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In addition to surgical management, corticosteroids have proven to be beneficial in the management of acute symptoms related to CNS tumors, and have been widely used for many decades, with dexamethasone (DM) representing the most commonly used agent. However, lately published in vitro data possibly indicates a DM-induced suppression of oncogene-induced senescence (OIS) in a preclinical pediatric low-grade glioma (pLGG) model, which, alongside data associating perioperative DM treatment with reduced event-free survival in adult glioma, raises questions concerning the safety of DM treatment in pLGG. A total of 172 patients with pLGG were retrospectively analyzed concerning the impact of perioperative DM application on postoperative short- and long-term tumor growth velocity and progression-free survival (PFS). Three-dimensional volumetric analyses of sequential MRI follow-up examinations were used for assessment of tumor growth behavior. Mean follow-up period accounted for 60.1 months. Sixty-five patients (45%) were perioperatively treated with DM in commonly used doses. Five-year PFS accounted for 93% following gross-total resection (GTR) and 57% post incomplete resection (IR). Comparison of short- and long-term postoperative tumor growth rates in patients with vs without perioperative DM application showed no significant difference (short-term: 0.022 vs 0.023 cm

Purpose Despite excellent long-term overall survival rates, pediatric low-grade gliomas (pLGG) show high variety of clinical behavior regarding progress or senescence post incomplete resection (IR). This study retrospectively analyzes tumor growth velocity (TGV) of pLGG before surgery and after IR to investigate the impact of surgical extent, tumor location and molecular BRAF status on postoperative residual tumor growth behavior. Methods Of a total of 172 patients with pLGG receiving surgical treatment, 107 underwent IR (66%). Fifty-three vs 94 patients could be included in the pre- and post-operative cohort, respectively, and were observed over a mean follow-up time of 40.2 vs 60.1 months. Sequential three-dimensional MRI-based tumor volumetry of a total of 407 MRI scans was performed to calculate pre- and postoperative TGV. Results Mean preoperative TGV of 0.264 cm3/month showed significant deceleration of tumor growth to 0.085 cm3/month, 0.024 cm3/month and −0.016 cm3/month after 1st, 2nd, and 3rd IR, respectively (p 2.03 cm3 associated with a higher risk of progress post IR (sensitivity 78,6%, specificity 76.3%, AUC 0.88). Postoperative TGV of BRAF V600E-mutant LGG was significantly higher than of BRAF wild-type LGG (0.123 cm3/month vs. 0.016 cm3/month, p = 0.047). Conclusion This data suggests that extensive surgical resection may impact pediatric LGG growth kinetics post incomplete resection by inducing a significant deceleration of tumor growth. BRAF-V600E mutation may be a risk factor for higher postoperative TGV.

Advances in the treatment of pediatric congenital heart disease have increased survival rates. Despite efforts to prevent neurological injury, many patients suffer from impaired neurodevelopmental outcomes. Compromised cerebral autoregulation can increase the risk of brain injury following pediatric cardiac surgery with cardiopulmonary bypass. Monitoring autoregulation and maintaining adequate cerebral blood flow can help prevent neurological injury.Our objective was to evaluate autoregulation parameters and to define the optimal blood pressure as well as the lower and upper blood pressure limits of autoregulation.Autoregulation was monitored prospectively in 36 infants after cardiopulmonary bypass surgery for congenital heart defects between January and December 2019. Autoregulation indices were calculated by correlating invasive arterial blood pressure, cortical oxygen saturation, and relative tissue hemoglobin levels with near-infrared spectroscopy parameters.The mean patient age was 4.1 ± 2.8 months, and the mean patient weight was 5.2 ± 1.8 kg. Optimal mean arterial pressure could be identified in 88.9% of patients via the hemoglobin volume index and in 91.7% of patients via the cerebral oxygenation index, and a lower limit of autoregulation could be found in 66.7% and 63.9% of patients, respectively. No significant changes in autoregulation indices at the beginning or end of the monitoring period were observed. In 76.5% ± 11.1% and 83.8% ± 9.9% of the 8 and 16 h monitoring times, respectively, the mean blood pressure was inside the range of intact autoregulation (below in 21.5% ± 25.4% and 11.3% ± 16.5% and above in 8.7% ± 10.4% and 6.0% ± 11.0%, respectively). The mean optimal blood pressure was 57.4 ± 8.7 mmHg and 58.2 ± 7.9 mmHg and the mean lower limit of autoregulation was 48.8 ± 8.3 mmHg and 45.5 ± 6.7 mmHg when generated via the hemoglobin volume index and cerebral oxygenation index, respectively.Postoperative noninvasive autoregulation monitoring after cardiac surgery in children can be reliably and safely performed using the hemoglobin volume index and cerebral oxygenation index and provides robust data. This monitoring can be used to identify individual hemodynamic targets to optimize autoregulation, which differs from those recommended in the literature. Further evaluation of this subject is needed.

