Structural and Functional Brain Imaging in Long-Term Survivors of Childhood Acute Lymphoblastic Leukemia Treated With Chemotherapy: A Systematic Review

Performance of the Wisconsin Card Sorting Test in Oncopediatric Patients in an Oncology Unit in Cali, Colombia: A Cross-Sectional Observational Study

BACKGROUND

In 2020, the prevalence of cancer rose to 844,778 cases among the population aged 0-19 years. Approximately 90% of individuals under 18 years of age reside in low- and middle-income countries, where cancer survivors report adverse outcomes that negatively impact their general health, emotional state, and external factors such as academic performance due to the effect of these outcomes on executive functions. The Wisconsin Cart Sorting Test (WCST) is the gold standard for evaluating executive functioning. Therefore, this article (1) reports the performance of the Wisconsin Card Sorting Test (WCST) in oncopediatric patients from Cali, Colombia; (2) indicates the reliability of the WCST; (3) describes the association between cancer type and executive functioning in patients; (4) describes the differences between patients with various executive deficits and their executive total scores; and (5) describes the association between cancer type and the presence of brain deficits based on the WCST.

METHODS

In this cross-sectional observational study, 24 oncopediatric patients were interviewed and evaluated via the WCST.

RESULTS

The mean age was 12.08 years (SD 3.98); 20.8% of the patients were women, 70.8% had a primary diagnosis of leukemia, 8% exhibited acquired brain deficits, and more than 75% displayed adequate functional indicators of executive functions. Robust statistics were employed to explore the differences between the types of diagnosis and performance in executive functions, and no statistically significant differences were found (p = 0.156). We found that the WCST has a reliable Cronbach's α of 0.804. Oncopediatric patients without brain deficits presented strong results in terms of executive functions (p = 0.002), with a moderate effect size (0.727).

CONCLUSIONS

The WCST is reliable for discriminating executive functioning among pediatric cancer patients. The evidence suggests that there were no differences in the executive functioning of the participants based on the types of cancer being evaluated.

Progression of brain injuries associated with methotrexate chemotherapy in childhood acute lymphoblastic leukemia

BACKGROUND

Brain bases and progression of methotrexate-associated neurotoxicity and cognitive disturbances remain unknown. We tested whether brain abnormalities worsen in proportion to intrathecal methotrexate(IT-MTX) doses.

METHODS

In this prospective, longitudinal study, we recruited 19 patients with newly diagnosed acute lymphoblastic leukemia 4-to-20 years of age and 20 matched controls. We collected MRI and neuropsychological assessments at a pre-methotrexate baseline and at week 9, week 22, and year 1 during treatment.

RESULTS

Patients had baseline abnormalities in cortical and subcortical gray matter(GM), white matter(WM) volumes and microstructure, regional cerebral blood flow, and neuronal density. Abnormalities of GM, blood flow, and metabolites worsened in direct proportions to IT-MTX doses. WM abnormalities persisted until week 22 but normalized by year 1. Brain injuries were localized to dorsal and ventral attentional and frontoparietal cognitive networks. Patients had cognitive deficits at baseline that persisted at 1-year follow-up.

CONCLUSIONS

Baseline abnormalities are likely a consequence of neuroinflammation and oxidative stress. Baseline abnormalities in WM microstructure and volumes, and blood flow persisted until week 22 but normalized by year 1, likely due to treatment and its effects on reducing inflammation. The cytotoxic effects of IT-MTX, however, likely contributed to continued, progressive cortical thinning and reductions in neuronal density, thereby contributing to enduring cognitive deficits.

IMPACT

Brain abnormalities at a pre-methotrexate baseline likely are due to acute illness. The cytotoxic effects of intrathecal MTX contribute to progressive cortical thinning, reductions in neuronal density, and enduring cognitive deficits. Baseline white matter abnormalities may have normalized via methotrexate treatment and decreasing neuroinflammation. Corticosteroid and leucovorin conferred neuroprotective effects. Our findings suggest that the administration of neuroprotective and anti-inflammatory agents should be considered even earlier than they are currently administered. The neuroprotective effects of leucovorin suggest that strategies may be developed that extend the duration of this intervention or adapt it for use in standard risk patients.

