Olfactory schwannomas - an enigmatic clinical entity.

Olfactory Schwannomas (OS) are a rare, benign tumour entity. Throughout literature, only few cases have been reported. We describe here a case of a 75-year-old female with a contrast enhanced mass lesion in the anterior fossa, who underwent a surgical removal and its histopathological analysis was consistent with a schwannoma. The description of the origin of this tumour is intriguing and enigmatic. Although rare, this type of tumour should always be included in the differential diagnosis of anterior fossa lesions. Further research on the pathogenesis and the natural course of OS is needed.

Robot-assisted versus navigated transpedicular spine fusion: A comparative study.

BACKGROUND: The aim of this study was to compare the intraoperative and postoperative outcomes between a robot-assisted versus a navigated transpedicular fusion technique. METHODS: This retrospective analysis included patients who underwent transpedicular posterior fusion of the spine due to trauma, pyogenic spondylodiscitis and osteoporosis. Surgery was done either with a robot-assisted or a percutaneous navigated transpedicular fusion technique. The outcome analysis included the duration of surgery, the radiation exposure, the postoperative screw position and complications. RESULTS: A total of 60 patients were operated and 491 screws were analysed. No statistical difference was seen in the applied cumulative effective radiation dose per patient. The radiological assessment revealed a more accurate screw placement with robot assistance. A learning curve could be observed in robot-assisted fusion. CONCLUSION: Robot-assisted and navigated transpedicular fusion techniques are both effective and safe. Robot-assisted transpedicular spine fusion goes along with higher placement accuracy but its implementation needs an adequate learning curve.

Rare Case of Convexity Meningioma Growing into Arachnoid Cyst.

BACKGROUND: Meningioma growing into an arachnoid cyst is an extremely rare event. Only 3 cases are reported in the literature. In 2 of them, an operative procedure in or near the arachnoid cyst preceded tumor growth. CASE DESCRIPTION: We report a case of a patient requiring marsupialization of an arachnoid cyst of the middle cranial fossa. On follow-up, 3 years postoperatively he showed no signs of recurrence or tumor growth. One year later, the fourth year after surgery on the cyst, he presented with large tumor growth into the former cyst's cavity. Pathologic workup after resection revealed an atypical meningioma (World Health Organization grade II). CONCLUSIONS: We discuss the possible pathogenesis in light of the scarce published literature, as well as the differential diagnosis of this rapidly growing tumor.

Hemodynamic Stress, Inflammation, and Intracranial Aneurysm Development and Rupture: A Systematic Review.

BACKGROUND: There seems to be a pathogenetic link between hemodynamics and inflammatory arterial wall alteration leading to the development and rupture of intracranial aneurysms (IAs). Noninvasive assessment of the inflammatory status of the aneurysm wall may guide the management of unruptured IAs by identifying reliable markers for increased rupture risk. METHODS: We conducted a qualitative systematic review following the ENTREQ (Enhancing Transparency in Reporting the Synthesis of Qualitative Research) framework. A search was made in MEDLINE/PubMed, Embase, and CINAHL from database inception to October 2017 using the terms "intracranial aneurysm" and "cerebral aneurysm" linked with the following key words: inflammation, hemodynamic(s), remodeling, macrophages, neutrophils, lymphocytes, complement system, vascular smooth muscle cells, mast cells, cytokines, and inflammatory biomarkers. RESULTS: One hundred and twenty-three articles were included in the review. CONCLUSIONS: In this systematic review, we explore the relationship between hemodynamic stress, inflammation, vascular remodeling, and the formation and rupture of IAs to develop novel strategies to predict the individual risk of aneurysmal rupture.

Meningioma surgery in the elderly: outcome and validation of 2 proposed grading score systems.

BACKGROUND: Although population age increases, published evidence on meningioma treatment in the elderly is scarce. OBJECTIVE: In order to improve selection for surgery, we investigated our patients' collective, using 2 proposed risk assessment systems, the Clinical-Radiological Grading System (CRGS) and the SKALE score (sex, Karnofsky, American Society of Anesthesiology [ASA] score, location, edema). METHODS: We retrospectively assessed morbidity and mortality in 164 patients aged ≥ 65, operated on for an intracranial meningioma. Medical and surgical records were reviewed and analyzed. CRGS and SKALE scores were calculated. The ability of both CRGS and SKALE and all single factors to predict death within 12 months was analyzed by the use of multivariate logistic regression modeling. RESULTS: Eleven patients died (6.7%). Logistic regression for CRGS/SKALE showed a significant relationship with 12 months mortality. Age, Simpson resection grade, and sex were not significant predictors when investigated alone. In multivariate logistic regression, including all proposed factors, only concomitant disease and edema (CRGS) as well as ASA score and preoperative Karnofsky Performance Scale (SKALE) showed a significant relationship to mortality. After stepwise reduction of the full multivariate regression model to its significant terms, only concomitant disease and ASA remained significant for CRGS (P < .001) and SKALE (P = .003), respectively. CONCLUSION: Meningioma resection in the elderly is possible with some mortality. We were unable to reproduce the utility of 2 proposed grading systems for mortality prediction when extending to younger patients. In single-factor analysis, only concomitant disease and ASA score remained significant. The decision whether to operate should be taken individually. Patients with severe concomitant disease or high ASA score should be advised not to undergo surgical therapy independently from other factors.

