The neurodevelopmental price of survival in children with malignant brain tumours

Clinical Characteristics, Treatment, and Survival Outcome of Ependymoma in Infants

BACKGROUND

Treatment modalities of ependymoma in infants remain controversial. Postoperative adjuvant radiotherapy could prolong overall survival but has the potential to affect nervous system development in infants. The role of adjuvant chemotherapy in prolonging overall survival for infants with ependymoma is still unclear. Therefore we designed this study to explore the effect of treatment modalities on survival time of infants with ependymoma.

METHODS

We studied 72 infants with ependymoma from the Surveillance, Epidemiology, and End Results database in this retrospective analysis. Univariate and multivariate Cox proportional hazard models were adopted to determine hazard ratios and compare overall survival.

RESULTS

Among 72 infants with ependymoma, 35 were male (48.6%) and 37 were female (51.4%). The 5-year overall survival of all patients was 67%. Forty-six infants (63.9%) received gross total resection, 20 (27.8%) received subtotal resection, and 6 (8.3%) did not receive surgical resection or only autopsy. Twenty-one infants (29.2%) received radiotherapy, and 45 (62.5%) received chemotherapy. Multivariate analysis revealed that patients accepted surgical resection (No vs. gross total resection, P < 0.001; No vs. subtotal resection, P = 0.026) and chemotherapy (No vs. Yes, P = 0.024) are the independent prognostic factors for overall survival.

CONCLUSIONS

Treatment modality is associated with survival time in infants with ependymoma. The extent of resection and chemotherapy were independent prognostic factors for infants with ependymoma.

Cerebellar Functional Lateralization From the Perspective of Clinical Neuropsychology

Objective: The cerebellar functional laterality, with its right hemisphere predominantly involved in verbal performance and the left one engaged in visuospatial processes, has strong empirical support. However, the clinical observation and single research results show that the damage to the right cerebellar hemisphere may cause extralinguistic and more global cognitive decline. The aim of our research was to assess the pattern of cognitive functioning, depending on the cerebellar lesion side, with particular emphasis on the damage to the right cerebellar hemisphere.

Method: The study sample consisted of 31 patients with focal cerebellar lesions and 31 controls, free of organic brain damage. The Addenbrooke’s Cognitive Examination ACE III and the Trail Making Test TMT were used to assess patients’ cognitive functioning.

Results: Left-sided cerebellar lesion patients scored lower than controls in attention and visuospatial domain, but not in language, fluency, and memory functions. Participants with right-sided cerebellar lesion demonstrated a general deficit of cognitive functioning, with impairments not only in language and verbal fluency subscales but also in all ACE III domains, including memory, attention, and visuospatial functions. The TMT results proved that cerebellar damage is associated with executive function impairment, regardless of the lesion side.

Conclusion: The cognitive profiles of patients with cerebellum lesions differ with regard to the lesion side. Left-sided cerebellar lesions are associated with selective visuospatial and attention impairments, whereas the right-sided ones may result in a more global cognitive decline, which is likely secondary to language deficiencies, associated with this lateral cerebellar injury.

Case-based review: ependymomas in adults

Ependymomas are rare primary central nervous system (CNS) tumors in adults. They occur most commonly in the spinal cord, and have classically been graded histologically into World Health Organization (WHO) grades I, II, or III based on the level of anaplasia. Recent data are showing that genetic heterogeneity occurs within the same histological subgroup and that ependymomas arising from different CNS locations have different molecular signatures. This has renewed interest in developing targeting therapies based on molecular profiles especially given the variable outcomes with radiation and the poor results with cytotoxic agents. In this paper, we present the case of a 46-year-old woman with a classic presentation of spinal cord ependymoma and discuss the current histopathological and molecular classification for ependymomas as well as current guidelines for patient management.

Neuropsychological consequences of childhood medulloblastoma and possible interventions: A review

BACKGROUND

Children who have been treated for a medulloblastoma often suffer long-term cognitive impairments that often negatively affect their academic performance and quality of life. In this article, we will review the neuropsychological consequences of childhood medulloblastoma and discuss the risk factors known to influence the presence and severity of these cognitive impairments and possible interventions to improve their quality of life.

METHODS

This narrative review was based on electronic searches of PubMed to identify all relevant studies.

RESULTS

Although many types of cognitive impairments often emerge during a child's subsequent development, the core cognitive domains that are most often affected in children treated for a medulloblastoma are processing speed, attention and working memory. The emergence and magnitude of these deficits varies greatly among patients. They are influenced by demographic (age at diagnosis, parental education), medical and treatment-related factors (perioperative complications, including posterior fossa syndrome, radiation therapy dose, etc.), and the quality of interventions such as school adaptations provided to the child or rehabilitation programs that focus on cognitive skills, behavior and psychosocial functioning.

