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

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.

Methylphenidate improves cognitive function and health-related quality of life in survivors of childhood brain tumours

OBJECTIVES

The growing population of survivors of childhood brain tumors present the challenge of long-term quality of survival. The domains most affected by tumor and treatment are those implicated in development of typical intellectual functions: attention, working memory, and processing speed, with consequent effects upon function and quality of life. In this paper we present service evaluation data on the 12-month effect upon processing speed, visual and auditory attentional domains in 29 patients receiving methylphenidate aged 5-16 years (Mean=10.6).

METHODS

Patients received immediate-release methylphenidate and were converted to modified-release as appropriate. Mean optimal dose of immediate-release methylphenidate was 0.34 mg/kg per dose (range 0.2-0.67).

RESULTS

Patients showed a significant positive impact of methylphenidate on attention in all tests of selective visual attention from the Test of Everyday Attention for Children 2. A significant improvement was also shown on response time. Significant change was not found on psychometric measures of sustained auditory or visual attention, or selective auditory attention. Ratings of Health-Related Quality of Life showed a positive benefit of methylphenidate at 12 months. Side effects were minimal and not statistically significant.

CONCLUSIONS

Survivors of childhood brain tumor with attentional and processing speed deficit show clinical benefit from methylphenidate.

Practical adaptive skills in pediatric brain tumor survivors: the contribution of medical factors and social determinants of health

Pediatric brain tumor survivors demonstrate weaknesses in adaptive functioning, most notably practical adaptive skills; however, the specific areas of weakness within practical skills are unknown. This study examined the aspects of practical adaptive functions that are most impacted in brain tumor survivors, and identified medical and socio-demographic variables that predicted outcomes. The sample included 117 pediatric brain tumor patients seen for a clinical neuropsychological evaluation and whose parents completed the Adaptive Behavior Assessment System, Second or Third Edition. T-tests compared practical adaptive skills to normative means. Correlations examined associations between medical and socio-demographic variables and each of the practical adaptive subscales (Community Use, Home Living, Health & Safety, Self-Care). Significant correlations were entered into linear regression models for each practical adaptive skill. All practical subscales were significantly below the normative mean. Community Use was positively correlated with age at diagnosis and negatively correlated with treatment burden, time since diagnosis, and neighborhood deprivation. Health and Safety was positively correlated with age at diagnosis. Home Living was positively correlated with neighborhood deprivation. Self-Care was positively correlated with age at diagnosis and parental education. Specific medical and socio-demographic factors predicted practical adaptive functioning, highlighting the importance of considering the role of medical and socio-demographic determinants of health on adaptive functioning outcomes in pediatric brain tumors.

A systematic review of pediatric neuropsychological outcomes with proton versus photon radiation therapy: A call for equity in access to treatment

OBJECTIVE

There is increasing interest in the utilization of proton beam radiation therapy (PRT) to treat pediatric brain tumors based upon presumed advantages over traditional photon radiation therapy (XRT). PRT provides more conformal radiation to the tumor with reduced dose to healthy brain parenchyma. Less radiation exposure to brain tissue beyond the tumor is thought to reduce neuropsychological sequelae. This systematic review aimed to provide an overview of published studies comparing neuropsychological outcomes between PRT and XRT.

METHOD

PubMed, PsychINFO, Embase, Web of Science, Scopus, and Cochrane were systematically searched for peer-reviewed published studies that compared neuropsychological outcomes between PRT and XRT in pediatric brain tumor patients.

RESULTS

Eight studies were included. Six of the studies utilized retrospective neuropsychological data; the majority were longitudinal studies (n = 5). XRT was found to result in lower neuropsychological functioning across time. PRT was associated with generally stable neuropsychological functioning across time, with the exception of working memory and processing speed, which showed variable outcomes across studies. However, studies inconsistently included or considered medical and sociodemographic differences between treatment groups, which may have impacted neuropsychological outcomes.

CONCLUSIONS

Despite methodological limitations, including limited baseline neuropsychological evaluations, temporal variability between radiation treatment and first evaluation or initial and follow-up evaluations, and heterogenous samples, there is emerging evidence of sociodemographic inequities in access to PRT. With more institutions dedicating funding towards PRT, there may be the opportunity to objectively evaluate the neuropsychological benefits of patients matched on medical and sociodemographic variables.

Working Memory and Processing Speed Predict Math Skills in Pediatric Brain Tumor Survivors

OBJECTIVE

Childhood brain tumor (BT) survivors are at risk for working memory (WM) and processing speed (PS) deficits, which impact other cognitive domains. This study aimed to characterize WM, PS, and untimed mathematics calculation performance in pediatric BT survivors at least 2 years post-diagnosis, identify medical factors associated with deficits in mathematics, and examine whether WM and/or PS predict mathematics performance in this clinical sample.

