Publications
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Høstmælingen, Christina; Sundseth, Jarle; Latysheva, Anna & Frič, Radek
(2026).
Juvenile lumbar disc herniation: impact of delayed diagnosis and surgical treatment on outcome in a 10-year single-center series.
Acta Neurochirurgica.
ISSN 0001-6268.
168(1).
doi:
10.1007/s00701-026-06956-7.
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Frič, Radek; Tran, Anh Thu Nora; Due-Tønnessen, Bernt Johan; Nilsson, Daniel & Foss-Skiftesvik, Jon
(2026).
Nordic survey on practice of neurosurgical management of craniopharyngioma in children.
Child's Nervous System.
ISSN 0256-7040.
42.
doi:
10.1007/s00381-026-07153-8.
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Purpose
Management of childhood-onset craniopharyngioma (CP) may be challenging, given its rarity and complexity as well as the risks associated with treatment. We aimed at investigating how the practice of neurosurgical management of CP in children differs among neurosurgical centres in Nordic countries.
Methods
We performed a survey containing 28 questions and focusing on organization of care, expertise availability, treatment decisions and strategies, and follow-up routines, respectively. The survey was distributed to 21 neurosurgical centres in five Nordic countries.
Results
We obtained answers from 18 centres (86% response rate). In 61% of centres, only 0–1 new cases are treated per year. In only one country (Denmark), the neurosurgical treatment of pediatric CP is centralized to one centre. While all cases are discussed at MDT meetings before surgery and during the follow-up, management strategies, including surgical indications, goals, and approaches, vary substantially among responding centres.
Conclusion
The practice of neurosurgical management of pediatric CP in the Nordic countries is characterized by relatively low case volumes, differing management strategies, as well as varying degrees of centralization and collaboration between pediatric and adult neurosurgeons. Although some practical aspects may be unique for healthcare practised in the Nordic countries, the results of this survey and, in particular, the embedded discussion of centralization – either restricted to surgery or including complete management of pediatric CP – seem relevant and may provide useful insights also to neurosurgeons outside of the Nordics.
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Magnadóttir, Thórdís; Impieri, Davide & Frič, Radek
(2025).
Lukking av bløtvevsdefekter ved kirurgi for åpent ryggmargsbrokk.
Tidsskrift for Den norske legeforening (Tidsskriftet).
ISSN 0029-2001.
145(10).
doi:
10.4045/tidsskr.24.0610.
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Tuft, Mia; Berger, Ylva Østby; Marthinsen, Pål Bache; Due-Tønnessen, Bernt Johan & Frič, Radek
(2025).
Surgical treatment of subependymal giant cell astrocytoma in patients with tuberous sclerosis complex - an institutional experience and results (preprint ahead of review 2024).
Child's Nervous System.
ISSN 0256-7040.
41(1).
doi:
10.1007/s00381-025-06779-4.
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Frič, Radek; Beyer, Mona K. & Due-Tønnessen, Bernt Johan
(2024).
Regression of Chiari malformation type 2 following early postnatal meningomyelocele repair—a retrospective observation from an institutional series of patients.
Child's Nervous System.
ISSN 0256-7040.
40,
p. 3641–3646.
doi:
10.1007/s00381-024-06586-3.
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Frič, Radek; Bryne, Eline; Warsza, Bogna; Due-Tønnessen, Bernt Johan & Eide, Per Kristian
(2024).
Preoperative estimation of intracranial compliance in symptomatic children with Chiari malformation type 1: impact on outcome and risk of complications.
Acta Neurochirurgica.
ISSN 0001-6268.
166(1),
p. 1–11.
doi:
10.1007/s00701-024-05897-3.
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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.
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Frič, Radek; Bryne, Eline; Warsza, Bogna & Eide, Per Kristian
(2024).
Intracranial pulse pressure amplitude as an indicator of intracranial compliance: observations in symptomatic children with Chiari malformation type I.
Journal of Neurosurgery: Pediatrics.
ISSN 1933-0707.
34(3),
p. 293–300.
doi:
10.3171/2024.4.PEDS24168.
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Frič, Radek; Ringstad, Geir & Eide, Per Kristian
(2023).
