Background: Clear cell chondrosarcoma (CCC) is a rare, low-grade, subtype of chondrosarcoma. It arises most commonly in the epiphyses of the certain longbones. Spinal involvement is extremely rare, but when present it most frequently involves the thoracic spine. Complete surgical resection is the best curative treatment, with radiation therapy being a consideration for inoperable tumours. Methods: We report a case of a 70-year-old gentleman with CCC of the T7-8 thoracic spine. Gross en-bloc spondylectomy of the T6-8 vertebral bodies with expandable cage reconstruction and T3-11 instrumented fusion were performed. Results: Histological examination revealed a cellular neoplasm composed of well-defined, round to oval cells with abundant clear cytoplasm embedded in a loose cartilaginous matrix with large numbers of admixed osteoclast-type giant cells and scattered bone trabeculae between the lesional cells. The patient experienced significant improvement in neurological function and was discharged from hospital in stable condition seven days after surgery. Conclusions: CCC is a rare variant of chondrosarcoma that rarely involves the osseous spine. In this location, treatment may be challenging given the presence of spinal cord and nerve roots. Given the lack of effective chemotherapy and radiation therapy for CCC, en-bloc resection of CCC involving the spine should be considered.

Background: Immunosuppressive therapy is a risk factor for lymphoproliferative disorders. We present a case of primary CNS B-cell lymphoma in the setting of iatrogenic immunosuppression from azathioprine usage. A literature review is provided. Methods: Case report Results: 64-year-old male presents with several weeks of cognitive decline, impaired speech, and headache with a history of ulcerative colitis (on azathioprine and 5-ASA) with no radiological evidence of systemic malignancy. MR showed left frontal extra-axial mass (4.0 x 2.4 x 4.0 cm) with heterogeneous enhancement of a solid component with local dural thickening. The enhancing mass had solid and cystic components. Radiological differential included dural metastasis, atypical meningioma or unusual intra-axial mass including GBM with some dural involvement. He underwent surgical resection, which showed a primary CNS lymphoma, diffuse large B-cell, CD 20 + and EBV +. Post-operatively his cognition improved. Azathioprine was stopped and 5-ASA was increased. He proceeded with MPVC (methotrexate, procarbazine, vincristine, and cytarabine) chemotherapy. Conclusions: Our case shows isolated extra-nodal CNS manifestation of lymphoma in the context of immunosuppressive medications with strikingly atypical MR findings leading to a pre-operative diagnostic dilemma. Treatment is challenging and needs to be individually tailored due to a need for stopping immunosuppressive agents in conjunction with CNS lymphoma treatment.

Background: The purpose of the study was to evaluate the impact of BRAF inhibitors on survival outcomes in patients receiving stereotactic radiosurgery (SRS) for melanoma brain metastases. Methods: We prospectively collected treatment outcomes for 80 patients with melanoma brain metastases who underwent SRS. Thirty-five patients harbored the BRAF mutation (BRAF-M) and 45 patients did not (BRAF-WT). Results: The median overall survival from first SRS procedure was 11.2 months if treated with a BRAF inhibitor and 4.5 months for BRAF-WT. Actuarial survival rates for BRAF-M patients on an inhibitor were 54% and 41% at 6 and 12 months after radiosurgery, in contrast to 28% and 19% for BRAF-WT. Overall survival was extended for patients on a BRAF inhibitor if initiated at or after the first SRS. The local control rate did not differ based on BRAF status and was over 90%. Patients with higher KPS, fewer treated metastases, controlled systemic disease, RPA class 1 and BRAF-M patients had extended overall survival. Conclusions: Patients with BRAF-M treated with both SRS and BRAF inhibitors, at or after SRS, have increased overall survival. As patients live longer due to more effective systemic and local therapies, close surveillance and early management of intracranial disease with SRS will become increasingly important.

Background: On imaging, thrombosed aneurysms can be mistaken for tumor with potentially disastrous consequences. Methods: We present two cases of aneurysms mimicking tumor. Results:Patient 1 (6 months of left-sided facial weakness): MRI demonstrated a 3.3 cm, T1-isotense, T2-hypertense heterogeneous enhancing mass favored to represent a CPA schwannoma. Biopsy revealed a thrombosed aneurysm. DSA subsequently revealed an area of contrast penetration, treated by parent artery (AICA) obliteration. Two-year follow-up revealed stable occlusion with reduced mass effect. Patient 2 (1 year of headaches): Imaging demonstrated an extra-axial T1-mixed, T2-hyperintense heterogeneously enhancing mass in the left CPA adjacent to the vertebral artery, enlarging from 1.7 cm to 3.2 cm over 2 years. DSA revealed slow, crescentic filling with suggestion of arborisation distally. Patient deteriorated due to mass effect requiring a VP shunt and passed away from SAH 3 months later. Imaging review revealed crescentic filling of the remnant lumen on CE-MRA and signal voids on T2 in both cases, which may suggest the aneurysm diagnosis. However our cases did not have other features such as lamellated thrombus or pulsation artifact. Conclusions: Central contrast enhancement does not necessarily preclude the diagnosis of thrombosed aneurysm. The possibility of revascularization or penetration of contrast through the thrombus in giant aneurysms needs to be considered.