CONCLUSION

These patients require specialized and coordinated multidisciplinary rehabilitation follow-up that provides timely and adapted assessments and culminates in personalized intervention goals being set with the patient and the family. Follow-up should be continued until referral to adult services.

Cognitive function in children with brain tumors in the first year after diagnosis compared to healthy matched controls

BACKGROUND

Improved survival of children with brain tumors (BTs) has increased focus on ameliorating morbidity. To reduce the risk of progressive cognitive decline, remedial strategies need to be instituted early, based upon accurate appraisal of need, yet few studies have investigated cognition in BT children early post-diagnosis. The study aims were to investigate cognition in children with primary BTs 1, 6, and 12 months post-diagnosis compared with healthy children, exploring the impact of disease and treatment variables.

METHODS

Forty-eight children aged 2-16 years with primary BTs, referred to a Regional Neurosurgical Unit over the 2-year study period were eligible for enrollment. The "best friends" model was used to recruit matched controls. Cognition was assessed using age-appropriate Wechsler Intelligence scales; Children's Memory Scale; Test of Everyday Attention for Children, and Wechsler Quicktest.

RESULTS

Patients with BTs had significantly reduced performance compared to controls early post-diagnosis in tests of Performance IQ, processing speed, verbal and visual memory, and selective attention. Improved performance over 12 months was seen in patients with BTs although also, for some measures, in controls. Significant deficits in cognitive performance were seen one year post-diagnosis for Verbal IQ; processing speed, visual and verbal immediate memory, and selective attention. Infratentorial site, high tumor grade, hydrocephalus, radiotherapy, and chemotherapy were associated with poorer functioning.

CONCLUSION

Early cognitive impairment is present in BT children, sometimes prior to radiotherapy/chemotherapy treatment, and is associated with hydrocephalus, high tumor grade and infratentorial site. Future studies should investigate the role of early rehabilitation in improving cognition.

Enhanced lithium-induced brain recovery following cranial irradiation is not impeded by inflammation

Radiation-induced brain injury occurs in many patients receiving cranial radiation therapy, and these deleterious effects are most profound in younger patients. Impaired neurocognitive functions in both humans and rodents are associated with inflammation, demyelination, and neural stem cell dysfunction. Here we evaluated the utility of lithium and a synthetic retinoid receptor agonist in reducing damage in a model of brain-focused irradiation in juvenile mice. We found that lithium stimulated brain progenitor cell proliferation and differentiation following cranial irradiation while also preventing oligodendrocyte loss in the dentate gyrus of juvenile mice. In response to inflammation induced by radiation, which may have encumbered the optimal reparative action of lithium, we used the anti-inflammatory synthetic retinoid Am80 that is in clinical use in the treatment of acute promyelocytic leukemia. Although Am80 reduced the number of cyclooxygenase-2-positive microglial cells following radiation treatment, it did not enhance lithium-induced neurogenesis recovery, and this alone was not significantly different from the effect of lithium on this proinflammatory response. Similarly, lithium was superior to Am80 in supporting the restoration of new doublecortin-positive neurons following irradiation. These data suggest that lithium is superior in its restorative effects to blocking inflammation alone, at least in the case of Am80. Because lithium has been in routine clinical practice for 60 years, these preclinical studies indicate that this drug might be beneficial in reducing post-therapy late effects in patients receiving cranial radiotherapy and that blocking inflammation in this context may not be as advantageous as previously suggested.

Treatment strategies for initially disseminated intracranial germinomas: experiences at a single institute

PURPOSE

Initially disseminated intracranial germinomas (IDIGs) can be observed in pre-adult and adolescent brain tumor patients. However, the disease prognosis is undetermined, and the method of optimal treatment remains controversial.

METHODS

From January 1990 to January 2011, data on 91 intracranial germinoma patients (≤20 years old) were gathered from the Pediatric Brain Tumor database at Taipei Veterans General Hospital. A total of seven patients with a median age of 17.0 years had IDIGs (lesion sites >2), including IDIGs in the ventricular system or the spinal column. Craniospinal irradiation (CSI) plus a primary or metastatic boost was the mainstay strategy for radiotherapy. Six out of a total of seven patients (85.7%) also received systemic chemotherapy (CHT) after radiotherapy. Survivals rates between IDIGs and patients without dissemination were estimated using the Kaplan-Meier method.