Introduction Peripheral and intraspinal schwannomas are common and clinically complex pathologies in patients with Neurofibromatosis Type 2 (NF2) and Schwannomatosis (SWNT). Functional preservation and pain relief are the major goals in treating these tumors. Methods This retrospective observational study investigates the clinical and functional outcome of 205 operated peripheral (n = 148, 72%) and intraspinal (n = 57, 28%) schwannomas in 85 patients (53 NF2, 32 SWNT) treated at our department between 2006 and 2017. Associated factors such as genetics, age, and location were evaluated. Results Persisting drug-resistant pain was the most common symptom (84%, n = 173) and indication for surgery (54%, n = 110). Improvement in pain intensity was postoperatively seen in 81%. Peripheral nerve schwannomas exhibited worse pain intensity preoperatively compared to intraspinal lesions (p = 0.017 NF2, p = 0.029 SWNT). More total resections could be achieved in 93% of SWNT vs. 82% of NF2-associated tumors, p = 0.030). NF2 patients with intraspinal lesions were more neurologically affected (p p = 0.027), and less pain (p = 0.024) in NF2-associated tumors. Mosaic NF2 patients had worse pain levels before surgery, and SWNT patients had a worse neurological function and more pain compared to non-mosaic or non-mutated cases. Conclusions Resection of peripheral and intraspinal schwannomas is an effective and low-risk treatment in both NF2 and SWNT. Patients with severe pain have a particular benefit from surgical treatment. Intraspinal lesions are associated with worse neurological function whereas peripheral lesions showed a higher pain intensity. The influence of mutations needs to be further investigated in larger cohorts.

Funder: Eberhard Karls Universität Tübingen (1020), OBJECTIVES: Impaired cerebral blood flow is a first-line reason of ischemic-hypoxic brain injury in children. The principal goal of intensive care management is to detect and prevent further cerebral blood flow deficits. This can be achieved by actively managing cerebral perfusion pressure (CPP) using input from cerebrovascular autoregulation (CAR). The main objective of the current study was to investigate CAR after cardiac arrest in children. METHODS: Nineteen consecutive children younger than 18 years after cardiopulmonary resuscitation, in whom intracranial pressure (ICP) was continuously measured, were included. Blood pressure and ICP were continuously monitored via ICM + software and actively managed using the pressure reactivity index (PRx) to achieve and maintain an optimal CPP. Outcome was scored using the extended Glasgow outcome scale (eGOS) at discharge and 6 months. RESULTS: Eight children died in hospital. At 6 months, further 4 children had an unfavorable (eGOS1-4) and 7 a favorable (eGOS5-8) outcome. Over the entire monitoring period, we found an elevated ICP (24.5 vs 7.4 mmHg), a lower CPP (50.3 vs 66.2 mmHg) and a higher PRx (0.24 vs - 0.01), indicating impaired CAR, in patients with unfavorable outcome. The dose of impaired autoregulation was significantly higher in unfavorable outcome (54.6 vs 29.3%). Analyzing only the first 72 h after cardiac arrest, ICP ≥ 10 mmHg and PRx > 0.2 correlated to unfavorable outcome. CONCLUSIONS: Significant doses of impaired CAR within 72 h after resuscitation are associated with unfavorable outcome. The inability to restore autoregulation despite active attempts to do so as well as an elevated ICP may serve as a bad prognostic sign indicating a severe initial hypoxic-ischemic brain injury.

Vestibular schwannomas (VS) usually manifest between the 5th and 8th decade of life. Most pediatric cases are associated with Neurofibromatosis type 2 and sporadic VS are rare in this age group. Few case series have been published. We report on our institutional series of sporadic VS in children. We included all cases between 2003 and 2021; 28 of 1635 patients harbored a sporadic VS and were younger than 21 years old. A retrospective review of clinical parameters and surgical data as well as outcomes was performed. All procedures were performed via a retrosigmoid approach. Preoperative imaging was assessed, and tumor volumetry was performed. Mean follow-up was 28 months, symptomatology was diverse. Most children and adolescents presented with hearing loss and tinnitus. All cases with multiple preoperative magnetic resonance imaging scans showed volumetric tumor growth between 1 and 18%/month (mean 8.9 ± 5.6%). Cystic tumor morphology and bone erosion was seen in larger tumors. Gross total resection was possible in 78% of patients and no recurrence was observed. All patients with subtotal resection showed tumor regrowth. Sporadic VS in children are rare and present with a high clinical variability. Surgical resection is the primary therapy and is feasible with favorable results comparable to the adult age group.