Background: Animal models of human cerebral aneurysms have been a vital part of the development of endovascular treatments for decades. Rabbit models have been successfully used to simulate the morphology and hemodynamics of human intracranial aneurysms. However, the lack of mechanical testing of human intracranial aneurysm tissue limits our understanding of the mechanisms of aneurysm rupture. The goal of this project is to develop techniques for the mechanical testing of fusiform aneurysms in a rabbit model. Methods: Fusiform aneurysms were created using the right carotid artery using an elastase-based method. Thirty fusiform aneurysms and healthy rabbit carotid artery samples were then collected from our lab and tested with a uniaxial and biaxial loading system. Rectangular strips of aneurysm and healthy tissue were obtained in the axial and circumferential direction with a micro-cutting instrument. The test samples were gripped by a custom-designed micro-clamp and placed in a bath of phosphate-buffered saline at 37˚C temperature. Results: Maximum stress of healthy and aneurysm arteries are 50 Kpa and 0.6 Kpa Conclusions: The strength of healthy tissue was significantly higher than tissue from the fusiform aneurysm. These techniques will provide us with strategies for the eventual testing of human intracranial tissue and may help us to understand mechanisms of aneurysm rupture.

Background: The diagnosis of cerebral vasospasm, either by digital subtraction angiography (DSA), or now more commonly by computerized tomographic angiography (CTA) occurs in up to 70% of patients with aneurysmal subarachnoid hemorrhage (aSAH). The lack of standardization among vasospasm grading has made its clinical correlation with delayed cerebral ischemia challenging Methods: 36 of the 764 aSAH patients found on the St. Michael’s Hospital RIS database had both DSA and CTA performed, at time of admission and again between day 2 and 14 following SAH. Two blinded neuroradiologists graded all vessels for vasospasm on two separate scales, by consensus for DSA and independently for CTA Results: Comparing CTA and DSA, Grading Scale (GS)1 had the highest Spearman Correlation Coefficient (SCC): 0.691 (P<0.001) for Rater (R)1, and 0.687 (P<0.001) for R2. SCC was higher when only considering proximal vessels. Cohen’s Kappa (CK) measuring inter-rater reliability was 0.695 (P<0.001) for GS2 and 0.681 (P<0.001) for GS1. CK was higher in anterior circulation vessels, and tended to decrease with increasing vasospasm grade. Conclusions: Although either scale will provide the benefits of standardization to clinical practice and research, GS1 is recommended as it is more intuitive and provides higher SCCs, with only slightly lower CKs.

Background: Flow diverters (FDs) are increasingly used for bifurcation aneurysms. Failure of aneurysm occlusion may be caused by residual flow maintaining patency of the jailed branch along with the aneurysm. Methods: Sixteen wide-necked lingual-carotid artery bifurcation aneurysms were created in 8 canines. Patent aneurysms were randomly allocated 4 weeks later to flow diversion combined with jailed branch occlusion using coils and/or Onyx (n=6) or flow diversion alone (n=8). Angiographic results of aneurysm occlusion at three months were scored using an ordinal scale. Pathology specimens were photographed and neointimal coverage estimated. Results: Fourteen aneurysms were patent at one month. FD deployment was successful in all cases, but at 3 month follow-up, 3 devices had prolapsed into the aneurysm. None of the bifurcation aneurysms treated with FD alone were occluded at 3 months. Endovascular branch occlusion combined with flow diversion significantly improved aneurysm occlusion rates (median angiographic score of 2) compared to flow diversion alone (median score of 0: P=0.0137). Flow-limiting parent vessel stenosis was not observed in any arteries. Devices were covered with thick neointima in most cases. Conclusions: Treatment failures following flow diversion of bifurcation aneurysms can be caused by persistent flow to the jailed branch. Branch occlusion combined with flow diversion may improve angiographic occlusion of canine aneurysms.