Characterization of brain development with neuroimaging in a female mouse model of chemotherapy treatment of acute lymphoblastic leukemia

Background

Survivors of pediatric acute lymphoblastic leukemia (ALL) exhibit abnormal neurocognitive outcomes that are possibly due to exposures to neurotoxic chemotherapy agents. This study aimed to determine the feasibility of characterizing long-term neuroanatomical changes with in vivo neuroimaging in a preclinical model of treatment for ALL.

Methods

Female mice (C57BL/6) were randomly assigned to a saline control group (n=10) or a treatment group (n=10) that received intrathecal methotrexate and oral dexamethasone (IT-MTX + DEX). Mice were subsequently scanned three times on a 7T MRI at ages 3, 6, and 12 months (T1, T2, and T3, respectively), which corresponds with human age-equivalents spanning early to late adulthood. Regional brain volumes were automatically segmented, and volume change between timepoints (i.e., T1 to T2; and T2 to T3) were compared between groups (i.e., saline vs. IT-MTX + DEX).

Results

Five mice in the IT-MTX + DEX group, and seven mice in the saline group completed all three scans. Between T1 and T2, volumetric change was significantly different between groups in total gray matter [estimate =2.06, 95% confidence interval (CI): 0.27-3.84], the cerebrum (estimate =1.62, 95% CI: 0.14-3.09), claustrum (estimate =0.06, 95% CI: 0.02-0.09), amygdala (estimate =0.16, 95% CI: 0.03-0.29), and striatum (estimate =0.18, 95% CI: 0.01-0.35), with the IT-MTX + DEX group exhibiting a more robust increase in volume than the saline-treated group. Between T2 and T3, group differences in structural brain development were evident for total white matter (estimate =-0.14, 95% CI: -0.27 to -0.01), and the corpus callosum (estimate =-0.09, 95% CI: -0.19 to 0.00) and amygdala (estimate =-0.05, 95% CI: -0.10 to 0.00). In contrast to the rapid brain growth observed earlier in development (i.e., T1 to T2), the IT-MTX + DEX group exhibited an attenuated increase in volume relative to the saline-treated group between T2 and T3.

Conclusions

The results demonstrate feasibility of modeling pediatric ALL treatment in a preclinical model and highlight the potential of using preclinical neuroimaging models to gain insight into brain development throughout survivorship.

Case report: Exploring chemoradiotherapy-induced leukoencephalopathy with 7T imaging and quantitative susceptibility mapping

Chemotherapy and radiotherapy are widely used in the treatment of central nervous system tumors and acute lymphocytic leukemia even in the pediatric population. However, such treatments run the risk of a broad spectrum of cognitive and neurological deficits. Even though the correlation with cognitive decline is still not clear, neuroradiological defects linked to white matter injury and vasculopathies may be identified. Thanks to the use of 7T MRI it is possible to better define the vascular pattern of the brain lesions with the added advantage of identifying their characteristics and anatomical localization, which, however, are not evident with a conventional brain scan. Moreover, the use of Quantitative Susceptibility Mapping (QSM) makes it possible to discriminate between calcium deposits on vessels (chemo-radiation-induced) and hemoglobin deposition in radio-induced cavernomas, speculating, as a result, about the pathophysiology of iatrogenic brain damage. We describe the case of a 9 year-old boy with a T-type acute lymphoid leukemia who had previously been treated with polychemotherapy and high-dose RT. To better define the child's neuroradiological pattern, 7T MRI and QSM were performed in addition to conventional imaging examinations. Our case report suggests the potential usefulness of a QSM study to distinguish radio-induced vascular malformations from mineralizing microangiopathy.

Neurocognitive and psychosocial outcomes in survivors of childhood leukemia with Down syndrome

OBJECTIVE

The primary aim of this study was to assess the feasibility of a developmentally tailored neurocognitive assessment in survivors of childhood acute leukemia with Down syndrome (DS-leukemia). A secondary aim was to compare outcomes in the DS-leukemia group to a historical comparison group of individuals with DS and no history of childhood cancer.

METHODS

Survivors of DS-leukemia (n = 43; 56% male, mean [SD] age at diagnosis = 4.3 [4.5] years; age at evaluation = 15 [7.9] years) completed a neurocognitive assessment battery that included direct measures of attention, executive function, and processing speed, and proxy ratings of attention problems and executive dysfunction. Direct assessment outcomes were compared to a historical comparison cohort of individuals with DS and no history of childhood cancer (DS-control; n = 117; 56% male, mean [SD] age at evaluation = 12.7 [3.4] years).