We reviewed our experience in managing of NF2-associated vestibular schwannoma (VS) in children and young adults regarding the effect of surgery and postoperative bevacizumab treatment. A total of 579 volumetric and hearing data sets were analyzed. The effect of surgery on tumor volume and growth rate was investigated in 46 tumors and on hearing function in 39 tumors. Long-term hearing follow-up behavior was compared with 20 non-operated ears in additional 15 patients. Sixteen operated VS were treated with bevacizumab. Mutation analysis of the NF2 gene was performed in 25 patients. Surgery significantly slowed down VS growth rate. Factors associated with a higher growth rate were increasing patient age, tumor volume, and constitutional truncating mutations. Immediately after surgery, functional hearing was maintained in 82% of ears. Deterioration of hearing was associated with initial hearing quality, larger tumor volumes, and larger resection amounts. Average hearing scores were initially better in the group of non-operated VS. Over time, hearing scores in both groups worsened with a similar dynamic. During bevacizumab treatment of residual tumors, four different patterns of growth were observed. Decompression of the internal auditory canal with various degrees of tumor resection decreases the postoperative tumor growth rates. Carefully tailored BAEP-guided surgery does not cause additional hearing deterioration. Secondary bevacizumab treatment showed heterogenous effects both regarding tumor size and hearing preservation. It seems that postoperative tumor residuals, that grow slower, behave differently to bevacizumab than reported for not-operated faster growing VS.

Purpose The hallmark of neurofibromatosis type 2 (NF2) is the presence of bilateral vestibular schwannomas (VS) which however have not yet developed or grown to large size in children and young adolescents. Therefore, early diagnosis in pediatric patients without family history of NF2 has to be made by signs and symptoms not related to VS which will be reviewed in this study. Methods A total of 70 children diagnosed for NF2 at an age of < 18 years were identified from our patient cohort. Age and symptoms, signs and pathology at symptom onset, age at NF2 diagnosis and symptoms leading to diagnosis as well as genetic findings were retrospectively reviewed. Results The average age at symptom/sign onset was 8 ± 6 (range 0–17) years and 11 ± 5 (range 1–17) years at time of diagnosis. Fifteen children had a positive family history and were diagnosed upon additional clinical symptoms. The most frequent first presenting symptom/signs were ophthalmological abnormalities (49%), followed by cutaneous features (40%), non-VS-related neurological deficits (33%), and symptoms attributable to VS (21%). VS were not only the most common symptomatic neoplasm but also the most frequent pathological evidence for the diagnosis (72%). In 42 patients with available genetic testing results, pathogenic mutations were most frequently identified (n = 27). Conclusion The presenting symptoms in NF2 children appear “unspecific” or less specific for classical NF2 compared with adult NF2 patients, posing a challenge particularly for cases without family history. In children, ophthalmological and cutaneous features should raise clinical suspicion for NF2 and referral to an NF2 specialized center is recommended.

Introduction Peripheral nerve sheath tumours in children are a rare and heterogeneous group, consisting mostly of benign tumours as well as malignant neoplasms. Especially in the paediatric population, diagnostics and indication for therapy pose relevant challenges for neurosurgeons and paediatric neurologists alike. Most paediatric cases that need surgical intervention are associated to neurofibromatosis type 1 (NF1). Methods We retrospectively reviewed all paediatric cases treated at the Department of Neurosurgery in Tübingen between 2006 and 2017 for peripheral nerve sheath tumours. We analysed clinical signs, symptoms, histology, association to an underlying phacomatosis and sensory/motor function. Results Of the 82 identified patients, the majority had NF1 (76.8%). Nine children bore a sporadic tumour without underlying phacomatosis (11%), 8 had NF2 (9.8%) and 2 schwannomatosis (2.4%), A total of 168 surgical interventions were performed, and 206 tumours were removed. Indication for surgery was in most instances significant tumour growth (45.2%) followed by pain (33.9%). New deficits led to surgery in 12.5% of interventions; malignancy was suspected in 8.3%. Histopathology revealed mostly neurofibromas (82.5%), divided into cutaneous neurofibromas (10.7%), infiltrating plexiform neurofibromas (25.7%) and peripheral nerve-born neurofibromas (46.1%). 12.1% of tumours were schwannomas, 2.9% MPNST, 1.5% ganglioneuroma (n = 3) and 1 hybrid-neurofibroma and perineurinoma each. Leading symptoms, such as pain and motor and sensory deficits, improved after 125/166 interventions (74.4%), remained unchanged following 39 interventions (23.2%) and worsened in 4 occasions (2.4%). Conclusion Surgery is safe and effective for (neurofibromatosis associated) peripheral nerve sheath tumours in the paediatric population; however, management needs a multidisciplinary setting. We propose early surgical resection in paediatric patients with peripheral nerve sheath tumours with significant growth, or pain, or motor deficit, or suspected malignancy.