Background: We present a rare case of a left-sided carotid cavernous fistula (CCF) that presented 15 months post initial trauma with right-sided ophthalmic signs and symptoms. Highlighted is a contralateral endovascular approach to treating this traumatic CCF. Methods: Described is a case of a left-sided CCF caused by a self-inflicted gun shot wound to the head that was initially treated conservatively by neurosurgery and opthomology. The patient presented 15 months later with headache, acute right-sided periorbital swelling, severe right eye and facial pain. Results: Angiography confirmed the presence of a left-sided CCF with preferential drainage into the right cavernous sinus and right superior ophthalmic vein. The left internal carotid artery (ICA) was shown to be narrow and irregular. Multiple attempts to navigate the micro catheter through the vessel were unsuccessful. Instead, the fistula was embolized using a contralateral approach through the right internal carotid artery and across the anterior communicating artery. Imaging post-operatively confirmed successful occlusion of the CCF. Conclusions: This case is a rare example of a left-sided ICA occlusion secondary to trauma presenting 15 months after the initial injury with right-sided ophthalmic signs and symptoms. It is also one of only a few in the literature that describe successful treatment of traumatic CCF through a contralateral approach.

Background: Cross-clamp ischemia during carotid endarterectomy (CEA) can cause perioperative stroke. Selectively shunting patients based on intraoperative monitoring modalities that assess risk for ischemia can reduce the occurrence of immediate stroke. An experience with combined cerebral oximetry and stump pressure measurement to direct selective shunting is presented here. Methods: Study comparing intraoperative monitoring data, the decision to shunt, and presence of immediate post-operative deficits. Patients were shunted if either cerebral oxygen saturation dropped by more than 10% by cerebral oximetry, or stump pressure during cross-clamping was less than 40 mmHg. Cross-clamp ischemia was determined by the presence of ipsilateral neurological deficit upon awakening. Results: 245 patients were included in this study. 22% were shunted. Patients who were not shunted were significantly more likely to have collateral blood flow detected on angiography. Immediate post-operative stroke was not encountered in any of the patients included in the study. One patient who met shunting criteria but was excluded since he could not have a shunt inserted due to difficult anatomy did suffer stroke. Conclusions: With the dual-monitoring criteria presented here, 22% of patients were shunted. With the exception of one patient who could not have a shunt placed, no immediate post-operative stroke was encountered.

Background: Spinal dural arteriovenous fistulas (dAVF) are a significant but treatable cause of progressive myelopathy. The goal of treatment is disconnection of the fistula, which is often accomplished through an open surgical approach. We report two cases using a minimally invasive surgical (MIS) approach for dAVF ligation with intraoperative digital subtraction angiography (DSA) to confirm occlusion. Methods: Case report. Results: Two patients presented with progressive thoracic myelopathy and were identified to have fistulous connections at the left L1 and T8 levels respectively. Intraoperatively, a left femoral puncture was performed and a 5-French (40 cm) sheath was inserted. Patients were positioned prone and intraoperative spinal DSA was performed using the Siemens Zeego. Once the feeding radicular artery was visualized, image overlay and cross-hair laser was used to trace and localize the fistulous zone. A unilateral single level MIS hemi-laminectomy was performed. The fistulous zone and accompanying nerve root were exposed and small hemostatic clips were applied followed by surgically disconnection. Finally, intraoperatively video angiography as well as spinal DSA were performed for confirmation. Conclusions: MIS disconnection with intraoperative DSA is a safe and effective technique for treating spinal dAVFs. Patients benefit from quicker recovery and shorter hospital stay.

Background: Premature occlusion of draining veins during surgical resection of arteriovenous malformations (AVM’s) can lead to disastrous consequences. Interestingly, some authors have recently demonstrated effective endovascular trans-venous Onyx embolization of select AVM’s. Methods: Case report Results: A 71-year old female presented to the hospital with sudden onset right sided weakness and sensory change. Investigations revealed right fronto-parietal ICH secondary to a parasagittal Rolandic AVM with arterial supply from ACA and MCA branches. Drainage occurs via a single large cortical vein to the superior sagittal sinus. Partial intra-arterial embolization was initially performed. Surgical resection of the remaining nidus was deemed high risk. A craniotomy was performed and the large cortical draining vein was cannulated with a 4Fr micro-puncture system under direct visualization. A DMSO compatible micro-catheter was navigated retrograde close to the nidus. The draining vein was occluded using a surgical clip, and Onyx was immediately injected. Retrograde complete embolization of the AVM was observed. A total of 3ml of Onyx was injected, and the catheter was left in-situ. Patient was discharge 2 weeks later with minimal deficits. Conclusions: Open trans-venous embolization is a viable option for select AVM’s with a single draining vein and are not favorable candidates for trans-arterial embolization, surgery or radiation.