METHODS

Retrospective data were gathered from 72 BT survivors between 7 and 21 years of age ( M =13.64 y, SD =4.01 y) for a clinical neuropsychologic evaluation. All participants completed Wechsler measures of WM and PS and a measure of untimed mathematics calculation.

RESULTS

WM, PS, and the mathematics calculation were significantly lower than the normative mean. Math scores were not correlated with any of the examined medical factors. PS was negatively correlated with the Neurological Predictor Scale and positively correlated with age at diagnosis. Both WM and PS were associated with math outcomes and accounted for 30.4% and 19.2% of the variance, respectively.

CONCLUSIONS

The findings indicate that WM and PS contribute to mathematics performance in pediatric BT survivors. Examining mathematics performance should be a part of clinical neuropsychological evaluations. Interventions to improve mathematics performance in this population should also focus on WM and compensatory strategies for slowed PS.

Tumor region associated with specific processing speed outcomes

OBJECTIVE

Processing speed (PS) is a vulnerable cognitive skill in pediatric cancer survivors as a consequence of treatments and, less consistently, tumor region. Studies conventionally examine graphomotor PS; emerging research suggests other aspects of PS may be impacted. This study examined types of PS in pediatric brain tumor survivors to determine which aspects are impaired. Given discordance across studies, we additionally investigated the relationship between brain region and PS.

METHODS

The sample consisted of 167 pediatric brain tumor patients (100 supratentorial). PS (oral naming, semantic fluency, phonemic fluency, motor speed, graphomotor speed, visual scanning) was gathered via clinical neuropsychological assessment. To examine PS by region, infratentorial and supratentorial groups were matched on age at diagnosis and neuropsychological assessment, and time since diagnosis.

RESULTS

The whole sample performed below normative means on measures of oral naming (p < .001), phonemic fluency (p < .001), motor speed (p = .03), visual scanning (p < .001), and graphomotor speed (p < .001). Only oral naming differed by region (p = .03), with infratentorial tumors associated with slower performance. After controlling for known medical and demographic risk factors, brain region remained a significant predictor of performance (p = .04). Among the whole sample, greater than expected proportions of patients with impairment (i.e., >1 standard deviation below the normative mean) were seen across all PS measures. Infratentorial tumors had higher rates of impairments across all PS measures except phonemic fluency.

CONCLUSIONS

Results indicate pediatric brain tumor survivors demonstrate weaknesses in multiple aspects of PS, suggesting impairments are not secondary to peripheral motor slowing alone. Additionally, tumor region may predict some but not all neuropsychological outcomes in this population.

Sluggish cognitive tempo profiles in survivors of childhood cancer as compared to children with attention-deficit/hyperactivity disorder

PURPOSE

Neurocognitive late effects including problems with attention have been reported in pediatric oncology survivors. While some researchers have characterized these late effects as similar to symptoms of attention-deficit/hyperactivity disorder, inattentive presentation (ADHD-I), there remains some controversy as to whether these concerns in oncology patients are best conceptualized according to an ADHD-I or sluggish cognitive tempo (SCT) framework. The aim of this study was to describe SCT symptoms in children with ADHD-I or oncology diagnoses; identify groups of SCT symptoms among children with brain tumors (BT), acute lymphoblastic leukemia (ALL), or ADHD-I; and identify whether specific SCT profiles are associated with these diagnoses.

METHODS

The sample was comprised of 364 youth (146 BT, 149 ADHD-I, 69 ALL) referred for a neuropsychological evaluation at an academic medical center. Caregivers completed the SCT scale as part of the clinical evaluation.

RESULTS

Groups differed on mean scores for the SCT scales (Total, Sleepy/sluggish, Low initiation, and Daydreamy) by diagnosis (all p < 0.05), with the ADHD-I group having higher SCT symptoms on all scales. Latent profile analysis showed significant differences between latent SCT classes according to ADHD-I versus cancer diagnosis. The ADHD-I group was significantly more likely to be in the high SCT class compared to the oncology groups.

CONCLUSION

Findings add to the understanding of SCT symptoms in pediatric oncology survivors. There is utility in applying the SCT framework to the oncology population; however, pediatric survivors are likely to be rated differently than youth with ADHD-I. Implications and future directions are discussed.

