Cognitive and Academic Outcome After Benign or Malignant Cerebellar Tumor in Children

Language outcomes in children who underwent surgery for the removal of a posterior fossa tumor: A systematic review

BACKGROUND

Children who underwent posterior fossa tumor removal may have spoken or written language impairments. The present systematic review synthesized the literature regarding the language outcomes in this population. Benefits of this work were the identification of shortcomings in the literature and a starting point toward formulating guidelines for postoperative language assessment.

METHODS

A systematic literature search was conducted, identifying studies with patients who had posterior fossa surgery before 18 years of age. Included studies were narratively synthesized to understand language outcomes by language function (e.g., phonology, morphosyntax) at a group and individual level. Furthermore, the influence of several mediators (e.g., postoperative cerebellar mutism syndrome (pCMS), tumor type) was investigated. A critical evaluation of the language assessment tools was conducted.

RESULTS

The narrative synthesis of 66 studies showed that a broad spectrum of language impairments has been described, characterized by a large interindividual heterogeneity. Patients younger at diagnosis, receiving treatment for a high-grade tumor and/or radiotherapy and diagnosed with pCMS seemed more prone to impairment. Several gaps in language assessment remain, such as a baseline preoperative assessment and the assessment of pragmatics and morphosyntax. Further, there were important methodological differences in existing studies which complicated our ability to accurately guide clinical practice.

CONCLUSION

Children who had posterior fossa surgery seem to be at risk for postoperative language impairment. These results stress the need for language follow-up in posterior fossa tumor survivors.

Cerebellar Dysfunction and Relationship With Psychopathology, Cognitive Functioning, Resilience, and Coping in Schizophrenia

ABSTRACT

In this study, we examined the cerebellar dysfunction in schizophrenia by evaluating the clinical, cognitive, resilience, and coping correlates of cerebellar signs (CSs) in 162 subjects (63 patients with schizophrenia and 99 healthy controls). The presence of CS was evaluated based on six clinical tests. Measures to assess the severity of psychopathology, cognitive functioning, resilience, and frequency of coping strategies used were included. Patients had more CS than controls. Patients with more CS were older, had more severe psychopathology, had poorer performance on Brief Assessment of Cognition for Schizophrenia token motor task, and used less self-distraction as a coping strategy than those with fewer CS. Patients without CS used less self-blame coping at higher level of resilience. The association of less self-distraction with more CS may be related to cognitive inflexibility as a result of cerebellar dysfunction. Greater attentiveness to the presence of CS in schizophrenia patients may aid in better management of their psychotic condition.

Survival and long-term socioeconomic consequences of childhood and adolescent onset of brain tumours

AIM

To evaluate survival distributions, long-term socioeconomic consequences, and health care costs in patients with childhood and adolescent onset of brain tumours in a Danish nationwide prospective cohort study.

METHOD

A search of national registries identified 2283 patients (1198 males, 1085 females; mean age 9 years 6 months [SD 5 years 7 months]) diagnosed with a brain tumour between 1980 and 2015 and aged no older than 18 years at diagnosis. These were compared with sex-, age-, and residency-matched comparison individuals. Patients with malignant tumours were compared with those with benign tumours. Survival distributions were estimated by the Kaplan-Meier method and hazard ratio by the Cox proportional hazard model. Socioeconomic data at age 20 and 30 years were assessed.

RESULTS

The probability of mortality was highest during the first year after tumour diagnosis. In young adulthood, the patients were generally less likely to be married, had lower grade-point averages, educational levels, and income, were less likely to be in employment, and had higher health care costs than comparison individuals. Patients with malignant tumours had worse outcomes with respect to education, employment, and health care costs than those with benign tumours.

INTERPRETATION

A diagnosis of brain tumour in childhood and adolescence adversely affects survival and has negative long-term socioeconomic consequences, especially in patients with malignant tumours. These patients require continuous social support.

A review of long-term deficits in memory systems following radiotherapy for pediatric posterior fossa tumor

INTRODUCTION

In recent years, progress in pediatric posterior fossa tumor (PFT) treatments has improved survival rates. However, the majority of survivors present neurocognitive sequelae that impact academic achievement.

METHODS

This review examines the literature from 2000 to 2020 on long-term outcomes in different memory systems for survivors of pediatric PFT, considering the impact of radiotherapy which is a well-known prognostic factor for global neurocognitive function.