RESULTS

Rates of valid task completion ranged from 54% to 95%, suggesting feasibility for most direct assessment measures. Compared to the DS-control group, the DS-leukemia group had significantly lower completion rates on measures of executive function (p = 0.008) and processing speed (p = 0.018) compared to the DS-control group. There were no other significant group differences in completion rates. Compared to the DS-control group, the DS-leukemia group had significantly more accurate performance on two measures of executive function (p = 0.032; p = 0.005). Compared to the DS-control group, the DS-leukemia group had significantly more problems with executive function as identified on proxy ratings (6.5% vs. 32.6%, p = <0.001).

CONCLUSION

Children with Down syndrome (DS) are at increased risk for developing acute leukemia compared to the general population but are systematically excluded from neurocognitive outcome studies among leukemia survivors. This study demonstrated the feasibility of evaluating neurocognitive late effects in leukemia survivors with DS using novel measures appropriate for populations with intellectual developmental disorder.

[Recent research on cognitive impairment in children with acute lymphoblastic leukemia]

Acute lymphoblastic leukemia (ALL) is the most common malignant neoplastic disease in children. With the continuous improvement in diagnosis and treatment, there has been an increasing number of ALL children who achieve long-term survival after complete remission; however, a considerable proportion of these children have cognitive impairment, which has a serious adverse impact on their learning, employment, and social life. This article reviews the latest research on cognitive impairment in children with ALL from the aspects of the influencing factors, detection techniques, and prevention/treatment methods for cognitive impairment.

Causes of New-Onset Seizures and Their Treatment in Children With Non-CNS Malignancies: A Retrospective Study in a Tertiary Care Center

BACKGROUND

Seizures occur in up to 13% of children with non-central nervous system (CNS) malignancies, but little is known about their causes and optimal diagnostic and therapeutic approaches. Here we sought to determine etiologies and clinical trajectories of new-onset seizures in this patient population.

METHODS

A retrospective chart review over a 10-year period was conducted at the American University of Beirut Medical Center to identify children with non-CNS malignancies and at least one new-onset seizure. Data were collected on the underlying malignancy, seizure etiology, clinical course, treatments, electroencephalograms, and brain imaging.

RESULTS

New-onset seizures occurred in 56 children (2-year median follow-up), most commonly in the context of acute lymphoblastic leukemia, lymphomas, and sarcomas. In 19 children, the first seizure consisted of status epilepticus. The most common etiologies were cerebrovascular accidents, posterior reversible encephalopathy syndrome, and metastasis. Forty-nine patients received anti-seizure medications (ASMs). Withdrawal of ASMs was successful in 19 children with normal initial or follow-up brain imaging but failed in three patients with persistent brain lesions. The remaining children, all of whom except two had structural brain abnormalities, received chronic ASMs and remained seizure free for a median period of 2 years at the last follow-up in survivors.

CONCLUSIONS

Not only are seizures in children with non-CNS cancers often indicative of a serious brain insult, but they can also be challenging in the form of status epilepticus. An urgent diagnostic evaluation is therefore needed to expedite treatment, which should be tailored to the chronicity of the underlying cause.

Cranial MRI in Childhood Acute Leukemia during Treatment and Follow-Up Including the Impact of Intrathecal MTX-A Single-Center Study and Review of the Literature

Due to high survival rates, long-term sequelae, especially neurotoxicity, need to be considered in childhood acute leukemias. In this retrospective analysis of morphologic changes of the brain in children treated for acute leukemias, we included 94 patients (77 ALL, 17 AML; 51 male, 43 female; median age: 5 years) from a single center. We analyzed 170 cranial MRI scans (T2, FLAIR axial) for morphologic alterations of the brain and variations of the ventricular width (GDAH). In addition, the corresponding literature was reviewed. More than 50% of all patients showed cerebral pathomorphologies (CP). They were seen more often in children with ALL (55.8%), ≤ 6 years of age (60.8%), in relapse (58.8%) or after CNS irradiation (75.0%) and included white matter changes, brain atrophy, sinus vein thrombosis and ischemic events. GDAH significantly enlarged mainly in children up to 6 years, with relapse, high-risk leukemias or ALL patients. However, GDAH can normalize again. The number of intrathecal Methotrexate applications (≤12 vs. >12) showed no correlation to morphologic alterations besides a significant increase in GDAH (−0.3 vs. 0.9 mm) between the first and last follow-up MRI in ALL patients receiving >12 ith. MTX applications. The role of ith. MTX on CP needs to be further investigated and correlated to the neurocognitive outcome of children with acute leukemias.

