Relationships between cognitive flexibility performance and adaptive behavior outcomes in survivors of pediatric brain tumor

Objective: Survivors of pediatric brain tumors are at increased risk of executive function (EF) and adaptive behavior difficulties. While previous research suggests that executive dysfunction impacts suboptimal adaptive outcomes, the specific elements of EF influencing this relationship remain unexplored. This study examines the relationship between cognitive flexibility and adaptive behavior in survivors compared to healthy controls. Methods: 86 survivors (Mage(SD)=23.41(4.24), 44 females) and 86 controls (Mage(SD)=23.09(4.50), 44 females) completed the Delis-Kaplan Executive Function System Trail Making Test (TMT) and Verbal Fluency Test (VFT). The Letter-Number Sequencing (LNS) and Category Switching (CS) conditions were isolated as measures of cognitive flexibility. Informants provided responses to obtain adaptive behavior ratings using the Scales of Independent Behavior-Revised (SIB-R). Linear regressions explored relationships between cognitive flexibility and SIB-R scores in survivors compared to controls. Results: For both TMT and VFT, the relationship between cognitive flexibility and adaptive behavior was significantly different between survivors and controls for SIB-R scores in Social Communication, Community Living, and Personal Living Skills (p<.0125). Survivors' better LNS performance predicted greater SIB-R scores across the same 3 domains (all p= <.001, r2semipartial=.08). Similarly, survivors' better CS performance predicted greater SIB-R scores across the same 3 domains (p = 0.002 to .02, r2semipartial =.03 to .04). No significant relationships were found in controls (all p >.05). After adjusting for working memory and inhibitory control, most relationships remained significant in survivors (p= <.001 to .046, r2semipartial=.02 to .08). Conclusion: These findings reveal a robust, positive relationship between cognitive flexibility performance and adaptive behaviors specific to survivors.

Effects of cognitive-motor intervention for pediatric posterior fossa tumor survivors: results of a pilot study

The purpose of this prospective pilot study was to evaluate the feasibility and effects of cognitive-motor intervention on the cognitive and motor abilities of pediatric survivors of posterior fossa tumors. The study involved patients aged 7 to 18 years with cognitive deficits who had completed primary treatment for posterior fossa tumors. 25 participants (Mage=11.3 ± 2.93, 64% male; 17 medulloblastoma, 1 ependymoma, 1 desmoplastic medulloblastoma, 6 piloid astrocytoma; 22 in remission (Mmonths =45), 3 in stabilization (Mmonths=49)) were recruited from the Research Institute for Brain Development and Peak Performance. The intervention consisted of two phases with a 3-month break for home training, and a total duration of 6 months. Each phase lasted 7 weeks and included two assessment procedures (pre- and post-intervention) and 10 training sessions over a period of 5 weeks (two 3-hour sessions per week). At baseline and pre- and post-intervention, all participants underwent a battery of cognitive and motor tests. Each training session included gross motor training (GMT), graphomotor training (GT), and cognitive-motor training (CMT). Statistical analysis was performed using the Friedman test for repeated measures and post-hoc Durbin-Conover test. The results indicated significant improvements in visuospatial working memory, visual attention, eye-hand coordination, semantic verbal fluency, auditory-motor synchronization, reaction time, and a decrease in the rate of ataxia. These improvements remained stable even in the absence of direct intervention. The findings demonstrate positive effects and feasibility of the intervention and suggest the need for further research in this area including randomized controlled feasibility studies with a larger sample.

Adaptive functioning and academic achievement in pediatric survivors of acute lymphoblastic leukemia: Associations with executive functioning, socioeconomic status, and academic support

OBJECTIVES

This study examines associations of functional outcomes (adaptive functioning and academic achievement) with executive functioning (EF), socioeconomic status (SES), and academic support in pediatric acute lymphoblastic leukemia (ALL) survivors.

METHODS

Fifty survivors of B-lineage ALL treated with chemotherapy-only (42% female, 76% NHW, ages 6-19) were evaluated on performance-based EF and academic achievement, and parent-rated EF and adaptive functioning. Area deprivation and child opportunity (i.e., SES) were extracted using census blocks and tracts. Academic support data were extracted from chart review.