RESULTS

Of the 43 articles selected, 31 explored working memory, 19 episodic memory, 9 semantic memory and 2 procedural memory. Irradiated survivors had scores of < -2 standard deviation (SD) (n = 4 studies/25) or between -2SD and -1SD (n =7 studies/25) for working memory; < -1SD for anterograde memory (n = 11/13), with a progressive decline in these two memory systems; < -1SD (n = 4/7) in semantic memory, and a deficit in perceptual-motor procedural learning (n = 1/1). Reducing craniospinal irradiation dose, limiting tumor bed boosts, and using proton therapy seem to have had a beneficial effect with better preservation of the memory score and a reduction in the decline over time. Non-irradiated survivors had memory systems that were less affected, with preservation of anterograde memory and maintenance of long-term stability.

CONCLUSION

Memory deficits are a core feature in survivors of pediatric PFT, especially when treatment requires radiotherapy. To limit these effects, dose constraints for specific brain areas involved in memory should be defined. During long-term follow-up, specific attention is essential to identify these deficits in order to limit their impact on the quality of life.

A prospective behavioral and imaging study exploring the impact on long-term memory of radiotherapy delivered for a brain tumor in childhood and adolescence

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Common long-term memory defects after pediatric brain tumor affect school achievement

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The hippocampi, the cerebellum and cerebellar-cortical networks play a role in several memory systems.

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This study will provide long-term neuropsychological data about four different memory systems.

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We will investigate the correlations between neuropsychological, neuroimaging and radiotherapy dose data.

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Imaging will be structural (3DT1), microstructural (DTI), functional (rs-fMRI), vascular (ASL) and metabolic (spectroscopy).

Background

Posterior fossa tumors represent two thirds of brain tumors in children. Although progress in treatment has improved survival rates over the past few years, long-term memory impairments in survivors are frequent and have an impact on academic achievement. The hippocampi, cerebellum and cerebellar-cortical networks play a role in several memory systems. They are affected not only by the location of the tumor itself and its surgical removal, but also by the supratentorial effects of complementary treatments, particularly radiotherapy. The IMPALA study will investigate the impact of irradiation doses on brain structures involved in memory, especially the hippocampi and cerebellum.

Methods/design

In this single-center prospective behavioral and neuro-imaging study, 90 participants will be enrolled in three groups. The first two groups will include patients who underwent surgery for a posterior fossa brain tumor in childhood, who are considered to be cured, and who completed treatment at least 5 years earlier, either with radiotherapy (aggressive brain tumor; Group 1) or without (low-grade brain tumor; Group 2). Group 3 will include control participants matched with Group 1 for age, sex, and handedness. All participants will perform an extensive battery of neuropsychological tests, including an assessment of the main memory systems, and undergo multimodal 3 T MRI. The irradiation dose to the different brain structures involved in memory will be collected from the initial radiotherapy dosimetry.

Discussion

This study will provide long-term neuropsychological data about four different memory systems (working memory, episodic memory, semantic memory, and procedural memory) and the cognitive functions (attention, language, executive functions) that can interfere with them, in order to better characterize memory deficits among the survivors of brain tumors. We will investigate the correlations between neuropsychological and neuroimaging data on the structural (3DT1), microstructural (DTI), functional (rs-fMRI), vascular (ASL) and metabolic (spectroscopy) impact of the tumor and irradiation dose. This study will thus inform the setting of dose constraints to spare regions linked to the development of cognitive and memory functions.

Trial registration

ClinicalTrials.gov: NCT04324450, registered March 27, 2020, updated January 25th, 2021. Retrospectively registered, https://www.clinicaltrials.gov/ct2/show/NCT04324450.

Neuropsychiatric Symptoms After Brain Tumor Resection in Children and Adolescents: A Scoping Review

BACKGROUND

Brain tumors are one of the most common solid tumors in pediatric populations, with their treatments having significant neuropsychiatric impact.

OBJECTIVE

The objective of this study was to review the literature on neuropsychiatric sequelae after surgical resection of brain tumors in children and adolescents.

METHODS

Using a scoping method, we reviewed empirical articles describing pediatric patients with brain tumors who underwent partial or total resection and examined major neuropsychiatric domains postoperatively over time.

