The eTHINK Study: Cognitive and Behavioral Outcomes in Children with Hemophilia.

OBJECTIVE: To assess cognitive, behavioral, and adaptive functions in children and young adults with hemophilia treated according to contemporary standards of care. STUDY DESIGN: eTHINK was a US-based, prospective, cross-sectional, observational study (September 2018 through October 2019). Males (aged 1-21 years) with hemophilia A or B of any severity, with or without inhibitors, were eligible. Participants underwent neurological examinations and age-appropriate neuropsychological assessments, including standardized tests/ratings scales of early development, cognition, emotional/behavioral adjustment, and adaptive skills. RESULTS: 551 males with hemophilia A (n=433) or B (n=101) were enrolled. Performance on cognitive tests was largely comparable with that of age-matched US population norms, although participants in certain age groups (4-5 and 10-21 years) performed worse on measures of attention and processing speed. Furthermore, adolescents and young adults and those with comorbid attention-deficit/hyperactivity disorder (ADHD; n=64) reported more adaptive and executive function problems in daily life. Incidence of ADHD in adolescents (21%) was higher than expected in the general population. CONCLUSIONS: In general, males with hemophilia demonstrated age-appropriate intellectual, behavioral, and adaptive development. However, specific patient/age groups showed poorer attention performance and concerns for executive and adaptive development. This study established a normative data set for monitoring neurodevelopment in individuals with hemophilia and highlights the importance of screening and intervention for challenges with cognitive and adaptive skills in this population.

Proceedings of the first global meeting of the Posterior Fossa Society: state of the art in cerebellar mutism syndrome.

PURPOSE: The Posterior Fossa Society, an international multidisciplinary group, hosted its first global meeting designed to share the current state of the evidence across the multidisciplinary elements of pediatric post-operative cerebellar mutism syndrome (pCMS). The agenda included keynote talks from world-leading speakers, compelling abstract presentations and engaging discussions led by members of the PFS special interest groups. METHODS: This paper is a synopsis of the first global meeting, a 3-day program held in Liverpool, England, UK, in September 2022. RESULTS: Topics included nosology, patient and family experience, cerebellar modulation of cognition, and cerebellar cognitive affective syndrome. In addition, updates from large-scale studies were shared as well as abstracts across neuroradiology, neurosurgery, diagnosis/scoring, ataxia, and rehabilitation. CONCLUSIONS: Based on data-driven evidence and discussions, each special interest group created research priorities to target before the second global meeting, in the spring of 2024.

Nonacog beta pegol prophylaxis in children with hemophilia B: safety, efficacy, and neurodevelopmental outcomes for up to 8 years.

Background: Nonacog beta pegol (N9-GP) is an extended half-life PEGylated factor (F)IX product with established efficacy and short-term safety in persons with hemophilia B (HB). Long-term safety has been evaluated for polyethylene glycol exposure but not N9-GP. Objectives: To assess safety, neurodevelopmental, and efficacy outcomes of children with HB receiving N9-GP prophylaxis across 2 open-label, single-arm, phase 3 studies: paradigm5 (previously treated patients [PTPs]) and paradigm6 (previously untreated patients [PUPs]) in this interim analysis. Methods: PTPs (aged ≤12 years) and PUPs (aged <6 years) with severe/moderate (≤2% FIX level) HB were recruited to N9-GP prophylaxis (40 IU/kg once weekly) in paradigm5 and paradigm6, respectively. Safety assessments included FIX inhibitor incidence, adverse events, neurocognitive and neurologic outcomes, polyethylene glycol concentration in plasma, and medical events of special interest. Efficacy endpoints included bleeds, N9-GP hemostatic effect, and FIX consumption. Results: Overall, 25 patients in paradigm5 and 50 patients in paradigm6 received N9-GP and were followed for up to 8 and 6 years, respectively. No inhibitory antibodies were reported in PTPs; 4 of the 50 PUPs developed inhibitors. Extensive evaluation revealed no neurocognitive or neurologic concerns with N9-GP use in children during the study period. Across both studies, few adverse events were reported as possibly related to N9-GP. High hemostatic response rate, high treatment adherence, low annualized bleeding rates, and no new target joints were reported. Conclusion: These data provide the longest follow-up for an extended half-life FIX and confirm the long-term efficacy of N9-GP prophylaxis in children with HB with no observed neurocognitive or neurologic safety concerns.