Low versus High Intracranial Compliance in Adult Patients with Chiari Malformation Type 1–Comparison of Long-Term Outcome After Tailored Treatment.
World Neurosurgery.
ISSN 1878-8750.
173,
p. e699–e707.
doi:
10.1016/j.wneu.2023.02.134.
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Background
In patients with Chiari malformation type 1 (CMI) presenting with low intracranial compliance (ICC), foramen magnum decompression (FMD) often fails and the complication rate may be higher. We therefore routinely perform a preoperative assessment of ICC from intracranial pressure measurement. Patients with low ICC are treated with ventriculoperitoneal shunt (VPS) before FMD. In this study, we assess the outcome of patients with low ICC, compared with patients with high ICC treated with FMD alone.
Methods
We reviewed the clinical and radiologic data of all consecutive patients with CMI treated between April 2008 and June 2021. ICC was assessed by overnight measurement of the pulsatile intracranial pressure: mean wave amplitude (MWA) above a previously defined threshold for abnormality was considered a surrogate marker for low ICC. The outcome was scored by Chicago Chiari Outcome Scale.
Results
Of 73 patients, 23 with low ICC (average MWA 6.8 ± 1.2 mm Hg) received VPS before FMD, whereas 50 with high ICC (average MWA 4.4 ± 1.0 mm Hg) received only FMD. After a mean follow-up of 78.7 ± 41.4 months, 96% of all patients subjectively improved. The mean Chicago Chiari Outcome Scale score was 13.1 ± 2.2. Enlargement of cerebrospinal fluid space in the foramen magnum was achieved in 95% and regression of syringomyelia in 74% of cases. We found no significant difference in outcome between the patients with low and high ICC.
Conclusions
By identifying patients with CMI associated with low ICC and tailoring their treatment by VPS before FMD, we achieved favorable clinical and radiologic outcomes comparable to those with high ICC.
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Frič, Radek; König, Marton; Due-Tønnessen, Bernt Johan; Ramm-Pettersen, Jon-Terje & Berg-Johnsen, Jon
(2023).
Long-term outcome of patients treated for craniopharyngioma: a single center experience.
British Journal of Neurosurgery.
ISSN 0268-8697.
doi:
10.1080/02688697.2023.2179600.
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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.
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Frič, Radek; Sorteberg, Angelika; Wallace, Sean Ciaran; Server, Andrés; Due-Tønnessen, Bernt Johan & Wiedmann, Markus
(2022).
Moyamoya hos barn.
Tidsskrift for Den norske legeforening (Tidsskriftet).
ISSN 0029-2001.
142(13),
p. 1–9.
doi:
10.4045/tidsskr.21.0776.
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Moyamoya er en sjelden sykdom som rammer hjernens blodårer hos barn og unge voksne. Den kan forårsake både hjerneinfarkt og hjerneblødninger. Selv om det finnes etablerte diagnostiske kriterier og undersøkelser, fører begrenset kunnskap ofte til feildiagnostisering og forsinket diagnose. Behandlingen består av platehemmende medisiner og kirurgisk revaskularisering. Prognosen etter vellykket kirurgi er god, men sykdommen krever et dedikert behandlerteam. Moyamoya er en kronisk og progressiv sykdom, karakterisert av gradvis stenosering/okklusjon av den intrakraniale delen av arteria carotis interna samt proksimale segment av a. cerebri anterior, a. cerebri media og (sjeldnere) blodårene i bakre kretsløp. Ettersom sykdommen progredierer langsomt, utvikler det seg et nettverk av nye kollaterale blodårer rundt de stenoserte/okkluderte karsegmentene som opprettholder vevsperfusjonen. Disse kollateralkarene er små og utsatt for ruptur med blødning, aneurismedannelse og trombosering. Kollateralnettverket sees ved konvensjonell cerebral angiografi hvor det minner om en «sky av røyk» (moyamoya på japansk). Ytterligere kollaterale blodårer danner seg fra hjernehinnene (leptomeningene) eller gjennom dura fra grener til a. carotis externa. Vi gir i denne kliniske oversikten en oppdatering om sykdommen, med fokus på barn, basert på egne erfaringer og gjennomgang av relevant litteratur.
