Indirect functional connectivity does not predict overall survival in glioblastoma.

BACKGROUND: Lesion network mapping (LNM) is a popular framework to assess clinical syndromes following brain injury. The classical approach involves embedding lesions from patients into a normative functional connectome and using the corresponding functional maps as proxies for disconnections. However, previous studies indicated limited predictive power of this approach in behavioral deficits. We hypothesized similarly low predictiveness for overall survival (OS) in glioblastoma (GBM). METHODS: A retrospective dataset of patients with GBM was included (n = 99). Lesion masks were registered in the normative space to compute disconnectivity maps. The brain functional normative connectome consisted in data from 173 healthy subjects obtained from the Human Connectome Project. A modified version of the LNM was then applied to core regions of GBM masks. Linear regression, classification, and principal component (PCA) analyses were conducted to explore the relationship between disconnectivity and OS. OS was considered both as continuous and categorical (low, intermediate, and high survival) variable. RESULTS: The results revealed no significant associations between OS and network disconnection strength when analyzed at both voxel-wise and classification levels. Moreover, patients stratified into different OS groups did not exhibit significant differences in network connectivity patterns. The spatial similarity among the first PCA of network maps for each OS group suggested a lack of distinctive network patterns associated with survival duration. CONCLUSIONS: Compared with indirect structural measures, functional indirect mapping does not provide significant predictive power for OS in patients with GBM. These findings are consistent with previous research that demonstrated the limitations of indirect functional measures in predicting clinical outcomes, underscoring the need for more comprehensive methodologies and a deeper understanding of the factors influencing clinical outcomes in this challenging disease.

HER2 expression and genOmic characterization of rESected brain metastases from colorectal cancer: the HEROES study.

BACKGROUND: Little is known about prognostic factors of brain metastases (BM) from colorectal cancer (CRC). HER2 amplification/overexpression (HER2+) was previously described; its impact on prognosis remains uncertain. METHODS: In the translational study HEROES, extensive molecular analysis was performed on primary CRC (prCRC) and their matched resected BM by means of NGS comprehensive genomic profiling and HER2 status as assessed by immunohistochemical/ in situ hybridization. Count of tumour-infiltrating lymphocytes (TILs) was also performed. PRIMARY OBJECTIVE: to describe the molecular landscape of paired BM/prCRC. SECONDARY OBJECTIVES: to search for new prognostic biomarkers of outcome after BM resection: intracranial-only Progression-Free Survival (BM-iPFS), Progression-Free Survival (BM-PFS), and Overall Survival (BM-OS). RESULTS: Out of 22 patients having paired samples of prCRC and BM, HER2+ was found on 4 (18%) BM, 3 (75%) of which also HER2+ in matched prCRC. Lower tumour mutation burden (HR 3.08; 95%CI 1.06-8.93; p = 0.0386) and HER2-negative BM (HER2neg) (HR 7.75;95%CI 1.97-30.40; p = 0.0033) were associated with longer BM-iPFS; HER2neg BM (HR 3.44; 95%CI 1.03-11.53; p = 0.0449) and KRASmut BM (HR 0.31; 95%CI 0.12-0.80; p = 0.0153) conferred longer BM-PFS. Longer BM-OS was found in pts with TILs-enriched (≥1.6/HPF) BM (HR 0.11; 95%CI0.01-0.91; p = 0.0403). CONCLUSIONS: This study shows HER2+ enrichment in both BM and their prCRC. TILs-enriched BM conferred better BM-OS.

Impressive response to dabrafenib and trametinib plus silybin in a heavily pretreated IDH wild-type glioblastoma patient with BRAFV600E -mutant and SOX2 amplification.

