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.

Spontaneous intracranial hypotension may result in debilitating postural headaches and severe neurological symptoms due to secondary cerebellar sagging. The most common cause is the cerebrospinal fluid (CSF) leak within the spinal canal. Although previously reported in only a few cases, also paraspinal lymphatic malformations causing vertebral bone destruction may occasionally result in CSF leak to these pathological formations. Here, we present a case of a 9-year-old girl with generalized lymphatic anomaly (GLA) presenting with severe postural headache. Radiological imaging revealed a typical feature of cerebellar sagging. Myelography localized the CSF leakage into vertebral bodies of C7 and Th1, which both were partly involved in pathological paravertebral masses of known lymphatic anomaly, and from there along the right C8 nerve root sleeve into the anomaly. As the C8-nerve root could not be ligated due to the risk of significant neurological injury, we attempted image-guided targeted percutaneous epidural placement of a blood patch directly into the foramen at the affected level. The procedure resulted in obliteration of the fistula and regression of cerebellar sagging, with significant relief of symptoms. Although it is an extremely rare coincidence, patients with paraspinal lymphatic malformations may develop intraspinal CSF leak into these pathological formations. The present case report suggests that besides a direct surgical obliteration of the fistula and sacrificing the nerve root, a targeted percutaneous epidural blood patch may be a possible alternative in the case of a functionally important nerve root.

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.

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.

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.

Left-handedness should not be overrated as a risk factor for postoperative speech impairment in children after posterior fossa tumour surgery: a prospective European multicentre study.

PURPOSE: Cerebellar mutism syndrome (CMS) is a severe neurological complication of posterior fossa tumour surgery in children, and postoperative speech impairment (POSI) is the main component. Left-handedness was previously suggested as a strong risk factor for POSI. The aim of this study was to investigate the relationship between handedness and the risk of POSI. METHODS: We prospectively included children (aged < 18 years) undergoing surgery for posterior fossa tumours in 26 European centres. Handedness was assessed pre-operatively and postoperative speech status was categorised as either POSI (mutism or reduced speech) or habitual speech, based on the postoperative clinical assessment. Logistic regression was used in the risk factor analysis of POSI as a dichotomous outcome. RESULTS: Of the 500 children included, 37 (7%) were excluded from the present analysis due to enrolment at a reoperation; another 213 (43%) due to missing data about surgery (n = 37) and/or handedness (n = 146) and/or postoperative speech status (n = 53). Out of the remaining 250 (50%) patients, 20 (8%) were left-handed and 230 (92%) were right-handed. POSI was observed equally frequently regardless of handedness (5/20 [25%] in left-handed, 61/230 [27%] in right-handed, OR: 1.08 [95% CI: 0.40-3.44], p = 0.882), also when adjusted for tumour histology, location and age. CONCLUSION: We found no difference in the risk of POSI associated with handedness. Our data do not support the hypothesis that handedness should be of clinical relevance in the risk assessment of CMS.

[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.

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.

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.

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.

Chiari type 1-a malformation or a syndrome? A critical review.

OBJECTIVE: As the understanding of pathophysiology behind Chiari malformation still is limited, the treatment of Chiari malformation type 1 remains rather empirical. This may result in suboptimal treatment strategy and outcome in many cases. In this review, we critically address whether the condition known today as Chiari malformation type I should rather be denoted Chiari syndrome. METHODS: The current knowledge of Chiari malformation type 1 is summarized from the historical, etymological, genetic, clinical, and in particular pathophysiological perspectives. RESULTS: There are several lines of evidence that Chiari malformation type 1 represents a condition significantly different from types 2 to 4. Unlike the other types, the type 1 should rather be considered a syndrome, thus supporting the reasons to reappraise the traditional classification of Chiari malformations. CONCLUSION: We propose that Chiari malformation type 1 should rather be denoted Chiari syndrome, while the notation malformation is maintained for types 2-4.

A recurrent de novo missense pathogenic variant in SMARCB1 causes severe intellectual disability and choroid plexus hyperplasia with resultant hydrocephalus.

PURPOSE: SMARCB1 encodes a subunit of the SWI/SNF complex involved in chromatin remodeling. Pathogenic variants (PV) in this gene can give rise to three conditions. Heterozygous loss-of-function germline PV cause rhabdoid tumor predisposition syndrome and schwannomatosis. Missense PV and small in-frame deletions in exons 8 and 9 result in Coffin-Siris syndrome, which is characterized by intellectual disability (ID), coarse facial features, and fifth digit anomalies. METHODS: By a gene matching approach, individuals with a similar SMARCB1 PV were identified. Informed consent was obtained and patient data were collected to further establish genotype-phenotype relationship. RESULTS: A recurrent de novo missense PV (c.110G>A;p.Arg37His) in exon 2 of SMARCB1, encoding the DNA-binding domain, was identified in four individuals from different genetic centers. They shared a distinct phenotype consisting of profound ID and hydrocephalus due to choroid plexus hyperplasia. Other shared features include severe neonatal feeding difficulties; congenital heart, kidney, and eye anomalies; obstructive sleep apnea; and anemia. CONCLUSION: The p.Arg37His PV in the DNA-binding domain of SMARCB1 causes a distinctive syndrome, likely through a gain-of-function or dominant-negative effect, which is characterized by severe ID and hydrocephalus resulting from choroid plexus hyperplasia. This report broadens the phenotypic spectrum associated with PV in SMARCB1.

