Recent Advances in Neuropsychological Outcomes and Intervention in Pediatric Stroke.

Over the past 15 years, there have been significant advances in the treatment of acute and chronic medical consequences of stroke in childhood. Given high rates of survival in pediatric stroke, practitioners are tasked with treating the ongoing motor and neuropsychological sequelae in patients over the course of their development. This article provides a review of the current literature on neuropsychological outcomes in pediatric stroke, including intelligence, academics, language, visual-spatial skills, attention, executive functions, memory, and psychosocial function. Recent developments in functional neuroimaging are discussed, with a particular focus on language outcomes. We further review the current research on cognitive and behavioral rehabilitation and introduce intervention models in pediatric stroke. In the final section, we discuss future directions for clinical practice and research in pediatric stroke.

Children with perinatal stroke are at increased risk for autism spectrum disorder: Prevalence and co-occurring conditions within a clinically followed sample.

OBJECTIVE: Children with perinatal stroke are at increased risk for developmental language disorders, learning difficulties, and other mental health conditions. However to date, autism (ASD) prevalence in this group has not been reported. Given that early identification of ASD is essential to promoting optimal outcomes, our goal was to establish prevalence of ASD in children with perinatal stroke. METHOD: A prospectively enrolled, single-center stroke registry maintained at our institution since 2005 was queried for all potentially eligible patients with a history of perinatal stroke. Information regarding stroke features, ASD diagnosis/concern, intellectual disability/global developmental delay, cerebral palsy/hemiparesis, epilepsy, and language disorder were collected via retrospective chart review from electronic health records. RESULTS: 311 children were identified, of which 201 complete records were analyzed. Twenty-three cases were formally diagnosed with ASD (11.4%). First concerns were noted in toddlerhood (Mage = 2.66 years), yet the average age of diagnosis was 6.26 years. Children with ASD were more likely to have earlier diagnoses of intellectual disability/global developmental delay or a mixed receptive-expressive language disorder (ps < .001) but did not differ on CP/hemiplegia or epilepsy diagnoses. Risk for ASD increased with accumulating diagnoses. DISCUSSION: Children with perinatal stroke have an increased prevalence of ASD (11.4%) than in the general population. ASD concerns arise at a similar age as the general population, yet ASD is diagnosed almost two years later than the general population and 3.60 years after first concerns present. Co-occurring neurological conditions are common. Clinicians must be aware of increased prevalence and implement screening as part of routine care for all pediatric patients with perinatal stroke.

Brief report: Relationship between performance testing and parent report of attention and executive functioning profiles in children following perinatal arterial ischemic stroke.

Children with perinatal arterial ischemic stroke (PAIS) have increased rates of attention and executive functioning (EF) weaknesses. Research in other pediatric disorders has documented poor consistency between parent report of these skills and performance-based measures. We compared these data sources in children with PAIS. Forty full-term (≥37 weeks) children ages 3-16 (median = 7.2 years; 58% male) with PAIS completed neuropsychological testing and composite scores were created for seven attention and EF domains (Processing Speed; Attention; Working Memory; Verbal Retrieval; Inhibitory Control; Flexibility/Shifting; Planning). Parents completed "real-world" functioning questionnaires (ADHD Rating Scale-IV, BRIEF). Correlational analysis were used to compare parent and performance measures. Correlations between ADHD Rating Scale-IV scores and the performance-based Attention and Inhibition composite scores were nonsignificant. Significant negative correlations were found between the BRIEF GEC and performance-based Verbal Retrieval and Processing Speed composites, but remaining GEC/composite comparisons were nonsignificant. Analyses between parent report BRIEF index scores and the corresponding performance-based domain identified one significant negative correlation between the BRIEF Working Memory Index and the Working Memory composite score. While children with PAIS demonstrate difficulties in attention and EF on both parent report and performance measures, little significance was found in comparisons of these two types of measures. There may be several explanations for this dissociation: measures assessing different aspects of the same underlying construct; performance-based measures lacking ecological validity; and parents underestimating/underreporting their child's deficits. Thus, multiple sources of informant and performance data are necessary to make more accurate conclusions about functioning in these domains.

[Formula: see text]Attention and executive functioning profiles in children following perinatal arterial ischemic stroke.

