Background: Objective methods to assess the influence of significant stress on neurosurgical bimanual psychomotor performance have not been developed. We utilized NeuroTouch, a virtual reality simulator, to answer two questions: 1) What is the impact of significant stress on bimanual psychomotor performance during the resection of a simulated tumor? 2) Does stress influence performance immediately following the stressful episode? Methods: Uncontrollable ‘intraoperative’ bleeding during one of the tumor resections resulting in simulated patient cardiac arrest served as the acute stressor. Six neurosurgeons, 6 senior and 6 junior neurosurgical residents and 6 senior medical students were studied. The evaluated advanced tier 2 metrics were efficiency index, ultrasonic aspirator path length index, suction coordination index and ultrasonic aspirator bimanual forces ratio. Results: The stress scenario significantly decreased the efficiency index of all groups and significantly decreased performance for many groups for suction coordination index and ultrasonic aspirator path length index. Performance in all advanced tier 2 metrics returned to pre-stress levels in post stress resection scenarios. Conclusions: Our results are consistent with the concept that acute stress initiated by severe intraoperative bleeding significantly decreases bimanual psychomotor performance during the acute episode but had no significant influence on immediate post stress operative performance.

Background: The use of 3D endoscopy for posterior fossa surgery gradually adopted. In this study we compare the 3D to classic 2D endoscopy in evaluating neurovascular complexes in posterior fossa. Methods: Twenty retrosigmoid craniotomies, with a maximal diameter of 2cm were performed under neuronavigation on 10 fresh cadaveric heads. The posterior fossa dura matter was opened with a C-shaped incision and the base of the dural flap was placed over the sigmoid sinus. We used 3D and 2D endoscopes, with 0 and 45 degree angulations, connected to high definition camera lenses for optimal visualization of posterior fossa structures. Results: The superior, middle and inferior neurovascular complexes of the cerebellopontine angle were better visualized with 3D comparing to 2D endoscope. A detailed view of the porus trigeminous and structures associated with the tentorial incisura was also attained with 3D endoscopy. Conclusion: The high quality and resolution obtained by 3D endoscopy makes it a potentially valuable surgical and teaching tool in the armamentarium for endoscopic posterior fossa surgery. The stereoscopic view of the critical neurovascular structures of the posterior fossa, offered by 3D images, allows for a more detailed dissection in the difficult area of the cerebellopontine angle.

Introduction: Low pressure hydrocephalus is a known complication of prolonged hydrocephalus sometimes treatable with continued low-pressure drainage at subatmospheric pressures. Clarke et. al. and Filipidis et. al. have reported poor outcomes when treating very low pressure hydrocephalus (VLPH). We present 4 cases of very low pressure hydrocephalus (VLPH) following transnasal endoscopic resection of suprasellar lesions and hypothesize that poor prognostic cases can be identified thereby avoiding prolonged futile treatments. Methods: We performed a retrospective chart review of 4 cases of VLPH and tried to identify metrics contributing to successful treatment. We examined the Pearson correlations between Glasgow Coma Scale and ventricle-to-brain ratio (VBR); volume of CSF drained; net fluids; and serum sodium, urea, and creatinine. Results: Our investigation reveals that Glasgow Coma Score is positively correlated with increased CSF drainage and negatively correlated with increased ventricle-to-brain ratio. The most important determinant of good outcome is brain compliance as measured by the brain’s ability to maintain a good GCS score in the face of wide ranges in ventricle-to-brain ratio (VBR). Conclusion: We propose that futile prolonged subatmospheric drainage be avoided by declining treatment in patients who have ventriculitis and patients who have a narrow range of ventricle-to-brain ratio (VBR) concurrent with a good neurological examination.