Motor Functioning and Intelligence Quotient in Paediatric Survivors of a Fossa Posterior Tumor Following a Multidisciplinary Rehabilitation Program

BACKGROUND

Short- and long-term consequences after treatment for childhood fossa posterior tumors are extensively reported in the literature; however, papers highlighting physical function throughout rehabilitation and its correlation with Intelligence Quotient (IQ) are sparse. This study aims to describe the physical functioning and IQ of these survivors, their progression during rehabilitation, and the association with histopathological tumor classification. Additionally, the correlation between gross motor functioning and cognitive functioning was investigated.

METHODS

This retrospective single-center cohort study included 56 children (35 (62.5%) males and 21 (37.5%) females, with an average age of 6.51 years (SD 4.13)) who followed a multidisciplinary program at the Child Rehabilitation Centre, Ghent University Hospital in the period from 2005 to 2020. Descriptive statistical analysis was performed with the use of non-parametric tests and linear regression to determine the relationship between gross motor functioning and IQ.

RESULTS

This report shows impaired motor and intelligence performance in children with a fossa posterior tumor. Although multidisciplinary rehabilitation is beneficial, it is not able to counteract the further decline of several motor skills and intelligence during oncological treatment, more specifically in children with a medulloblastoma. A correlation between gross motor function and total IQ was found.

CONCLUSION

Pediatric survivors of a fossa posterior tumor experience impaired physical and intellectual functions, with more decline during oncological treatment despite simultaneous multidisciplinary rehabilitation.

Default-Mode Network Connectivity Changes Correlate with Attention Deficits in ALL Long-Term Survivors Treated with Radio- and/or Chemotherapy

Simple Summary

Both chemotherapy and radiotherapy play a role in the neurocognitive impairment of long-term survivors from acute lymphoblastic leukemia, but it is unknown if similar mechanisms are involved. We assessed neurocognitive alterations, brain tissue volumes, and functional connectivity of the main hubs of the default-mode network, in 13 patients treated with chemotherapy and radiotherapy (Group A) and in 13 treated with chemotherapy only (Group B). Correlations with neuropsychological scores, independent of group, were assessed for regions that showed significant differences between the two groups at neuroimaging. Compared to Group B, Group A performed significantly worse at the digit span and digit symbol tests and showed increased functional connectivity between the medial prefrontal cortex and the rolandic operculi, along with the absence of differences in regional brain tissue volumes. Functional connectivity in these regions correlated inversely with speed of processing in both groups, suggesting that similar mechanisms may be involved in the neurocognitive deficits in both groups.

Abstract

Whether chemotherapy (ChT) and radiotherapy (RT) determine neurocognitive impairment in acute lymphoblastic leukemia long-term survivors (ALL LTSs) through similar mechanisms affecting the same brain regions is still unknown. We compared neurocognitive alterations, regional brain tissue volumes (by voxel-based morphometry), and functional connectivity of the main default-mode network hubs (by seed-based analysis of resting state functional MRI data), in 13 ALL LTSs treated with RT and ChT (Group A) and 13 treated with ChT only (Group B). Group A performed significantly worse than Group B at the digit span and digit symbol tests (p = 0.023 and 0.013, respectively). Increased connectivity between the medial prefrontal cortex (the main anterior hub of the default-mode network) and the rolandic operculi was present in Group A compared to Group B, along with the absence of significant differences in regional brain tissue volumes. In these regions, the functional connectivity correlated inversely with the speed of processing scores, independent of treatment group. These results suggest that similar mechanisms may be involved in the neurocognitive deficits in ALL LTS patients, regardless of the treatment group. Further studies are needed to clarify whether these changes represent a direct expression of the mechanisms underlying the cognitive deficits or ineffective compensatory phenomena.