitive, language and motor skills were assessed directly using age-appropriate, standardised tools. Parents rated their mental health, and child social and adaptive abilities. Participants were classified as 'resilient' (74%) or 'vulnerable' based on 12-month cognitive scores. The resilient group demonstrated more intact acute neurological status and higher language and adaptive abilities 1-month post-stroke; 88% of the vulnerable group had strokes involving both cortical and subcortical regions. Neonatal stroke, large lesions, cortical-only lesions, and middle cerebral artery involvement were associated with poorer cognition over the 12 months post-stroke. Absence of seizures and older age at stroke predicted better cognitive outcomes. In summary, most children surviving PS are cognitively resilient at 12 months post-insult. Risk and protective factors identified may guide targeted clinical intervention for more vulnerable children. Future research is needed to explore cognitive resilience trajectories beyond 12 months post-stroke.

Treadmill exercise improves neurological function by inhibiting autophagy and the binding of HMGB1 to Beclin1 in MCAO juvenile rats

AIMS

Treadmill exercise is a beneficial treatment following childhood stroke. Thus, studies focusing on the neuroprotective mechanism of exercise training during postischemic treatment in children with ischemic stroke are urgently needed. We evaluated the effects of treadmill exercise on autophagy after cerebral ischemia in young rats.

MAIN METHODS

Rats (23-25 days old) underwent cerebral ischemia-reperfusion (CI/R) surgery. The experimental animals were divided into 5 groups, and some groups received either treadmill exercise, a rapamycin (RAPA) injection or combination therapy for 3 or 7 days. We performed a series of experimental tests including neurological scoring, hematoxylin-eosin staining (H&E), Nissl staining, triphenyl tetrazolium chloride (TTC) staining, Western blot analysis (WB), immunofluorescence (IF), enzyme-linked immunosorbent assay (ELISA), transmission electron microscopy (TEM) and Terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick end labeling (TUNEL) fluorescence.

KEY FINDINGS

The experimental data indicated that treadmill exercise inhibited autophagy in the ischemic penumbra, inhibited high mobility group box 1 (HMGB1) translocation and binding to Beclin1, reduced apoptosis, reduced infarct volumes, and aided in functional recovery. However, RAPA promoted the opposite effects of treadmill exercise.

SIGNIFICANCE

We found that treadmill exercise improves the neurological deficits induced by CI/R by inhibiting autophagy and HMGB1 binding to Beclin1.

Postintensive Care Syndrome in Pediatric Critical Care Survivors: Therapeutic Options to Improve Outcomes After Acquired Brain Injury

PURPOSE OF REVIEW

Children surviving the pediatric intensive care unit (PICU) with neurologic illness or injury have long-term morbidities in physical, cognitive, emotional, and social functioning termed postintensive care syndrome (PICS). In this article, we review acute and longitudinal management strategies available to combat PICS in children with acquired brain injury.

RECENT FINDINGS

Few intervention studies in this vulnerable population target PICS morbidities. Small studies show promise for both inpatient- and outpatient-initiated therapies, mainly focusing on a single domain of PICS and evaluating heterogeneous populations. While evaluating the effects of interventions on longitudinal PICS outcomes is in its infancy, longitudinal clinical programs targeting PICS are increasing. A multidisciplinary team with inpatient and outpatient presence is necessary to deliver the holistic integrated care required to address all domains of PICS in patients and families. While PICS is increasingly recognized as a chronic problem in PICU survivors with acquired brain injury, few interventions have targeted PICS morbidities. Research is needed to improve physical, cognitive, emotional, and social outcomes in survivors and their families.

Nonpharmacological rehabilitation interventions for motor and cognitive outcomes following pediatric stroke: a systematic review