Considering Functional Outcomes as Efficacy Endpoints in Pediatric Low-Grade Glioma Clinical Trials: An FDA Educational Symposium.

In October 2022, the Food and Drug Administration (FDA) Oncology Center of Excellence (OCE) hosted an educational symposium entitled, "Considering Functional Outcomes as Efficacy Endpoints in Pediatric Low-Grade Glioma (pLGG) Clinical Trials." The symposium brought together patient advocates, regulators from the FDA and the European Medicines Agency (EMA), and an international group of academic thought leaders in the field of pediatric neuro-oncology to discuss the potential role of functional outcomes, including visual acuity, motor function, and neurocognitive performance, as endpoints in clinical trials enrolling patients with pLGG. The panel discussed challenges and opportunities regarding the selection, implementation, and evaluation of clinical outcome assessments in these functional domains and outlined key considerations for their inclusion in future clinical trial design and role in new drug development.

Sensory Processing in Children and Adolescents with Neurofibromatosis Type 1.

Despite the evidence of elevated autistic behaviors and co-occurring neurodevelopmental difficulties in many children with neurofibromatosis type 1 (NF1), we have a limited understanding of the sensory processing challenges that may occur with the condition. This study examined the sensory profile of children and adolescents with NF1 and investigated the relationships between the sensory profiles and patient characteristics and neuropsychological functioning. The parent/caregivers of 152 children with NF1 and 96 typically developing children completed the Sensory Profile 2 (SP2), along with standardized questionnaires assessing autistic behaviors, ADHD symptoms, internalizing symptoms, adaptive functioning, and social skills. Intellectual functioning was also assessed. The SP2 data indicated elevated sensory processing problems in children with NF1 compared to typically developing children. Over 40% of children with NF1 displayed differences in sensory registration (missing sensory input) and were unusually sensitive to and unusually avoidant of sensory stimuli. Sixty percent of children with NF1 displayed difficulties in one or more sensory modalities. Elevated autistic behaviors and ADHD symptoms were associated with more severe sensory processing difficulties. This first detailed assessment of sensory processing, alongside other clinical features, in a relatively large cohort of children and adolescents with NF1 demonstrates the relationships between sensory processing differences and adaptive skills and behavior, as well as psychological well-being. Our characterization of the sensory profile within a genetic syndrome may help facilitate more targeted interventions to support overall functioning.

Sex- and age-related differences in autistic behaviours in children with neurofibromatosis type 1.

This study investigated sex and age differences in autistic behaviours in children with neurofibromatosis type 1 (NF1) who scored within the clinical range on the Social Responsiveness Scale - Second Edition (T score ≥ 60). Thirty-four males and 28 females (3-16 years) were assessed with the Autism Diagnostic Observation Schedule - Second Edition and Autism Diagnostic Interview - Revised. Across both measures, males exhibited greater social communication deficits relative to females. Age-related abatement of social communication difficulties was observed for males but not females. Conversely, no sex differences were found for restricted/repetitive behaviours, which were stable over time for both males and females. The findings are discussed within the context of broader neurodevelopmental considerations that are common in NF1.

Understanding the Neurofibromatosis Type 1 (NF1) experience and the priorities of individuals with NF1 and their caregivers for cognitive and social-emotional research.