Isocitrate dehydrogenase wild-type glioblastoma is the most frequent primary brain tumor in adult patients and its prognosis is still dismal with a median survival of about 1 year. BRAF V600E mutation, an important target for personalized therapy, has been identified in about 3% of these patients, but few data are available from prospective studies on the role of anti-BRAF drugs in adult glioblastoma patients. Moreover, SOX2 gene amplification and overexpression can represent an important mechanism of resistance to BRAF inhibitors by STAT3 gene activation. We present the case of a heavily pretreated 42-year-old man with BRAF V600E mutant and SOX2 amplification glioblastoma having a radiologic and metabolic [analyzed by a brain 18F-fluoro-ethyl-tyrosine([18F]FET) PET/MRI] complete response to the combination therapy with dabrafenib plus trametinib and silybin, a potent STAT3 inhibitor. The patient is currently undergoing treatment after a total of 24 months of continuation therapy with a good safety profile. In conclusion, we showed a promising activity of the personalized treatment of BRAF and MEK inhibitors in patient with BRAF V600E mutant glioblastoma; silybin can play an important role in decreasing drug resistance during BRAF inhibitor therapy, especially in patients with SOX2 amplification.

Association between thyroid function and regorafenib efficacy in patients with relapsed wild-type IDH glioblastoma: a large multicenter study.

PURPOSE: Regorafenib demonstrated encouraging results in recurrent glioblastoma patients. Some studies showed that changes in circulating thyroid hormones (fT3, fT4, fT3/fT4 ratio) can be considered as prognostic factors in patients with various types of tumors. We designed this study to investigate the relationship between baseline thyroid variables and outcome in IDH-wild type GBM patients who were treated with regorafenib. METHODS: This multicenter retrospective study included recurrent IDH-wild-type glioblastoma patients treated with regorafenib. Only patients with baseline thyroid function values (TSH, fT3, fT4, fT3/fT4 ratio) available were evaluated. RANO criteria were used to analyze neuroradiological response. Survival curves were estimated using the Kaplan-Meier method. The relationships between baseline thyroid variables (TSH, fT3, fT4, fT3/fT4) and survival (PFS, OS) were investigated with Cox regression models. RESULTS: From November 2015 to April 2022, 134 recurrent IDH-wildtype GBM patients were treated with regorafenib and 128 of these had information on baseline thyroid function value. Median follow-up was 8 months (IQR 4.7-14.0). Objective Response Rate was 9% and Disease Control Rate was 40.9%. Median PFS was 2.7 months (95%CI 2.2-3.6) and median OS was 10.0 months (95%CI 7.0-13.0). Lower baseline TSH value in the blood was correlated with a higher rate of disease progression to regorafenib (p = 0.04). Multivariable analyses suggested a non-linear relationship between PFS (p = 0.01) and OS (p = 0.03) with baseline fT3/fT4 ratio. CONCLUSION: In recurrent wild-type IDH glioblastoma patients, baseline fT3/fT4 ratio showed a non-linear relationship with survival, with different impacts across the spectrum of fT3/fT4 ratio. Moreover, baseline TSH may be a predictor of regorafenib activity.

Aesthetic transaxillary subpectoral placement of vagus nerve stimulator in children and young adults: A technical note.

INTRODUCTION: Vagus nerve stimulation (VNS) is a neuromodulation therapy for drug-resistant epilepsy (DRE), refractory status epilepticus, and treatment-resistant depression. The lead is tunneled into the subcutaneous space and connected to the generator, which is usually implanted in a subcutaneous pocket below the clavicle. Surgical complications in the chest region include skin breakdown or infection. An alternative approach is to perform a subclavear subpectoral implantation. In our surgical series, we report a new aesthetic implantation method for VNS generators in children and young patients: the transaxillary subpectoral placement. MATERIALS AND METHODS: From May 2021 to May 2023, 10 vagus nerve stimulation generators were placed subpectorally with a transaxillary approach by the authors. We considered operative time, surgical complications such as blood loss, infections, device migration, pain, and adverse events at follow-up. RESULTS: In this surgical series, we reviewed all cases of subpectoral implantation of VNS generators in children and young adults at our institution in the last 2 years. All patients were treated with subpectoral Sentiva 1000 (Livanova PLC) insertion with axillary access by a neurosurgeon and a pediatric surgeon. The operative time was slightly longer compared to the traditional subcutaneous implant. All generators reported impedances within the optimal range. Blood loss was not significant and no other perioperative complications were reported. Patients and families were highly satisfied with the outcomes in terms of comfort and aesthetic results after surgery and at the last follow-up. No cases of infection occurred, and no malfunctions or displacements of the generator were registered at clinical follow-up. CONCLUSION: The transaxillary subpectoral placement of theVNS generator is an aesthetic and anatomic approach, which provides several benefits to children and young adults.

