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ZusammenfassungFür die Implantation von Elektroden bei Verdacht auf insuläre Epilepsie stehen verschiedene Zugänge zur Verfügung: 1) offen über eine Kraniotomie, 2) stereotaktisch, wobei die Elektroden orthogonal oder schräg über den Frontallappen und Parietallappen implantiert werden. Die stereotaktische Implantation wird rahmenbasiert, navigationsbasiert oder roboterunterstützt durchgeführt. Die unterschiedlichen Zugänge haben jeweils Vor- und Nachteile in Bezug auf die Anatomie, Funktion und Abdeckung des Inselkortex. Diese Aspekte werden in dieser Übersichtsarbeit ausgeführt.

BACKGROUND Medical-imaging-based three-dimensional (3D) printed models enable improvement in skills training, surgical planning, and decision-making. This pilot study aimed to use multimodality imaging and to add and compare 3D ultrasound as a future standard to develop realistic neonatal brain models including the ventricular system. METHODS Retrospective computed tomography (CT), magnetic resonance imaging (MRI), and 3D ultrasound-based brain imaging protocols of five neonatal patients were analyzed and subsequently segmented with the aim of developing a multimodality imaging-based 3D printed model. The ventricular anatomy was analyzed to compare the MRI and 3D ultrasound modalities. RESULTS A realistic anatomical model of the neonatal brain, including the ventricular system, was created using MRI and 3D ultrasound data from one patient. T2-weighted isovoxel 3D MRI sequences were found to have better resolution and accuracy than 2D sequences. The surface area, anatomy, and volume of the lateral ventricles derived from both MRI and 3D ultrasound were comparable. CONCLUSIONS We created an ultrasound- and MRI-based 3D printed patient-specific neonatal brain simulation model that can be used for perioperative management. To introduce 3D ultrasound as a standard for 3D models, additional dimensional correlations between MRI and ultrasound need to be examined. IMPACT We studied the feasibility of implementing 3D ultrasound as a standard for 3D printed models of the neonatal brain. Different imaging modalities were compared and both 3D isotropic MRI and 3D ultrasound imaging are feasible for printing neonatal brain models with good dimensional accuracy and anatomical replication. Further dimensional correlations need to be defined to implement it as a standard to produce 3D printed models.

Background New-onset seizures after cranioplasty (NOSAC) are reported to be a frequent complication of cranioplasty (CP) after decompressive hemicraniectomy (DHC). There are considerable differences in the incidence of NOSAC and contradictory data about presumed risk factors in the literature. We suggest NOSAC to be a consequence of patients’ initial condition which led to DHC, rather than a complication of subsequent CP. We conducted a retrospective analysis to verify our hypothesis. Methods The medical records of all patients ≥ 18 years who underwent CP between 2002 and 2017 at our institution were evaluated including incidence of seizures, time of seizure onset, and presumed risk factors. Indication for DHC, type of implant used, timing of CP, patient age, presence of a ventriculoperitoneal shunt (VP shunt), and postoperative complications were compared between patients with and without NOSAC. Results A total of 302 patients underwent CP between 2002 and 2017, 276 of whom were included in the outcome analysis and the incidence of NOSAC was 23.2%. Although time between DHC and CP differed significantly between DHC indication groups, time between DHC and seizure onset did not differ, suggesting the occurrence of seizures to be independent of the procedure of CP. Time of follow-up was the only factor associated with the occurrence of NOSAC. Conclusion New-onset seizures may be a consequence of the initial condition leading to DHC rather than of CP itself. Time of follow-up seems to play a major role in detection of new-onset seizures.

Background The role of surgery in the management of pediatric non-pilocytic infiltrative thalamic gliomas needs to be revisited specifically with regard to molecularly defined subtypes. Methods A retrospective review of a consecutive series of children operated on a thalamic tumor between 1992 and May 2018 was performed. Neuroimaging data were reviewed for localization and extent of resection; pathology was re-reviewed according to the current WHO classification, including assessment of histone H3 K27 mutational status. Results Forty-nine patients with a thalamic tumor aged < 18 years at diagnosis were identified. Twenty-five patients (51%) had a non-pilocytic infiltrative glioma, of which the H3 K27M status was available in 22. Fourteen patients were diagnosed as diffuse midline glioma (DMG) H3 K27M mutant. There was no statistically significant difference in survival between patients harboring the H3 K27M mutation and wildtype. Resection (“any resection > 50%” vs “biopsy”) and histological tumor grade (“°II” vs “°III+°IV”) were statistically significant predictors of survival (univariate: p = 0.044 and p = 0.013, respectively). These results remained significant on multivariate analysis (HR 0.371/p = 0.048, HR 9.433/p = 0.035). Conclusion We advocate to still consider an attempt at maximal safe resection in the multidisciplinary treatment of unilateral thalamic non-pilocytic gliomas irrespective of their H3 K27-mutational status.

