Regression of Chiari malformation type 2 following early postnatal meningomyelocele repair-a retrospective observation from an institutional series of patients.

PURPOSE: Spontaneous regression of Chiari malformation type 2 (CM2) is observed rarely, as CM2 is associated with meningomyelocele (MMC) that is surgically repaired either pre- or early postnatally. While the radiological regression of CM2 occurs frequently following prenatal repair of MMC, it has been reported in only a few studies after postnatal repair. METHODS: From the consecutive series of children with postnatally repaired MMC, we reviewed the clinical and radiological data regarding CM2, particularly its regression either spontaneously or following CSF diversion. RESULTS: Eighteen children underwent postnatal repair of MMC between February 2011 and April 2023. CM2 was present in 16 (89%), and hydrocephalus in 15 children (83%), requiring shunting in 14 of them. During the mean clinical observation time (from birth to April 2023) of 59 ± 51 months, three children with CM2 (19%) underwent 1-2 foramen magnum decompressions (FMD), five children (28%) 1-4 surgical untethering procedures and 13 children with shunted hydrocephalus (93%) 1-5 shunt revisions. Out of sixteen children with CM2, we observed regression of CM2 on MRI in only one case (6%) during the mean radiological follow-up (from birth to the last MRI taken) of 49 ± 51 months. CONCLUSION: In our experience, spontaneous regression of CM2 in children with postnatally repaired MMC occurs quite rarely. Pathophysiological mechanisms behind the development of CM2 in children with MMC remain unclear, but our observation supports the hypothesis of an association between the downward displacement of the hindbrain and the low intraspinal pressure secondary to CSF leakage in children born with MMC.

Preoperative estimation of intracranial compliance in symptomatic children with Chiari malformation type 1: impact on outcome and risk of complications.

BACKGROUND: The role of reduced intracranial compliance (ICC) in the outcome after foramen magnum decompression (FMD) was demonstrated in adults with Chiari malformation Type 1 (CMI). However, similar observations from children treated for CMI are missing. METHODS: We reviewed pediatric cases of CMI referred to FMD between 2006 and 2022. Children with clinical and/or radiological signs suggesting reduced ICC (Group A) underwent overnight measurements of the pulsatile intracranial pressure (ICP): mean ICP wave amplitude (MWA) served as a surrogate marker of ICC. Children with more typical symptoms of CMI (Group B) underwent FMD without preoperative ICC estimation. This study presents the clinical, radiological, and outcome differences between these groups. RESULTS: Sixty-four children (mean age 11.1 ± 4.3 years) underwent FMD: In Group A (n = 30), the finding of reduced ICC as estimated from preoperative ICP measurement resulted in CSF diversion (ventriculoperitoneal shunt) before FMD in 11 children. Two patients required shunt due to complications after FMD (total shunt rate 43%). In Group B (n = 34) treated with FMD without preoperative ICC estimation, five children (15%) required shunting due to complications. In Group A, we found a significantly higher frequency of headache, nausea, fatigue, and dizziness. The outcome assessed by the modified Chicago Chiari Outcome Scale (mean follow-up 83 ± 57 months) was comparable between the groups, but the complication rate after FMD was significantly lower in Group A (7% vs. 32%; p = 0.011). The number of procedures (ICP measurement, FMD, shunt, re-do FMD, shunt revisions) was significantly higher in Group A (2.6 ± 0.9 vs. 1.5 ± 1.1 per patient; p < 0.001). CONCLUSION: In symptomatic children with CMI, the preoperative estimation of ICC from the overnight measurement of pulsatile ICP was more reliable for identifying those with reduced ICC than clinical and radiological assessment alone. When children with abnormally reduced ICC were identified and treated with CSF diversion before FMD, the complication rate was significantly reduced.

Parents' Perception of the Benefit of Receiving a Patient Information Leaflet Prior to Attending a Craniofacial Multidisciplinary Team Appointment.

OBJECTIVE: To investigate how a patient information leaflet describing what to expect during a craniofacial multidisciplinary team (MDT) appointment is experienced by parents of children with craniofacial anomalies (CFAs) and whether it helps with preparation for the appointment. DESIGN: Combination of qualitative and quantitative design. SETTING: Norwegian National Unit for Craniofacial Surgery. PARTICIPANTS: Thirty-three parents of children with CFAs completed the questionnaire and fourteen were subsequently interviewed. INTERVENTIONS: A patient information leaflet, sent to all parents before their MDT appointment. MAIN OUTCOME MEASURES: Descriptive questionnaire data and interview data. RESULTS: All parents (N = 33, 100%) found the leaflet easy to understand, while 31 (93.9%) found it provided helpful information. However, many first-time attendees still found the MDT setting overwhelming. CONCLUSIONS: A leaflet may be helpful for parents when preparing for their child's MDT appointment. However, some parents may need additional support and information related to their child's treatment pathway.