RESULTS

The median follow-up time for all seven patients was 67.5 months (range, 10.3-142.3 months). None of the IDIG patients experienced a recurrence or mortality after the completion of treatment. The 5- and 10-year disease-free survival (DFS) between IDIG and non-dissemination patients were 100%, 100%, 93.0% and 78.6%, respectively (p = 0.339). The 5- and 10-year overall survival (OS) between IDIGs and non-dissemination cases were 100%, 100%, 93.7% and 89.4%, respectively (p = 0.473).

CONCLUSIONS

IDIG patients did not show reduced survival compared to non-dissemination patients if optimal radiotherapy and chemotherapy were used together.

Neuropsychological Outcomes of Children Treated for Posterior Fossa Tumours:A Review

The posterior fossa region of the brain is a frequent site for tumour development in children, with over half of all childhood tumours occurring at this site. The principal brain structure implicated at this site is the cerebellum. Children treated for posterior fossa tumours can have a wide range of neurological and psychosocial problems. This paper describes the literature to date that addresses the neuropsychological impact of tumour and treatment in children with posterior fossa tumours. This paper reviews the literature on the causes of morbidity in this group. It discusses the recent research on the role of the cerebellum in outcomes and the studies that identify variables that interact with radiation effects.

Adaptive functioning in children in the first six months after surgery for brain tumours

PURPOSE

To examine the adaptive functioning of children who underwent surgery for brain tumours with a view to analyse the related acute impairments and to describe their short-term outcome.

METHOD

We investigated adaptive functioning in 25 children (ranging from 2 to 18 years of age) for 40 days and again 3 and 6 months after they underwent surgery for various brain tumours. The Vineland Adaptive Behaviour Scales (VABS) were used to assess their adaptive functioning, considering the four main domains and all the subdomains.

RESULTS

The results remained stable over the follow-up period considered. The domain in which the scores were most severely affected was Daily Living, followed by the Socialisation and Communication domains. Within the Communication domain, the abilities investigated in the Receptive subdomain revealed the worst impairments. Within the Daily Living domain, impairments were most evident in the children's capacity to take care of themselves and handle domestic activities. In the Socialisation domain, Play and Leisure Time, and Interpersonal Relationships were the subdomains most severely impaired.

CONCLUSIONS

These findings are relevant because identifying children's adaptive functioning difficulties sooner could help their rehabilitation to be tailored and thus have a positive fallout on their long-term outcome.

The developmental neurotoxicity study of platinum compounds. Effects of cisplatin versus a novel Pt(II) complex on rat cerebellum

In the field of experimental oncology, many efforts are being carried out to search new platinum-based drugs overcoming the CNS toxicity and drug resistance. One of the adopted strategies is the synthesis of platinum compounds able to form Pt-DNA adducts different from the cisplatin ones or to react with other subcellular targets. In this context a novel Pt(II) complex, [Pt(O,O'-acac)(γ-acac)(DMS)](PtAcacDMS), was synthesized which reacts preferentially with protein thiols or thioethers. In this work we investigated the in vivo effects of cisplatin and PtAcacDMS on normal development. Moreover, to verify the dose-dependence of the effects, different groups of animals were treated with 5 μg/g or 10 μg/g body weight of cisPt and PtAcacDMS. We have focused our attention on the cerebellum because it provides a useful model system to evaluate the outcomes of perinatal treatment with chemotherapeutic agents on key CNS developmental processes such as neural cells proliferation, migration and differentiation. We have demonstrated the ability of both cisPt and PtAcacDMS to reach the brain tissue once injected. The brain platinum content after PtAcacDMS treatment was notably higher (approximately 4-fold as much) than after cisPt. The platinum accumulation in the brain was still considerable 7 days after PtAcacDMS administration. However, compared with cisplatin, PtAcacDMS induces less severe changes on fundamental events of neuroarchitecture development, such as no high apoptotic events, less altered granule cell migration and Purkinje cell dendrite growth, suggesting a low neurotoxicity of this new Pt complex for normal CNS. The mild damages could be attributable to the different subcellular target of this compound as well as to a greater efficiency of the cell repair system to recognize the drug-target adducts and to repair them. Together with the previously demonstrated antineoplastic effectiveness in vitro, the findings here reported suggest PtAcacDMS as a potential alternative to cisplatin indicating, at the same time, that the choice of platinum compounds with new subcellular targets could be a strategy to prevent neurotoxicity induced by cisplatin and overcome drug resistance induced by mutations in the intrinsic apoptotic pathway.

Optimal treatment for intracranial germinoma: can we lower radiation dose without chemotherapy?

PURPOSE

To review the effectiveness of reduced-dose and restricted-volume radiation-only therapy in the treatment of intracranial germinoma and to assess the feasibility of reducing or eliminating the use of chemotherapy.