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Niehusmann, Pitt; Stensvold, Einar; Leske, Henning; Pietsch, Torsten; Goschzik, Tobias & Gielen, Gerrit H.
[Show all 10 contributors for this article]
(2022).
Molecular pathological insights reveal a high number of unfavorable risk patients among children treated for medulloblastoma and CNS-PNET in Oslo 2005–2017.
Pediatric Blood & Cancer.
ISSN 1545-5009.
69(9),
p. 1–8.
doi:
10.1002/pbc.29736.
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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.
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Frič, Radek; Langvatn, Erlend Aambø; Due-Tønnessen, Bernt Johan & Eide, Per Kristian
(2021).
The role of pulsatile and static intracranial pressure measurements in the management of children with craniosynostosis–an institutional experience from 49 patients.
Acta Neurochirurgica.
ISSN 0001-6268.
163(7),
p. 2015–2023.
doi:
10.1007/s00701-020-04680-4.
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Lundar, Tryggve; Due-Tønnessen, Bernt Johan; Frič, Radek; Sundseth, Jarle Østberg; Brandal, Petter & Due-Tønnessen, Paulina
(2021).
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.
World Neurosurgery.
ISSN 1878-8750.
150,
p. E228–E235.
doi:
10.1016/j.wneu.2021.02.131.
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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.
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Lundar, Tryggve; Due-Tønnessen, Bernt Johan; Frič, Radek; Brandal, Petter & Due-Tønnessen, Paulina
(2021).
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).
World Neurosurgery.
ISSN 1878-8750.
158,
p. e810–e819.
doi:
10.1016/j.wneu.2021.11.070.
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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.
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Lundar, Tryggve; Due-Tønnessen, Bernt Johan & Frič, Radek
(2021).
Comment on: A retrospective analysis of recurrent paediatric ependymoma reveals extremely poor survival and infectiveness of current treatments across central nervous locations and molecular subgroups.
Pediatric Blood & Cancer.
ISSN 1545-5009.
doi:
10.1002/pbc.29193.
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Lundar, Tryggve; Due-Tønnessen, Bernt Johan; Frič, Radek; Sundseth, Jarle Østberg; Brandal, Petter & Due-Tønnessen, Paulina
(2021).
Outcome after treatment of pediatric supratentorial ependymoma: long-term follow-up of a single consecutive institutional series of 26 patients.
British Journal of Neurosurgery.
ISSN 0268-8697.
p. 1–9.
doi:
10.1080/02688697.2021.1914821.
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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.
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Fric, Radek; Nedregaard, Bård; Heimdal, Ketil Riddervold; Weber, Clemens & Due-Tønnessen, Bernt Johan
(2021).
Ruptured Aneurysm of the Anterior Communicating Artery in a Newborn: A Case Report and Review of the Literature.
Central European Neurosurgery.
ISSN 2193-6315.
doi:
10.1055/s-0041-1739209.
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Lundar, Tryggve; Due-Tønnessen, Bernt Johan; Fric, Radek; Brandal, Petter & Due-Tønnessen, Paulina
(2020).
Adult outcome after treatment of pediatric posterior fossa ependymoma: long-term follow-up of a single consecutive institutional series of 22 patients with more than 5 years of survival.
Journal of Neurosurgery: Pediatrics.
ISSN 1933-0707.
26(1),
p. 22–26.
doi:
10.3171/2020.1.PEDS19700.
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Lundar, Tryggve; Due-Tønnessen, Bernt Johan; Frič, Radek; Brandal, Petter; Stensvold, Einar & Due-Tønnessen, Paulina
(2020).
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.
Child's Nervous System.
ISSN 0256-7040.
37,
p. 427–433.
doi:
10.1007/s00381-020-04859-1.
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Abstract 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.
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Frič, Radek; Due-Tønnessen, Bernt Johan; Lundar, Tryggve; Egge, Arild; Krossnes, Bård Kronen & Due-Tønnessen, Paulina
[Show all 8 contributors for this article]
(2020).
Long-term outcome of posterior fossa medulloblastoma in patients surviving more than 20 years following primary treatment in childhood.
Scientific Reports.
10:9371,
p. 1–7.
doi:
10.1038/s41598-020-66328-8.
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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.