Introduction: Tele-medicine has gained in popularity worldwide, particularly to help offer medical expertise, healthcare delivery and education to developing nations. There is little literature reporting the implementation or analysis of tele-assitance in the setting of surgical education. We have implemented a tele-assistance system, called Remote Education, Augmented Communication, Training and Supervision (REACTS), as a tool to augment mentor-student education in the operating room. This system allows the mentor to observe the student during surgery remotely through screen sharing technology with integrated visual and audio interaction. The goal of this study is to assess the safety and the benefit of REACTS as an educational tool. Methods: Prospective observational study to evaluate the safety and qualitative benefit of REACTS. Results: REACTS was used in 20 cases, including 5 placement of EVDs, 5 pterional craniotomies, 5 Sylvian fissures dissection, 5 lumbar discectomies, and 5 lumbar spine decompressions. No untoward or adverse events were observed. It was judged to be a positive influence on resident and fellow education by the mentors. The main pitfall in its use is to appropriately select the learner for a given procedure. Conclusion: REACTS surgical system is a safe, and a useful adjunct tool for neurosurgical operative education.

Background: Parasagittal meningioma is a common type of intracranial meningiomas. Surgical resection of such lesions can result in injury to superior sagittal sinus. In rare occasions, extended craniotomy might be required for uncontrollable hemorrhage from a lacerated venous wall. Objective: In order to avoid extended craniotomy, we attempted a surgical technique that would provide more sustained control over the lacerated venous sinus. Method: A 56 year old lady underwent surgical resection for parasagittal meningioma. The lateral wall of the superior sagittal sinus was preached while scraping the tumor capsule from the sinus wall. Owing to difficulty in controlling the bleeding site, a tack up falx-assisted tension suture was attempted with a mass of Gelfoam and Surgicel over the laceration. Results: Adequate control for the venous sinus laceration. Conclusion: The falx-assisted suturing technique is quick, easy to perform and efficient in maintaining a constant tamponade effect over the lacerated site. We highly recommend such technique prior to extending the craniotomy over an injured venous sinus.

Purpose: CTA is becoming the frontline modality to reveal aneurysms in patients with SAH. However, in about 20% of SAH patients no aneurysm is found. In these cases, intra-arterial DSA is still performed. Our aim was to evaluate whether negative findings on CTA can reliably exclude aneurysms in patients with acute SAH. Materials and Method: We conducted a retrospective analysis of all DSA performed from August 2010 to July 2014 in patients with various indications. We selected patient who presented with SAH and had a negative CTA. Findings of the CTA were compared with DSA. Results: 857 DSA were performed during the study period. 51(5.95%) patients with SAH and negative findings on CTA who underwent subsequent DSA were identified. Of these, only 3(5.9%) of patients had positive findings on the DSA. One patient had a posterior inferior cerebellar artery aneurysm on the DSA, not seen on CTA due to the incomplete coverage of the head. Second patient’ CTA did not show any evidence of aneurysm. DSA showed suspicious dissection of the right vertebral artery, potentially iatrogenic. The third patient’s DSA showed suspicious tiny protuberance from left ICA, possibly infundibulum. Conclusion: In patients with SAH, negative CTA findings are reliable in ruling out aneurysms in any pattern of SAH on CT.

Introduction: Carotid occlusion is a rare but serious complication of retropharyngeal abscess (RPA). Management questions that must be addressed include the choice between reconstruction and occlusion in the setting of an active infectious process. Case Report: A 4 year old female presented with hoarseness, shortness of breath, and a right-sided Horner’s syndrome. A CT scan confirmed the diagnosis of RPA, and contrast studies showed no filling in the right internal carotid artery (ICA). Surgical exploration of the abscess disrupted the occluded artery, causing deep, uncontrolled bleeding. Emergent angiographic evaluation was completed, and the decision was made to sacrifice the ICA. The patient recovered on antibiotics, but the Horner’s syndrome persisted. Discussion: The presence of a carotid artery occlusion must be ruled out in the setting of a RPA. When suspected, it should be investigated further. Therapeutic decisions regarding sacrifice or reconstruction of the carotid artery are burdened by risks associated with the setting of an infection, notably infection and systemic dissemination. Conclusion: The presence of a carotid occlusion is a serious complication resulting from a RPA that can lead to permanent neurological deficit. Endovascular vessel sacrifice is a viable treatment option for carotid occlusion in the setting of a retropharyngeal abscess, but must be considered on a case-by-case basis.