Complications and mortality of Cushing's disease: report on data collected over a 20-year period at a referral centre.

CONTEXT: Cushing's disease (CD) is rare condition burdened by several systemic complications correlated to higher mortality rates. The primary goal of clinicians is to achieve remission, but it is unclear if treatment can also increase life expectancy. AIM: To assess the prevalence of cortisol-related complications and mortality in a large cohort of CD patients attending a single referral centre. MATERIALS AND METHODS: The clinical charts of CD patients attending a referral hospital between 2001 and 2021 were reviewed. RESULTS: 126 CD patients (median age at diagnosis 39 years) were included. At the last examination, 78/126 (61.9%) of the patients were in remission regardless of previous treatment strategies. Patients in remission showed a significant improvement in all the cardiovascular (CV) comorbidities (p < 0.05). The CV events were more frequent in older patients (p = 0.003), smokers and persistent CD groups (p < 0.05). Most of the thromboembolic (TE) and infective events occurred during active stages of the disease. The CV events were the most frequent cause of death. The standardized mortality ratio (SMR) resulted increased in persistent cases at the last follow-up (SMR 4.99, 95%CI [2.15; 9.83], p < 0.001) whilst it was not higher in those in remission (SMR 1.66, 95%CI [0.34; 4.85], p = 0.543) regardless of the timing or number of treatments carried out. A younger age at diagnosis (p = 0.005), a microadenoma (p = 0.002), and remission status at the last follow-up (p = 0.027) all increased survival. Furthermore, an elevated number of comorbidities, in particular arterial hypertension, increased mortality rates. CONCLUSIONS: Patients with active CD presented a poor survival outcome. Remission restored the patients' life expectancy regardless of the timing or the types of treatments used to achieve it. Persistent CD-related comorbidities remained major risk factors.

Acute hydrocephalus following post-traumatic peri-mesencephalic subarachnoid hemorrhage: an uncommon and potentially fatal event in children.

PURPOSE: In pediatric, head trauma acute hydrocephalus is an uncommon but possible complication. Association with a subarachnoid hemorrhage is poorly described. METHODS: We described a case of an 8-year-old girl with acute hydrocephalus secondary to peri-mesencephalic subarachnoid hemorrhage after mild head trauma resolved with external ventricular drainage. Furthermore, we have conducted a review of the literature about this complication in pediatric head trauma. DISCUSSION AND CONCLUSION: Acute hydrocephalus related to post-traumatic peri-mesencephalic subarachnoid hemorrhage (tSAH) is an unknown entity in pediatric head trauma. According to our experience, traumatic peri-mesencephalic SAH should be under close clinical monitoring to identify post-traumatic hydrocephalus (PTH), a potentially fatal complication in pediatric mild head trauma.

Acquired Chiari type I malformation: a late and misunderstood supratentorial over-drainage complication.

