Global neurosurgery amongst the EANS community: Where are we at?

•Awareness of Global Neurosurgery opportunities is limited in the EANS and a minority have had previous experiences with such activities.•Most training programs and job environments don't encourage participation in Global Neurosurgery and mentors are lacking.•However, most European neurosurgeons and trainees remain interested in Global Neurosurgery and are willing to participate.•Junior trainees is the group with the highest rate of interest for Global Neurosurgery.•Barriers exist that may limit participation in Global Neurosurgery, and funding is the most relevant.

Atypical Teratoid/Rhabdoid Tumor (AT/RT) With Molecular Features of Pleomorphic Xanthoastrocytoma.

Atypical teratoid/rhabdoid tumor (AT/RT) is a highly malignant central nervous system tumor predominantly occurring in infants that may also arise in older children and adults. Rare secondary AT/RT developing from other tumors such as pleomorphic xanthoastrocytoma (PXA) are on record, but AT/RT presenting with molecular features of PXA have not been described. Here, we report 3 malignant central nervous system tumors in children (10, 13, and 18 y old). All tumors were located in the temporal lobe. In 2 cases, there was no history of a low-grade precursor lesion; in 1 case anaplastic PXA had been diagnosed 3 months earlier. Histopathologically, all tumors were composed of RT cells and showed frank signs of malignancy as well as loss of nuclear SMARCB1/INI1 protein expression. Two cases displayed homozygous deletions of the SMARCB1 region while the third case showed an exon 7 mutation (c.849_850delGT; p.Met283Ilefs*77). Of note, DNA methylation profiles did not group with AT/RT or other tumor entities using the Heidelberg Brain Tumor Classifier (version v11b4). By unsupervised t-distributed stochastic neighbor embedding analysis and hierarchical clustering analysis, however, all tumors clearly grouped with PXA. Genome-wide copy number analysis revealed homozygous CDNK2A/B deletions and gains of whole chromosome 7. BRAF V600E mutations could be demonstrated in all cases. In conclusion, the possibility of AT/RT with molecular features of PXA needs to be taken into account and warrants molecular characterization of AT/RT especially in older children. Since treatments targeting mutated BRAF are available, identification of such cases may also have therapeutic consequences.

Ventriculoperitoneal Shunt Complications in the European Idiopathic Normal Pressure Hydrocephalus Multicenter Study.

BACKGROUND: Ventriculoperitoneal shunt (VP-shunt) is the standard of treatment for idiopathic normal pressure hydrocephalus (iNPH). However, a thorough investigation of VP-shunt complications in this population is lacking. OBJECTIVE: To present the analysis and the rates of complications progressively occurring during the first year after shunt surgery in the patients with iNPH included in the European multicenter (EU-iNPH) study. METHODS: Patients (n = 142) were prospectively included in the EU-iNPH study by 13 institutions. All patients received a programmable VP-shunt. One hundred fifteen patients completed the 12-mo follow-up. Reexaminations were performed 1, 3, and 12 mo after surgery. Data regarding symptomatic over- or underdrainage, infections, malposition, subdural collections, and shunt surgery were collected and analyzed. RESULTS: Thirty patients (26%) experienced symptoms due to shunt underdrainage. Symptomatic overdrainage was reported in 10 (9%). Shunt adjustments were made in 43 (37%). Shunt malposition was recognized as the primary cause of shunt malfunction in 8 (7%), while only 1 infection (0.9%) occurred. Subdural hematoma was diagnosed in 7 (6%) and was treated by increasing the opening pressure of the valve in 5 patients. Hygroma was diagnosed in 10 (9%), requiring surgery in 1 patient. Overall, 17 patients (15%) underwent 19 shunt surgeries. CONCLUSION: The advances in valve technology, a careful opening pressure setting, and rigorous follow-up allow a significant reduction of complications, which can be usually managed nonsurgically within the first 3 to 6 mo.

Erdheim-Chester disease mimicking an intracranial trigeminal schwannoma: case report.