RESULTS

Compared to population norms, pediatric ALL survivors demonstrated significantly lower overall adaptive skills and performance in word reading and math calculation (all p ≤ .011). Frequencies of impairment were significantly elevated on all adaptive scales and in math calculation compared to the population (all p ≤ .002). Parent-rated EF significantly predicted overall adaptive skills (p < .001), while performance-based EF significantly predicted word reading and math calculation (all p < .05). Adaptive functioning was not associated with neighborhood-specific variables or academic support. However, academic support predicted word reading (p < .001), while area deprivation and academic support predicted performance-based EF (all p ≤ .02).

CONCLUSIONS

Screening of functional outcomes, targeted intervention, and neuropsychological monitoring are necessary to support pediatric ALL survivors' neurocognitive and psychosocial development.

BRIEF-A: Factor structure and measurement invariance across self-report and informant forms

OBJECTIVE

This study analyzes the psychometric properties of the two forms (self-report and informant) of the Behavior Rating Inventory of Executive Function-Adult version (BRIEF-A) in a sample of healthy Portuguese adults.

METHOD

The participants were 608 adults, 304 of whom answered the self-report form (ages 18-59; 137 male and 167 female) and 304 who answered the informant form (ages 18-70; 110 male and 194 female).

RESULTS

The internal consistency for the indexes and the Global Executive Composite was very good (≥.90), whereas for the scales they were either acceptable (between .70 and .80) or good (≥.80), except for the Inhibit scale in both forms. Confirmatory factor analysis was used to test seven competing factor models for each of the forms. The original two-factor model (Behavioral Regulation and Metacognition Indexes) showed a slightly better model fit than the three-factor model (Behavioral Regulation, Emotional Regulation, and Metacognition Indexes) in both forms. The multiple-group analysis of the two-correlated-factor model across forms was supported (configural, metric, and partial scalar invariance).

CONCLUSIONS

Overall, the BRIEF-A showed adequate psychometric properties, suggesting that it is a useful instrument to assess everyday executive functioning in healthy Portuguese adults.

Cerebellar-Subcortical-Cortical Systems as Modulators of Cognitive Functions

Over the past few decades, research has established that the cerebellum is involved in executive functions; however, its specific role remains unclear. There are numerous theories of cerebellar function and numerous cognitive processes falling under the umbrella of executive function, making investigations of the cerebellum's role in executive functioning challenging. In this review, we explored the role of the cerebellum in executive functioning through clinical and cognitive neuroscience frameworks. We reviewed the neuroanatomical systems and theoretical models of cerebellar functions and the multifaceted nature of executive functions. Using attention deficit hyperactivity disorder and cerebellar tumor as clinical developmental models of cerebellar dysfunction, and the functional magnetic resonance imaging literature, we reviewed evidence for cerebellar involvement in specific components of executive function in childhood, adolescence, and adulthood. There is evidence for posterior cerebellar contributions to working memory, planning, inhibition, and flexibility, but the heterogeneous literature that largely was not designed to study the cerebellum makes it difficult to determine specific functions of the cerebellum or cerebellar regions. In addition, while it is clear that cerebellar insult in childhood affects executive function performance later in life, more work is needed to elucidate the mechanisms by which executive dysfunction occurs and its developmental course. The limitations of the current literature are discussed and potential directions for future research are provided.

The Neurological Predictor Scale Predicts Adaptive Functioning via Executive Dysfunction in Young Adult Survivors of Childhood Brain Tumor

OBJECTIVES

Survivors of childhood brain tumors experience neurological sequelae that disrupt everyday adaptive functioning (AF) skills. The Neurological Predictor Scale (NPS), a cumulative measure of tumor treatments and sequelae, predicts cognitive outcomes, but findings on its relation to informant-reported executive dysfunction (ED) and AF are mixed. Given known effects of frontal-subcortical system disruptions on AF, this study assessed the NPS' relationship with AF as mediated by frontal systems dysfunction, measured by the Frontal Systems Behavior Scale (FrSBe).

METHODS

75 participants (Mage = 23.5, SDage = 4.5) were young adult survivors of childhood brain tumors at least 5 years past diagnosis. FrSBe and Scales of Independent Behavior-Revised (SIB-R), a measure of AF, were administered to informants. Parallel multiple mediator models included Apathy and ED as mediators, and age at diagnosis and time between diagnosis and assessment as covariates.

RESULTS

More complex treatment and sequelae were correlated with poorer functioning. Mediation models were significant for all subscales: Motor Skills (MS), p = .0001; Social Communication (SC), p = .002; Personal Living (PL), p = .004; Community Living (CL), p = .007. The indirect effect of ED on SC and CL was significant; the indirect effect of Apathy was not significant for any subscales.