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.

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.

Chiari malformation type 1 ­ diagnosis and treatment. / Chiari-malformasjon type 1 ­ diagnostikk og behandling.

Chiari malformation denotes a pathological caudal ectopy of the cerebellar tonsils below the level of the foramen magnum. Several types of the condition exist, of which Type 1 is the most common. It often results in few if any symptoms, and in many cases is detected as an incidental finding when an MRI is performed. Symptoms such as headache, dizziness or nausea may be related to narrowing of the foramen magnum due to blocked circulation of spinal fluid. Surgical treatment must be considered in symptomatic cases.

Neurosurgical treatment of gangliogliomas in children and adolescents: long-term follow-up of a single-institution series of 32 patients.

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.

Outcome for children treated for medulloblastoma and supratentorial primitive neuroectodermal tumor (CNS-PNET) - a retrospective analysis spanning 40 years of treatment.

BACKGROUND: Medulloblastoma (MB) and supratentorial primitive neuroectodermal tumor of the central nervous system (CNS-PNET) are among the most common pediatric brain tumors. The diagnosis, treatment, and outcome of MB/CNS-PNET patients treated during the last four decades at Oslo University Hospital (OUH) are described. MATERIAL AND METHODS: All patients younger than 20 years of age diagnosed and treated for MB/CNS-PNET at OUH between 1 January 1974 and 31 December 2013 were identified. RESULTS: We found 175 patients. In 13 of them, the diagnosis was changed upon histopathological review and in 4 patients part of the treatment was administered at other hospitals. Thus, 158 patients were included for further analysis. Eight patients did not receive adjuvant therapy because of a dismal clinical condition. The overall 5-year survival rate for MB and CNS-PNET was 54%, for MB 57%, and for CNS-PNET 41%. Gross total resection (GTR) was achieved in 118 patients and 5-year overall survival for patients with GTR versus those with non-GTR differed significantly with 64% versus 22%. Cytological examination of the cerebrospinal fluid was performed in 52 patients. A total of 126 patients received radiotherapy as part of the primary treatment and 24 did not due to young age. Median time from surgery to start of radiotherapy was 33 days. Duration of radiotherapy was more than 48 days in 22% of patients. At the time of analysis, 63 patients were alive and disease-free, one alive with disease, and 94 patients were deceased; 84 of these due to MB/CNS-PNET and 10 due to supposed late effects from the treatment. CONCLUSIONS: Survival was comparable to data from other population-based studies. The importance of GTR for survival was corroborated. Reporting real-world data remains crucial to know the true outcome of patients treated outside clinical trials.

Long-term follow-up after endoscopic trans-sphenoidal surgery or initial observation in clivus chordomas.

BACKGROUND: Resection of clivus chordomas through extensive skull base approaches is associated with high mortality and morbidity even in experienced hands. We report our experience with endoscopic trans-sphenoidal surgery, or a "wait-and-scan" strategy in selected patients. METHOD: Ten patients were diagnosed with clivus chordomas during an 8-year period. Six patients underwent primary treatment with endoscopic trans-sphenoidal surgery, followed by adjuvant proton-beam therapy in three of these patients. Four patients with minor symptoms were followed-up untreated. Mean follow-up was 91 months. RESULTS: Of the six patients operated on, total or gross total resection was achieved in four, partial resection in one and biopsy was taken in one. Preoperative cranial neuropathies resolved in three out of five patients, and no new cranial nerve palsies were encountered. Postoperative cerebrospinal fluid leak occurred in one patient. Four patients were initially followed-up without any treatment, and three of these have remained stable without tumour progression for a mean of 94 months. Due to a slow, though progressive growth of tumour, one patient was operated on after 80 months of initial observation. CONCLUSIONS: The natural course of clivus chordomas has yet to be defined. The endoscopic trans-sphenoidal approach is a valid, minimally invasive alternative for the treatment of clival chordomas, and in selected patients a "wait and scan" strategy can be considered. Our long-term results show low mortality and good functional outcome. An endonasal endoscopic trans-sphenoidal approach should be a principal part of the armamentarium of surgeons treating clivus chordomas.

Perioperative monitoring of pulsatile and static intracranial pressure in patients with Chiari malformation type 1 undergoing foramen magnum decompression.

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.

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.

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.