Erdheim-Chester disease (ECD) is non-Langerhans histiocytosis that can affect multiple organ systems. It usually affects middle-aged patients, and only a few reports of ECD in children appear in the literature. Central nervous system involvement is a common feature that usually occurs as infiltration of the hypothalamus-pituitary axis, cerebellum, and/or brainstem. Meningeal involvement occurs less commonly. In this article, the authors discuss a rare pediatric case of ECD presenting as an infiltrative mass of the trigeminal nerve and resembling the clinical and imaging features of a trigeminal schwannoma.

High-Field iMRI in transsphenoidal pituitary adenoma surgery with special respect to typical localization of residual tumor.

BACKGROUND: Intraoperative high-field magnetic resonance imaging (iMRI) is used as an immediate intraoperative quality control, evaluating the extent of tumor removal during the surgical procedure and allowing us to extend resections in those cases where tumor remnants are documented. The aim of the study was to analyze the typical localization of residual tumor remnants, detected by iMRI during transsphenoidal surgery of pituitary adenomas. METHODS: We reviewed a series of 72 patients. All patients presented with macroadenomas with or without suprasellar extension. After high-field MRI investigation, we divided the series preoperatively into totally resectable (TR) and non-totally resectable (NTR) tumors. Tumor remnants were documented by iMRI, obtained directly after tumor removal, as well as by intraoperative surgical inspection of the sellar content. RESULTS: In the TR group, we observed 23 cases suspicious for tumor remnants, located anteriorly, laterally, posteriorly, and suprasellar under descending folds of the diaphragm. Continuing surgery, upon a "second inspection", tumor resection could be completed in all cases. CONCLUSIONS: Incomplete removal of resectable pituitary adenomas could be avoided in a higher number of cases with the knowledge of the location of the typical remnant tumors. In those cases where it is not possible to achieve a complete resection of adenoma, further treatment can be planned at an earlier stage, without any need to wait for the conventional postoperative MRI scan performed 2 to 3 months after surgery.

Bilateral osteomas arising from the internal auditory canal: case report.

OBJECTIVE: Osteomas arising from the internal auditory canal and developing in the cerebellopontine angle have rarely been reported. We present the first case of bilateral osteomas in this region and describe our management strategy. CLINICAL PRESENTATION: A 30-year-old woman presented with strong vertigo, tinnitus, and hypacusis on the left side. Brain magnetic resonance imaging and computed tomographic scans displayed bilateral cerebellopontine angle osteomas arising from the internal auditory canal. The larger tumor on the left side was found to be compressing the vestibulocochlear nerve. INTERVENTION: Surgery was performed on the symptomatic side via the retrosigmoid approach, and the tumor was removed completely. The vertigo resolved completely after surgery, and the patient had no further tinnitus attacks. An audiogram showed slightly improved hearing with a mean of 20 dB in the main speech area. CONCLUSION: Osteomas should be considered in patients with bilateral cerebellopontine angle tumors. Surgical removal might provide resolution of symptoms.

Neuronavigational endoscopic endonasal sellar and parasellar surgery using a 2-mm-diameter lens rigid-rod endoscope: a cadaver study.

OBJECTIVE: Most of the endoscopes used for endonasal transsphenoidal surgery use 4-mm diameter lenses. The applicability of a newly developed neuroendoscope with a lens diameter of only 2 mm was tested in endonasal transsphenoidal pituitary surgery. METHODS: The newly developed rigid-rod neuroendoscope with a 2-mm lens and an endoscope with a 4-mm lens were coupled with a navigation system and used for this comparative study. Comparison between the views obtained with these two devices was performed in a model and in formalin-fixed cadaver heads. A pure endonasal approach was used to reach and explore the sellar and parasellar regions. The navigation system was used to locate the same position in both lenses for image comparison. RESULTS: The sellar and parasellar regions could be reached and explored using the new endoscope with the 2-mm lens and an oval-shaped irrigation and suction channel. The visual field appeared to be reduced compared with that of the 4-mm lens. However, this reduction was compensated by greater mobility and easier introduction and maneuvering of the instruments at the sellar level. Reduced image size and brightness were also found using the 2-mm lens compared with the 4-mm lens. These differences could be overcome by increasing the amount of light and enlarging the image but with subsequent reduction in image resolution. CONCLUSION: The small diameter of this neuroendoscope resulted in good maneuverability and maintained a fine quality of vision. Children and patients with small nostrils are good candidates for the use of such a device.