BACKGROUND: Patient engagement is increasingly recognized as a valuable, essential aspect of Neurofibromatosis research given the unique experiences and morbidities associated with the diagnosis. Engaging patients and families can enhance the relevance, methodology, and feasibility of clinical trials. METHODS: A REDCap survey ascertaining information on NF-related morbidities, priorities, and interests in cognitive and social-emotional research, and willingness to participate in research was dispensed to 4,565 individuals consented to the Children's Tumor Foundation (CTF) Registry with NF1. This included children and adults with NF1 and parents/caregivers of children with NF1. RESULTS: 525 individuals fully completed the survey: 295 parents/caregivers (Mage child = 10.12, range = 3-24), 194 adults with NF1 (Mage = 45.73, range = 19-81), and 36 children with NF1 (Mage = 12.61, range = 10-17). Less than 10% of respondents have participated in cognitive research, while 42.4-49.5% indicated having sought opportunities for cognitive research. Most (79.4-82.4%) respondents reported that cognitive research is very/extremely important, with learning/academics and emotional functioning were priorities. Willingness to participate in research aligned with areas of importance. CONCLUSION: Analysis highlights that most survey respondents believe cognitive and social-emotional research is very important, but a relatively small number have participated. This finding may highlight poor dissemination of information of research opportunities to the broader NF community and limitations to access based on geography or other factors. Respondents indicate that learning/academic problems and emotional challenges to be research priorities. Continuing to engage patients and families with NF is expected to enhance the value and engagement in cognitive research.

MEK inhibitors for neurofibromatosis type 1 manifestations: Clinical evidence and consensus.

The wide variety of clinical manifestations of the genetic syndrome neurofibromatosis type 1 (NF1) are driven by overactivation of the RAS pathway. Mitogen-activated protein kinase kinase inhibitors (MEKi) block downstream targets of RAS. The recent regulatory approvals of the MEKi selumetinib for inoperable symptomatic plexiform neurofibromas in children with NF1 have made it the first medical therapy approved for this indication in the United States, the European Union, and elsewhere. Several recently published and ongoing clinical trials have demonstrated that MEKi may have potential benefits for a variety of other NF1 manifestations, and there is broad interest in the field regarding the appropriate clinical use of these agents. In this review, we present the current evidence regarding the use of existing MEKi for a variety of NF1-related manifestations, including tumor (neurofibromas, malignant peripheral nerve sheath tumors, low-grade glioma, and juvenile myelomonocytic leukemia) and non-tumor (bone, pain, and neurocognitive) manifestations. We discuss the potential utility of MEKi in related genetic conditions characterized by overactivation of the RAS pathway (RASopathies). In addition, we review practical treatment considerations for the use of MEKi as well as provide consensus recommendations regarding their clinical use from a panel of experts.

Delineating the autistic phenotype in children with neurofibromatosis type 1.

BACKGROUND: Existing research has demonstrated elevated autistic behaviours in children with neurofibromatosis type 1 (NF1), but the autistic phenotype and its relationship to other neurodevelopmental manifestations of NF1 remains unclear. To address this gap, we performed detailed characterisation of autistic behaviours in children with NF1 and investigated their association with other common NF1 child characteristics. METHODS: Participants were drawn from a larger cross-sectional study examining autism in children with NF1. The population analysed in this study scored above threshold on the Social Responsiveness Scale-Second Edition (T-score ≥ 60; 51% larger cohort) and completed the Autism Diagnostic Interview-Revised (ADI-R) and/or the Autism Diagnostic Observation Schedule-Second Edition (ADOS-2). All participants underwent evaluation of their intellectual function, and behavioural data were collected via parent questionnaires. RESULTS: The study cohort comprised 68 children (3-15 years). Sixty-three per cent met the ADOS-2 'autism spectrum' cut-off, and 34% exceeded the more stringent threshold for 'autistic disorder' on the ADI-R. Social communication symptoms were common and wide-ranging, while restricted and repetitive behaviours (RRBs) were most commonly characterised by 'insistence on sameness' (IS) behaviours such as circumscribed interests and difficulties with minor changes. Autistic behaviours were weakly correlated with hyperactive/impulsive attention deficit hyperactivity disorder (ADHD) symptoms but not with inattentive ADHD or other behavioural characteristics. Language and verbal IQ were weakly related to social communication behaviours but not to RRBs. LIMITATIONS: Lack of genetic validation of NF1, no clinical diagnosis of autism, and a retrospective assessment of autistic behaviours in early childhood. CONCLUSIONS: Findings provide strong support for elevated autistic behaviours in children with NF1. While these behaviours were relatively independent of other NF1 comorbidities, the importance of taking broader child characteristics into consideration when interpreting data from autism-specific measures in this population is highlighted. Social communication deficits appear similar to those observed in idiopathic autism and are coupled with a unique RRB profile comprising prominent IS behaviours. This autistic phenotype and its relationship to common NF1 comorbidities such as anxiety and executive dysfunction will be important to examine in future research. Current findings have important implications for the early identification of autism in NF1 and clinical management.