Long-term outcome of patients treated for craniopharyngioma: a single center experience.

PURPOSE: Treatment of craniopharyngiomas (CP) is challenging due to their proximity to critical neural structures, risk of serious complications and impaired quality of life after treatment. Recurrences may occur many years after surgical resection. However, long-term outcome data are still scarce. The purpose of this retrospective study was therefore to assess the long-term results after treatment of patients with CP. MATERIAL AND METHOD: Patients surgically treated for a histologically verified CP at Oslo University Hospital between 1992 and 2015 and with at least a 5-year follow-up were included. Patients' medical records and radiological studies were reviewed. RESULTS: Sixty-one patients (mean age 35.8 ± 22.2 years) were included; 18 patients (30%) were children <18 years of age. The incidence for the study period and the referral population was 1.1 cases/million/year, with trimodal peak incidence at 6, 32 and 59 years of age. The commonest presenting symptoms were visual disturbances (62%), headache (43%) and endocrine dysfunction (34%). The transcranial approach was utilized in 79% of patients. Gross total resection (GTR) was achieved in 59%. The surgical complication rate was 20%. Three patients (5%) received radiotherapy or radiosurgery after primary resection. The mean follow-up was 139 ± 76 months, with no patients lost to follow-up. Postoperatively, 59% of patients had panhypopituitarism and 56% diabetes insipidus. Eighteen patients (30%) developed tumour recurrence after a mean follow-up of 26 ± 25 months. The 10-year overall survival (OS) rate was 75%, whereas the disease-specific survival (DSS) rate was 84%, and recurrence-free survival (RFS) 61%. Subtotal resection (STR) (p = .01) and systemic comorbidity (p = .002) were associated with worse DSS. CONCLUSION: Surgical treatment of CP, even though combined with adjuvant radiotherapy in only selected cases, provides good long-time OS and DSS, and relatively good functional outcome in long-term survivors despite postoperative morbidity, particularly endocrine dysfunction. Systemic comorbidity and STR are individual negative prognostic factors.

Ruptured Aneurysm of the Anterior Communicating Artery in a Newborn: A Case Report and Review of the Literature.

We report the case of a 3-week-old neonate who presented with massive subarachnoid and intraventricular hemorrhage from a ruptured aneurysm of the anterior communicating artery (ACommA). An attempt on endovascular treatment ended up with therapeutic closure of the parent artery. However, since further investigation revealed a disastrous supratentorial cerebral infarction as a result of the hemorrhage, active treatment was terminated and the neonate died a few days after the initial stroke. To the best of our knowledge and after reviewing available literature, this is one of only five cases of ACommA aneurysm in newborns reported to date. Bleeding from an ACommA aneurysm in a neonate thus represents an extreme clinical rarity. There are no available data comparing the efficacy and safety of microsurgical versus endovascular treatment in neonates and small infants, but the latter option may at least reduce the risk associated with open surgery and further blood loss in this age group.

[Moyamoya disease in children] / Moyamoya hos barn.

Moyamoya is a rare condition that affects the blood vessels of the brain in children and young adults. It can cause both ischaemic stroke and cerebral haemorrhage. Although established diagnostic criteria and examinations exist, limited knowledge of the condition often leads to a mistaken or delayed diagnosis. Treatment consists of antiplatelet drugs and surgical revascularisation. Prognosis after successful surgery is good, but the disease requires a dedicated medical team.

Molecular pathological insights reveal a high number of unfavorable risk patients among children treated for medulloblastoma and CNS-PNET in Oslo 2005-2017.