METHODS AND MATERIALS

Between January 1996 and March 2007, a retrospective analysis was performed that included 38 patients who received either reduced radiation alone (30 Gy for 26 patients) or reduced radiation with chemotherapy (n = 12 patients). All 38 patients received extended focal (including whole-ventricle) irradiation and were followed up until February 2008. Overall survival (OS) and relapse-free survival (RFS) rates were calculated. Variables associated with survival were evaluated by univariate Cox proportional hazards regression.

RESULTS

Median follow-up was 62.4 months (range, 10.1-142.5 months). The total 5-year OS rate was 93.7%. The 5-year OS and RFS rates for patients receiving radiation only were 100% and 96.2%, respectively. The rates for those receiving radiation plus chemotherapy were 83.3 % and 91.7%, respectively (not statistically significant). No predictive factor was significantly associated with the OS or RFS rate. Chemotherapy had no significant effect on survival but was associated with a higher incidence of treatment-related toxicity.

CONCLUSIONS

A further decrease in the radiation dose to 30 Gy with whole-ventricle irradiation is sufficient to treat selected patients with intracranial germinoma. Wide-field irradiation or chemotherapy should be avoided as these methods are unnecessary. Thus, reduction of the radiation dose to 30 Gy may be feasible, even without chemotherapy.

Survival following treatment for intracranial ependymoma: a review

The actual definition of survival rates following treatment for intracranial ependymomas is substantially influenced by the strict interaction among different factors. Age, location, and grading, for example, act together, negatively influencing the prognosis of younger children also invariably influenced by the more demanding role of surgery and the still limited use, up to recently, of radiotherapy under 3 years of age. In the same direction, the worse prognosis in most series of infratentorial ependymomas if compared with their supratentorial counterpart should be cautiously considered, midline posterior fossa tumors having completely different implications from those originating or predominantly extending to the cerebellopontine angle, where the extent of surgery has more invariably to compare with patients' quality of life. New radiotherapic regimens and their applications in infancy are promisingly demonstrating an improvement of present prognostic criteria, with the limit of still insufficient information on their long-term secondary effects. Similarly, molecular biology research studies, though still in their preclinical stage, are prompting to change the concept of a substantially chemoresistant tumor helping to stratify these lesions with the final aim of targeted pharmacological therapies. In the present review paper, we investigated singularly the role that the more commonly considered prognostic factors have had in the literature on survival of children affected by intracranial ependymomas, trying to elucidate their cumulative effect on the actual knowledge of this issue.

Surgical considerations in fourth ventricular ependymoma with the transcerebellomedullary fissure approach in focus

INTRODUCTION

Within the existing consensus for the best management of pediatric infratentorial ependymomas (PIE), surgery is the most important stage, where complete removal should be the perfect aim, before complementing it with chemo- or radiotherapy. That, however, remains a challenge even for the most skillful surgeons because of the vicinity of important brainstem and cranial nerve structures involved and is particularly difficult in lateral extensions.

MATERIALS AND METHODS

The paper analyzes the current trends of PIE treatment with emphasis on resection difficulties created by lateral extensions. Anatomical analysis and clinical application of the cerebellomedullary fissure dissection has created specific approaches, providing safe route to the lateral recess and cerebellopontine area by dividing safely tenia and tonsils and biventer lobes retraction.

DISCUSSION AND CONCLUSION

Bilateral and unilateral approaches have been developed. This approach prevents the damage of transvermian access and the resulting cerebellar mutism in some cases. Indications, technique and benefits of transcerebellomedullary fissure types of approaches are discussed.

Extended focal radiotherapy of 30 Gy alone for intracranial synchronous bifocal germinoma: a single institute experience

OBJECTS

To evaluate the disease characteristics and treatment outcomes for patients with intracranial synchronous bifocal germinomas treated with extended focal irradiation alone.

METHODS

Between January 1996 and March 2007, seven patients (three males and four females) with intracranial synchronous bifocal germinomas treated at Taipei Veterans General Hospital were reviewed. The median age at diagnosis was 14 years (range, 11-28 years). Four patients had surgery before radiotherapy. All patients underwent extended focal irradiation encompassing the whole ventricle system with a total radiation dose of 30 Gy (2 Gy daily). No patient received scheduled systemic chemotherapy before or after radiotherapy. Disease characteristics, treatment outcomes, and the impact of lesion numbers (single vs. bifocal) on survivals were investigated.

RESULTS

With a median follow-up time of 49 months (range, 20-66 months), the 2- and 5-year survival rates were both 100%. After treatment, all patients had good performance without recurrence. No severe complication was observed. In comparison, the overall survival (OS, p = 0.475) and the disease-free survival (DFS, p = 0.537) rates were not significantly different between bifocal- and single-lesion groups. Lesion numbers did not affect both OS and DFS. In addition, the incidence of neuraxial seeding was not higher in patients with bifocal germinomas as compared to those with single lesion.