RESULTS

The initial search yielded 15,543 articles. After duplicate removal, abstract screening, and review, 44 articles were included. Cognitive deficits were the most widely studied outcomes and found to be associated with tumor location, operative variables, perioperative complications, treatment types, and psychosocial factors. Cerebellar mutism, or posterior fossa syndrome, commonly co-occurred with emotional and behavioral dysregulation after posterior fossa resections. Depression, anxiety, and somatization were frequently grouped together as "distress," with higher rates among pediatric patients with brain tumor than among healthy peers. Problematic school behaviors, antisocial, and attention-deficit traits were increased; however, several other behaviors (e.g., risky sexual behaviors, substance use) were equal or lower when compared to peers. Posttraumatic stress disorder was highly prevalent and often interfered with social functioning. Delirium, eating disorders, and longer-term outcomes received inadequate attention.

CONCLUSION

Identifying risk factors of neuropsychiatric sequelae and their impact after pediatric brain tumor resection is important for prognostication and the development of tailored management strategies for these children and adolescents.

Can National Tests from the Last Year of Compulsory School Be Used to Obtain More Detailed Information about Academic Performance in Children Treated for Brain Tumours? A Nationwide, Population-Based Study from Sweden

Simple Summary

Children treated for brain tumours often suffer from late-appearing complications, including impaired cognitive performance. In this study, 475 Swedish children diagnosed with a brain tumour before their 15th birthday and 2197 matched controls were included. Data from compulsory national tests performed school year nine in the first foreign language English, the mother tongue Swedish and mathematics were analysed. These tests offered more detailed information on academic strengths and weaknesses than the final grades, as different skill sets were assessed. Cases performed worse than controls in English tests than in Swedish and mathematics tests, and they may have performed better in oral than written tasks. There were larger differences between girls treated for brain tumours and their female controls than between boys treated for brain tumours and their male controls. National tests may be useful to complement neuropsychological follow-ups. Characterising these shortcomings is essential to provide appropriate support and prevent social isolation.

Abstract

Children treated for brain tumours often have late-appearing complications that may affect their school performance. Uneven skill profiles may help reveal late complications that can be compensated for but otherwise remain undetected. We investigated Swedish national school tests of oral, reading and writing skills in the first foreign language (English), the mother tongue (Swedish) and mathematics. Data were obtained from The Swedish Childhood Cancer Registry and Statistics Sweden. The results from 475 children diagnosed with a brain tumour before their 15th birthday and 2197 matched controls showed that children treated for brain tumours evinced more difficulties with national tests than controls in almost all subtests, especially in the subject English, and that they may perform better on oral than written tasks. There were larger differences between female cases and controls than between male cases and controls; age at diagnosis played a significant role for some subtests, whereas tumour grade did not. Missing information from national tests proved to be a strong predictor of poor academic performance. Our results show that regular educational follow-ups, as a complement to neuropsychological follow-ups, are important for all children treated for brain tumours, regardless of sex, age at diagnosis or tumour grade.

The role of cerebellum in the child neuropsychological functioning

This chapter proposes a review of neuropsychologic and behavior findings in pediatric pathologies of the cerebellum, including cerebellar malformations, pediatric ataxias, cerebellar tumors, and other acquired cerebellar injuries during childhood. The chapter also contains reviews of the cerebellar mutism/posterior fossa syndrome, reported cognitive associations with the development of the cerebellum in typically developing children and subjects born preterm, and the role of the cerebellum in neurodevelopmental disorders such as autism spectrum disorders and developmental dyslexia. Cognitive findings in pediatric cerebellar disorders are considered in the context of known cerebellocerebral connections, internal cellular organization of the cerebellum, the idea of a universal cerebellar transform and computational internal models, and the role of the cerebellum in specific cognitive and motor functions, such as working memory, language, timing, or control of eye movements. The chapter closes with a discussion of the strengths and weaknesses of the cognitive affective syndrome as it has been described in children and some conclusions and perspectives.

Reintegration Into School After Treatment for a Brain Tumor: The Child's Perspective

This multiple case study investigated perspectives of childhood brain tumor survivors on reintegration into school over a 2-year period. Semistructured interviews were conducted with 5 children at 3 times to obtain an extensive view of their overall school experience. Thematic analysis of data resulted in 4 themes: “school life and participation,” “peer relations and friendships,” “performance and difficulties,” and “support and follow-up.” Childhood brain tumor survivors consider school attendance as part of a normal disease-free life. Social contact and friendships represent their main motivating factors for returning to school. Attitudes and feelings regarding performance, difficulties, and support vary among survivors and change over time. In conclusion, continuity in learning and social contact established before the return facilitate the reintegration process. A comprehensive assessment of their academic and psychosocial functioning should be organized on reentry. Systematic follow-up by parents, school staff, and health professionals throughout the child’s school career is required.