BACKGROUND: An unexplained regional difference in survival was observed in previous publications on outcome for children treated for medulloblastoma and supratentorial primitive neuroectodermal tumor (CNS-PNET) in Norway. We aimed now to reevaluate and perform a retrospective molecular-based risk stratification of all embryonal brain tumors (excluding atypical teratoid rhabdoid tumors [ATRT]) in pediatric patients, who underwent surgery and treatment at Oslo University Hospital between 2005 and 2017. PROCEDURE: Specimens from all patients <20 years of age with initial diagnosis of medulloblastoma or CNS-PNET were reviewed. Molecular analyses comprised NanoString gene expression, molecular inversion probe profiling, Sanger sequencing, and 850K-methylation analysis. Whole chromosomal aberration signatures were assessed in standard-risk non-WNT/non-SHH medullobastomas for molecular risk stratification. RESULTS: We identified 53 non-ATRT embryonal tumors among which 33 were medulloblastomas. Molecular genetic parameters including whole chromosomal aberration signatures allowed classification of 17 medulloblastomas as molecular high risk. These patients had a significantly worse 5-year overall survival than the remaining 16 medulloblastoma patients (52.9% vs. 87.1% p = 0.036). Five patients in our cohort had tumors that are considered as new entities in the 2021 classification of tumors of the central nervous system. Five tumors were re-classified as nonembryonal tumors after review. CONCLUSION: Molecular-based risk stratification of standard-risk non-WNT/non-SHH medulloblastoma enabled superior identification of medulloblastomas with dismal prognosis. Our cohort demonstrated a significantly increased fraction of standard-risk non-WNT/non-SHH medulloblastoma with molecular high-risk profile compared to other studies, which might have contributed to previously reported unfavorable outcome data.

Whole-exome sequencing in syndromic craniosynostosis increases diagnostic yield and identifies candidate genes in osteogenic signaling pathways.

Craniosynostosis (CS) is a common congenital anomaly defined by premature fusion of one or more cranial sutures. Syndromic CS involves additional organ anomalies or neurocognitive deficits and accounts for 25%-30% of the cases. In a recent population-based study by our group, 84% of the syndromic CS cases had a genetically verified diagnosis after targeted analyses. A number of different genetic causes were detected, confirming that syndromic CS is highly heterogeneous. In this study, we performed whole-exome sequencing of 10 children and parents from the same cohort where previous genetic results were negative. We detected pathogenic, or likely pathogenic, variants in four additional genes (NFIA, EXTL3, POLR2A, and FOXP2) associated with rare conditions. In two of these (POLR2A and FOXP2), CS has not previously been reported. We further detected a rare predicted damaging variant in SH3BP4, which has not previously been related to human disease. All findings were clustered in genes involved in the pathways of osteogenesis and suture patency. We conclude that whole-exome sequencing expands the list of genes associated with syndromic CS, and provides new candidate genes in osteogenic signaling pathways.

Choroid Plexus Tumors in Children: Long-Term Follow-Up of Consecutive Single-Institutional Series of 59 Patients Treated over a Period of 8 Decades (1939-2020).

OBJECTIVE: To present long-term follow-up of a consecutive single-institutional series of patients treated for choroid plexus tumors over 8 decades. METHODS: From 1939 to 2020, 59 children were treated for choroid plexus tumors. Median age at diagnosis was 1.7 years. RESULTS: Gross total resection was achieved in 51 patients (86%). Ten patients (17%) underwent >1 resection. During the first 4 decades of the study (1939-1979), 14 patients with plexus papillomas were treated. Operative mortality was 50%, with 6 of the remaining 7 patients experiencing excellent survival with follow-up periods of 41-81 years. In the last 4 decades (1980-2020), 38 patients had low-grade tumors, and all were alive at the latest follow-up (range, 0.5-39 years). Observed 5-year survival in this subgroup was 100% (n = 30), as was observed 10-year survival (n = 26). One of 7 (14%) patients with atypical choroid plexus papilloma and 3 of 31 patients (10%) with choroid plexus papilloma underwent a second resection owing to recurrent tumor. At last follow-up, 47 patients (80%) were alive; 45 (96%) had a Barthel Index score of 100 and 2 had a Barthel Index score of 50. Today 25 patients are adults (20-59 years old); 17 work full-time, 4 work part-time, and 4 are unable to work. CONCLUSIONS: Low-grade choroid plexus tumors can be cured with gross total resection alone, with excellent long-term survival and functionality. The vast majority of survivors live independently as adults and work full-time. Recurrences are uncommon (8.7%), appear within the first few years after primary surgery, and can be treated with repeat resections.

Intraoperative DNA methylation classification of brain tumors impacts neurosurgical strategy.