Perinatal arterial ischemic stroke (PAIS) is a form of childhood stroke; the majority of those affected experience neurologic sequelae, including motor, language and neurocognitive impairments. This study examines the attention and executive functioning (EF) profiles of children following PAIS, as well as the impact of age and sex. In this single-center cross-sectional study, 40 children aged 3 to 16 years (median age 7.2 years; 58% male) who have suffered a PAIS underwent a comprehensive neuropsychological battery to assess attention and EF. Parents completed behavioral questionnaires regarding real-world functioning. Composite scores were calculated for seven attention and EF domains (Attention, Working Memory, Verbal Retrieval, Inhibitory Control, Flexibility/Shifting, Planning/Organization, and Processing Speed). The results for all measured domains of attention and EF are significantly lower in the participants compared to the normative samples (p < .001), with the exception of Working Memory. However, increasing difficulty with Working Memory is associated with developing age. Older age at time of testing is also associated with a higher incidence of clinically-elevated attention deficit hyperactivity disorder (ADHD) symptoms. Sex is not associated with performance measures or parental report of functioning. The participants demonstrate mild-to-moderate attention and EF impairment compared to the normative population. Clinicians, families, and educators should be informed about the neurocognitive sequelae of PAIS and the need for close developmental surveillance in this population to identify vulnerable children and initiate appropriate therapeutic interventions in a timely fashion.

Neuropsychological implications of Cobalamin C (CblC) disease in Hispanic children detected through newborn screening.

Cobalamin C (CblC) disease is the most common inborn error of cobalamin metabolism and recent data has indicated a higher prevalence among children of Hispanic heritage in particular. The purpose of this study was to (a) describe the neuropsychological characteristics of a pilot sample of Hispanic children with CblC disease and (b) explore potential differences in outcome based on underlying genetic mutation(s) and biochemical levels. Six Hispanic children (ages 2-10) diagnosed with CblC disease through newborn screening (NBS) underwent neuropsychological evaluation with a bilingual examiner. Biochemical levels and underlying mutation(s) were obtained through medical records. The overall sample performed below normative expectations across neuropsychological domains, including general cognition, adaptive functioning, language ability, and visual-motor integration. Underlying mutations and associative clinical phenotypes were found to significantly predict general cognitive abilities, while plasma methionine and Hcy at the time of diagnosis were significantly correlated with language outcomes. Despite limited sample size, results indicate that Hispanic children with CblC disease detected through NBS and treated early experience neuropsychological deficits even when treated with current standard treatments. However, consistent with prior research in non-Hispanic children with CblC disease, underlying mutations and early biochemical levels may predict better outcomes in this population as well.

Clinical Predictors of Attention and Executive Functioning Outcomes in Children After Perinatal Arterial Ischemic Stroke.

BACKGROUND: Children with perinatal arterial ischemic stroke (PAIS) are at risk for later neurocognitive and behavioral deficits, yet the clinical predictors of these outcomes are understudied. We examined the influence of clinical and infarct characteristics on attention and executive functioning in children following PAIS. METHODS: Forty children born at term (≥37 weeks' gestation) with PAIS (28 with neonatal arterial ischemic stroke and 12 with presumed PAIS) underwent a comprehensive neuropsychological battery at age three to 16 years (median age 7.2 years; 58% male) to assess attention and executive functioning. Parents also completed questionnaires regarding real-world functioning. Clinical variables including perinatal stroke subtype, infarct characteristics (location, laterality, and volume), and the presence of comorbid epilepsy were ascertained from the medical record. RESULTS: Presumed PAIS, larger infarct volume, and comorbid epilepsy negatively influenced the performance on attention and executive functioning measures. These clinical variables were also associated with greater functional problems on parent reports, including a higher frequency of attention-deficit/hyperactivity disorder symptoms and greater difficulties in some subdomains of executive functioning. Infarct location and laterality were not associated with performance measures or parental report of functioning. CONCLUSION: Although all children with PAIS are at risk for later deficits in attention and executive functioning, those with presumed PAIS, larger infarct size, and comorbid epilepsy appear to be the most vulnerable. As they approach and reach school age, these children should undergo neuropsychological assessment to ensure timely implementation of therapeutic interventions and behavioral strategies.

Executive functioning profiles from the BRIEF across pediatric medical disorders: Age and diagnosis factors.

The objective of the study was to compare executive functioning (EF) profiles across several pediatric medical conditions and explore the influence of age of diagnosis and evaluation. A retrospective, cross-sectional study of 734 children aged 5 to 18 years was conducted across five medical groups (brain tumor, leukemia [ALL], epilepsy [EPI], neurofibromatosis type 1 [NF1], and ornithine transcarbamylase deficiency [OTC-D]), attention deficit hyperactivity disorder (ADHD) controls, and matched healthy controls. We compared groups across the scales of a parent-completed Behavior Rating Inventory of Executive Functioning (BRIEF) using a repeated measures analysis of variance (ANOVA). Separate ANOVAs were conducted to look at age factors. The results showed that the ADHD group differed from all other groups and had the highest level of reported EF problems. The NF1 and OTC-D groups differed significantly from the healthy comparison group for overall EF problems, while the EPI and cancer groups did not. Working memory was the most elevated scale across medical groups, followed by plan/organize. Children with medical disorders were two to four times more likely than healthy controls to have clinically significant problems in several EF domains. There was a main effect for age at diagnosis and age at evaluation. A subset of children with medical disorders were found to have parent-reported EF difficulties, with particular vulnerability noted in working memory and organizational/planning skills. This has relevance for the development of interventions that may be helpful across disorders. Children with particular diagnoses and earlier age of diagnosis and evaluation had greater reported EF problems.