Background: Deficiencies in design and reporting of randomized controlled trials (RCTs) limit their validity. The quality of recent RCTs in neuro-oncology was analyzed to assess adequacy of design and reporting. Methods: The MEDLINE and EMBASE databases were searched to identify non-surgical RCTs (years 2000-2010). The CONSORT and Jadad scales were used to assess the quality of design/reporting. A PRECIS-based scale was used to designate studies on the pragmatic-explanatory continuum. Spearman’s test was used to assess correlations. Regression analysis was used to assess associations. Results: Overall, 44 RCTs were identified; majority (23 studies) were chemotherapy-based. High grade gliomas (43%) and metastases (41%) were top pathologies. The majority of studies were multi-center (70%), ITT (61%), and did not collaborate with biostatisticians (70%). Half of the studies were funded by industry (50%). The median CONSORT and Jadad scores were similar in radiation and chemotherapy-based trials (34 and 35 vs 3 and 2, respectively). The impact factor was significantly associated with higher quality (p<0.01). Multi-center trials were more likely to result in positive outcomes (p = 0.02). Conclusion: Deficiencies in the quality of design and reporting of RCTs in neuro-oncology persist. Quality improvement is necessary. In parallel, alternative strategies may be required.

Introduction: Variety of tumors could involve the skull; however, very few may occur over the midline. Some may affect venous blood flow of superior sagittal sinus. Few challenging cases are presented Material: 1-Rare case of osteoblastoma over the torcula, (headache, visual symptoms, papilledema, VI nerve palsy). 2- Rare case of metastatic liposarcoma involving midsagital sinus, partially occluding it (headache and visual blurring). 3- A huge atypical (grade2) meningioma over the vertex Method: Case #1, the tumor over the venous confluences (torcula) was removed easily, without any complications. Complete resolution of symptoms Case #2, complete en-block resection of tumor, with sacrifice of mid-sagittal portion of sinus, without any neurological sequellae. Case #3, subtotal resection, followed by radiotherapy.

Discussion &Conclusion: Anterior 3rd of sagital sinus could be sacrificed (if necessary), without major consequences. However, whenever mid or posterior portion of the sinus is involved, interruption of venous flow could pose very serious complications. Occasionally, chronic compression of sinus may force increasing collateral venous return, in which case one may attempt a complete resection of the lesion, with sacrifice of part of the sinus, as in our second case. In the region of torcula, however, one should be very careful not to damage it

Background: Endometrial carcinoma (EC) is a rare cause of central nervous system metastases, with only 115 cases reported in the literature. There have only been 4 cases reported in the literature for the serous carcinoma subtype. This case study describes a new case of serous carcinoma metastasizing to the brain and demonstrates some of the potential characteristics of this subset. Case: A 77 year old female presented to the emergency department with a 2 week history of progressive left sided weakness and speech difficulties, and a known history of EC diagnosed approximately 3 years earlier. Imaging showed a right temporoparietal tumour. She underwent debulking of this tumour and was found to have a metastasis from her previously known serous carcinoma. Results: In comparing the serous subtype to the 115 known cases, many characteristics show similar patterns to EC as a whole; there could be a predominance to infratentorial lesions with the serous subtype, as 2/4 known metastases were cerebellar compared to only 25% of all endometrial carcinomas. Conclusions: There are possibly different characteristics of metastasizing of various EC subtypes. Before any conclusions can be drawn about the characteristics of any subtype, more data needs to be available for accurate interpretation.