Affected Aspects Regarding Literacy and Numeracy in Children Treated for Brain Tumors

The aim of this study was to investigate the test results of reading speed, reading comprehension, word comprehension, spelling, basic arithmetic skills, and number sense (intuitive understanding of numbers) by children treated for brain tumors. This is a retrospective study based on medical records, including standardized academic tests. In the years of 2010 to 2014, all children in the area of Stockholm between 7 and 18 years (IQ <70) who had no major linguistic or motor difficulties after they had undergone treatment for brain tumors were offered a special education assessment one year after treatment, at school start, or the year before a transition from one stage to another. Our results indicate that children treated for a brain tumor are at risk of having difficulties in spelling, reading speed, and arithmetic and that the test performance may decline over years in arithmetic and spelling. Children diagnosed at age 0 to 6 years may need extra tutoring at school start, especially in basic arithmetic skills. In both reading and mathematics, many children perform better on tests focused on understanding than on tests focused on speed. Continuous special needs assessments including different aspects of literacy and numeracy, are important for understanding each child’s specific needs.

Measurement of neurodevelopmental changes in children treated with radiation for brain tumors: what is a true 'baseline?'

OBJECTIVE

To review the various ways in which baseline neuropsychological functioning is measured in the extant literature on pediatric brain tumors, describe the pros and cons of each approach, and increase the awareness of researchers as to the implications of each.

METHOD

We reviewed the literature from 1993 to 2013, and classified studies by baseline approach and explicitness of selection of approach.

RESULTS

There are multiple approaches to operationalizing baseline levels of ability and to assess change from baseline. Each approach has strengths and weaknesses, and selection may depend on the question under investigation. Approaches to baseline estimation varied widely with a trend over time toward reliance on statistical modeling. Researchers were often insufficiently explicit about the reasons for adopting a particular approach. The common use of standardized scores requires caution as they obscure critical inferential limitations about change and magnitude of change. Some viable approaches were infrequently used, such as actuarial prediction formulas. Multiple simultaneous methods akin to theory testing and formal methods of construct validation could enhance scientific yield since all approaches are fallible.

CONCLUSIONS

Estimating baseline neuropsychological functioning is very challenging, particularly when it concerns children in the preschool years. Nevertheless, it is a crucial methodological decision with important implications for the interpretation of research findings that needs to be dealt with explicitly.

Core deficits and quality of survival after childhood medulloblastoma: a review

Background

Medulloblastoma is the most common malignant central nervous system tumor in children. Treatment most often includes surgical resection, craniospinal irradiation, and adjuvant chemotherapy. Although survival has improved dramatically, the tumor and its treatments have devastating long-term side effects that negatively impact quality of survival (QoS). The objective was to review the literature on QoS following childhood medulloblastoma.

Methods

This narrative review is based on a Medline database search and examination of the reference lists of papers selected.

Results

Frequent problems after medulloblastoma treatment include medical complications, such as long-term neurological and sensory (hearing loss) impairments; endocrine deficits, including growth problems; and secondary tumors. Neurocognitive impairment is repeatedly reported, with decreasing cognitive performances over time. Although all cognitive domains may be affected, low processing speed, attention difficulties, and working memory difficulties are described as the core cognitive deficits resulting from both cerebellar damage and the negative effect of radiation on white matter development. Long-term psychosocial limitations include low academic achievement, unemployment, and poor community integration with social isolation. Important negative prognostic factors include young age at diagnosis, conventional craniospinal radiotherapy, presence of postoperative cerebellar mutism, and perioperative complications. The influence of environmental factors, such as family background and interventions, remains understudied.

Conclusion

Future studies should focus on the respective impact of radiation, cerebellar damage, genomic and molecular subgroup parameters, and environmental factors on cognitive and psychosocial outcomes. Long-term (probably lifelong) follow-up into adulthood is required in order to monitor development and implement timely, suitable, multi-disciplinary rehabilitation interventions and special education or support when necessary.

Consensus paper on post-operative pediatric cerebellar mutism syndrome: the Iceland Delphi results

INTRODUCTION

Confusion has surrounded the description of post-operative mutism and associated morbidity in pediatric patients with cerebellar tumors for years. The heterogeneity of definitions and diagnostic features has hampered research progress within the field, and to date, no international guidelines exist on diagnosis, prevention, treatment, or follow-up of this debilitating condition. An international group of clinicians and researchers from multiple relevant disciplines recently formed a cohesive panel to formulate a new working definition and agree upon standardized methods for diagnosis and follow-up.