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Frič, Radek; Ringstad, Geir & Eide, Per Kristian
(2019).
Chiari-malformasjon type 1 – diagnostikk og behandling.
Tidsskrift for Den norske legeforening (Tidsskriftet).
ISSN 0029-2001.
139(10),
p. 1–8.
doi:
10.4045/tidsskr.18.0455.
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Langvatn, Erlend Aambø; Frič, Radek; Due-Tønnessen, Bernt Johan & Eide, Per Kristian
(2019).
Intracranial volume versus static and pulsatile intracranial pressure values in children with craniosynostosis.
Journal of Neurosurgery: Pediatrics.
ISSN 1933-0707.
24(1),
p. 66–74.
doi:
10.3171/2019.2.PEDS18767.
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Lundar, Tryggve; Due-Tønnessen, Bernt Johan; Frič, Radek; Brandal, Petter; Stensvold, Einar & Due-Tønnessen, Paulina
(2019).
Adult outcome after neurosurgical treatment of brain tumours in the first year of life: long-term follow-up of a single consecutive institutional series of 34 patients.
Acta Neurochirurgica.
ISSN 0001-6268.
161(9),
p. 1793–1798.
doi:
10.1007/s00701-019-04014-z.
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Background
Long-term results for adult patients who underwent surgery for paediatric brain tumours in the first year of life have not been reported.
Methods
We performed a retrospective study on surgical morbidity, mortality rate, academic achievement and/or work participation in patients who underwent primary tumour resection for a brain tumour as infants in the period from 1973 to 1998. Gross motor function and activities of daily life were scored according to the Barthel Index.
Findings
Thirty-four consecutive children were included. No patient was lost to follow-up. Twenty-two children (65%) underwent gross total resection (GTR), 10 had subtotal resections (STR) and 2 had only partial resection during primary surgery. Nine children were additionally surgically treated for hydrocephalus (HC), many of them with repeat operations for shunt malfunction during follow-up. Three children died within 30 days following GTR of highly vascular tumours. Seventeen (50%) of the infants had high-grade tumours with 1-month, 1-year and 20-year survival figures of 88, 30 and 30%. The corresponding figures for 17 patients treated for low-grade tumours were 94%, 88% and 88%, respectively. Seventeen patients (50%) are still alive as adult long-term survivors at median age of 29 years (range 20 to 43 years). Three died after 29, 30 and 41 years, respectively. At the latest follow-up, 16 out of 17 long-term survivors have a Barthel Index (BI) of 100, while the remaining one has a BI of 40. Two long-term survivors of a high-grade tumour treated 30 and 35 years ago are severely handicapped and have no working capacity. The 15 long-term survivors after treatment for a low-grade tumour are all in daily activity as students (4), in part-time work (3) or full-time work (8).
Conclusion
A brain tumour occurring in the first year of life is a serious threat to the patient and the family, particularly in case of high-grade tumours. In our small cohort, the results from long-term survivors of high-grade tumour group are depressing and confirm the deleterious effect of radiotherapy given to infants decades ago. The infants with low-grade tumours who could be treated with surgical resection without any adjuvant therapy show a good clinical outcome as adults. For parents of these latter patients, the results are far better than feared in advance
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Lundar, Tryggve; Due-Tønnessen, Bernt Johan; Frič, Radek; Egge, Arild; Krossnes, Bård Kronen & Due-Tønnessen, Paulina
[Show all 8 contributors for this article]
(2018).
Neurosurgical treatment of gangliogliomas in children and adolescents: long-term follow-up of a single-institution series of 32 patients.
Acta Neurochirurgica.
ISSN 0001-6268.
160(6),
p. 1207–1214.
doi:
10.1007/s00701-018-3550-8.