Purpose: Hemangiopericytoma and Meningioma appear similar on routine diagnostic imaging. Diffusion weighted images (DWI) has been used to characterize different types of tumors. The purpose of this study was to assess whether DWI can be used to differentiate hemangiopericytoma from meningioma on diagnostic imaging. Materials and Methods: In a retrospective study, our tumor database was analyzed for diagnosis of hemangiopericytoma with DWI available at the time of diagnostic imaging. These patients were then matched based on location and size of the tumor in a ratio of 1 hemangiopericytoma vs. 2 matched meningioma. The minimum and mean Apparent Diffusion Coefficient (ADC) was measured in the tumor and the contralateral Normal Appearing White Matter (NAWM) to calculate a normalized ADC (nADC) as the ratio of the two. The two tumors were also subjectively assessed for their heterogeneity. Results: Seven patients with histopathological diagnosis of hemangiopericytoma were matched based on size and location with 14 patients of meningioma. Primary meningioma were significantly homogeneous (p<0.001) in appearance compared to hemangiopericytomas. Hemangiopericytomas had a higher mean ADC compared to that of meningioma (p<0.001). Conclusion: Hemangiopericytoma showed heterogeneity on DWI and significantly higher ADC compared to that of meningiomas in our small study. This needs to be confirmed in a study with a larger sample size.

Introduction: Visual dysfunction is one of the primary indications for surgical management of pituitary tumors with the goal of terminating the progressive decline in vision. Unfortunately, it is difficult to predict how successful surgical decompression will be in these patients. The purpose of this study was to assess the structural changes seen in the anterior visual pathway after pituitary tumor resection. Methods: 13 patients (7F) underwent endoscopic tumor resection for pituitary macroadenoma. Each patient underwent a full ophthalmologic assessment including optical coherence tomography (OCT) preoperatively and postoperatively at 3-6months and 9-12months. Post-surgical changes in the retinal nerve fiber layer thickness (RNFLT) for each eye (N=26) were compared in cases with normal preoperative RNFLT (greater than 80 μm) versus those with abnormally thinned RNFLT (less than 80 μm). Results: For 9 cases with thinned RNFLT preoperatively (mean=70.1 μm±8.5), there was a significant decline in RNFLT at 3-6 months follow-up (mean change= −3.8 μm;p=0.002), which did not recover even at 9-12months after surgery (mean=67.6 μm±12.7). Contrastingly, eyes with normal RNFLT preoperatively (mean=89.7 μm±9.4) did not show significant postoperative thinning (mean change= −1.9 μm). Conclusion: Even after a complete surgical decompression, there are ongoing structural changes in the anterior visual pathway in patients with compressive neuropathy. There may be a point of no return where surgical decompression may not prevent further structural degeneration.

Background: The occurrence of familial brain tumours, particularly gliomas, hemangioblastomas in Von Hippel Lindau and other endocrine neoplasia, is well documented in the literature. On the other hand, familial pineal tumours are extremely rare and only a handful of cases have been reported. Methods and Results: Two female siblings presented at ages 12 and 15 with histories of progressive headaches. Neurological examination in each was completely normal. Magnetic Resonance Imaging confirmed the presence of cystic and solid lobulated pineal lesions with mild enhancement, consistent with pineocytoma, in both girls. Follow-up for 15 years in the first sibling and 4 years in the second showed no evolution in radiological or clinical manifestations. No active treatments have been carried out. Conclusion: The occurrence of familial pineal lesions raises the possibility of a close relationship between heredity and oncogenicity, and should be further explored.