CONCLUSIONS

More complex tumor treatment and sequelae were associated with poorer long-term AF via increased ED. Cognitive rehabilitation programs may focus on the role of executive function and initiation that contribute to AF, particularly SC and CL skills, to help survivors achieve comparable levels of independence in everyday function as their peers.

Oral processing speed as a key mechanism in the relationship between neurological risk and adaptive functioning in survivors of pediatric brain tumors

PURPOSE

Brain tumor (BT) survivors are at risk for difficulties with adaptive functioning (AF). Recent work has associated neurological risk with poorer AF outcomes using the Neurological Predictor Scale (NPS), a quantification of neurological risk factors. Survivors also have poorer attention, processing speed, and working memory, which are all important for AF. The current study examined whether these cognitive constructs explain the relationship between the NPS and AF in survivors.

METHODS

Ninety-five adult BT survivors and 135 healthy controls were recruited from the Atlanta area. The Oral Symbol Digits Modalities test was used to measure processing speed, Digit Span Backward assessed working memory, and Digit Span Forward measured attention. Informants completed the Scales of Independent Behavior (SIB-R) to measure AF. Group differences and correlations were assessed, and the PROCESS macro for SPSS tested indirect effects.

RESULTS

Survivors were significantly lower on AF and cognitive measures compared with controls. Attention span and processing speed had significant indirect effects in relationship between NPS and AF individually, but processing speed was the only variable with a significant indirect effect when all cognitive variables were included in the model. The NPS and processing speed together account for approximately 39% of variance in AF outcomes.

CONCLUSIONS

BT survivors in our sample have lower AF than controls, and processing speed appears to be particularly important in explaining the relationship between neurological risk and AF. In the future, the development of interventions aimed at increasing young adult independence should target both cognitive processing speed and AF skills.

Neuropsychological functioning in survivors of childhood medulloblastoma/CNS-PNET: The role of secondary medical complications

OBJECTIVE

To investigate the long-term cognitive consequences of malignant pediatric brain tumor and its treatment, and factors explaining variability in cognitive functioning among survivors. Method: A geographical cohort of survivors of pediatric medulloblastoma (MB) and supratentorial primitive neuroectodermal tumor (CNS-PNET), treated between 1974 and 2013, was invited to participate. Of the 63 surviving patients, 50 (79%) consented to participation. The participants were tested with a battery of neuropsychological tests covering a wide age range. Verbal cognition, nonverbal cognition, processing speed, attention, memory, executive functioning, and manual dexterity were assessed. The participants were between 5:5 and 51:11 years of age at time of assessment. Assessments took place on average 19 years after primary tumor resective surgery. Results: One participant had a severe intellectual disability. For the rest, IQ varied from 52 to 125, with a mean score of 88.0 (SD 19.7). Twenty-eight (56%) of the participants had full-scale IQ scores in the age-average range or above. Gender, age at operation, time since operation, the presence of secondary medical complications, and treatment variables explained 46% of the variability in IQ scores, F(4,44) =  9.5, p<.001. The presence of endocrine insufficiency in combination with either epilepsy and/or hydrocephalus was associated with lowered IQ, lowered processing speed, and memory impairments. Conclusion: Patients treated for childhood MB and CNS-PNET have a lifelong risk of medical sequelae, including impaired cognitive functioning. This study adds to the literature by demonstrating the importance of following neuropsychological functioning closely, especially processing speed, learning, and memory, in survivors who have multiple secondary medical complications.

Cognitive mediators of adaptive functioning outcomes in survivors of pediatric brain tumors treated with proton radiotherapy

BACKGROUND

Cranial radiotherapy (RT) is associated with risk for cognitive and adaptive dysfunction. Proton RT (PRT) is a technique hypothesized to spare cognition by reducing exposure to nontarget brain tissue. However, little is known regarding functional outcomes in survivors of pediatric brain tumor (BT) treated with PRT. The present study examined the relationship between cognitive and adaptive outcomes in pediatric BT survivors post-PRT.

METHODS

Survivors treated with either focal (n = 33) or craniospinal irradiation (CSI; n = 37) PRT completed neurocognitive evaluations approximately 5 years post-treatment. Results of intelligence testing and ratings of adaptive functioning are reported. Mediation models examined the relationship among radiation field, cognition, and adaptive functioning.