Anatomical study of the pterygopalatine fossa using an endoscopic endonasal approach: spatial relations and distances between surgical landmarks.

OBJECT: The pterygopalatine fossa is an area that lies deep within the skull base. The recent extensive use of the endoscopic endonasal approach has provided neurosurgeons with a method to reach various areas of the skull base through a less invasive approach than traditional transcranial or transfacial approaches. This study aims to provide neurosurgeons with new data concerning direct endoscopic measurements and precise anatomical topography features of the pterygopalatine fossa. METHODS: An anatomical dissection of six fixed cadaver heads (12 pterygopalatine fossae) was performed to analyze spatial relationships and distances between the most important neurovascular structures in this region, and to estimate the size of the endoscopic surgical field for operations in this area. The endoscopic endonasal approach offers direct access to the pterygopalatine fossa through its anteromedial walls. CONCLUSIONS: Using an endoscopic endonasal approach makes it possible to identify all of the anatomical landmarks of the pterygopalatine fossa and almost all of the contiguous skull base areas.

The endoscopic endonasal approach to the lateral recess of the sphenoid sinus via the pterygopalatine fossa: comparison of endoscopic and radiological landmarks.

OBJECTIVE: The endoscopic endonasal approach offers the opportunity to reach the pterygopalatine fossa, the lateral recess of the sphenoid sinus, and other areas of the cranial base through a minimally invasive approach. This study compares the anatomy of these areas when observed through an endoscopic endonasal view with the anatomy of the same regions as they appear in computed tomographic scans. The aim was to identify and correlate the corresponding anatomic structures, providing the surgeons with anatomic landmarks to guide them when operating in these areas through an endoscopic endonasal approach. METHODS: An anatomic dissection of six fixed cadaver heads was performed by an endoscopic endonasal approach. A step-by-step comparison of endoscopic and radiological images was made to identify the landmarks of the surgical field. RESULTS: The step-by-step comparison of endoscopic and radiological images acquired during the endoscopic endonasal approach to the lateral recess of the sphenoid sinus via the pterygopalatine fossa allowed the identification of all the relevant anatomic landmarks of the procedure. CONCLUSION: The endoscopic endonasal approach via the pterygopalatine fossa offers direct, minimally invasive access to the lateral recess of the sphenoid sinus, which can be monitored in each phase through consistent radiological imagery.

Neuronavigational neuroendoscopic surgery. Frameless free-hand maneuvering of a handy rigid-rod neuroendoscope on visualized three-dimensional computerized image guidance: trajectory to the prepontine cistern in cadaver study.

BACKGROUND: Considering the separate benefits of neuronavigation and neuroendoscopy, neuroendoscopic surgery with the aid of neuronavigation systems will play an increasingly important role in the future. Bearing this in mind, the present research project was conducted to facilitate neuronavigational neuroendoscopic surgery along the pathway to the prepontine cistern using cadaver heads. MATERIALS AND METHODS: A computer-aided, frameless image-guided stereotactic navigation system and a new type of handy rigid-rod neuroendoscope were used. The ideal entry point and the safest trajectory to the prepontine cistern through the foramen of Monro were defined in two formalin-fixed cadaver heads and clinical brain MRI data. Then, maneuvering of the neuroendoscope with the aid of the neuronavigation system was performed. RESULTS: Straight trajectories from the entry point to the prepontine cistern could be designed. For the registration accuracy of the tip of the neuroendoscope, the virtual image registered a mean error distance of 5.42 mm away from the reference point along the axis of vertical line. However, free-hand maneuvering enabled the neuroendoscope to be finely manipulated without damaging brain tissues. Neuroendoscopic anatomical views of the interpeduncular and prepontine cistern were also acquired. CONCLUSION: Interactive use of free-hand maneuvering of the handy rigid-rod neuroendoscope together with frameless neuronavigation systems plot the way to true neuronavigational neuroendoscopic surgery in a safe and reliable manner. This pairing of the most recent technological neurosurgical options with better understanding of neuroendoscopic anatomy enables the neurosurgeon to acquire broader treatment options for central nervous system diseases.