Purpose Neurofibromatosis type 1 (NF1) syndrome is a common rare/orphan disease that manifests itself early in the paediatric age. It imposes a considerable burden upon patients as well as on caregivers. Decisions regarding optimal care often rely on several medical instances working together as a team. Methods The authors reviewed the literature and supplied a description of their own clinical work at the NF1 centres. Results The experience of a multidisciplinary teamwork of three NF centres was summarized in order to enhance awareness for possible multidisciplinary ways of delivery of health and health-related aspects of care to NF1 patients. Both population-focused research centres and family-focused centres were reviewed. Conclusions Chronic rare diseases that start in the paediatric age mandate long-term follow-up most often by several disciplines. NF1 syndrome is an example of a multidisciplinary centre in order to enhance the quality of care.

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.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.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.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.

BACKGROUND: Brain tumours are the most common solid tumours in childhood. Half of these tumours occur in the posterior fossa, where surgical removal is complicated by the risk of cerebellar mutism syndrome, of which postoperative speech impairment (POSI) is a cardinal symptom, in up to 25% of patients. The surgical approach to midline tumours, mostly undertaken by transvermian or telovelar routes, has been proposed to influence the risk of POSI. We aimed to investigate the risk of developing POSI, the time course of its resolution, and its association with surgical approach and other clinical factors. METHODS: In this observational prospective multicentre cohort study, we included children (aged

Qualitative, noninvasive assessment of intracranial pressure is of eminent importance in pediatric patients in many clinical situations and can reliably be performed using transorbital ultrasonographic measurement of the optic nerve sheath diameter (ONSD). MRI-based determination of ONSD can serve as an alternative if ultrasound (US) is not possible or available for various reasons, for example, in small, incompliant children. This study investigates repeatability and observer reliability of US ONSD and correlation and bias of US- versus MRI-based ONSD assessment in pediatric patients.One hundred fifty children diagnosed with tumor (n = 40), hydrocephalus (n = 42), and other cranial pathologies (n = 68) were included. Bilateral ONSD was quantified by US using a 12-MHz linear array transducer. This was compared with ONSD measured in simultaneously acquired (≤24 h) T2-weighted MRI scans of the orbit.Repeatability of individual US values and intraobserver ONSD was outstanding (Cronbach's α = 0.984 and 0.996, respectively). Overall mean values for ONSD were 5.8 ± 0.88 mm and 5.7 ± 0.89 mm for US and MRI, respectively. Correlation between US and MRI-based ONSD was strong (r = 0.976, P 0.01). Bland and Altman analysis showed a mean bias of 0.078 mm. A repeated-measures correlation (rRepeatability and reliability of US ONSD determination is excellent. In case US ONSD assessment is not possible or available, MRI scans can serve as an excellent alternative. The difference of US and MRI ONSD is minimal and insignificant, and thus, both techniques can complement each other.

OBJECTIVE Hypertonic saline (HTS) is commonly used in children to lower intracranial pressure (ICP) after severe traumatic brain injury (sTBI). While ICP and cerebral perfusion pressure (CPP) correlate moderately to TBI outcome, indices of cerebrovascular autoregulation enhance the correlation of neuromonitoring data to neurological outcome. In this study, the authors sought to investigate the effect of HTS administration on ICP, CPP, and autoregulation in pediatric patients with sTBI. METHODS Twenty-eight pediatric patients with sTBI who were intubated and sedated were included. Blood pressure and ICP were actively managed according to the autoregulation index PRx (pressure relativity index to determine and maintain an optimal CPP [CPPopt]). In cases in which ICP was continuously > 20 mm Hg despite all other measures to decrease it, an infusion of 3% HTS was administered. The monitoring data of the first 6 hours after HTS administration were analyzed. The Glasgow Outcome Scale (GOS) score at the 3-month follow-up was used as the primary outcome measure, and patients were dichotomized into favorable (GOS score 4 or 5) and unfavorable (GOS score 1–3) groups. RESULTS The mean dose of HTS was 40 ml 3% NaCl. No significant difference in ICP and PRx was seen between groups at the HTS administration. ICP was lowered significantly in all children, with the effect lasting as long as 6 hours. The lowering of ICP was significantly greater and longer in children with a favorable outcome (p < 0.001); only this group showed significant improvement of autoregulatory capacity (p = 0.048). A newly established HTS response index clearly separated the outcome groups. CONCLUSIONS HTS significantly lowered ICP in all children after sTBI. This effect was significantly greater and longer-lasting in children with a favorable outcome. Moreover, HTS administration restored disturbed autoregulation only in the favorable outcome group. This highlights the role of a “rescuable” autoregulation regarding outcome, which might be a possible indicator of injury severity. The effect of HTS on autoregulation and other possible mechanisms should be further investigated.