RESULTS

The PRT CSI group demonstrated worse cognitive outcomes than the PRT Focal group across each cognitive index (Cohen's d = 0.56-0.70). Parent ratings of adaptive functioning were also worse in the PRT CSI group than the PRT Focal group (Global Adaptive Composite, d = 0.53; conceptual skills, d = 0.67). Cognitive performance fully mediated the relationship between radiation field and adaptive outcomes, while controlling for group differences in tumor histology and RT dose.

CONCLUSIONS

Focal PRT survivors demonstrated generally positive outcomes with weaknesses in processing speed and aspects of adaptive functioning. CSI exposure was associated with more consistently poor cognitive and adaptive outcomes. The increased risk for adaptive dysfunction in the PRT CSI group appeared due to the effects of CSI on cognition. Efforts to reduce the volume of tissue exposure to RT remain important.

Executive dysfunction in neuro-oncology: Behavior Rating Inventory of Executive Function in adult primary brain tumor patients

Adult primary brain tumor (PBT) survivors report persistent cognitive difficulties before, during, and after treatment, which are problematic for everyday functioning. Cognitive domains often affected by cancer treatment appear to be attention and executive functioning (EF). One validated measure developed to assess an individual's EF within daily living is the Behavior Rating Inventory of Executive Function-Adult (BRIEF-A). To date, no published research has investigated the EF profile of PBT patients using the BRIEF-A. Seventy-four PBT patients completed the BRIEF-A. Descriptive analyses were conducted to determine the self-reported EF profile in PBT patients. T-tests preliminarily compared the performance of PBT patients to four other comparison groups: mild cognitive impairment (MCI; n = 23), attention-deficit/hyperactivity disorder-unmedicated (ADHD-U; n = 27), traumatic brain injury (TBI; n = 23), and healthy controls (HC; n = 26). PBT BRIEF-A group means were average across subscales and indexes, yet the prevalence of significant elevations ranged from 12 to 50%. The Metacognition Index demonstrated 38% elevation prevalence compared to 22% in Behavioral Regulation. Approximately 61% of the sample had at least one clinically elevated scaled score. PBT patients reported significantly more EF impairment than HC and significantly less than ADHD-U. No significant differences were found between the PBT and MCI groups or PBT and TBI groups. Despite group means not reaching clinical impairment, a substantial proportion of patients with PBTs endorse executive dysfunction. Elevations were most prominent in metacognitive abilities over behavioral dysregulation. Notably, the EF profile of PBT patients was remarkably similar to that of MCI and TBI, increased when compared to HC, and well below ADHD-U.

White matter network topology relates to cognitive flexibility and cumulative neurological risk in adult survivors of pediatric brain tumors

Adult survivors of pediatric brain tumors exhibit deficits in executive functioning. Given that brain tumors and medical treatments for brain tumors result in disruptions to white matter, a network analysis was used to explore the topological properties of white matter networks. This study used diffusion tensor imaging and deterministic tractography in 38 adult survivors of pediatric brain tumors (mean age in years = 23.11 (SD = 4.96), 54% female, mean years post diagnosis = 14.09 (SD = 6.19)) and 38 healthy peers matched by age, gender, handedness, and socioeconomic status. Nodes were defined using the Automated Anatomical Labeling (AAL) parcellation scheme, and edges were defined as the mean fractional anisotropy of streamlines that connected each node pair. Global efficiency and average clustering coefficient were reduced in survivors compared to healthy peers with preferential impact to hub regions. Global efficiency mediated differences in cognitive flexibility between survivors and healthy peers, as well as the relationship between cumulative neurological risk and cognitive flexibility. These results suggest that adult survivors of pediatric brain tumors, on average one and a half decades post brain tumor diagnosis and treatment, exhibit altered white matter topology in the form of suboptimal integration and segregation of large scale networks, and that disrupted topology may underlie executive functioning impairments. Network based studies provided important topographic insights on network organization in long-term survivors of pediatric brain tumor.

•

Long term brain tumor survivorship is associated with altered white matter networks.

•

Hub regions were preferentially impacted in survivors.

•

Network properties explain cognitive flexibility differences between survivors and peers.

Co-occurrence and Severity of Neurodevelopmental Burden (Cognitive Impairment, Cerebral Palsy, Autism Spectrum Disorder, and Epilepsy) at Age Ten Years in Children Born Extremely Preterm

BACKGROUND

This study aims to determine the prevalence of neurodevelopmental impairments at age ten years among children born extremely preterm (less than 28 weeks gestational age) and to offer a framework for categorizing neurological limitations.