The mediating role of ADHD symptoms between executive function and social skills in children with neurofibromatosis type 1.

Children with neurofibromatosis type 1 (NF1) often experience executive dysfunction, attention deficit/hyperactivity disorder (ADHD) symptoms and poor social skills, however, the nature of the relationships between these domains in children with NF1 is unclear. This study investigated these relationships using primary caregiver ratings of executive functions, ADHD symptoms and social skills in children with NF1. Participants were 136 children with NF1 and 93 typically developing (TD) controls aged 3-15 years recruited from 3 multidisciplinary neurofibromatosis clinics in Melbourne and Sydney, Australia, and Washington DC, USA. Mediation analysis was performed on primary outcome variables: parent ratings of executive functions (Behavior Rating Inventory of Executive Function, Metacognition Index), ADHD symptoms (Conners-3/Conners ADHD Diagnostic and Statistical Manual for Mental Disorders Scales) and social skills (Social Skills Improvement System-Rating Scale), adjusting for potential confounders (full scale IQ, sex, and social risk). Results revealed significantly poorer executive functions, elevated ADHD symptoms and reduced social skills in children with NF1 compared to controls. Poorer executive functions significantly predicted elevated ADHD symptoms and poorer social skills. Elevated ADHD symptoms significantly mediated the relationship between executive functions and social skills problems although did not fully account for social dysfunction. This study provides evidence for the importance of targeting ADHD symptoms as part of future interventions aimed at promoting prosocial behaviors in children with NF1.

Computerized Working Memory Training for Children With Neurofibromatosis Type 1 (NF1): A Pilot Study.

INTRODUCTION: The present study aimed to evaluate the feasibility and efficacy of CogmedRM, a computerized, home-based working memory (WM) training program, in children with NF1. METHOD: A pre-post design was used to evaluate changes in performance-based measures of attention and WM, and parent-completed ratings of executive functioning. Children meeting eligibility criteria completed CogmedRM over 9 weeks. Primary outcomes included compliance statistics and change in attention and WM scores. RESULTS: Thirty-one children (52% male; M age = 10.97 ± 2.51), aged 8-15, were screened for participation; 27 children (87%) evidenced WM difficulties and participated in CogmedRM training. On average, participants completed 19.7 out of 25 prescribed sessions, with an adherence rate of 69%. Participants demonstrated improvements in short-term memory, attention, and executive functioning (all Ps < .05). CONCLUSION: Results suggest that computerized, home-based WM training programs may be both feasible and efficacious for children with NF1 and cognitive deficits.

Impact of MEK Inhibitor Therapy on Neurocognitive Functioning in NF1.

BACKGROUND AND OBJECTIVES: Neurofibromatosis type 1 (NF1)-associated cognitive impairments carry significant lifelong morbidity. The lack of targeted biologic treatments remains a significant unmet need. We examine changes in cognition in patients with NF1 in the first 48 weeks of mitogen-activated protein kinase inhibitor (MEKi) treatment. METHODS: Fifty-nine patients with NF1 aged 5-27 years on an MEKi clinical trial treating plexiform neurofibroma underwent pretreatment and follow-up cognitive assessments over 48 weeks of treatment. Performance tasks (Cogstate) and observer-reported functioning (BRIEF) were the primary outcomes. Group-level (paired t tests) and individual-level analyses (Reliable Change Index, RCI) were used. RESULTS: Analysis showed statistically significant improvements on BRIEF compared with baseline (24-week Behavioral Regulation Index: t (58) = 3.03, p = 0.004, d = 0.24; 48-week Metacognition Index: t (39) = 2.70, p = 0.01, d = 0.27). RCI indicated that more patients had clinically significant improvement at 48 weeks than expected by chance (χ2 = 11.95, p = 0.001, odds ratio [OR] = 6.3). Group-level analyses indicated stable performance on Cogstate (p > 0.05). RCI statistics showed high proportions of improved working memory (24-week χ2 = 8.36, p = 0.004, OR = 4.6, and 48-week χ2 = 9.34, p = 0.004, OR = 5.3) but not visual learning/memory. Patients with baseline impairments on BRIEF were more likely to show significant improvement than nonimpaired patients (24 weeks 46% vs 8%; χ2 = 9.54, p = 0.008, OR = 9.22; 48 weeks 63% vs 16%; χ2 = 7.50, p = 0.02, OR = 9.0). DISCUSSION: Our data show no evidence of neurotoxicity in 48 weeks of treatment with an MEKi and a potential clinical signal supporting future research of MEKi as a cognitive intervention.