Sleep problems and their relationship to cognitive and behavioral outcomes in young children with traumatic brain injury.

This study examined the effect of traumatic brain injury (TBI) in young children on sleep problems and the relationship of sleep problems to neuropsychological and psychosocial functioning. Participants were drawn from an ongoing longitudinal study of injury in young children recruited from 3 to 6 years of age. They constituted three groups: orthopedic injury (OI; n=92), complicated mild/moderate TBI (mTBI; n=55); and severe TBI (sTBI; n=20). Caregivers completed the Children's Sleep Habits Questionnaire (CSHQ), as well as ratings of behavioral adjustment, adaptive functioning, and everyday executive function at 1, 6, 12, and 18 months postinjury. Retrospective ratings of preinjury sleep and psychosocial functioning were obtained at the initial assessment. Children completed neuropsychological testing at all occasions. Children with complicated mTBI demonstrated more total sleep problems than children with OI at 6 months postinjury, but not at 12 or 18 months. Children with sTBI displayed more bedtime resistance and shorter sleep duration than those with complicated mTBI or OI at several occasions. Across groups, total sleep problems predicted more emotional and behavioral problems and worse everyday executive function as rated by parents across follow-up occasions. In contrast, sleep problems were generally not related to neuropsychological test performance. The results suggest that young children with TBI demonstrate more sleep problems than children with injuries not involving the head. Sleep problems, in turn, significantly increase the risk of poor psychosocial outcomes across time, but are not associated with worse neuropsychological test performance.

Ammonia control and neurocognitive outcome among urea cycle disorder patients treated with glycerol phenylbutyrate.

UNLABELLED: Glycerol phenylbutyrate is under development for treatment of urea cycle disorders (UCDs), rare inherited metabolic disorders manifested by hyperammonemia and neurological impairment. We report the results of a pivotal Phase 3, randomized, double-blind, crossover trial comparing ammonia control, assessed as 24-hour area under the curve (NH3 -AUC0-24hr ), and pharmacokinetics during treatment with glycerol phenylbutyrate versus sodium phenylbutyrate (NaPBA) in adult UCD patients and the combined results of four studies involving short- and long-term glycerol phenylbutyrate treatment of UCD patients ages 6 and above. Glycerol phenylbutyrate was noninferior to NaPBA with respect to ammonia control in the pivotal study, with mean (standard deviation, SD) NH3 -AUC0-24hr of 866 (661) versus 977 (865) µmol·h/L for glycerol phenylbutyrate and NaPBA, respectively. Among 65 adult and pediatric patients completing three similarly designed short-term comparisons of glycerol phenylbutyrate versus NaPBA, NH3 -AUC0-24hr was directionally lower on glycerol phenylbutyrate in each study, similar among all subgroups, and significantly lower (P < 0.05) in the pooled analysis, as was plasma glutamine. The 24-hour ammonia profiles were consistent with the slow-release behavior of glycerol phenylbutyrate and better overnight ammonia control. During 12 months of open-label glycerol phenylbutyrate treatment, average ammonia was normal in adult and pediatric patients and executive function among pediatric patients, including behavioral regulation, goal setting, planning, and self-monitoring, was significantly improved. CONCLUSION: Glycerol phenylbutyrate exhibits favorable pharmacokinetics and ammonia control relative to NaPBA in UCD patients, and long-term glycerol phenylbutyrate treatment in pediatric UCD patients was associated with improved executive function (ClinicalTrials.gov NCT00551200, NCT00947544, NCT00992459, NCT00947297). (HEPATOLOGY 2012).

Clinical outcomes of neonatal onset proximal versus distal urea cycle disorders do not differ.