Objective Cranioplasty (CP) is considered as a straightforward and technically unchallenging operation; however, complication rates are high reaching up to 56%. Presence of a ventriculoperitoneal shunt (VPS) and timing of CP are reported risk factors for complications. Pressure gradients and scarring at the site of the cranial defect seem to be critical in this context. The authors present their experiences and lessons learned. Methods A consecutive series of all patients who underwent CP at the authors’ institution between 2002 and 2017 were included in this retrospective analysis. Complications were defined as all events that required reoperation. Logistic regression analysis and chi-squared test were conducted to evaluate the complication rates according to suspected risk factors. Results A total of 302 patients underwent cranioplasty between 2002 and 2017. The overall complication rate was 17.5%. Complications included epi-/subdural fluid collection (7.3%) including hemorrhage (4.6%) and hygroma (2.6%), bone graft resorption (5.3%), bone graft infection (2.0%), and hydrocephalus (5.7%). Overall, 57 patients (18.9%) had undergone shunt implantation prior to CP. The incidence of epi-/subdural fluid collection was 19.3% in patients with VPS and 4.5% in patients without VPS, OR 5.1 (95% CI 2.1–12.4). Incidence of hygroma was higher in patients who underwent early CP. Patients with temporary shunt ligation for CP did not suffer from complications. Conclusion CP in patients with a VPS remains a high-risk procedure. Any effort to understand the pressure dynamics and to reduce factors that may trigger the formation of a large epidural space must be undertaken.

Glioblastoma (GB) is one of the most vascularized of all solid tumors and, therefore, represents an attractive target for antiangiogenic therapies. Many lesions, however, quickly develop escape mechanisms associated with changes in the tumor microenvironment (TME) resulting in rapid treatment failure. To prevent patients from adverse effects of ineffective therapy, there is a strong need to better predict and monitor antiangiogenic treatment response. We utilized a novel physiological magnetic resonance imaging (MRI) method combining the visualization of oxygen metabolism and neovascularization for classification of five different TME compartments: necrosis, hypoxia with/without neovascularization, oxidative phosphorylation, and aerobic glycolysis. This approach, termed TME mapping, was used to monitor changes in tumor biology and pathophysiology within the TME in response to bevacizumab treatment in 18 patients with recurrent GB. We detected dramatic changes in the TME by rearrangement of its compartments after the onset of bevacizumab treatment. All patients showed a decrease in active tumor volume and neovascularization as well as an increase in hypoxia and necrosis in the first follow-up after 3 months. We found that recurrent GB with a high percentage of neovascularization and active tumor before bevacizumab onset showed a poor or no treatment response. TME mapping might be useful to develop strategies for patient stratification and response prediction before bevacizumab onset.

In this study, we investigated the variability of vascular hysteresis loop (VHL) shapes and the spatial heterogeneity of neovascularization and microvascular alterations using vascular architecture mapping (VAM) in patients with recurrent glioblastoma during bevacizumab mono-therapy. VAM data were acquired in 13 patients suffering from recurrent glioblastoma prior to and 3 months after bevacizumab treatment onset using a dual contrast agent injections approach as part of routine MRI. Two patients were additionally examined after the first cycle of bevacizumab to check for early treatment response. VHLs were evaluated as biomarker maps of neovascularization activity: microvessel type indicator (MTI) and curvature (Curv) of the VHL-long-axis. Early response to bevacizumab was dominated by reduction of smaller microvasculature (around 10 µm). In the 3-month follow-up, responding tumors additionally showed a reduction in larger microvasculature (>20 µm). VAM biomarker images revealed spatially heterogeneous microvascular alterations during bevacizumab treatment. Responding, non-responding, progressive, and remote-progressive tumor areas were observed. MTI may be useful to predict responding and non-responding tumor regions, and Curv to assess severity of vasogenic edema. Analysis of VHLs in combination with VAM biomarkers may lead to a new perspective on investigating the spatial heterogeneity of neovascularization and microvascular alterations in glioblastoma during antiangiogenic therapy.