METHODS

Consensus was obtained using the modified nominal group technique, involving four rounds of online Delphi questionnaires interspersed with a structured consensus conference with lectures, group work, and open discussion sessions.

RESULTS

A new, proposed definition of "post-operative pediatric CMS" was formed, preliminary recommendations for diagnostic and follow-up procedures were created, two working groups on a new scoring scale and risk prediction and prevention were established, and areas were identified where further information is needed.

DISCUSSION

The consensus process was motivated by desire to further research and improve quality of life for pediatric brain tumor patients. The Delphi rounds identified relevant topics and established basic agreement, while face-to-face engagement helped resolve matters of conflict and refine terminology. The new definition is intended to provide a more solid foundation for future clinical and research work. It is thought as a consensus for moving forward and hopefully paves the way to developing a standard approach to this challenging problem with the advent of better scoring methods and ultimate goal of reducing the risk of CMS.

Clinical characteristics and late effects in CNS tumours of childhood: Do not forget long term follow-up of the low grade tumours

AIM

To investigate clinical characteristics and late effects of CNS tumours in childhood with a special focus on low-grade tumours, especially low-grade astrocytoma and glioneuronal tumours.

METHODS

A retrospective population based study was performed at Uppsala University Children's Hospital, a tertiary referral centre for children with CNS tumours. Patients were identified from the National Brain Tumour Registry and the National Epilepsy Surgery Registry. Hospital medical records were analysed for patients with a follow up of ≥5 years after diagnosis. A re-evaluation of the neuro-pathological diagnosis was performed.

RESULTS

A total of 193 patients (age 0-17.99 years) during a twelve-year period (1995-2006) were included; 149 survived ≥5 years. Three larger subgroups could be identified: astrocytic, embryonal and glioneuronal tumours. A supratentorial location was found in 52%. Medical late effects were mainly neurological and endocrinological, affecting 81% and 26% of surviving patients. Cognitive late effects were a frequent finding in the whole group but also in low-grade astrocytoma and glioneuronal tumours (53% and 67%). Thirty per cent had some kind of pedagogic support in school.

CONCLUSION

Late effects are common in long-term survivors of CNS tumours in childhood. Low-grade astrocytoma and glioneuronal tumours are no exception, and the findings support the need for long-term follow up.

Monitoring and Assessment of Neuropsychological Outcomes as a Standard of Care in Pediatric Oncology

Central nervous system cancers or exposure to CNS-directed therapies increase risk for neuropsychological deficits. There are no accepted guidelines for assessment of neuropsychological functioning in this population. A multifaceted literature search was conducted and relevant literature reviewed to inform the guidelines. Studies of neuropsychological outcomes are widely documented in the pediatric oncology literature. There is strong evidence of need for neuropsychological assessment, but insufficient evidence to guide the timing of assessment, nor to recommend specific interventions. Children with brain tumors and others at high risk for neuropsychological deficits should be monitored and assessed for neuropsychological deficits.

[Neurocognitive outcome in childhood brain tumor survivors]

Advances in treatment have significantly improved the survival rate of children with brain tumour. This review describes risk factors of late neurocognitive effect, the different type of neurocognitive side effect according to the type of tumour and the rehabilitation. The best knowledge of cognitive sequelae allowed to propose supported appropriate and specific disorders including school facilities for younger and adaptation of professional situation for adults. Furthermore, this understanding allows to link with the patient's quality of life and to approach the person in its specificity and overall.

Morphological brain lesions of pediatric cerebellar tumor survivors correlate with inferior neurocognitive function but do not affect health-related quality of life

PURPOSE

We aimed to determine whether extent of morphological brain injury in pediatric cerebellar tumor survivors correlates with neurocognitive function and health-related quality of life (HrQoL).

METHODS

Seventeen cerebellar pilocytic astrocytoma (cPA) and 17 medulloblastoma (MB) survivors were examined for HrQoL, intelligence using the German version of the WISC-III, attention, working memory, and visual motor coordination. MRI scans were analyzed for extent of posterior fossa brain tissue loss.