Paediatric ventriculomegaly without obvious signs or symptoms of raised intracranial pressure (ICP) is often interpreted as resulting from either relative brain atrophy, arrested “benign” hydrocephalus, or “successful” endoscopic third ventriculostomy (ETV). We hypothesise that the typical ICP “signature” found in symptomatic hydrocephalus can be present in asymptomatic or oligosymptomatic children, indicating pressure-compensated, but active hydrocephalus. A total of 37 children fulfilling the mentioned criteria underwent computerised ICP overnight monitoring (ONM). Fifteen children had previous hydrocephalus treatment. ICP was analysed for nocturnal dynamics of ICP, ICP amplitudes (AMP), magnitude of slow waves (SLOW), and ICP/AMP correlation index RAP. Depending on the ONM results, children were either treated or observed. The ventricular width was determined at the time of ONM and at 1-year follow-up. The recordings of 14 children (group A) were considered normal. In the 23 children with pathologic recordings (group B), all ICP values and dependent variables (AMP, SLOW) were significantly higher, except for RAP. In group B, 12 of 15 children had received a pre-treatment and 11 of 22 without previous treatment. All group B children received treatment for hydrocephalus and showed a significant reduction of frontal-occipital horn ratio at 1 year. During follow-up, a positive neurological development was seen in 74% of children of group A and 100% of group B. Ventriculomegaly in the absence of signs and symptoms of raised ICP was associated in 62% of cases to pathological ICP dynamics. In 80% of pre-treated cases, ETV or shunt failure was found. Treating children with abnormal ICP dynamics resulted in an outcome at least as favourable as in the group with normal ICP dynamics. Thus, asymptomatic ventriculomegaly in children deserves further investigation and, if associated with abnormal ICP dynamics, should be treated in order to provide a normalised intracranial physiology as basis for best possible long-term outcome.

Simple Summary Peripheral nerve sheath tumors are associated with significant morbidity. Clinical presentation, tumor location, and therapeutic strategies are variable. We aim to provide high-quality data concerning the results of interdisciplinary operative approaches for surgical resection of schwannomas. Understanding the anatomical and functional challenges of surgical interventions in the peripheral nervous system can help to enhance the outcomes of these therapies. We aim to highlight the need for interdisciplinarity and provide evidence for both excellent functional outcomes, as well as improved quality of life for patients undergoing sporadic schwannoma surgery. Abstract Most sporadic peripheral nerve sheath tumors in adults are schwannomas. These tumors usually present with significant pain but can also cause neurological deficits. Symptomatology is diverse, and successful surgical interventions demand interdisciplinarity. We retrospectively reviewed 414 patients treated between 2006 and 2017 for peripheral nerve sheath tumors. We analyzed clinical signs, symptoms, histology, and neurological function in the cohort of adult patients with schwannomas without a neurocutaneous syndrome. In 144 patients, 147 surgical interventions were performed. Mean follow-up was 3.1 years. The indication for surgery was pain (66.0%), neurological deficits (23.8%), significant tumor growth (8.8%), and suspected malignancy (1.4%). Complete tumor resection was achieved on 136/147 occasions (92.5%). The most common location of the tumors was intraspinal (49.0%), within the cervical neurovascular bundles (19.7%), and lower extremities (10.9%). Pain and neurological deficits improved significantly (p ≤ 0.003) after 131/147 interventions (89.1%). One patient had a persistent decrease in motor function after surgery. Complete resection was possible in 67% of recurrent tumors, compared to 94% of primary tumors. There was a significantly lower chance of complete resection for schwannomas of the cervical neurovascular bundle as compared to other locations. The surgical outcome of sporadic schwannoma surgery within the peripheral nervous system is very favorable in experienced peripheral nerve surgery centers. Surgery is safe and effective and needs a multidisciplinary setting. Early surgical resection in adult patients with peripheral nerve sheath tumors with significant growth, pain, neurological deficit, or suspected malignancy is thus recommended.

In children with a traumatic brain injury, the duration of autoregulation impairment correlates with the neurological outcome. This pilot study explored whether a similar relation exists in nontraumatic hypoxic–ischemic brain injury following resuscitation.