Recommendations for Social Skills End Points for Clinical Trials in Neurofibromatosis Type 1.

OBJECTIVE: To review parent-report social skills measures to identify and recommend consensus outcomes for use in clinical trials of social deficit in children and adolescents (ages 6-18 years) with neurofibromatosis type 1 (NF1). METHODS: Searches were conducted via PubMed and ClinicalTrials.gov to identity social skills outcome measures with English language versions used in clinical trials in the past 5 years with populations with known social skills deficits, including attention-deficit/hyperactivity disorder and autism spectrum disorder (ASD). Measures were rated by the Response Evaluation in Neurofibromatosis and Schwannomatosis (REiNS) Neurocognitive Committee on patient characteristics, use in published studies, domains assessed, availability of standard scores, psychometric properties, and feasibility to determine their appropriateness for use in NF1 clinical trials. RESULTS: Two measures were ultimately recommended by the committee: the Social Responsiveness Scale-2 (SRS-2) and the Social Skills Improvement System-Rating Scale (SSIS-RS). CONCLUSIONS: Each of the 2 measures assesses different aspects of social functioning. The SSIS-RS is appropriate for studies focused on broader social functioning; the SRS-2 is best for studies targeting problematic social behaviors associated with ASD. Researchers will need to consider the goals of their study when choosing a measure, and specific recommendations for their use are provided.

Recommendations for Measurement of Attention Outcomes in Preschoolers With Neurofibromatosis.

Children with neurofibromatosis type 1 (NF1) are at increased risk for attention problems. While most research has been conducted with school-aged cohorts, preschool-aged children offer a novel developmental window for clinical studies, with the promise that treatments implemented earlier in the developmental trajectory may most effectively modify risk for later difficulties. Designing research studies around the youngest children with NF1 can result in intervention earlier in the developmental cascade associated with NF1 gene abnormalities. Furthermore, clinical trials for medications targeting physical and psychological aspects of NF1 often include individuals spanning a wide age range, including preschool-aged children. In a prior report, the REiNS Neurocognitive Subcommittee made recommendations regarding performance-based and observer-rated measures of attention for use in clinical trials and highlighted the need for separate consideration of assessment methods for young children. The observer-rated Attention-Deficit/Hyperactivity Disorder Rating Scale-Preschool version is recommended as a primary outcome measure. The NIH Toolbox Flanker, Dimensional Change Card Sort, and List Sort Working Memory tasks and Digits Forward from the Differential Ability Scales-2nd Edition (performance-based measures) are recommended as secondary outcome measures. Specific methodologic recommendations for inclusion of preschoolers in clinical trials research are also offered.

Assessing neuropsychological phenotypes of pediatric brain tumor survivors.

INTRODUCTION: Pediatric brain tumor survivors (PBTS) are at risk for both neurocognitive impairments and psychological difficulties, yet these two domains have historically been discretely examined, with assessment of psychosocial outcomes rarely included in studies of cognitive outcomes. Taking a person-centered approach, the current study aimed to more comprehensively evaluate PBTS late effect profiles, including both neurocognitive and psychological sequelae, and predictors of these profiles. METHOD: PBTS (N = 89) were assessed in a pediatric neuropsychological clinic between May 2009 and May 2018, diagnosed at least 1 year prior, and off-treatment for at least 3 months (Mage  = 6.57 years, SD = 4.53; 46.1% female). Parent- and teacher-report of psychological symptoms, and performance-based measures of neurocognitive functioning were examined using latent profile analysis. The R3STEP procedure identified predictors of class membership. RESULTS: The optimal model identified four classes characterized by: (1) average functioning across all measures ("Average," n = 47), (2) average psychosocial functioning and impaired neurocognitive functioning ("Cognitive Deficit," n = 25), (3) elevated social problems and significant neurocognitive impairments ("Social/Cognitive Deficit," n = 9), and (4) impaired visual planning and problem-solving and elevated parent-reported psychosocial problems, but average processing speed, working memory, and teacher-reported psychosocial outcomes ("Discrepant," n = 8). Ethnicity, race, radiation treatment, and diagnoses of neurofibromatosis 1, hydrocephalus, and cerebellar mutism syndrome were significant predictors of class membership (ps < 0.05). CONCLUSION: The present study identified distinct phenotypes with unique patterns of relations among neurocognitive and psychological domains. These findings are a vital first step toward identifying those at highest risk for poor outcomes and informing interventions that effectively address interrelated treatment targets for specific groups.