Modern management of rare brain metastases in adults.

Brain metastases (BM) represent the main cause of intracranial neoplasms in adults, while being relatively less common in children. Today, better treatment options of the primary malignancy lead to higher remission rates as well as prolonged stable clinical conditions. This may in part explain the increased incidence of BM. Morbidity and mortality rates in patients with malignancies deteriorate significantly in cases of metastatic involvement of the central nervous system. Nowadays, especially modern management using surgical, medical, and radiotherapeutic options for treatment of BM tends to improve survival rates and enhance quality of life. Nonetheless, almost all treatment options are considered as palliative. In this review, we outline current knowledge of the incidence, diagnostic facilities, and therapeutic management of rare BM, with consideration of the basic aspects of the primary malignancy.

Iatrogenic tension pneumothorax resulting in pneumocephalus after insertion of a ventriculoperitoneal shunt: an unusual complication.

We report the case of an iatrogenic tension pneumothorax related to the placement of a ventriculoperitoneal shunt, followed by pneumocephalus. The patient was pending cranioplasty and shunt placement after decompressive craniectomy for acute subdural hematoma and posttraumatic hydrocephalus. Facilitating the severe and potential life-threatening complication was a severe obesity of the patient as well as incorrect surgical technique.

Significance of intraoperative motor function monitoring using transcranial electrical motor evoked potentials (MEP) in patients with spinal and cranial lesions near the motor pathways.

Intraoperative motor evoked potential (MEP) monitoring in patients with spinal and cranial lesions is thought to be a valuable tool for prevention of postoperative motor deficits. Aim of this study was to investigate its diagnostic value in a spinal and a cranial patient group. Ninety-six patients, 31 with spinal and 65 with intracranial lesions, were studied. Transcranial stimulation was performed with a high-frequency electrical train stimulation using two subdermal needle electrodes. MEPs were recorded from the pathology-related muscles. Decreasing amplitudes of 50% or more, increasing stimulus intensities of 20% or more or increased latencies were taken as warning criteria. MEP recording was possible in 90% of the spinal and 98% of the cranial group. With two further exclusions, 28 patients of the spinal and 62 of the cranial group were analyzed. We saw a temporary maximum amplitude reduction of 50% or more and an increase in stimulation intensity of 20% or more in 8 spinal and 29 cranial patients. Five of the spinal and nine of the cranial patients deteriorated in motor function postoperatively. One patient with normal MEP monitoring showed a temporary motor weakness postoperatively. Latencies were normal in all patients. Given both warning criteria, intraoperative MEP changes had a sensitivity of 83%/ 100% and a specificity of 86%/ 62% (spinal/ cranial group). The positive predictive value of MEP changes for postoperative motor function deterioration was 63%/ 31%, and the negative predictive value was 95%/ 100%. Transcranial electrical monitoring of MEP is a practicable and safe method. However, there are many events, which can cause amplitude changes of MEP independent from surgical manipulations. Although sensitivity is high for both groups, this results in a moderate specificity for the cranial group and a low positive predictive value for both groups.

Alike performance during nonverbal episodic learning from diversely imprinted neural networks.

Performance on neuropsychological testing permits inferences to be made regarding neural networks required to solve the task. In healthy young human subjects it is common sense that differential performance in cognitive tasks results from recruitment of different neural networks and that alike performance results from recruitment of alike neural networks. It was the goal of the present study to investigate whether these assumptions are also valid in cross-cultural studies. To address this, we used functional MRI during a nonverbal episodic memory task with repeated learning of abstract geometric patterns. Behavioural performance in this task was alike over repeated trials in native Chinese and Caucasian subjects. Given this equivalent performance, the distinct pattern of neuronal activation observed is interpreted as the outcome of different culturally imprinted processing routines. In the 'what' and 'where' framework of visuo-spatial processing initial learning in Chinese subjects activated the dorsal stream for analysis of spatial features whereas Caucasians recruited the ventral stream for object identification. With repeated learning Chinese subjects integrated visuo-spatial processing to object coding and vice versa. Thus, imprints of culture result in activation of distinct neural networks and mandate monitoring of both behavioural performance and neural recruitment in cross-cultural studies of cognition.