CONCLUSIONS

Intracranial germinomas are extremely radiosensitive. Young patients with synchronous bifocal germinomas could be successfully treated with extended focal 30-Gy radiotherapy alone. The therapeutic advantage using this regimen needs to be further evaluated with larger sample size and longer follow-up time.

Multifactorial analysis of predictors of outcome in pediatric intracranial ependymoma

Pediatric ependymomas are enigmatic tumors, and their clinical management remains one of the more difficult in pediatric oncology. The identification of biological correlates of outcome and therapeutic targets remains a significant challenge in this disease. We therefore analyzed a panel of potential biological markers to determine optimal prognostic markers. We constructed a tissue microarray from 97 intracranial tumors from 74 patients (WHO grade II-III) and analyzed the candidate markers nucleolin, telomerase catalytic subunit (hTERT; antibody clone 44F12), survivin, Ki-67, and members of the receptor tyrosine kinase I (RTK-I) family by immunohistochemistry. Telomerase activity was determined using the in vitro-based telomere repeat amplification protocol assay, and telomere length was measured using the telomere restriction fragment assay. Primary tumors with low versus high nucleolin protein expression had a 5-year event-free survival of 74%+/-13% and 31%+/-7%, respectively. Multivariate analysis identified low nucleolin expression to be independently associated with a more favorable prognosis (hazard ratio=6.25; 95% confidence interval, 1.6-24.2; p=0.008). Ki-67 and survivin correlated with histological grade but not with outcome. Immunohistochemical detection of the RTK-I family did not correlate with grade or outcome. Telomerase activity was evident in 19 of 22 primary tumors, with telomere lengthening and/or maintenance occurring in five of seven recurrent cases. Low nucleolin expression was the single most important biological predictor of outcome in pediatric intracranial ependymoma. Furthermore, telomerase reactivation and maintenance of telomeric repeats appear necessary for childhood ependymoma progression. These findings require corroboration in a clinical trial setting.

MYB function in normal and cancer cells

The transcription factor MYB has a key role as a regulator of stem and progenitor cells in the bone marrow, colonic crypts and a neurogenic region of the adult brain. It is in these compartments that a deficit in MYB activity leads to severe or lethal phenotypes. As was predicted from its leukaemogenicity in several animal species, MYB has now been identified as an oncogene that is involved in some human leukaemias. Moreover, recent evidence has strengthened the case that MYB is activated in colon and breast cancer: a block to MYB expression is overcome by mutation of the regulatory machinery in the former disease and by oestrogen receptor-alpha (ERalpha) in the latter.

CNS progenitor cells and oligodendrocytes are targets of chemotherapeutic agents in vitro and in vivo

Background

Chemotherapy in cancer patients can be associated with serious short- and long-term adverse neurological effects, such as leukoencephalopathy and cognitive impairment, even when therapy is delivered systemically. The underlying cellular basis for these adverse effects is poorly understood.

Results

We found that three mainstream chemotherapeutic agents – carmustine (BCNU), cisplatin, and cytosine arabinoside (cytarabine), representing two DNA cross-linking agents and an antimetabolite, respectively – applied at clinically relevant exposure levels to cultured cells are more toxic for the progenitor cells of the CNS and for nondividing oligodendrocytes than they are for multiple cancer cell lines. Enhancement of cell death and suppression of cell division were seen in vitro and in vivo. When administered systemically in mice, these chemotherapeutic agents were associated with increased cell death and decreased cell division in the subventricular zone, in the dentate gyrus of the hippocampus and in the corpus callosum of the CNS. In some cases, cell division was reduced, and cell death increased, for weeks after drug administration ended.

Conclusion

Identifying neural populations at risk during any cancer treatment is of great importance in developing means of reducing neurotoxicity and preserving quality of life in long-term survivors. Thus, as well as providing possible explanations for the adverse neurological effects of systemic chemotherapy, the strong correlations between our in vitro and in vivo analyses indicate that the same approaches we used to identify the reported toxicities can also provide rapid in vitro screens for analyzing new therapies and discovering means of achieving selective protection or targeted killing.

Primary postoperative chemotherapy without radiotherapy for intracranial ependymoma in children: the UKCCSG/SIOP prospective study

BACKGROUND

Over half of childhood intracranial ependymomas occur in children younger than 5 years. As an adjuvant treatment, radiotherapy can be effective, but has the potential to damage the child's developing nervous system at a crucial time-with a resultant reduction in IQ and cognitive impairment, endocrinopathy, and risk of second malignancy. We aimed to assess the role of a primary chemotherapy strategy in avoiding or delaying radiotherapy in children younger than 3 years with intracranial ependymoma.