RESULTS

We found significant correlations between amount and extent morphological brain lesions of pediatric cerebellar tumor survivors and several cognitive impairments including intelligence and attention in both patient groups. These were in total more pronounced in MB patients when compared to cPA patients. Still, function loss and brain lesions detected on conventional MRI did not influence HrQoL.

CONCLUSIONS

These findings support the notion that long-term neurocognitive deficits of pediatric posterior fossa tumor survivors significantly correlate with brain tissue damage. The cerebellum plays a role in regulating higher-order functions. On the contrary, the extent brain injury is not detected by HrQoL assessment.

Disrupted sensorimotor synchronization, but intact rhythm discrimination, in children treated for a cerebellar medulloblastoma

The aim of this study was to investigate the temporal abilities of children treated by surgery for a malignant tumor in the cerebellum, both in the perception and the production of rhythm. Children with a diagnosed medulloblastoma and age-matched control children were tested in a rhythm discrimination task and a sensorimotor synchronization task. Their motor and cognitive capabilities were also assessed through a battery of age-adapted neuropsychological tests. The results did not show any significant difference in performance between groups for the discrimination task. On the contrary, children with cerebellar lesions produced longer and more variable inter-tap intervals (ITI) in their spontaneous motor tempo (SMT) than did the control children. However, the length and, to a lesser extent, the variability of their SMT decreased after a synchronization phase, when they had been instructed to tap in synchrony with a beep. During the synchronization task, the children with medulloblastoma succeeded to modify the length of their ITI in response to an auditory rhythm, although with better success when the inter-stimuli intervals (ISI) were shorter than when they were longer than the ITIs of their own SMT. Correlational analyses revealed that children's poorer synchronization performance was related to lower scores in neuropsychological tests assessing motor dexterity and processing speed.

Cognitive disorders in pediatric medulloblastoma: what neuroimaging has to offer

Medulloblastomas are the most common malignant childhood brain tumors arising in the posterior fossa. Treatment improvements for these tumors have meant that there are a greater number of survivors, but this long-term patient survival has increased the awareness of resulting neurocognitive deficits. Impairments in attention, memory, executive functions, and intelligence quotient demonstrate that the cerebellum likely plays a significant role in numerous higher cognitive functions such as language, cognitive, and emotional functions. In addition, children with medulloblastoma not only have cerebellar lesions but also brain white matter damages due to radiation and chemotherapy. Functional neuroimaging, a noninvasive method with many advantages, has become the standard tool in clinical and cognitive neuroscience research. By reviewing functional neuroimaging studies, this review aims to clarify the role of the cerebellum in cognitive function and explain more clearly cognitive sequelae due to polytherapy in children with medulloblastoma. This review suggests that the posterior cerebellar lobes are crucial to maintaining cognitive performance. Clinical investigations could help to better assess the involvement of these lobes in cognitive functions.

Neurocognitive consequences of a paediatric brain tumour and its treatment: a meta-analysis

AIM

This meta-analysis provides a systematic review of studies into intellectual and attentional functioning of paediatric brain tumour survivors (PBTS) as assessed by two widely used measures: the Wechsler Intelligence Scale for Children (3rd edition; WISC-III) and the Conners' Continuous Performance Test (CPT).

METHOD

Studies were located that reported on performance of PBTS (age range 6-16y). Meta-analytic effect sizes were calculated for Full-scale IQ, Performance IQ, and Verbal IQ as measured by the WISC-III, and mean hit reaction time, errors of omission, and errors of commission as measured by the CPT. Exploratory analyses investigated the possible impacts of treatment mode, tumour location, age at diagnosis, and time since diagnosis on intelligence.

RESULTS

Twenty-nine studies were included: 22 reported on the WISC-III in 710 PBTS and seven on CPT results in 372 PBTS. PBTS performed below average (p(s) <0.001) on Full-scale IQ (Cohen's d=-0.79), Performance IQ (d=-0.90), and Verbal IQ (d=-0.54). PBTS committed more errors of omission than the norm (d=0.82, p<0.001); no differences were found for mean hit reaction time and errors of commission. Cranial radiotherapy, chemotherapy, and longer time since diagnosis were associated with lower WISC-III scores (p(s) <0.05).

INTERPRETATION

PBTS have seriously impaired intellectual functioning and attentiveness. Being treated with cranial radiotherapy and/or chemotherapy as well as longer time since diagnosis leads to worse intellectual functioning.