Introduction: Serum lactate levels are useful indicators of illness severity such as sepsis. Previous investigations have shown that lactate is a potential biomarker for glioma malignancy; mechanism of which may be related to Warburg effect - accelerated lactate production when tumors uniquely undergo aerobic glycolysis. Our study reveals a correlation between serum lactate and meningioma WHO grade. We also observed a relationship between radiation effect on metastatic brain tumors and lactate levels. Methods: Data was collected from the charts of 14 patients with grade I meningiomas, 6 grade II meningiomas, and 9 metastatic brain tumors who underwent resection at our institution from 2013-2014. T test and ANCOVA were carried using R software controlling for base deficit. Results: The mean age was 53 years, with 75% females. There was a statistically significant change in intra- and post-operative lactate during meningioma resections, which had a strong positive correlation with grade (p<0.005). Interestingly, the lactate rise was not significant for metastatic brain tumors (p=0.13), but had a positive correlation with tumors that received pre-operative radiation (p<0.05). Conclusion: Lactate is a potential non-invasive biomarker for brain tumor malignancy, as demonstrated in gliomas and meningiomas. Identifying metabolic biomarkers and their relationship to tumor pathology is important to understanding disease processes and improving patient care.

Background: Meningiomas represent the commonest benign intracranial tumor and surgical resection is the first line treatment. Tumor recurrence after surgical resection is common. The aim of this study is to identify peri-operative predictors of meningioma recurrence following surgical resection Methods: This was a retrospective hospital-based study of all surgical cases between January 1990 and June 2014. Information regarding age, gender, peri-operative imaging parameters such as peri-tumoral edema or post-operative hemorrhage or residual, and grade were collected. Linear and volumetric measurements (of both tumor volume and volume of edema) were collected as well. Results: Overall, 464 patients were reviewed; n=154(34%) percent of patients were male. The grade distribution was: 296 (74.6%) were Grade I, 78 (19.6%) Grade II, and 23 (5.8%) Grade III. Post-operative tumor bed hemorrhage, noted in 119 (29.9%) of cases, and preoperative peri-tumoral edema volume were significant predictors of tumor recurrence following resection (P= 0.002 and 0.037, respectively). These parameters did not correlate with the MIB-1 index, tumour residual, grade of the tumour, or primary versus recurrent presentation. Conclusions: Pre-operative peri-tumoral edema and post-operative tumor bed hemorrhage are independent predictive of tumor recurrence. Identification of other molecular and/or radiological predictive of recurrence factors could add in our understanding of meningioma behavior.

Background: The impact of second surgery on recurrence remains unclear, with few definitive studies to date. This study sought to identify major predictors of survival after second surgery. Methods: A retrospective chart review was conducted for 21 patients who underwent elective surgery for GBM recurrence, at our institution, in the past 6 years. Kaplan Meier was applied to determine the significance of the variables on survival time. The Mann Whitney U test was used to determine whether the median survival time differed significantly between groups, for the factors of interest. Results: Among variables examined, age, less than ≥50 (P=0.04) was significant. Patients younger than 50, had a median survival period of 11.8 months, while patients, age 50 or older, survived a median time of 4.2 months. Though chemotherapy after reoperation was not found to statistically significantly extend survival time on Kaplan-Meier (P=0.08), the median survival time was found to be significantly higher in patients that received chemotherapy (10.6 months) after reoperation, compared with those who did not (3.9 months), using the Mann Whitney U test (P=0.05). Conclusions: These results confirm that younger patients survive longer after second surgery and indicate that a second round of chemotherapy may prolong survival.

Background: Gamma knife radiosurgery (GKR) is an effective treatment modality for local control of brain metastases. The predictors of response of cystic brain metastases (CBM) to GKR is not well understood. To measure progression and determine treatment prognostic factors, we quantified the percentage cystic and solid components of brain metastases before and after GKR treatment. Methods: 71 patients with CBM treated with GKR from 2006 to 2010 were selected from our institution’s database. Volumetric analysis was performed on MRIs done on treatment date and the latest MRI. Clinical data and dosimetry parameters were reviewed to identify factors that predicted a response of cystic component and overall tumour control. Results: Metastatic lesions from the lung had significantly larger cystic components (by volume) prior to GKR than metastasis of colorectal origin (p=0.039), and also had significantly larger cystic/total ratios than metastases from the breast (p=0.023). Post-treatment, a trend of >25% improvement in both cystic and solid components of tumours was seen in lung primaries (p=0.239). Metastatic brain tumours of colorectal origin demonstrated the best treatment response of the cystic component. Conclusion: The primary cancer pathology of the CBM has an effect on the response to GKR, and can be used as a prognosticator of changes in cystic and solid volumes of lesions.