The aim of this review was to evaluate the evidence for nonpharmacological rehabilitation interventions for motor and cognitive impairment following pediatric stroke. A literature search was conducted using multiple scientific databases. Studies were included if (1) the study population was > 50% pediatric (< 18 years) stroke, (2) a diagnosis of stroke was explicitly stated, (3) there were ≥ 3 pediatric stroke participants included in the study sample, and (4) motor or cognitive outcome measures were used to assess effect of treatment. Levels of evidence were assigned to each study to determine the strength of the evidence for each intervention. A total of 18 articles met inclusion criteria. Most studies (N = 14) examined rehabilitation of the upper limb, with constraint-induced movement therapy (CIMT) as the most common intervention. Overall, the evidence supports the use of CIMT, forced use therapy, repetitive transcranial magnetic stimulation, functional electrical stimulation, and robotics, but suggests no beneficial effect of transcranial direct current stimulation. Very few studies assessed interventions for the lower limb (N = 1) or cognitive impairment (N = 3).Conclusion: Effective rehabilitation approaches are important for optimizing outcomes in children who have had a stroke. Although the number of published clinical trials has increased in recent years, little evidence-based guidance exists for this clinical population. What is Known: • Pediatric stroke is a significant cause of disability in children that is often associated with long-term motor and cognitive sequelae. • There is a need to establish a knowledge base regarding available evidence-based rehabilitation therapies for this clinical population. What is New: • Most studies examining interventions for motor function focus on upper limb rehabilitation, whereas few studies have investigated interventions for improving lower limb or cognitive impairment. • An important gap exists regarding evidence-based rehabilitative treatment approaches for pediatric stroke.

Is the 1298A>C polymorphism in the MTHFR gene a risk factor for arterial ischaemic stroke in children? The results of meta-analysis

An elevated level of homocysteine is a risk factor for vascular diseases, brain atrophy and several other disorders. The 1298A>C polymorphism (rs1801131) leads to mildly decreased MTHFR activity. Previously, it was observed that the MTHFR 1298A>C polymorphism in combined analysis with the MTHFR 677C>T polymorphism increases homocysteine levels. However, conflicting results on its relation to ischaemic stroke in children can be found. We conducted a meta-analysis to analyse possible connections between the MTHFR 1298A>C polymorphism and ischaemic stroke in paediatric patients. We identified available data published before December 2016 using appropriate keywords and searching PubMed as well as the references cited in the found articles. Eight case-control studies were included in the meta-analysis (426 children with stroke and 778 controls). Statistical analyses were made using R and Comprehensive Meta-Analysis softwares to investigate the impact of polymorphism in four models: dominant, recessive, additive and allelic. No publication bias was observed in the meta-analysis. We demonstrated no relationship between the 1298A>C polymorphism and ischaemic stroke in children in the case of recessive, additive and allelic models. However, the results of the dominant model analysis should be treated with caution due to the sensitivity analysis results. After omitting one of the included study, we observed a significant association between the carriers of the MTHFR C allele (cases with AC + CC genotypes) and ischaemic stroke in children (OR 1.35 95% CI 1.02-1.79, p = 0.035 in a fixed effects model). In conclusion, the 1298A>C polymorphism in the MTHFR gene is not a risk factor for ischaemic stroke in paediatric patients.

Assessment of executive functions in children and adolescents with acquired brain injury (ABI) using a novel complex multi-tasking computerised task: The Jansari assessment of Executive Functions for Children (JEF-C©)

Objectives: The Jansari assessment of Executive Functions for Children (JEF-C^©) is a new non-immersive computerised assessment of executive functions. The objectives of the study were to test the feasibility and validity of JEF-C^© in children and adolescents with acquired brain injury (ABI). Methods: Twenty-nine patients with ABI aged 10-18 years and 30 age-and gender-matched controls were tested. Participants performed JEF-C^©, Wechsler Abbreviated Scale of Intelligence (WASI) and the Behavioural Assessment of the Dysexecutive Syndrome for Children (BADS-C), while parents completed the Behaviour Rating Inventory of Executive Function (BRIEF) questionnaire. Results: The JEF-C^© task proved feasible in patients with ABI. The internal consistency was medium (Cronbach's alpha = 0.62 and significant intercorrelations between individual JEF-C^© constructs). Patients performed significantly worse than controls on most of the JEF-C^© subscales and total score, with 41.4% of participants with ABI classified as having severe executive dysfunction. No significant correlations were found between JEF-C^© total score, the BRIEF indices, and the BADS-C. Significant correlations were found between JEF-C^© and demographic characteristics of the sample and intellectual ability, but not with severity/medical variables. Conclusion: JEF-C^© is a playful complex task that appears to be a sensitive and ecologically valid assessment tool, especially for relatively high-functioning individuals.