Processing Speed and Time since Diagnosis Predict Adaptive Functioning Measured with WeeFIM in Pediatric Brain Tumor Survivors

Simple Summary

Brain tumor (BT) survivors show difficulties in adaptive functioning (AF) and in acquiring independence (e.g., graduating, finding employment, building strong relationships, and being independent). The aim of our observational retrospective study is to explore the contribution of different clinical and cognitive variables in explaining and predicting the AF outcomes of BT survivors, measured with the Functional Independence Measure for Children (WeeFIM). The analysis demonstrated that processing speed and time since diagnosis are the main explanatory variables. Other clinical factors, such as age at diagnosis and hydrocephalus, differentially influence functional skills according to distinct domains (i.e., self-care, mobility, and cognition). The identification of the clinical factors influencing AF could suggest targets on which to focus attention. By successfully assessing, understanding, and managing AF, it will be possible to improve its management in pediatric BT survivors.

Abstract

(1) Background: Brain tumor (BT) survivors show difficulties in the acquisition of developmental milestones, related to academic achievement, vocational employment, social relationships, and autonomy. The skills underlying adaptive functioning (AF) are usually damaged in BT survivors due to the presence of the brain tumor, treatment-related factors, and other neurological sequelae. In this study, we aimed to explore the contribution of different cognitive factors in children with BT to AF, considering diagnosis-related variables. (2) Methods: Standardized cognitive assessment was undertaken and clinical information was collected from a retrospective cohort of 78 children with a BT, aged between 6 and 18 year old at the time of the assessment. Regression models were computed to investigate the influence of the selected variables on daily functional skills as measured by the Functional Independence Measure for Children (WeeFIM). (3) Results: The analyses showed that the main explanatory variables are processing speed and time since diagnosis. Other clinical variables, such as age at diagnosis and hydrocephalus, differentially influence functional skills according to distinct domains (i.e., self-care, mobility, and cognition). (4) Conclusions: The main explanatory variables of AF that emerged in our models point to a potential target of improving AF management in pediatric BT survivors.

Graph Theoretical Analysis of Brain Network Characteristics in Brain Tumor Patients: A Systematic Review

Graph theory is a branch of mathematics that allows for the characterization of complex networks, and has rapidly grown in popularity in network neuroscience in recent years. Researchers have begun to use graph theory to describe the brain networks of individuals with brain tumors to shed light on disrupted networks. This systematic review summarizes the current literature on graph theoretical analysis of magnetic resonance imaging data in the brain tumor population with particular attention paid to treatment effects and other clinical factors. Included papers were published through June 24^th, 2020. Searches were conducted on Pubmed, PsycInfo, and Web of Science using the search terms (graph theory OR graph analysis) AND (brain tumor OR brain tumour OR brain neoplasm) AND (MRI OR EEG OR MEG). Studies were eligible for inclusion if they: evaluated participants with a primary brain tumor, used graph theoretical analyses on structural or functional MRI data, MEG, or EEG, were in English, and were an empirical research study. Seventeen papers met criteria for inclusion. Results suggest alterations in network properties are often found in people with brain tumors, although the directions of differences are inconsistent and few studies reported effect sizes. The most consistent finding suggests increased network segregation. Changes are most prominent with more intense treatment, in hub regions, and with factors such as faster tumor growth. The use of graph theory to study brain tumor patients is in its infancy, though some conclusions can be drawn. Future studies should focus on treatment factors, changes over time, and correlations with functional outcomes to better identify those in need of early intervention.

White matter hyperintensity volumes are related to processing speed in long-term survivors of childhood cerebellar tumors

PURPOSE

Across several clinical populations, higher white matter hyperintensity (WMH) burden is consistently associated with decreases in cognitive performance, especially processing speed. Research of childhood cancer survivors has not utilized WMH quantification methodology to better understand the impact of WMH burden and its relationship with core cognitive skills. The present study aimed to quantify WMH volumes in a sample of long-term survivors of childhood cerebellar tumor and investigate the relationships with performance on a measure of oral processing speed. To further explore brain-behavior relationships, multivariate sparse canonical correlations was employed to identify WMH areas that predict processing speed performance.

METHODS

Thirty-five survivors and 56 healthy controls underwent neuroimaging and completed a measure of oral processing speed. The survivor group was further divided based on treatment (i.e., chemoradiation therapy (n = 20) vs. surgery only (n = 15)) to better understand the impact of treatment.

RESULTS

Survivors, and especially those treated with chemoradiation therapy, showed higher total WMH volumes and slower processing speed. Higher total WMH volumes were significantly associated with poorer processing speed (r = - 0.492, p = 0.003). Multivariate brain-behavior relationships revealed that periventricular WMHs were significantly associated with slower processing speed performance (p < 0.05).

CONCLUSION

Results exemplify that long-term survivors treated with and without chemoradiation therapy are at increased risk of developing higher WMH volumes compared to healthy peers. In addition, processing speed was robustly shown to be related to periventricular WMHs using an automated neuroimaging pipeline. This methodology to monitor WMH burden has the potential to be implemented efficiently with routine clinical neuroimaging of cancer survivors.