METHODS

Between December, 1992, and April, 2003, we enrolled 89 children with ependymoma who were aged 3 years or younger at diagnosis, of whom nine had metastatic disease on pre-operative imaging. After maximal surgical resection, children received alternating blocks of myelosuppressive and non-myelosuppressive chemotherapy every 14 days for an intended duration of 1 year. Radiotherapy was withheld unless local imaging (ie, from the child's treatment centre) showed progressive disease.

FINDINGS

50 of the 80 patients with non-metastatic disease progressed, 34 of whom were irradiated for progression. The 5-year cumulative incidence of freedom from radiotherapy for the 80 non-metastatic patients was 42% (95% CI 32-53). With a median follow-up of 6 years (range 1.5-11.3), overall survival for the non-metastatic patients at 3 years was 79.3% (95% CI 68.5-86.8) and at 5 years 63.4% (51.2-73.4). The corresponding values for event-free survival were 47.6% (36.2-58.1) and 41.8% (30.7-52.6). There was no significant difference in event-free or overall survival between complete and incomplete surgical resection, nor did survival differ according to histological grade, age at diagnosis, or site of disease. In 47 of 59 (80%) patients who progressed, relapse resulted from local control only. The median time to progression for the 59 patients who progressed was 1.6 years (range 0.1-10.2 years). The median age at irradiation of the whole group was 3.6 years (range 1.5-11.9). For the 80 non-metastatic patients, the 23 who achieved the highest relative dose intensity of chemotherapy had the highest post-chemotherapy 5-year overall survival of 76% (95% CI 46.6-91.2), compared with 52% (33.3-68.1) for the 32 patients who achieved the lowest relative dose intensity of chemotherapy.

INTERPRETATION

This protocol avoided or delayed radiotherapy in a substantial proportion of children younger than 3 years without compromising survival. These results suggest, therefore, that primary chemotherapy strategies have an important role in the treatment of very young children with intracranial ependymoma.

Role of Endogenous Neural Stem Cells in Neurological Disease and Brain Repair

These examples show that stem-cell-based therapy of neuro-psychiatric disorders will not follow a single scheme, but rather include widely different approaches. This is in accordance with the notion that the impact of stem cell biology on neurology will be fundamental, providing a shift in perspective, rather than introducing just one novel therapeutic tool. Stem cell biology, much like genomics and proteomics, offers a "view from within" with an emphasis on a theoretical or real potential and thereby the inherent openness, which is central to the concept of stem cells. Thus, stem cell biology influences many other, more traditional therapeutic approaches, rather than introducing one distinct novel form of therapy. Substantial advances have been made i n neural stemcell research during the years. With the identification of stem and progenitor cells in the adult brain and the complex interaction of different stem cell compartments in the CNS--both, under physiological and pathological conditions--new questions arise: What is the lineage relationship between t he different progenitor cells in the CNS and how much lineage plasticity exists? What are the signals controlling proliferation and differentiation of neural stem cells and can these be utilized to allow repair of the CNS? Insights in these questions will help to better understand the role of stem cells during development and aging and the possible relation of impaired or disrupted stem cell function and their impact on both the development and treatment of neurological disease. A number o f studies have indicated a limited neuronal and glial regeneration certain pathological conditions. These fundamental observations have already changed our view on understanding neurological disease and the brain's capacity for endogenous repair. The following years will have to show how we can influence andmodulate endogenous repair nisms by increasing the cellular plasticity in the young and aged CNS.

Brain tumors in children and adolescents: cognitive and psychological disorders at different ages

Cognitive and psychological disorders are among the most frequently observed sequelae in brain tumor survivors. The goal of this work was to verify the presence of these disorders in a group of children and adolescents diagnosed with brain tumor before age 18 years, differentiate these disorders according to age of assessment, identify correlations between the two types of impairments and define possible associations between these impairments and clinical variables. The study involved 76 patients diagnosed with brain tumor before age 18 years. Three age groups were formed, and all the patients received a standardized battery of age-matched cognitive and psychological tests. According to our findings, all three groups present with cognitive and psychological-behavioral disorders. Their frequency varies according to age of onset and is strongly associated to time since diagnosis. The performance intelligence quotient (PIQ) was more impaired than the verbal intelligence quotient (VIQ). Internalizing problems, withdrawal and social problems were the most frequent psychological disorders. Correlations were found between cognitive impairment and the onset of the main psychological and behavioral disorders. These findings are relevant as they point out the long-term outcome of brain tumor survivors. Hence, the recommendation to diversify psychological interventions and rehabilitation plans according to the patients' age.