Background: Brain tumours are the most common childhood tumours. Half of them are in the posterior fossa, where surgical removal is complicated by postoperative speech impairment (POSI) in up to 25% of patients. POSI manifests within days of surgery, while improvement takes weeks or months. The surgical approach to midline tumours, mostly undertaken by transvermian or telovelar routes, has been proposed to influence the risk of POSI. We investigated the risk of developing POSI, the time course of its resolution and its association with surgical approach and other clinical factors. Methods: 426 children aged 0–17·9 years undergoing primary surgery for a posterior fossa tumour at 26 centres in nine European countries were prospectively included. Speech was classified as either mutism, reduced or habitual at two weeks, two months, and one year after surgery. Findings: POSI developed in 30% of patients: Mutism in 15% (56/378) a median 1 day after surgery (IQR, 0–2; max 10) and reduced speech in 15% (58/378). In multivariate analysis, POSI was associated with using a telovelar approach (odds ratio (OR), 1·7; 95% CI, 1·03–2·9, p

INTRODUCTION: Optic pathway gliomas (OPG) in children carry significant morbidity and therapeutic challenges. The subgroup of pre-chiasmatic gliomas manifest with exopthalmus are a subgroup where, after blindness has occurred, an intraorbital and intradural resection is a curative option. We present a two-center cohort using two different surgical approaches and describe indication, technique, and long term surgical outcome. METHODS: A retrospective analysis in both centers was performed to included patients < 18 years at diagnosis with a pre-chiasmatic intra-orbital glioma, in whom a resection from the bulb to the chiasm was performed. RESULTS: 11 patients were included. 4 had NF1. Mean age at surgery was 7.0 years. Interval between diagnosis and surgery was 1-74 (median 10) months. Two had prior chemotherapy, one radiation, one both, one prior intraorbital surgery. In all 5 progression occurred. Indications for surgery were exophthalmos, pain, tumor progression or a combination. 8 patients (Group A) underwent an extradural trans-orbital-roof approach to resect intra-orbital tumour including the optic canal part plus intradural pre-chiasmatic resection. In 3 patients (Group B) a combined supra-orbital mini-craniotomy plus orbital frame osteotomy was used for intraorbital tumour-resection, excluding the optic canal part, plus intradural pre-chiasmatic resection. GTR was achieved in 7/8 of Group A and none had a recurrence (mean-FU 42 month). One residual behind the bulbus showed progression, treated by chemotherapy. All residuals in Group B were remnants of the optic nerve within optic canal remained stable (mean FU 11.8 months). No patient had a chiasmatic functional affection or permanent oculomotor deficits. Two after prior radiotherapy developed slight enophthalmos. CONCLUSION: In these selected patients surgical resection from bulb to chiasm (± removal of optic canal tumor) is safe without long-term sequela and with excellent cosmetic result. Surgery removes immediately exophthalmos and provides an effective long-term tumor control. It should be considered therapy of choice.

Despite the favourable outcome and excellent long-term overall survival rates, pediatric LGG show vast variety of clinical behavior and limited predictability regarding progress or senescence. We comparatively analyzed the tumor growth velocity (TGV) of PLGG post subtotal resection (STR) to investigate the impact of surgery, histological subtype, tumor location and the most frequent BRAF aberrations (BRAF V600E mutation vs KIAA1549-BRAF fusion) on tumor growth rates, aiming to identify potential variables to prognosticate further progress or senescence. A total of 53 patients vs 94 patients in the pre- and postoperative cohort, respectively, could be observed over a mean follow-up time of 40.2 vs 60.1 months. Distribution of histopathological diagnosis and tumor sites showed similarity to previously published cohort studies. Comparative analysis of pre- and postoperative TGV showed a significant difference as mean preoperative TGV accounted for 0.264 cm³/mo, while postoperative TGV after 1st, 2nd and 3rd STR showed reduction to 0.085 cm³/mo, 0.024 cm³/mo and -0.016 cm³/mo, respectively (p < 0.001). Results remained significant after excluding patients who had obtained (neo)adjuvant treatment. Resection extent showed remarkable correlation with postoperative reduction of TGV (R = 0.97, P < 0.001). Comparison of postoperative TGV of BRAF V600E mutant LGG and BRAF wild-type LGG showed significant difference of means (0.123 cm³/mo and 0.016 cm³/mo, p = 0.47), consistent to previous analyses, suggesting BRAF V600E positive LGG as a high-risk subgroup. Histological type, tumor location and BRAF-KIAA1549 fusion showed no significant impact on postoperative TGV. The results suggest that surgery, beyond cytoreductive purpose, impacts PLGG kinetics post STR by inducing a significant deceleration of tumor growth. As postoperative growth velocity showed clear correlation to resection extent and residual tumor burden, surgery, as radical as possible while preserving neurological function, appears to remain the mainstay of therapy besides advancing therapeutic approaches.