The purpose of this retrospective population based study was to investigate the effect of the extent of surgery on overall survival in young versus adult glioblastoma patients in Vorarlberg/Austria during the last 4 years.Forty-eight patients (median age 62.5 years, ranging from 25-82 years, 19 female and 29 male) with histologically proven glioblastoma received surgery (16 biopsies, 18 partial and 14 complete resections) and postoperative chemo-irradiation with concomitant and adjuvant temozolomide. The median follow up of the patient population was 11.7 months (ranging from 3 to 36 months). Postoperative temporary morbidity was found in 5 out of 48 (10.4%) patients, and no mortality or permanent morbidity occurred. One infection led to revision surgery.Altogether, the 12/24 months overall survival was 54/20.2% with a median survival of 13.7 months. In younger patients (65 yrs, median 57.5 yrs, 28 patients), the 12/24 months overall survival was 68.4/34.3% with 16.9 months median survival, in the elderly patients (65 yrs, median 73 yrs, 20 patients) the 12/24 months overall survival was 28.8/5.8%, with 7.7 months median survival (Log-rank, p = 0.0005). Extent of surgery influenced overall survival of the adult group nearly significantly (biopsy versus complete resection: p = 0.06), but did not affect overall survival of the elderly (p = 0.5).Overall survival of elderly glioblastoma patients treated with surgery and chemo-irradiation with concomitant and adjuvant temozolomide is significantly reduced compared to the younger patients. In addition, in the elderly the extent of surgery did not influence the prognosis in our population.

Efficacy and tolerability of levetiracetam (LEV) as perioperative seizure prophylaxis in supratentorial brain tumor patients were retrospectively studied. Between February 2007 and April 2009 in a single institution, 78 patients with primary or secondary supratentorial brain tumors [40 female, 38 male; mean age 57 years, from 27 to 89 years; gliomas in 42 patients (53.8%), brain metastases in 17 (21.8%), meningiomas in 16 (20.5%), 1 primary central nervous system (CNS) lymphoma patient, and 2 patients with radiation necrosis] received between 1,000 mg and 3,000 mg LEV perioperatively. Preoperatively, 30 patients had experienced seizures (38.5%), most commonly glioma patients (47.6%), but also meningioma patients (31.3%) or patients with brain metastases (23.5%). No more seizures occurred in patients receiving 1-3 g LEV preoperatively. Within the first week postoperatively, a single seizure occurred in two patients (2.6%). At the end of the follow-up period (mean 10.5 months, range 0-31 months), 71 of the 78 patients (91%) were seizure free and 21 (26%) patients were not taking antiepileptic drugs. We observed side-effects in five patients (6.4%), including non-tumor-associated progressive somnolence in three patients (1.5 g, 1.5 g, and 2 g LEV daily) and reactive psychosis in two patients (1 and 1.5 g LEV daily), regressing after dose reduction. Perioperative LEV in supratentorial brain tumor patients was well tolerated. Compared with the literature, it resulted in low (2.6%) [corrected] seizure frequency in the early postoperative period. Additionally, its advantage of lacking cytochrome P450 enzyme induction allowed early initiation of effective postoperative chemotherapy in malignant glioma patients.

Meningiomas of the ventricle system are extremely rare. We report on a series of 16 intraventricular meningiomas (IVMs) treated at our institution between 1980 and 2004, with a special interest on the surgical outcome of using the intra/inter-parietal and parieto-occipital approach and the benefits of neuro-navigation. A retrospective analysis of the medical files for clinicoradiological findings, surgical interventions and surgical outcome was carried out. In 16 IVM patients with a female/male ratio of 11:5, age ranged from 24 years to 84 years (median 44 years). Duration of symptoms ranged from a few days to several years, and the cardinal symptoms were signs of increased intracranial pressure (86%), followed by corticospinal tract signs (43%), visual field defects (36%), cognitive changes (29%) and seizures (7%). The majority of tumours was located in the trigone (88%), and one was found in each the temporal horn and in the fourth ventricle. Tumour size ranged from 2.5 cm to 8 cm (median 5 cm), and the radiological appearance was uniform. The neuropathological workup revealed most IVMs as meningothelial, transitional (mixed) or lymphoplasmacyte-rich meningiomas (81%). Three tumours were classified as atypical (19%) and the MIB-1 proliferation index ranged from 1% to 40%. Complete resection was possible in all but one case. The trigonal IVMs were resected via an intraparietal/inter-parietal or parieto-occipital approach, and neuro-navigation was used in eight tumours. We encountered one perioperative death and one severely disabled patient. All other patients had a Glasgow outcome scale score of 5, and most of the pre-existing symptoms disappeared or improved after surgery. IVMs are a surgically curable tumour entity in most cases. The intraparietal/inter-parietal and parieto-occipital approach is very safe, and neuro-navigation allows early devascularisation of the tumour.