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Object The object of this study was to delineate long-term results of the surgical treatment of pediatric tumors classified as ganglioglioma or gangliocytoma. Methods A cohort of consecutive patients 19 years or younger who had undergone primary resection of CNS tumors during the years 1980–2016 at a single institution were reviewed in this retrospective study of surgical morbidity, mortality, and academic achievement and/or work participation. Gross motor function and activities of daily living were scored using the Barthel Index (BI). Results Patient records for 32 consecutive children and adolescents who had undergone resection for a ganglioglioma were included in this study. Of the 32 patients, 13 were in the first decade at the first surgery, whereas 19 were in the second decade. The male/female ratio was 1.0 (16/16). No patient was lost to follow-up. The tumor was localized to the supratentorial compartment in 26 patients, to the posterior fossa in 5 patients, and to the spinal cord in 1 patient. Only two of the tumors were classified as anaplastic. Of the 30 low-grade tumors, 2 were classified as gangliocytomas, 6 were desmoplastic infantile gangliogliomas, and 22 were ordinary gangliogliomas. The aim of primary surgery was gross-total resection (GTR) and was achieved in 23 patients (71.9%). Altogether, 43 tumor resections were performed. Eight patients underwent a second resection from 1 to 10 years after primary surgery and three of these also had a third resection from 2 to 24 years after initial surgery. The reason for further resection was clinical (seizure control failure/recurrence of epilepsy or progressive neurological deficit) and/or residual tumor progression/recurrence. There was no operative mortality in this series and all 32 patients are alive with follow-up periods from 0.5 to 36 years (median 14 years). Observed 14-year survival is thus 100%. One out of two children with primary anaplastic tumor received local radiotherapy (proton) postoperatively. The other 31 patients did not have any kind of non-surgical adjuvant therapy. Twenty-one out of 26 children with supratentorial tumor had epilepsy as one of their presenting symptoms. Nineteen of these became seizure-free after initial surgery (18 of them after GTR), but 3 patients experienced recurrence of seizures within some years. Functional outcome in terms of ADL, schooling, and work participation was gratifying in most patients. Five patients have persistent hydrocephalus (HC), treated with ventriculoperitoneal (VP) shunts. Conclusion Low-grade gangliogliomas (GGs) can be surgically treated with good long-term results including seizure and tumor control as well as school and working participation.
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Ramm-Pettersen, Jon-Terje; Fric, Radek & Berg-Johnsen, Jon
(2017).
Long-term follow-up after endoscopic trans-sphenoidal surgery or initial observation in clivus chordomas.
Acta Neurochirurgica.
ISSN 0001-6268.
159(10),
p. 1849–1855.
doi:
10.1007/s00701-017-3236-7.
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Frič, Radek & Eide, Per Kristian
(2017).
Comparative observational study on the clinical presentation, intracranial volume measurements, and intracranial pressure scores in patients with either Chiari malformation Type I or idiopathic intracranial hypertension.
Journal of Neurosurgery.
ISSN 0022-3085.
126(4),
p. 1312–1322.
doi:
10.3171/2016.4.JNS152862.
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OBJECTIVE
Several lines of evidence suggest common pathophysiological mechanisms in Chiari malformation Type I (CMI) and idiopathic intracranial hypertension (IIH). It has been hypothesized that tonsillar ectopy, a typical finding in CMI, is the result of elevated intracranial pressure (ICP) combined with a developmentally small posterior cranial fossa (PCF). To explore this hypothesis, the authors specifically investigated whether ICP is comparable in CMI and IIH and whether intracranial volumes (ICVs) are different in patients with CMI and IIH, which could explain the tonsillar ectopy in CMI. The authors also examined whether the symptom profile is comparable in these 2 patient groups.
METHODS
The authors identified all CMI and IIH patients who had undergone overnight diagnostic ICP monitoring during the period from 2002 to 2014 and reviewed their clinical records and radiological examinations. Ventricular CSF volume (VV), PCF volume (PCFV), and total ICV were calculated from initial MRI studies by using volumetric software. The static and pulsatile ICP scores during overnight monitoring were analyzed. Furthermore, the authors included a reference (REF) group consisting of patients who had undergone ICP monitoring due to suspected idiopathic normal-pressure hydrocephalus or chronic daily headache and showed normal pressure values.
RESULTS
Sixty-six patients with CMI and 41 with IIH were identified, with comparable demographics noted in both groups. The occurrence of some symptoms (headache, nausea, and/or vomiting) was comparable between the cohorts. Dizziness and gait ataxia were significantly more common in patients with CMI, whereas visual symptoms, diplopia, and tinnitus were significantly more frequent in patients with IIH. The cranial volume measurements (VV, PCFV, and ICV) of the CMI and IIH patients were similar. Notably, 7.3% of the IIH patients had tonsillar descent qualifying for diagnosis of CMI (that is, > 5 mm). The extent of tonsillar ectopy was significantly different between the CMI and IIH cohorts (p < 0.001) but also between these 2 cohorts and the REF group. Pulsatile ICP was elevated in both cohorts without any significant between-group differences; however, static ICP was significantly higher (p < 0.001) in the IIH group.