The presenting symptoms of the tumor suppressor gene syndrome neurofibromatosis type 2 (NF2) are often non-specific and unrelated to the disease hallmark bilateral vestibular schwannomas (VS). However, age at onset and presenting symptoms may have predictive values for the clinical course of VS. In this retrospective single-center study, we addressed this issue by reviewing 106 patients with 194 VS. Presenting symptoms attributable to VS commonly occur in 87% of adults and 31% of children. Age at onset significantly correlates with tumor volumes at presentation (p = 0.034). In addition, age at onset significantly correlates with pure-tone average (p = 0.0001), speech discrimination scores (p = 0.001), age at beginning of hearing loss (p = 0.0001), age at deafness (p = 0.0001), and age at first surgery (p = 0.0001). Patients presenting with VS related symptoms had significantly (p &lt, 0.05) worse hearing values at presentation and after surgery. These patients also exhibited higher growth rates and tumor volumes compared to patients with non-VS related presenting symptoms, but this difference did not reach the significance level of p &lt, 0.05. Due to the late appearance of these symptoms, the time of beginning hearing loss, surgery and deafness is significantly delayed (p &lt, 0.05) compared to patients not presenting with VS. In summary, age at onset and type of presenting symptom provide excellent prognostic parameters for predicting VS- and hearing-related clinical course.

External hydrocephalus (eHC) is commonly defined as a subtype of infant “hydrocephalus” consisting of macrocepahly associated with enlarged subarachnoid space and no or mild ventriculomegaly. This status is thought to be related to impaired CSF absorption because of arachnoid villi immaturity. However, other factors like the venous system might be involved in the development of the clinical picture. All patients diagnosed with eHC received prospectively contrast-enhanced 3D MR phlebography. Venous sis abnormalities were graded depending on the number of affected sinus segments and type. External CSF space volume was quantified planimetrically. Seventeen patients with the typical clinical feature of eHC were included. In 15, venous sinus abnormalities were found. There was a significant correlation between the volume of the widened cortical subarachnoid space (CSAS) and the number of venous sinus segments affected. Conversely, ventricular volume was not correlated. These results support the hypothesis that impaired venous outflow plays a major role in external hydrocephalus development. Raised venous pressure increases intracranial pressure accelerating head growth, resulting in an enlargement of the cortical subarachnoid space. Increased venous pressure increases the capillary bed pressure and brain turgor preventing ventricular space to enlarge forcing displacement of ventricular CSF to the subarachnoid space. As a result, ventriculomegaly is rarely found. The descriptive term “external hydrocephalus” implying a primary etiology within the CSF system is misleading and this work supports the notion that venous hypertension is the leading cause of the clinical picture.

A correction to this paper has been published: https://doi.org/10.1007/s00381-021-05228-2

Objective The aim was to evaluate the potential of near infrared spectrometry (NIRS) monitoring enhanced by autoregulation parameters to detect clamp ischaemia during awake carotid endarterectomy (CEA). Methods This was a prospective, hypothesis generating, single centre observational study. Fifty-nine consecutive patients with carotid artery stenosis, of whom 15 (25%) were symptomatic, were enrolled. The patients underwent awake CEA with NIRS monitoring. Regional oxygen saturation (rSO2), relative tissue haemoglobin concentration (rTHb), and mean arterial blood pressure were captured by ICM + software (University of Cambridge Enterprise, Cambridge, UK). The cerebral oxygenation index (COx) and haemoglobin volume index (HVx) were calculated continuously. Two groups were formed depending on neurological symptoms: a symptomatic group with shunt insertion (shunt) and an asymptomatic group (no shunt). Results Eight patients (14%) became symptomatic and needed intra-operative shunting. The decrease in ipsilateral rSO2 was higher in the shunt group (13.5% vs. 5.3%) and rTHB increased on the non-operated side (+0.05 ± 0.01; p = .016). In symptomatic patients no significant change in rTHB was found during clamping, whereas in asymptomatic patients there was a bilateral increase (ipsilateral: + 0.06 [p = .022]; contralateral: + 0.06 [p = .010]). In asymptomatic patients, ipsilateral COx decreased after clamping (−0.06 ± 0.02; p = .024), indicating functional autoregulation. In symptomatic patients, ipsilateral COx increased to 0.32 (+0.19 ± 0.05; p = .048), indicating loss of autoregulation. Accordingly, pooled ipsilateral and contralateral data showed increasing HVx and COx in symptomatic patients (HVx, p Conclusion In addition to a drop in rSO2, the loss of autoregulatory capacity may be useful in identifying clinically significant clamping ischaemia during CEA under general anaesthesia and may allow optimisation of blood pressure management during awake CEA.