Cognition, ADHD Symptoms, and Functional Impairment in Children and Adolescents With Neurofibromatosis Type 1.

Objective: We examined the contribution of attention and executive cognitive processes to ADHD symptomatology in NF1, as well as the relationships between cognition and ADHD symptoms with functional outcomes. Methods: The study sample consisted of 141 children and adolescents with NF1. Children were administered neuropsychological tests that assessed attention and executive function, from which latent cognitive variables were derived. ADHD symptomatology, adaptive skills, and quality of life (QoL) were assessed using parent-rated questionnaires. Path analyses were conducted to test relationships among cognitive functioning, ADHD symptomatology, and functional outcomes. Results: Significant deficits were observed on all outcome variables. Cognitive variables did not predict ADHD symptomatology. Neither did they predict functional outcomes. However, elevated ADHD symptomatology significantly predicted functional outcomes. Conclusion: Irrespective of cognitive deficits, elevated ADHD symptoms in children with NF1 negatively impact daily functioning and emphasize the importance of interventions aimed at minimizing ADHD symptoms in NF1.

Social skills and autism spectrum disorder symptoms in children with neurofibromatosis type 1: evidence for clinical trial outcomes.

AIM: We examined key features of two outcome measures for social dysfunction and autism spectrum disorder traits, the Social Responsiveness Scale, Second Edition (SRS-2) and the Social Skills Improvement System - Rating Scales (SSIS-RS), in children with neurofibromatosis type 1 (NF1). The aim of the study was to provide objective evidence as to which behavioural endpoint should be used in clinical trials. METHOD: Cross-sectional behavioural and demographic data were pooled from four paediatric NF1 tertiary referral centres in Australia and the United States (N=122; 65 males, 57 females; mean age [SD] 9y 2mo [3y], range 3-15y). RESULTS: Distributions of SRS-2 and SSIS-RS scores were unimodal and both yielded deficits, with a higher proportion of severely impaired scores on the SRS-2 (16.4%) compared to the SSIS-RS (8.2%). Pearson's product-moment correlations revealed that both questionnaires were highly related to each other (r=-0.72, p<0.001) and to measures of adaptive social functioning (both p<0.001). Both questionnaires were significantly related to attention-deficit/hyperactivity disorder symptoms, but only very weakly associated with intelligence. INTERPRETATION: The SRS-2 and SSIS-RS capture social dysfunction associated with NF1, suggesting both may be suitable choices for assessing social outcomes in this population in a clinical trial. However, careful thought needs to be given to the nature of the intervention when selecting either as a primary endpoint. WHAT THIS PAPER ADDS: The Social Responsiveness Scale, Second Edition yielded a large deficit relative to population norms. The Social Skills Improvement System - Rating Scales yielded a moderate deficit relative to population norms. Both scales were highly correlated, suggesting that they are measuring a unitary construct.

Visual spatial learning outcomes for clinical trials in neurofibromatosis type 1.

Cognitive problems are common in children with neurofibromatosis type 1, representing a significant source of lifelong morbidity. Assessment of cognitive function has been challenging in the setting of clinical trials. Spatial learning deficits may be an important target for cognitive interventions. We leveraged a large, international cognitive study in affected children with NF1 treated with lovastatin to assess spatial learning using the "Arena Maze", a portable, computerized task that allows for retesting in the same environment. As with the parent study, spatial learning assessed with this task did not improve with lovastatin treatment.