OBJECTIVE: To compare the clinical course and outcome of patients diagnosed with one of 4 neonatal-onset urea cycle disorders (UCDs): deficiency of carbamyl phosphate synthase 1 (CPSD), ornithine transcarbamylase (OTCD), argininosuccinate synthase (ASD), or argininosuccinate lyase (ALD). STUDY DESIGN: Clinical, biochemical, and neuropsychological data from 103 subjects with neonatal-onset UCDs were derived from the Longitudinal Study of Urea Cycle Disorders, an observational protocol of the Urea Cycle Disorders Consortium, one of the Rare Disease Clinical Research Networks. RESULTS: Some 88% of the subjects presented clinically by age 7 days. Peak ammonia level was 963 µM in patients with proximal UCDs (CPSD or OTCD), compared with 589 µM in ASD and 573 µM in ALD. Roughly 25% of subjects with CPSD or OTCD, 18% of those with ASD, and 67% of those with ALD had a "honeymoon period," defined as the time interval from discharge from initial admission to subsequent admission for hyperammonemia, greater than 1 year. The proportion of patients with a poor outcome (IQ/Developmental Quotient <70) was greatest in ALD (68%), followed by ASD (54%) and CPSD/OTCD (47%). This trend was not significant, but was observed in both patients aged <4 years and those aged ≥ 4 years. Poor cognitive outcome was not correlated with peak ammonia level or duration of initial admission. CONCLUSION: Neurocognitive outcomes do not differ between patients with proximal UCDs and those with distal UCDs. Factors other than hyperammonemia may contribute to poor neurocognitive outcome in the distal UCDs.

Functional magnetic resonance imaging of working memory and response inhibition in children with mild traumatic brain injury.

The current pilot study examined functional magnetic resonance imaging (fMRI) activation in children with mild traumatic brain injury (mTBI) during tasks of working memory and inhibitory control, both of which are vulnerable to impairment following mTBI. Thirteen children with symptomatic mTBI and a group of controls completed a version of the Tasks of Executive Control (TEC) during fMRI scanning. Both groups showed greater prefrontal activation in response to increased working memory load. Activation patterns did not differ between groups on the working memory aspects of the task, but children with mTBI showed greater activation in the posterior cerebellum with the addition of a demand for inhibitory control. Children with mTBI showed greater impairment on symptom report and "real world" measures of executive functioning, but not on traditional "paper and pencil" tasks. Likewise, cognitive testing did not correlate significantly with imaging results, whereas increased report of post-concussive symptoms were correlated with increased cerebellar activation. Overall, results provide some evidence for the utility of symptom report as an indicator of recovery and the hypothesis that children with mTBI may experience disrupted neural circuitry during recovery. Limitations of the study included a small sample size, wide age range, and lack of in-scanner accuracy data.

Establishing a consortium for the study of rare diseases: The Urea Cycle Disorders Consortium.

The Urea Cycle Disorders Consortium (UCDC) was created as part of a larger network established by the National Institutes of Health to study rare diseases. This paper reviews the UCDC's accomplishments over the first 6years, including how the Consortium was developed and organized, clinical research studies initiated, and the importance of creating partnerships with patient advocacy groups, philanthropic foundations and biotech and pharmaceutical companies.

Intellectual, adaptive, and behavioral functioning in children with urea cycle disorders.

Inborn errors of urea synthesis lead to an accumulation of ammonia in blood and brain and result in high rates of mortality and neurodevelopmental disability. This study seeks to characterize the cognitive, adaptive, and emotional/behavioral functioning of children with urea cycle disorders (UCDs). These domains were measured through testing and parent questionnaires in 92 children with UCDs [33 neonatal onset (NO), 59 late onset (LO)]. Results indicate that children who present with NO have poorer outcome than those who present later in childhood. Approximately half of the children with NO performed in the range of intellectual disability (ID), including a substantial number ( approximately 30%) who were severely impaired. In comparison, only a quarter of the LO group was in the range of ID. There is also evidence that the UCD group has difficulties in aspects of emotional/behavioral and executive skills domains. In conclusion, children with UCDs present with a wide spectrum of cognitive outcomes. Children with NO disease have a much higher likelihood of having an ID, which becomes even more evident with increasing age. However, even children with LO UCDs demonstrate evidence of neurocognitive and behavioral impairment, particularly in aspects of attention and executive functioning.

Brief report: parental report of sleep behaviors following moderate or severe pediatric traumatic brain injury.

OBJECTIVE: Determine the effect of moderate and severe traumatic brain injuries (TBI) on the sleep of school-aged children. METHODS: A concurrent cohort-prospective design compared children aged 6-12 years who sustained moderate TBI (baseline n = 56), severe TBI (n = 53), or only orthopedic injuries (n = 80). Retrospective parental report of pre-injury sleep was collected about 3 weeks post-injury. Post-injury assessments occurred prospectively a mean of 6, 12, and 48 months later. RESULTS: Growth curve analyses compared the groups over time. The moderate TBI group had worse pre-injury sleep than the other groups. The moderate TBI and orthopedic injury groups displayed a small decline in sleep problems from pre- to post-injury. Children with severe TBI displayed increased post-injury sleep problems. CONCLUSIONS: Children who sustain severe TBI are at elevated risk for post-injury sleep problems. Because sleep problems may result in daytime impairments and family distress, additional clinical and research attention is warranted.