Time perception in children treated for a cerebellar medulloblastoma

The aim of the present study was to investigate temporal abilities in children treated by surgery for a malignant tumor in the cerebellum. Children with a diagnosed medulloblastoma and age-paired control children were given a temporal discrimination task (bisection task) and a temporal reproduction task with two duration ranges, one shorter than 1s and the other longer than 4s. The motor and cognitive capacities of these children were also assessed by a battery of age-adapted neuropsychological tests. The results did not show any significant difference in performance between the children with or without cerebellar lesions in the temporal discrimination task. It was only in the temporal reproduction task that the children with cerebellar lesions reproduced longer and more variable durations than the other children, but only for the short stimulus durations (≤ 1 s). In addition, a hierarchical regression analysis revealed that the best predictor of variance in temporal performance was a significantly lower processing speed in children with cerebellar lesions in comparison to their controls. These results indicated that the major cause of deficits in temporal judgments in children with cerebellar lesions was due to their inability to reproduce accurately short temporal intervals in association with low processing speed, rather than to a specific deficit in the perception of time.

Neurocognitive late effects of pediatric brain tumors of the posterior fossa: a quantitative review

Deficits in neurocognitive functioning are an important area of late effects in survivors of pediatric brain tumors; however, a quantitative analysis of the magnitude of these deficits in survivors of brain tumors of the posterior fossa has not been conducted. Despite tumor locations in the posterior regions of the brain, individual studies have documented deficits in a variety of domains, reflective of impairment in other brain regions. The current study provides a comprehensive meta-analysis of literature on neurocognitive late effects found in survivors of posterior fossa tumors. Results indicated significant deficits in both specific and broad indices of neurocognitive functioning, and the overall magnitude of effects across domains ranged from medium to large (g = -0.62 to -1.69) with a large mean overall effect size (g = -1.03). Moderator analyses indicated significantly greater effects for survivors diagnosed at a younger age and those who received radiation therapy. These findings underscore the importance of monitoring neurocognitive late effects in survivors of pediatric brain tumors of the posterior fossa, as well as the need for more consistent consideration of demographic, diagnostic, and treatment-related variables to allow for examination of factors that moderate these deficits.

Central nervous system tumors

Central nervous system tumors are the most frequent malignant tumor in children and the main cause of death in this age group after traffic accidents. The current estimates are that one adult in 2500 is a survivor of a brain tumor that occurred during childhood. These tumors are particularly heterogeneous in terms of histology/biology, treatment, and outcome. They share, however, a high risk of neurological and cognitive morbidity due to the disease itself and the treatment modalities (radiotherapy, surgery, and chemotherapy). Diagnosis is frequently delayed because symptoms are usually nonspecific at the beginning of the evolution. Posterior fossa is the most frequent site and the tumors present most frequently with signs of intracranial hypertension. Supratentorial tumors are more frequent in infants and in adolescents; seizures are not uncommon, especially for benign tumors. When adjuvant treatment is needed, radiotherapy is usually the mainstay apart from some histologies where chemotherapy may be sufficient: low-grade gliomas, desmoplastic medulloblastomas, malignant glial tumors in infants. Multidisciplinary care is best performed in tertiary care centers and should include early rehabilitation programs soon after surgery.

[Medulloblastomas: review]

INTRODUCTION

The term of "medulloblastoma" refers to cerebellar tumors belonging to the family of primitive neuro-ectodermic tumors (PNET). Medulloblastomas represent 40% of cerebellar tumors, 15 to 20% of brain tumors and the first cause of malignant brain tumors in childhood. Seventy to 80% of cases are diagnosed in children versus 20 to 30% in adults.

UPDATED KNOWLEDGE

Diagnosis is based on clinical and radiological exams, and proved on pathological analysis in association with molecular biology. Treatment comprises surgery, craniospinal radiotherapy except for children under five years of age and chemotherapy according to age and high-risk criteria. Medulloblastoma is a rare case of a central nervous system tumor which is radio- and chemo-sensitive. Treatment goals are, on one hand, to improve the survival rates and, on the other hand, to avoid late neurocognitive, neuroendocrine and orthopedic side effects related to radiation therapy, notably in children. The prognosis is relatively good, with a five year survival rate over 75% after complete resection of a localized tumor although sequelae may still compromise outcome.

PERSPECTIVES AND CONCLUSION

Management of patients with medulloblastoma implies a multidisciplinary approach combining the contributions of neurosurgery, neuroradiology, pediatric oncology, neuro-oncology and radiotherapy teams.