BACKGROUND: Brain tumor surgery must balance the benefit of maximal resection against the risk of inflicting severe damage. The impact of increased resection is diagnosis-specific. However, the precise diagnosis is typically uncertain at surgery due to limitations of imaging and intraoperative histomorphological methods. Novel and accurate strategies for brain tumor classification are necessary to support personalized intraoperative neurosurgical treatment decisions. Here, we describe a fast and cost-efficient workflow for intraoperative classification of brain tumors based on DNA methylation profiles generated by low coverage nanopore sequencing and machine learning algorithms. METHODS: We evaluated 6 independent cohorts containing 105 patients, including 50 pediatric and 55 adult patients. Ultra-low coverage whole-genome sequencing was performed on nanopore flow cells. Data were analyzed using copy number variation and ad hoc random forest classifier for the genome-wide methylation-based classification of the tumor. RESULTS: Concordant classification was obtained between nanopore DNA methylation analysis and a full neuropathological evaluation in 93 of 105 (89%) cases. The analysis demonstrated correct diagnosis in 6/6 cases where frozen section evaluation was inconclusive. Results could be returned to the operating room at a median of 97 min (range 91-161 min). Precise classification of the tumor entity and subtype would have supported modification of the surgical strategy in 12 out of 20 patients evaluated intraoperatively. CONCLUSION: Intraoperative nanopore sequencing combined with machine learning diagnostics was robust, sensitive, and rapid. This strategy allowed DNA methylation-based classification of the tumor to be returned to the surgeon within a timeframe that supports intraoperative decision making.

Outcome after treatment of pediatric supratentorial ependymoma: long-term follow-up of a single consecutive institutional series of 26 patients.

BACKGROUND: Long-term outcome after surgical treatment of supratentorial ependymoma (STE) in children has not been extensively reported. FINDINGS: We identified 26 children who underwent primary tumor resection of STE between 1953 and 2011, with at least 8 years follow-up. Ten patients (38%) had anaplastic and 16 had low grade ependymoma. Four of 15 children (26%) treated in the years 1953-1976 survived more than 5 years, but the observed 10-year survival was only 7%. One patient lived for 37 years, and second surgery for a local recurrent lesion disclosed a glioblastoma, possibly secondary to radiotherapy. In contrast, the observed 5-year survival rate for 11 children treated in the years 1992-2011 was 8/11 (73%) and observed 10- and 25-year survival rates were 70% and 66%, respectively. Eight patients were alive and tumor-free with follow-up periods of 8-27 (median 18) years, all treated after 1992. Five of these long-term survivors were 23-39 years old with full-time (n = 3) or part-time (n = 2) work. The last three patients were still children (9-12 years old): one with good function and two with major neurological deficits. The majority of patients (n = 18) received adjuvant radiotherapy and eight children no adjuvant treatment. Repeated resections for residual or recurrent tumor were necessary in 11 patients (42%), mostly due to local disease with progressive clinical symptoms. Eight patients underwent only one repeat resection, whereas three patients had two or more repeat resections within 18 years after initial surgery. Four patients were tumor-free after repeated resections at the latest follow-up, 2-13 years after last surgery. CONCLUSION: Pediatric STE has a marked risk for local recurrence even after gross total resection and postoperative radiotherapy, but survival has increased following the introduction of modern treatment in recent years. Repeated surgery is an important part of treatment and may lead to persistent tumor control.

Outcome After Treatment of Spinal Ependymoma in Children and Adolescents: Long-Term Follow-up of a Single Consecutive Institutional Series of 33 Patients Treated Over Eight Decades.

BACKGROUND: Long-term outcomes for pediatric patients treated for spinal ependymoma are unknown. METHODS: We performed a retrospective analysis of outcome data from 33 children and young adults (0-22 years) who were operated on for a spinal ependymoma at our institution during the last 8 decades (1938-2019). RESULTS: Nineteen patients are alive, with follow-up period up to 60 years. Twelve of them are tumor-free, and 7 are alive with disease. Fourteen patients are dead, 9 of them due to recurrent and/or progressive disease 1-56 years (median: 11 years) after the initial surgery. Four of the deceased patients were treated before 1948, 3 of them with excellent long-term survival for 62-66 years after the initial surgery. Tumor recurrence was observed in half of the patients, both local at the site of the primary tumor resection as well as widespread intraspinal presentations. Recurrences were observed within months but also occurred after up to 20 years after initial treatment. After the implementation of magnetic resonance imaging in 1987, details of recurrent disease became more easily demonstrated. Repeated resections were performed when the symptomatic spinal disease was in progress (n = 11). Furthermore, 2 patients have intracranial tumor manifestations, 1 of them underwent resection of a suprasellar tumor in 1991. Four deceased patients experienced aggressive extraspinal progressive disease requiring multiple surgeries, including pulmonary metastasis in 1 of them. CONCLUSIONS: Pediatric spinal ependymomas can be treated with favorable results and functional outcome may be good even after more than half a century of follow-up. Nevertheless, unexpected and late recurrences may occur, and life-long follow-up is therefore recommended.