PURPOSE: Acquired Chiari I malformation is an uncommon but possible late complication of supratentorial shunting in children. This condition can be caused by an abnormal thickening of the cranial vault and consequent reduction of the posterior cranial fossa (PCF) volume especially in children with already a small PCF volume. The management of Acquired Chiari I malformation is very challenging, and several options have been proposed for this condition. These are aimed to expand the PCF volume both through decompression and PCF remodeling in order to relieve symptoms of acquired Chiari I malformation. A cranial vault remodeling or a standard Chiari decompression is two proposed techniques aimed to expand the PCF volume thus relieving symptoms . METHODS: We describe the case of a 16-year-old girl undergone surgical removal of sellar-suprasellar glioneuronal tumor and ventriculo-peritoneal shunting, who developed an acquired symptomatic Chiari type I malformation some years after ventricular-peritoneal shunting. For this condition, she underwent successful standard Chiari decompression with C0-C1 craniectomy and duroplasty. RESULTS: We retrospectively analyzed MRI and CT scan performed during follow-up, in order to evaluate the volume of the posterior cranial fossa and to measure the variation of skull thickness at different periods. MRI and CT scan analysis showed a progressive thickening of the calvaria, in particular of the occipital bone, leading to a progressive reduction of PCF volume with the establishment of acquired Chiari type I malformation. In this case, standard C0-C1 Chiari decompression was effective in restoring PCF volume and relieving symptoms. CONCLUSION: Acquired Chiari I malformation due to chronic overhunting could be a severe and late complication in patient undergone supratentorial shunting. These patients require careful clinical and radiological follow-up to avoid over-drainage. According to our analysis, a careful selection of pediatric patients for supratentorial shunting should be made according to pre-operative PCF volume in order to foresee higher odds of possible late complications from over-drainage.

Vagus Nerve Stimulation in Treatment-Resistant Depression: A Case Series of Long-Term Follow-up.

OBJECTIVES: Vagus nerve stimulation (VNS) has been shown to be effective for treatment-resistant depression (TRD). However, long-term (>5 years) studies on the efficacy and tolerability of this treatment have been lacking. Here, we report a long-term clinical follow-up of 5 patients with severe and long-standing TRD, who received a VNS implant. METHODS: Of the initial 6 patients with TRD implanted with VNS at our center, 5 of them were followed for 6 to 12 years after implantation. Primary efficacy outcomes were clinical response and improved functioning at follow-up visits. The primary safety outcome was all-cause discontinuation, and the secondary safety outcomes were the number and the severity of adverse events. RESULTS: The VNS implant was associated with a sustained response (>10 years) in terms of clinical response and social, occupational, and psychological functioning in 3 patients. Two patients dropped out after 6 and 7 years of treatment, respectively. Vagus nerve stimulation was well tolerated by all patients, who reported only mild adverse effects. One patient, who discontinued concomitant drug treatment, had a hypomanic episode in the 10th year of treatment. The parameters of the VNS device were fine-tuned when life stressors or symptom exacerbation occurred. CONCLUSIONS: Our case series showed that VNS can have long-term and durable effectiveness in patients with severe multiepisode chronic depression, and this could be associated with its neuroplastic effects in the hippocampus. In light of good general tolerability, our findings support VNS as a viable treatment option for TRD.

The Methylation Analysis of the Glucose-Dependent Insulinotropic Polypeptide Receptor (GIPR) Locus in GH-Secreting Pituitary Adenomas.

The glucose-dependent insulinotropic polypeptide receptor (GIPR) is aberrantly expressed in about one-third of GH-secreting pituitary adenomas (GH-PAs) and has been associated with a paradoxical increase of GH after a glucose load. The reason for such an overexpression has not yet been clarified. In this work, we aimed to evaluate whether locus-specific changes in DNA methylation patterns could contribute to this phenomenon. By cloning bisulfite-sequencing PCR, we compared the methylation pattern of the GIPR locus in GIPR-positive (GIPR+) and GIPR-negative (GIPR-) GH-PAs. Then, to assess the correlation between Gipr expression and locus methylation, we induced global DNA methylation changes by treating the lactosomatotroph GH3 cells with 5-aza-2'-deoxycytidine. Differences in methylation levels were observed between GIPR+ and GIPR- GH-PAs, both within the promoter (31.9% vs. 68.2%, p < 0.05) and at two gene body regions (GB_1 20.7% vs. 9.1%; GB_2 51.2% vs. 65.8%, p < 0.05). GH3 cells treated with 5-aza-2'-deoxycytidine showed a ~75% reduction in Gipr steady-state level, possibly associated with the observed decrease in CpGs methylation. These results indicate that epigenetic regulation affects GIPR expression in GH-PAs, even though this possibly represents only a part of a much more complex regulatory mechanism.