METHODS

A multicenter, prospective cohort follow-up study recruited 889 ten-year-old children born from 2002 to 2004. We assessed prevalence of cognitive impairment, measured by intelligent quotient and tests of executive function, cerebral palsy (CP), autism spectrum disorder (ASD), and epilepsy singly and in combination. The three levels of impairment severity were: category I-no major neurodevelopmental impairment; category II-normal cognitive ability with CP, ASD, and/or epilepsy; and category III-children with cognitive impairment.

RESULTS

A total 214 of 873 children (25%) had cognitive impairment, 93 of 849 children (11%) had CP, 61 of 857 children (7%) had ASD, and 66 of 888 children (7%) had epilepsy. Further, 19% of all children had one diagnosis, 10% had two diagnoses, and 3% had three diagnoses. Decreasing gestational age was associated with increasing number of impairments (P < 0.001). Half the children with cognitive impairment and one third of children with CP, ASD, or epilepsy had a single impairment. Six hundred one (68% [95% CI, 64.5%-70.7%]) children were in category I, 74 (8% [95% CI, 6.6%-10.3%]) were in category II, and 214 (24% [95% CI 21.7%-27.4%]) were in category III.

CONCLUSIONS

Three quarters of children had normal intellect at age ten years; nearly 70% were free of neurodevelopmental impairment. Forty percent of children with impairments had multiple diagnoses.

Pituitary disorders as a predictor of apathy and executive dysfunction in adult survivors of childhood brain tumors

BACKGROUND

The relationship between apathy and endocrine dysfunction, both frequent outcomes of neurological insult, has not yet been investigated in brain tumor survivors. The present study aimed to assess the relationship between pituitary disorders and apathy and other facets of executive function in long-term adult survivors of childhood brain tumors and to differentiate between apathy and depression in this population.

PROCEDURE

Seventy-six adult survivors of childhood brain tumors at least 5 years past diagnosis participated. An informant completed the Frontal Systems Behavior Scale (FrSBe), and 75 of the 76 participants completed a Structured Clinical Interview for the DSM-IV-TR (SCID). Information on neuroendocrine dysfunction was obtained through medical chart review.

RESULTS

Clinically significant levels of apathy on the FrSBe were identified in 41% of survivors. Pituitary dysfunction significantly explained 9% of the variance in apathy scores and affected whether an individual presented with clinical levels of apathy. Pituitary dysfunction predicted higher levels of executive dysfunction but did not impact whether a participant reached clinical levels of executive dysfunction. A past major depressive episode (MDE) significantly predicted current apathy but showed no relationship with pituitary disorders. Radiation treatment predicted pituitary dysfunction but not the differences in apathy or executive functions.

CONCLUSIONS

Apathy and executive dysfunction in survivors of childhood brain tumors are strongly predicted by pituitary dysfunction, and individuals with pituitary dysfunction are more likely to present with clinical levels of apathy as adults. Clinical levels of apathy may present absent of current depression, and pituitary dysfunction impacts apathy uniquely.

Effects of manganese exposure on visuoperception and visual memory in schoolchildren

BACKGROUND

Manganese (Mn) is an essential metal involved in multiple physiological functions. Environmental exposure to airborne Mn is associated with neurocognitive deficits in humans. Children, whose nervous system is in development, are particularly susceptible to Mn neurotoxicity.

OBJECTIVE

The objective of this study was to assess the association between Mn environmental exposure, and effects on visuoperception and visual memory in schoolchildren.

METHODS

We assessed schoolchildren between 7 and 11 years old, with similar socioeconomic status, from the mining district of Molango (n=148) and Agua Blanca (n=119, non-mining area) in Hidalgo state, Mexico. The Rey-Osterrieth Complex Figure (ROCF) test was used to assess visuoperception and short-term visual memory. Hair manganese (MnH) concentrations were determined. Linear regression models were constructed to estimate the associations between MnH and ROCF scores, adjusted for potential confounders.

RESULTS

The geometric mean MnH was nine times higher in schoolchildren from the Mn mining area (5.25μg/g) than in schoolchildren from the non-mining area (0.55μg/g). For the ROCF Copy trial, MnH was significantly associated with an increase in distortion errors (tangency, closure), angle errors, overtracing (partial overtracing). In the Immediate Recall trial, MnH was significantly associated with increased overtracing (partial overtracing) and omissions, and negatively associated with the number of perceptual drawn units, total score and percentage immediate recall.

CONCLUSIONS

MnH is associated with alterations in visuoperception and short-term visual memory in schoolchildren exposed to airborne Mn.