Adult growth hormone replacement therapy and neuroimaging surveillance in brain tumour survivors

OBJECTIVE

Systematic collections of neuroimaging data are nonexistent in brain tumour survivors treated with adult growth hormone replacement therapy (AGHRT). We present our surveillance data.

DESIGN

In 1993, our unit implemented a policy of performing brain scans on every brain tumour survivor before starting AGHRT, with repeat neuroimaging at least once after 12-18 months' treatment. Reports for baseline scans and most recent scans were analysed for this retrospective study.

PATIENTS

All brain tumour survivors who received AGHRT (60 patients) were included in the analysis.

MEASUREMENTS

Evidence and extent of residual tumour, tumour progression, tumour recurrence, and secondary neoplasms (SN) on baseline scan and latest follow-up scan.

RESULTS

All patients had baseline scans performed. Follow-up scans were available in 41/45 (91%) patients who received AGHRT for more than 1 year (mean duration +/- SD of GHRT was 6.7 +/- 3.6 years). Sixteen patients had residual tumours, and SNs (all meningiomas) were demonstrated in three patients on baseline scans. Appearances remained stable in 34 (83%) patients during follow-up (extending to 17.4 +/- 8.3 years after tumour diagnosis). Of the 16 residual primary tumours, an incurable ependymoma continued to grow, and one meningioma progressed slightly in size over 7.7 years. Follow-up scans also revealed continued growth of the SNs detected at baseline, and five additional meningiomas (two in patients with a previous SN, confirming an excess risk in this subgroup, P = 0.02). All SNs occurred on average 22.8 (range 17-37) years after radiotherapy.

CONCLUSIONS

Our data do not suggest an increased rate of recurrence or progression of childhood brain tumours during AGHRT. Nonetheless, vigilance and long-term surveillance are needed in these patients in order to detect and monitor SNs, in particular in patients with a previous history of a SN. We endorse a proactive neuroimaging policy, preferably as part of a larger, controlled trial in the future.

The sequelae of cranial irradiation on human cognition

Cranial irradiation (CI) confers remediation of many CNS anomalies. CI, however, carries risks to cognitive performance. A wealth of data describes such deficits specifically in humans. Risk factors that promote increased susceptibility to cognitive decline have also been identified. This paper discusses and grades these risk factors, including age, gender, and the inclusion of chemotherapy, that increase the likelihood of pathologic cognitive development in the human population.

Parent proxy-reported health-related quality of life and fatigue in pediatric patients diagnosed with brain tumors and acute lymphoblastic leukemia

BACKGROUND

Pediatric patients with brain tumors (BT) are often excluded from health-related quality of life (HRQOL) studies even though they experience more severe disease and treatment-related sequelae than children with other types of cancer. Parent proxy assessments of HRQOL allow for greater inclusion of children who are developmentally immature, physically ill, or cognitively impaired.

METHODS

Parents of children ages 2-18 years who were diagnosed at Childrens Hospital Los Angeles and Children's Hospital San Diego with BT (n = 86) or acute lymphoblastic leukemia (ALL; n = 170) evaluated their children's HRQOL over the previous week using the parent-proxy versions of the Pediatric Quality of Life Inventory (PedsQL) 4.0 Generic Core scales, the PedsQL 3.0 Acute Cancer Module, and the PedsQL Multidimensional Fatigue scales. Multiple regression analyses were used to determine the independent effect of the child's diagnosis on HRQOL. Separate analyses were conducted for patients receiving treatment, patients who had not received treatment for < 12 months, and patients who had not received treatment for > or = 12 months.

RESULTS

Patients with BT exhibited more problems than patients with ALL in the physical, social, psychosocial, school, cognitive, and fatigue domains of HRQOL. The Core Physical Health, Core Psychosocial Health, and Fatigue Total scores for patients with BT demonstrated peak improvements for children who had not received treatment for < 12 months and sharp declines for children who had not received treatment for > or = 12 months. The Core Physical Health and Fatigue Total scores for patients with ALL were highest (better HRQOL) for those who had not received treatment for > or = 12 months.

CONCLUSIONS

Pediatric patients and survivors of BT experienced more fatigue and HRQOL problems than patients with ALL, and HRQOL differed by treatment status.

Effect of low doses of ionising radiation in infancy on cognitive function in adulthood: Swedish population based cohort study

OBJECTIVE

To determine whether exposure to low doses of ionising radiation in infancy affects cognitive function in adulthood.

DESIGN

Population based cohort study.

SETTING

Sweden.

PARTICIPANTS

3094 men who had received radiation for cutaneous haemangioma before age 18 months during 1930-59.