Cochlear implant in vestibular schwannomas: long-term outcomes and critical analysis of indications.

PURPOSE: To describe our institutional experience in cochlear implantation after vestibular schwannoma (VS) resection, and compare the audiological outcomes between sporadic and neurofibromatosis type 2 (NF2) VS sub-cohorts of patients, and in relation to preoperative contralateral hearing. METHODS: Seventeen patients (8 sporadic and 9 NF2-associated VSs) who had undergone VS resection and cochlear implant (CI) were analyzed retrospectively. Audiological outcomes at 24 months were correlated with preoperative clinical variables. The results according to VS type (sporadic vs. NF2-associated) and contralateral hearing (impaired vs. normal) were compared. RESULTS: Fourteen CIs were actively used by the patients (77.8%). Twenty-four months after CI activation, the median postoperative PTA (pure tone average) was 45.6 dB nHL and a measurable WRS (Word Recognition Score) was achieved by 44.4% of patients (median WRS = 40%). The median postoperative PTA in the implanted ear resulted better in the group with an impaired contralateral hearing (36.3 dB nHL vs. 78.8 dB nHL, p = 0.019). Good preoperative contralateral hearing status (A-B classes of AAO-HNS) was a negative prognostic factor for CI performance on open-set discrimination (OR = 28.0, 95% CI 2.07-379.25, p = 0.012). CONCLUSIONS: CI is a viable rehabilitative option for patients with sporadic or NF2-associated VS. A good contralateral hearing adversely affects CI outcome and should be taken into consideration for patients' selection and rehabilitation programs.

Rule Perseveration during Task-Switching in Brain Tumor: A Severe Form of Task-Setting Impairment.

It has been proposed that at least two distinct processes are engaged during task-switching: reconfiguration of the currently relevant task-set and interference resolution arising from the competing task-set. Whereas in healthy individuals the two are difficult to disentangle, their disruption is thought to cause different impairments in brain-damaged patients. Yet, the observed deficits are inconsistent across studies and do not allow drawing conclusions regarding their independence. Forty-one brain tumor patients were tested on a task-switching paradigm. We compared their performance between switch and repeat trials (switch cost) to assess rule reconfiguration, and between trials requiring the same response (congruent) and a different response for the two tasks (incongruent) to assess interference control. In line with previous studies, we found the greatest proportion of errors on incongruent trials, suggesting an interference control impairment. However, a closer look at the distribution of errors between two task rules revealed a rule perseveration impairment: Patients with high error rate on incongruent trials often applied only one task rule throughout the task and less frequently switched to the alternative one. Multivariate lesion-symptom mapping analysis unveiled the relationship between lesions localized in left orbitofrontal and posterior subcortical regions and perseveration scores, measured as absolute difference in accuracy between two task rules. This finding points to a more severe task-setting impairment, not reflected as a mere switching deficit, but instead as a difficulty in creating multiple stable task representations, in line with recent accounts of OFC functions suggesting its critical role in representing task states.

The burden of percutaneous vertebroplasty: an epidemiological nationwide study in Italy from 2009 to 2015.

PURPOSE: Percutaneous vertebroplasty (PV) is a minimally invasive technique requiring the injection of polymethylmethacrylate cement into a collapsed or weakened vertebral body to stabilize the fracture. The present study aims to determine the trends in PV procedures over the recent years. The longitudinal analysis of national registers may help to understand the yearly trends and the economic burden of PV. The evaluation of the yearly national costs of this procedure is essential to surgeons, policymaker, hospital administrator and the healthcare system. Moreover, to observe possible variation in the trend of hospitalization between countries, the data of the present study were compared to the US population. METHODS: Data of this study were collected from the National Hospital Discharge Reports reported at the Italian Ministry of Health regarding the years of this paper (2009-2015). The yearly number of hospital admission for PV, sex, age, days of hospitalization and primary diagnoses in the whole Italian population were calculated. RESULTS: 31,887 vertebroplasties were performed in Italy, with an incidence of 8.8 procedures for every 100,000 inhabitants. Females represented the majority of patients undergoing PV. The median length of hospital stay was 4.15 days. The mean hospital reimbursement was 4,629€ for each PV hospitalization. CONCLUSION: The burden of vertebral fracture is relevant in the Italian population, and PV constitutes a rapid and effective treatment. Compared to other countries, the costs of PV in Italy are relatively lower; however, it is important to define the incidence of this procedure to understand the economic trend of PV.