CONCLUSIONS
This study showed comparable and elevated pulsatile ICP, indicative of impaired intracranial compliance, in both CMI and IIH cohorts, while static ICP was higher in the IIH cohort. The data did not support the hypothesis that reduced PCFV combined with increased ICP causes tonsillar ectopy in CMI. Even though impaired intracranial compliance seems to be a common pathophysiological mechanism behind both conditions, the mechanisms explaining the different clinical and radiological presentations of CMI and IIH remain undefined.
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Frič, Radek; Pripp, Are Hugo & Eide, Per Kristian
(2017).
Cardiovascular risk factors in Chiari malformation and idiopathic intracranial hypertension.
Brain and Behavior.
7(5).
doi:
10.1002/brb3.677.
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Objectives
Both Chiari malformation type 1 (CMI, i.e., the idiopathic caudal ectopy of cerebellar tonsils into foramen magnum) and idiopathic intracranial hypertension (IIH) are characterized by reduced intracranial compliance (ICC) due to disturbed circulation of cerebrospinal fluid (CSF). An increasing body of evidence links cardiovascular disease to CSF circulation disturbances. The aim of this study was to explore whether the prevalence of cardiovascular risk factors in patients with CMI or IIH is higher than in the general population.
Materials and Methods
Among the patients with CMI or IIH treated at our department during the period 2003–2014, we identified those with history of arterial hypertension (AH), myocardial infarction (MI), angina pectoris (AP), or diabetes mellitus (DM). For comparison with a control population, we retrieved information about the prevalence of AH, MI, AP, and DM among participants of the North-Trøndelag Health Study 3 (HUNT3).
Results
Data from 48 CMI and 52 IIH cases were available. Compared to data from the 42,461 individuals participating in the HUNT3, we found increased prevalence of DM in male CMI as well as female IIH cases, and of AH in female IIH cases. Body mass index (BMI) was significantly increased in both female and male IIH cases. Prevalence of MI and AP in the CMI and IIH cohorts was extremely low and therefore not further studied.
Conclusions
This study provided evidence of an increased prevalence of DM in male CMI as well as female IIH cases and of AH in female IIH cases. Although requiring further exploration, these findings point to AH and
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Fric, Radek & Eide, Per Kristian
(2016).
Perioperative monitoring of pulsatile and static intracranial pressure in patients with Chiari malformation type 1 undergoing foramen magnum decompression.
Acta Neurochirurgica.
ISSN 0001-6268.
158(2),
p. 341–347.
doi:
10.1007/s00701-015-2669-0.
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Background
Patients with Chiari malformation type 1 (CMI) often present with elevated pulsatile and static intracranial pressure (ICP). The preferred treatment of CMI, foramen magnum decompression (FMD), is assumed to normalise ICP and craniospinal pressure dissociation. In order to further explore the mechanisms behind FMD, the present study investigated whether or not pulsatile and static ICP normalises immediately after FMD.
Method
The study included CMI patients undergoing FMD with perioperative ICP monitoring as a part of clinical management. The pulsatile and static ICP scores were retrieved from the department’s ICP database, and the clinical and radiological data from the patient records.
Results
Eleven patients were included in the study. During the first 3 days following FMD, mixed model analysis revealed no significant time-dependent differences of preoperatively elevated either pulsatile (mean wave amplitude, MWA; p = 0.85) and/or static (mean ICP, p = 0.90) ICP. Percentage of mean ICP >15 mmHg increased during days 2 and 3 after FMD. Two patients from the present series had to receive ventriculoperitoneal shunt after FMD in the early postoperative period.
Conclusions
The present observations suggest that anatomical restoration of cerebrospinal fluid pathways by FMD does not lead to immediate normalisation of preoperatively altered pulsatile and static ICP in patients with CMI. This finding may explain persistent symptoms during the early period after FMD.