The role of pulsatile and static intracranial pressure measurements in the management of children with craniosynostosis-an institutional experience from 49 patients.

BACKGROUND: Although measurement of intracranial pressure (ICP) has occasionally been utilized in children with craniosynostosis (CSS), data on parameters of pulsatile ICP in CSS are still lacking, and the role of pulsatile ICP measurements in the management of CSS is not well established. METHODS: From our department's database, we retrieved the data from children in whom the measurement of static and pulsatile ICP was a part of the diagnostic work-up in different clinical situations related to CSS. Both clinical and ICP data were retrospectively reviewed and analyzed. RESULTS: We identified 49 children with CSS, median age 4.4 years (range 0.2-18.9), in whom a total of 67 diagnostic ICP measurements were undertaken between 2002 and 2014. The CSS was syndromal in 23 cases. The rationale for ICP measurement was a question of indication for cranial vault expansion surgery (CVES) in 12 patients (Group 1), of its timing in 10 patients (Group 2), of suspected abnormally elevated ICP or hydrocephalus in 11 patients (Group 3), of indication for repeated CVES in 13 patients (Group 4), or shunt dysfunction in three patients (Group 5). The average mean ICP for the whole cohort was 15.1 ± 5.5 mmHg and mean wave amplitude (MWA) 5.3 ± 2.2 mmHg. There was no significant difference in ICP parameters when compared between Groups 1-5. Fundoscopy revealed papilledema in five out of 32 children (15.6%). There were significantly higher parameters of pulsatile ICP (MWA) in patients with papilledema, but no statistically significant difference in parameters of static ICP. CONCLUSIONS: In this cohort of pediatric patients with CSS presenting with various diagnostic challenges, we found the diagnostic measurement of static and pulsatile ICP useful in selecting the optimal treatment modality and timing of surgery. Papilledema was associated with elevated pulsatile ICP, a parameter that in previous studies has been shown to correlate with impaired intracranial compliance.

Outcomes in adulthood after neurosurgical treatment of brain tumors in the first 3 years of life: long-term follow-up of a single consecutive institutional series of 97 patients.

BACKGROUND: Long-term outcome for children who underwent surgery for brain tumors in the first 3 years of life is not well-known. METHODS: We performed a retrospective study on surgical morbidity, mortality rate, academic achievement, and work participation in children below 3 years of age who underwent primary tumor resection for a brain tumor in the period from 1973 to 1998. Gross motor function and activities of daily life were scored according to the Barthel Index. Long-term survivors were defined as with a survival from primary diagnosis of 20 years or more. FINDINGS: Ninety-seven consecutive children were included. No patient was lost to follow-up. Gross total resection was achieved in 67 children during the primary procedure, 25 had subtotal resections, and 5 had only partial resection. The 20-year survival figures for the 46 children with high-grade tumors was 33%, and the corresponding figures for 51 patients treated for low-grade tumors was 82%. Five of the 57 20-year-survivors died 21, 29, 30, 30, and 41 years, respectively, following primary surgery. Fifty of the 52 long-term survivors had a Barthel Index (BI) of 100, while the remaining two had a BI of 40. Twelve patients were long-term survivors after treatment for HG tumors (26%), while 40 of the 51 patients treated for LG tumors (78%) were alive. Thirty-two of the 52 long-term survivors were in full-time work and 29 of them after treatment for LG tumors. Another 10 were in part-time work, while the last 10 individuals had no working capacity. CONCLUSION: Survival is better for patients with low-grade tumors compared with those with high-grade tumors. The functional level of long-term survivors is affected by adjuvant therapy and radiotherapy in particular. Neurosurgical intervention in itself is safe and plausible for pediatric brain tumor patients below 3 years of age. However, there should be a focus on potential late affects, and survivors should be followed by knowledgeable clinical staff for the neoplastic disease as well as for potential side effects. In this consecutive series, a 33% 20-year survival for children treated for HG tumors and 82% for patients with LG tumors was observed. The patients with LG tumors who had been treated with surgical resection without any adjuvant therapy showed a good clinical outcome as adults, and two-thirds of them were in full-time work.