Operative Procedure in a Suprasellar Paediatric Lesion of the Optic Chiasm with Hydrocephalus Caused by a Papillary Glioneuronal Tumour.

INTRODUCTION: Paediatric tumours in the sellar and parasellar regions present clinical and surgical challenges due to anatomical position and behaviour. We illustrate a rare case which caused obstructive hydrocephalus. CASE PRESENTATION: The study included a 14-year-old girl with a glioneuronal tumour (40 mm) originating from the optic chiasm, obliterating the aqueduct, with consequent triventricular hydrocephalus. The patient underwent extended endoscopic endonasal surgery and repair of the skull-base deficiency using a multi-layer technique with fascia lata. The 12-month follow-up showed no complications or recurrences, with recovery in visual acuity. CONCLUSION: The immediate placement of external ventricular drainage, in combination with an extended trans-sphenoidal approach, is a safe and feasible option to treat suprasellar paediatric lesions with hydrocephalus.

Rapid disease progression in patient with mismatch-repair deficiency pituitary ACTH-secreting adenoma treated with checkpoint inhibitor pembrolizumab.

Secreting pituitary adenomas are tumors for which few treatment options are available, including surgical treatment and management of hormonal imbalance due to altered pituitary secretion. In case of inoperable relapse, radiotherapy or chemotherapeutic treatment can be considered; the effectiveness of these treatments, however, remains limited. In the immunotherapy era, it is necessary to select patients who can benefit from immunotherapeutic treatment. Mismatch repair deficiency is strongly associated with responsiveness to anti-PD-1 in other cancers and can be detected using immunohistochemistry for MLH1, MSH2, MHS6, and PMS2. In this case report, we report a case of rapid disease progression to pembrolizumab in a patient with a MMRd pituitary adrenocorticotropic hormone (ACTH)-secreting adenoma. For the best of our knowledge, we described for the first time, a poor efficacy of pembrolizumab in a patient with ACTH-secreting pituitary adenoma having mismatch repair deficiency probably caused by high levels of cortisol in this patient. Prospective study should be performed to assess the activity of immune checkpoint inhibitor alone or in association with temozolomide in this subsetting of pituitary adenomas.

Ultrasound-guided percutaneous brachiocephalic vein cannulation for ventriculoatrial shunt placement in a child.

OBJECTIVE: As far as the ventriculoatrial shunt placement in children is concerned, the percutaneous approach to the internal jugular vein under ultrasonographic control has been hitherto strongly recommended. Unfortunately, children still represent a challenge, having them peculiar characteristics for which the internal jugular vein cannulation shows some disadvantages. METHODS: In this manuscript, we describe a percutaneous placement of ventriculoatrial shunt via right brachiocephalic vein under intraoperative ultrasonographic control. CONCLUSIONS: Brachiocephalic vein cannulation in surgery provides notable advantages in paediatric population and it may be considered as the first choice in younger children.

Ultrasound-guided percutaneous ventriculopleural shunt placement: a minimally invasive technique.

OBJECTIVE: Ventriculopleural shunt is still considered a third-line option for CSF diversion, when both peritoneal and atrial cavity are contraindicated. Different approaches have been used and in modern surgery, lesser invasive techniques are predominant. The goal of this manuscript is to present a minimally invasive placement of a pleural catheter. METHODS: We describe a minimally invasive approach to the pleural space using an a-traumatic peel-away introducer under ultrasonographic intraoperative control. Furthermore, consideration about complications, follow-up and advantages of the abovementioned technique will be discussed. CONCLUSIONS: Percutaneous US guided placement for pleural catheter is a safer and modern minimally invasive approach to the pleural space. Pleural effusion is the predominant complication, encountered especially in younger children.