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Fric, Radek; Lindstrøm, Erika Kristina; Ringstad, Geir; Mardal, Kent-Andre & Eide, Per Kristian
(2016).
The association between the pulse pressure gradient at the cranio-cervical junction derived from phase-contrast magnetic resonance imaging and invasively measured pulsatile intracranial pressure in symptomatic patients with Chiari malformation type 1.
Acta Neurochirurgica.
ISSN 0001-6268.
158(12),
p. 2295–2304.
doi:
10.1007/s00701-016-2979-x.
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Background
In symptomatic Chiari malformation type 1 (CMI), impaired intracranial compliance (ICC) is associated with an increased cranio-spinal pulsatile pressure gradient. Phase-contrast magnetic resonance imaging (MRI) represents a non-invasive modality for the assessment of the pulse pressure gradient at the cranio-cervical junction (CCJ). We wished to explore how the MRI-derived pulse pressure gradient (MRI-dP) compares with invasively measured pulsatile intracranial pressure (ICP) in CMI, and with healthy controls.
Methods
From phase-contrast MRI of CMI patients and healthy controls, we computed cerebrospinal fluid (CSF) flow velocities and MRI-dP at the CCJ. We assessed bidirectional flow and compared the flow between the anterior and the posterior subarachnoid space at the CCJ. We computed total intracranial volume (ICV), ventricular CSF volume (VV), and posterior cranial fossa volume (PCFV). We analyzed the static and pulsatile ICP scores from overnight monitoring in CMI patients.
Results
Five CMI patients and four healthy subjects were included. The CMI group had a significantly larger extent of tonsillar ectopia, smaller PCFV, and a smaller area of CSF in the FM. The pulsatile ICP (mean ICP wave amplitude, MWA) was abnormally increased in 4/5 CMI patients and correlated positively with MRI-dP. However, the MRI-dP as well as the CSF flow velocities did not differ significantly between CMI and healthy subjects. Moreover, bidirectional flow was observed in both CMI as well as healthy subjects, with no significant difference.
Conclusions
In symptomatic CMI patients, we found a significant association between the pulse pressure gradient at the CCJ derived from phase-contrast MRI and the pulsatile ICP (MWA) measured invasively. However, the MRI-dP was close to identical in CMI patients and healthy subjects. Moreover, the CSF flow velocities at the CCJ and the occurrence of bidirectional flow were not different in CMI patients and healthy individuals. Further studies are required to determine the diagnostic role of phase-contrast MRI in CMI patients.
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Fric, Radek & Eide, Per Kristian
(2015).
Comparison of pulsatile and static pressures within the intracranial and lumbar compartments in patients with Chiari malformation type 1: a prospective observational study.
Acta Neurochirurgica.
ISSN 0001-6268.
157(8),
p. 1411–1423.
doi:
10.1007/s00701-015-2465-x.
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Fric, Radek & Eide, Per Kristian
(2011).
The presigmoid approach for removal of tumours causing ventral compression of the brainstem. Surgical results and postoperative quality of life.
British Journal of Neurosurgery.
ISSN 0268-8697.
25(1),
p. 86–93.
doi:
10.3109/02688697.2010.525266.
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Frič, Radek; Heier, Ingvild; Züchner, Mark; Gjertsen, Øivind & Rezai, Mehran
(2024).
Cerebrospinal fluid–lymphatic fistula in a child with generalized lymphatic anomaly treated with targeted blood patch — a rare case report and review of the literature.
Child's Nervous System.
ISSN 0256-7040.
40,
p. 1301–1305.
doi:
10.1007/s00381-024-06287-x.
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Lundar, Tryggve; Due-Tønnessen, Bernt Johan; Frič, Radek & Due-Tønnessen, Paulina
(2018).
Postoperative radiotherapy for pediatric brain tumor: a lesson learned from treatment of a 5-year-old girl for posterior fossa astrocytoma (WHO1) in 1967.
Acta Neurochirurgica.
ISSN 0001-6268.
160,
p. 2065–2066.
Full text in Research Archive
View all works in NVA
Published
Mar. 20, 2025 3:42 PM
- Last modified
May 22, 2025 3:34 PM