Social attainment in physically well-functioning long-term survivors of pediatric brain tumour; the role of executive dysfunction, fatigue, and psychological and emotional symptoms.

The purpose of this cross-sectional study was to investigate long-term social attainment in physically well-functioning adult survivors of pediatric brain tumour (PBT) and identify demographic, medical, and psychological factors related to poor social outcomes, with a special focus on the significance of executive dysfunction. One hundred and fourteen PBT survivors and a healthy control group provided personal data on social outcomes, i.e., education, work, and government benefits, and completed questionnaires on executive function (EF), psychological and emotional difficulties, and fatigue. A significantly higher number of survivors compared to healthy controls reported having received educational adjustments and substantial government benefits, and significantly more survivors than controls were currently not engaged in regular employment/training. PBT survivors and healthy controls did not differ on educational level or living situation. The factors most strongly associated with poor social outcomes were self-reported executive dysfunction, difficulties with adaptive functioning, and fatigue. The findings show that physically well-functioning PBT survivors are at risk of poorer social outcomes and financial dependence in adulthood compared to their healthy peers, and underline the importance of investigating EF in short- and long-term follow-ups. Future rehabilitation efforts should focus more on compensatory strategies for executive dysfunction and improving EF skills.

Benefits of clinical criteria and high-throughput sequencing for diagnosing children with syndromic craniosynostosis.

An accurate diagnosis of syndromic craniosynostosis (CS) is important for personalized treatment, surveillance, and genetic counselling. We describe detailed clinical criteria for syndromic CS and the distribution of genetic diagnoses within the cohort. The prospective registry of the Norwegian National Unit for Craniofacial Surgery was used to retrieve individuals with syndromic CS born between 1 January 2002 and 30 June 2019. All individuals were assessed by a clinical geneticist and classified using defined clinical criteria. A stepwise approach consisting of single-gene analysis, comparative genomic hybridization (aCGH), and exome-based high-throughput sequencing, first filtering for 72 genes associated with syndromic CS, followed by an extended trio-based panel of 1570 genes were offered to all syndromic CS cases. A total of 381 individuals were registered with CS, of whom 104 (27%) were clinically classified as syndromic CS. Using the single-gene analysis, aCGH, and custom-designed panel, a genetic diagnosis was confirmed in 73% of the individuals (n = 94). The diagnostic yield increased to 84% after adding the results from the extended trio-based panel. Common causes of syndromic CS were found in 53 individuals (56%), whereas 26 (28%) had other genetic syndromes, including 17 individuals with syndromes not commonly associated with CS. Only 15 individuals (16%) had negative genetic analyses. Using the defined combination of clinical criteria, we detected among the highest numbers of syndromic CS cases reported, confirmed by a high genetic diagnostic yield of 84%. The observed genetic heterogeneity encourages a broad genetic approach in diagnosing syndromic CS.

Long-term outcome of posterior fossa medulloblastoma in patients surviving more than 20 years following primary treatment in childhood.

The aim of the study was to analyze the long-term outcome (>20 years) after treatment of posterior fossa medulloblastoma (MB) in childhood. We analyzed data from patients treated for posterior fossa MB between 1974 (introduction of the first international treatment protocol in Norway) and 1987 (when use of radiotherapy was abandoned in children under 4 years of age). Out of 47 children, 24 survived >20 years. At the time of analysis, 16 patients (median age 41 years, range 32-52) were alive (median follow-up 34 years, range 30-42), while 8 patients died 22-41 years (median 31 years) after primary treatment: one late death (after 22 years) was due to tumor recurrence whilst other 7 deaths (after 23 to 41 years) were related to the detrimental effects of the treatment (secondary tumors, stroke, severe epilepsy and depression). Observed 20- and 30-year survival rates were 51% and 44%, respectively. Despite successful treatment of MB in childhood and satisfactory tumor control during the first 20 years following primary treatment, our data indicates that even long-term survivors may die from tumor recurrence. However, the main factors causing late mortality and morbidity in long-term survivors seem to be the complications related to radiotherapy given in childhood.