The rolling cyst: migrating intraventricular neurocysticercosis-a case-based update.

BACKGROUND: Neurocysticercosis is the most frequent parasitic disease of the central nervous system, and its incidence in the developed countries is increasing due to immigration and travels from endemic areas. The intraventricular location has been found to involve up to 61.3% of the patients; moreover, only 22 cases of migrating intraventricular cyst have been reported so far. Despite the rarity of the condition in western countries, its occurrence generates some concerns and the aim of this paper is to update the information concerning pathogenesis, clinical presentation, diagnosis and management of this entity. METHODS AND RESULTS: All the pertinent literature was analysed, focused on the cases of migrating intraventricular neurocysticercosis and its peculiar features. An illustrative case regarding a 14-year-old girl is also presented. CONCLUSIONS: Migrating intraventricular neurocysticercosis is a pathognomonic entity usually presenting with hydrocephalus, and its treatment is mainly surgical, preferring an endoscopic approach. When the resection of the intraventricular cyst is not performed, an accurate follow-up is mandatory to detect clinical changes due to a recurrent hydrocephalus or to the effect of the dying cyst on the surrounding area. In case of permanent shunt placement, the cysticidal and steroid treatment is recommended to reduce the risk of shunt failure.

Prone versus sitting position in pediatric low-grade posterior fossa tumors.

PURPOSE: The choice between sitting and prone position to access the infratentorial space in a suboccipital craniotomy is still a matter of debate. The comparisons in terms of complications and outcome of both positions are scarce, and the pediatric population is indeed more infrequent in these in scientific reviews. In this paper, we assess intraoperative and postoperative complications and neurological outcome in pediatric patients undergoing posterior cranial fossa surgery for pilocytic astrocytoma in sitting and prone position respectively. METHODS: We retrospectively analyzed 30 consecutive patients undergoing surgery for cerebellar pilocytic astrocytoma at the two neurosurgical units referring to the University of Padova Medical School from 1999 to 2017. Preoperative, intraoperative, and postoperative data were retrieved from our medical archives. RESULTS: The statistical analysis did not show any differences between the two groups in terms of preoperative, intraoperative, and postoperative data. The neurological status at last follow-up was similar in both groups of patients. CONCLUSIONS: Our results suggest that both sitting and prone position can be considered safe in suboccipital craniotomies. Further studies are needed to show if there are possible differences between these positions for other frequent pediatric tumors such as medulloblastomas and ependymomas.

Mathematical skills in children with pilocytic astrocytoma.

BACKGROUND: Pediatric patients with circumscribed cerebellar pilocytic astrocytoma (PA) tumors generally perform within the normal range on neuropsychological tests after a complete tumor resection. The outcome in academically relevant abilities such as mathematics, which in adults involve some cerebellar functions, is however much less understood. The aim of this study is to retrospectively investigate the neuroplasticity of mathematical skills and associated cognitive functions following cerebellar resection of PA in pediatric patients. METHODS: Twenty-two children (mean age = 11.2 + 1.8), including 11 PA patients (females = 6) and 11 healthy controls (females = 6), were administered a battery of mathematical (MaT) and neuropsychological tests. Single-case statistical analyses were carried out (Crawford's t) as well as between-group comparisons (Wilcoxon test). Spearman correlations between MaT and neuropsychological tests were calculated. RESULTS: Thirty-six percent of the patients showed difficulties in some mathematical tasks, 50% of them within a broader cognitive deficit. Verbal working memory was associated with MaT performance both in patients and controls while, crucially, visuospatial memory, and visual-motor integration were associated with MaT in patients only. Among patients, MaT correlated negatively with tumor size and positively with the interval surgery test. CONCLUSIONS: The results evince an overall recovery of mathematical abilities despite PA in the majority of patients. This functional reestablishment is supported by visuospatial and visuomotor integration functions that contribute to set up emerging mathematical skills in these patients. Higher levels of compensation are found in more developed tumors as compared to smaller ones.