Hearing-preserving partial resection of neurofibromatosis type 2 (NF2) associated vestibular schwannomas (VS) is a preferred treatment strategy, particularly for children and adolescents. However, the residual tumors do grow and lead at some point to continued hearing deterioration. An adjuvant bevacizumab treatment may provide an option for slowing down this process. In this retrospective study, we reviewed tumor volume and hearing data of 16 operated VS in nine patients younger than 30 years over a period of 63 to 142 months. All these patients had one or more bevacizumab treatment periods and most of them had a non-treatment period after surgery. Four different patterns of growth were observed for the residual tumors: (1) growth in the non-treatment periods, which slowed down in the treatment periods, (2) growth slowed down in one but not in another on-period, (3) unaffected growth, (4) no or minimal growth regardless of the treatment. Neither radiological regression of tumor volume nor hearing improvement were observed in the treatment periods. Accelerated hearing deterioration was observed in several non-treatment periods, but also in some treatment periods. No straightforward correlation can be drawn between tumor growth and hearing scores. Tumor growth and worsening of hearing between two measurement points were slightly less in the treatment periods, however, the differences were not significant, because variations were large. In conclusion, our comprehensive follow-up on 16 VS in nine NF2 patients did show heterogenous effects of bevacizumab on small residual vestibular schwannomas after surgery both regarding tumor size and hearing preservation. Thus, smaller and slower growing tumor residuals seem to behave differently to bevacizumab than reported for not-operated faster growing VS.

Hearing preservation is a major goal in the treatment of neurofibromatosis type 2 (NF2) associated vestibular schwannoma (VS), particularly in children and adolescents. In this study, we retrospectively reviewed hearing and volumetry data sets of 39 operated tumors (ears) in 23 patients under the age of 25 and in a follow-up period of 21 to 167 months. Hearing data over a compatible period on 20 other tumors, which did not receive surgery due to their less aggressive nature, were included for comparison. Surgery was carried out via a retrosigmoid approach with the brainstem auditory evoked potential (BAEP) guide. Immediately after surgery, functional hearing was maintained in 82% of ears. Average hearing scores were better in the non-surgery ears. However, the hearing scores in both groups worsened gradually with a similar dynamic during the 42-month postoperative follow-up period. No accelerated impairment of hearing was evident for the operated cases. Rather, the gap between the two hearing deterioration lines tended to close at the end of the follow-up period. Our result suggested that the BAEP-guided surgery did not cause additional hearing deterioration in the long-term and seemed to slow down hearing deterioration of those tumors that were initially more aggressive.

OBJECTIVE Cerebellar mutism syndrome (CMS) is a severe neurological complication of tumour surgery in the posterior fossa in childhood. The incidence is reported between 8 and 39%, where CMS sets in within days of surgery and resolves within months, yet long-term sequelae are seen in most patients. This prospective cohort study investigates the course of CMS and the surgical cause of the syndrome. POPULATION AND METHODS We included 500 children with a tumour in the posterior fossa with planned surgery or open biopsy. Enrolment was conducted between 2014 and 2020 in 26 centres in ten European countries. Speech, neurological symptoms and surgical procedure were registered in predefined standardized forms pre-operatively and at three post-operative follow-ups within one year. PRELIMINARY RESULTS A total of 426 children underwent primary surgery and were eligible for analyses. CMS occurred in 56 patients (13.1%) one day (median; IQR: 0–2 days) after surgery and resolved within 38 days (median; IQR: 4–52 days). Another 58 patients (13.6%) had less severe speech impairment. Mutism was associated with lower age (OR: 0.91 [95%CI: 0.85;0.98, p=0.014]), medulloblastoma (OR: 2.5 [95%CI: 1.4;4.7, p=0.0036]) and ATRT (OR: 12.9 [95%CI: 3.4;51.9, p=0.00018]) and tumour location in the fourth ventricle (OR: 4.0 [95%CI: 2.3;7.2, p CONCLUSION CMS is a common complication predominantly seen in younger children after tumour surgery for a medulloblastoma or ATRT in the fourth ventricle. The incidence is not related to the surgical access in this study population.

The classical dura opening for midline posterior fossa tumors in and around the 4th ventricle and the craniocervical junction is a Y-shaped incision. Several potential problems are associated with this technique. We used a technical variant, the U-shaped durotomy, previously described by Rhoton, offering several advantages. We report on the surgical results of the technique in a consecutive series of posterior fossa cases in children and adolescents. In all midline posterior fossa approaches, a U-shaped dural incision is standard in our institution. All cases were retrospectively analyzed regarding hydrocephalus, placement of EVD or lumbar drain, need for ETV or shunting during follow-up, and frequency of duraplasty, of pseudomeningocele, of primary watertight dural closure, of CSF leakage, and of venous sinus hemorrhage at opening. Fifty pediatric patients were included. In all easy occipital sinus, control was achieved and no additional dural retraction for tumor exposure required. In 49/50 patients, a primary watertight dura closure without duraplasty was achieved, also in re-do cases with previous U-shaped opening. One patient received a small periostium graft after having had a duraplasty following Y-shaped opening beforehand. No CSF fistula ever occurred and no pseudomeningocele was detected in any follow-up MRI. The U-shaped durotomy for dorsal midline approach to the 4th ventricle and craniocervical junction provides wide exposure to all tumors and allows for primary and watertight dura closure. Compared to published results and complications of classic Y-shaped dural opening, this method of durotomy and closure seems most advantageous.