MAIN OUTCOME MEASURES

Radiation dose to frontal and posterior parts of the brain, and association between dose and intellectual capacity at age 18 or 19 years based on cognitive tests (learning ability, logical reasoning, spatial recognition) and high school attendance.

RESULTS

The proportion of boys who attended high school decreased with increasing doses of radiation to both the frontal and the posterior parts of the brain from about 32% among those not exposed to around 17% in those who received > 250 mGy. For the frontal dose, the multivariate odds ratio was 0.47 (95% confidence interval 0.26 to 0.85, P for trend 0.0003) and for the posterior dose it was 0.59 (0.23 to 1.47, 0.0005). A negative dose-response relation was also evident for the three cognitive tests for learning ability and logical reasoning but not for the test of spatial recognition.

CONCLUSIONS

Low doses of ionising radiation to the brain in infancy influence cognitive abilities in adulthood.

Psychosocial and behavioral functioning among pediatric brain tumor survivors

OBJECTIVE

To describe the psychosocial and behavioral functioning, as described by patient, parent and teacher, of a cohort of adolescents who have been previously treated for a brain tumor.

METHODS

A cohort of 32 patients, 12-18 years old, were evaluated between 1 and 5 years post-treatment for brain tumor during the patient's regularly scheduled follow-up clinic appointment at the Dana-Farber Cancer Institute. The Self-Report questionnaire and the Parent-Report of the Behavioral Assessment System for Children (BASC) were administered to the patient and to one of the patient's parents, respectively. In addition, the BASC Teacher-Report was completed by the patient's teacher. Descriptive statistics were generated; binomial distribution analyses were carried out to assess whether the proportion of individuals with impaired performance on each measure exceeded normative expectations.

RESULTS

Comparison of the proportion of patients with elevated scores to normative expectations indicated no excess of elevated scores on any of the BASC scales of the Self-Report. However, parents endorsed items in the areas of attention problems and leadership; teachers endorsed items concerning learning problems; and both parents and teachers endorsed items indicative of somatization behaviors.

CONCLUSIONS

Parent and teacher feedback indicate some level of psychosocial and behavioral morbidity for adolescents treated for a brain tumor; this finding contrasts with adolescent Self-Report indicating no difficulties in behavioral and psychosocial functioning. The extent to which these vulnerabilities impact quality of life and the discrepancy between reporters should be assessed in follow-up studies with a larger cohort of patients.

Methylphenidate treatment

Methylphenidate is the psychotropic drug most commonly used to treat individuals suffering from developmental attention-deficit-hyperactivity disorder. Additional attention deficit is part of numerous neurologic diseases in childhood. Despite the vast extent of scientific research on methylphenidate, the use of this stimulant in the treatment of cognitive and behavioral dysfunction in children with epilepsy, brain tumor, leukemia, closed brain injury, encephalitis, meningitis, or mental retardation continues to be controversial. Only few data exist about the efficacy and side effects of methylphenidate treatment in children with this neurologic illness or history. The aim of the present study is to provide a review of this important clinical topic and perhaps to stimulate further controlled investigations.

Quality-of-life assessment in patients who had been surgically treated for cerebellar pilocytic astrocytoma in childhood

OBJECT

After radical surgery for childhood cerebellar astrocytomas, patients are considered to be cured. Long-term follow up demonstrates that these patients survive, with most of them leading a normal life. The study reported here was aimed at assessing the quality of life (QOL) of these adults, which is defined as a person's sense of well-being, as derived from his or her current experience of life as a whole.

METHODS

Twenty patients who had undergone surgery between 1970 and 1985 were enrolled in the study. In four patients ventriculoperitoneal shunts were in place; two of these patients had required more than six shunt revisions. At present, all patients have clear neuroimaging studies and their Karnofsky Performance Scale (KPS) scores are as follows: 70 in three, 80 in seven, 90 in six, and 100 in four. A QOL questionnaire was administered to the patients and to a control group consisting of 20 healthy volunteers of matching age and sex. The chi-square test was applied to compare patients and controls. Traditional questions on the level of education, work, whether the patients have their own families, and whether they possessed a driver's license were asked at the end of the questionnaire. In all the dimensions assessed except one (sex life), the difference between patients and control volunteers was significant, socializing and adolescence being the most striking ones. This was also true when the three patients with the lowest KPS scores and the worst QOL results were excluded.

CONCLUSIONS

By traditional standards, these patients appear to fare quite well. Nevertheless, their self-reported life experience is unsatisfying when compared with the control group. The authors conclude that psychosocial factors are critical to complete recovery and the QOL of children who undergo successful operations for benign cerebellar astrocytoma.