Introduction: This study sought to determine the overall and disease-specific latency period for radiological appearance of new intracranial metastases for patients with metastatic involvement of the brain. Methods: A retrospective chart review of patients with intracranial metastases between 2008–2010 was conducted. For each patient, the following were recorded: cancer type, gender, age at diagnosis of primary cancer and first intracranial metastases, treatments (chemotherapy, whole-brain-radiotherapy (WBRT), radiosurgery), and latency period for radiological appearance of new intracranial metastases. Results: 137 patients with multiple metastatic tumors were included in our study. Majority (>90%) of patients received chemotherapy and WBRT. The latency periods for appearance of new metastases for different cancer types were (in months): breast 12.7, lung 11.3, colorectal 9.0, melanoma 6.6, renal cell 8.1, other 8.1. The overall average latency period was 10.1 months. There was no relation between latency period for new metastases and the following: age at diagnosis of metastases(p=0.174), age at treatment(p=0.199), and cancer type(p=0.124). The latency period for new metastatic lesions differed significantly between males (8.1 months) and females (11.7 months) (p=0.009). Conclusions: The average latency period for new metastases is approximately 10 months. Our data suggests that males develop new metastatic tumors at a faster rate.

Background: Intramedullary spinal cord metastasis (ISCM) are rare with primary lung, breast and melanoma accounting for up to 80% of cases. Diagnosis is often delayed or incorrect and these lesions can often be mistaken for primary astrocytoma or ependymoma given similar radiologic features. Methods: We present the case of an 80 year-old male with rapidly progressive quadriparesis and an enhancing intramedullary lesion at C4-7 with diffuse peri-lesional edema. The patient had previously undergone resection of non-metastatic esophageal carcinoma. Results: Bone scan revealed no evidence of skeletal or organ metastases. The patient underwent C5-7 laminectomy and resection of tumor with intra-operative monitoring. Final pathology revealed metastatic adenocarcinoma consistent with esophageal primary. PETCT revealed recurrent esophageal disease and pleural-based metastatic deposits. The patient went on to receive palliative radiotherapy to the cervicothoracic spine. Neurologic status improved marginally. Conclusions: ISCM from primary esophageal carcinoma is extremely rare. We present to our knowledge one of three reports of such in the literature. Hematogenous dissemination via Batson’s plexus and peri-veretebral plexuses is thought to be the likely route of spread. Treatment is primarily palliative, however surgical resection should be considered in the absence of metastatic disease.

Background: Gangliocytoma is a WHO grade 1 tumour which is typically found in the brain. Incidence of this pathology occurring in the spinal cord is rare, accounting for 0.1%-0.4% of intramedullary spinal cord tumors. Methods: We present the case of a previously healthy 23-year-old male with bilateral weakness and accompanying sensory deficits progressing over several months. Magnetic resonance imaging (MRI) of the spine showed a C3-C6 enhancing, intramedullary mass. C3-6 laminoplasty and resection of the tumour was preformed under neurophysiologic monitoring. Post-operatively the patient had no new neurologic deficits. Results: Final histopathology was consistent for gangliocytoma with extensive calcifications as confirmed by two separate neuropathologists. Gross total resection was not possible due to decreased motor evoked potentials detected by electrophysiologic monitoring. Post-operative MRI revealed a residual tumour measuring 58×15×25 mm with no further abnormal foci of enhancement. Conclusions: Gangliocytoma of the cervical cord is exceedingly rare, however its natural history is unclear. In our experience, maximal safe resection is warranted with the goal of preserving neurological status.