Background: Inflicted head injury is a major cause of infant morbidity and mortality. The extent of traumatic brain injury in infants is often best characterized by diffusion weighted magnetic resonance imaging. In this cases series we describe four infants aged 6-19 months, with small unilateral subdural hematomas secondary to abusive head trauma accompanied by extensive areas of restricted diffusion weighted imaging isolated to the cerebral white matter. Methods: Retrospective, single-centre case series of four children with small unilateral subdural hematomas with early and delayed MR imaging with diffusion weighted imaging. Results: In three cases there was acute diffusion restriction ispilateral to the subdural, while in one case diffusion restriction was present bilaterally. All patients had multiple seizures and bilateral multilayered retinal hemorrhages. After non-surgical treatment, all patients survived albeit with significant motor and cognitive deficits and significant cortical atrophy on long-term followup imaging. Conclusions: These four cases highlight that relatively small subdural hematomas following child abuse can manifest with extensive white matter injury only evident at early stages with diffusion weighted imaging. We propose that selective white matter injury as a result of either reperfusion or axonal degeneration in response to the initial insult accounts for this novel pattern of infantile traumatic brain injury.

Background: Community awareness, attitudes and beleifs toward pediatric patients diagnosed with congenital neurosurgical conditions is not known in the Saudi population and the number of studies is few worldwide. Such attitudes have a direct impact on the quality of life of patients with these congenital conditions. This study aims to demonstrate the variation in awareness, attitudes and believes in the public and among health-care professionals towards patients diagnosed with congenital neurosurgical conditions and its associated factors. Methods: A survey consisting of 36 questions pertaining to Hydrocephalus, Brain Tumors and Spina Bifida awareness, attitudes and believes was distributed to Saudi citizens living in the eastern province older than 15 years of age among hospitals visitors, medical students, nutritionists, physicians, dentists, pharmacists, and nurses. Results: The analysis of the 1002 respondent of the questionnaire shows clear social stigmata and improper awareness, attitudes and believes toward pediatric patients diagnosed with congenital neurosurgical conditions. There are variable parameters on interest measured and analyzed and there are certain patterns observed as well. Conclusions: The analysis showed the importance of health education for the public to increase the level of awareness and it justifies why these factors should be addressed in the middle of patients’ management, community awareness and health planning.

Background: Dysembryoplastic neuroepithelial tumors (DNETs) and gangliogliomas are the most common cause of tumor-related seizures in children and adolescents. Little is known about predictors of surgical success, in terms of seizure freedom. All relevant papers since 1995 were identified. Methods: Over 4000 abstracts were screened on MedLine to identify data comparing tumor type (DNET vs. ganglioglioma) and predictors of post-operative seizure freedom. Results: Seventeen papers were identified encompassing 97 DNET and 95 ganglioglioma patients. Fifteen patients were found with other neuroglial tumors (NGT) or NGT not-otherwise-specified. DNET patients were found to have less frequent seizures, more likely to have second lobe involvement, and to achieve gross total resection. Seizure freedom was achieved in roughly 80% of patients, with no distinction by tumor type, with no surgery-related or peri-operative deaths. For DNETs, seizure freedom was associated with shorter seizure duration, simple lesionectomy, gross total resection, and shorter duration of follow-up. In ganglioglioma patients, seizure freedom was associated with younger age at surgery, secondary generalization (unexpectedly), absence of dysplasia, and gross total resection. Gross total resection was the strongest predictor. Conclusions: Epilepsy surgery for DNET and ganglioglioma had similar outcomes with gross total resection being the strongest predictor.

Background: Menkes disease is a rare, X-linked recessive disorder of the ATP7A gene, a copper transporter; resulting in systemic copper deficiency. The deficient function of copper-dependent enzymes manifests clinically with failure to thrive, seizures, hypotonia, coarse hair, connective tissue abnormalities, and neurodegeneration. Cerebral arteries are often elongated, tortuous, and fragile. Methods: This case report was prepared using the patient’s hospital chart, and a review of the literature undertaken using PubMed. Our case was subsequently compared and contrasted to known Menkes’ literature. Results: We present the case of a 2 month old male with Menkes disease who presented with new seizure onset in the setting of a Grade III intraventricular hemorrhage with hydrocephalus. He deteriorated into status epilepticus, and palliative care was instituted. On autopsy, pronounced tortuosity of his cerebral vasculature was noted, as well as a bilaterally cystic brain with an organizing hemorrhage on the ventral surface of the brainstem. Conclusions: Although Menkes disease often presents with seizures, neurologic deterioration, and abnormal cerebral vasculature; the quick demise subsequent to an intraventricular hemorrhage is somewhat unusual and discussed.

Background: Spontaneous sub-aponeurotic fluid collection (SSFC) is an uncommon and newly described entity of unknown etiology, observed in infants less than one year of age. In this paper, we report a series of 9 infants who presented to the Hospital for Sick Children with SSFC over the 2004 to 2015 period, focusing on the natural history of this rare condition. Methods: Data from the HSC was retrospectively reviewed. Patient age and gender, birth history, past medical history, laboratory findings, imaging characteristics, management, and outcome were analyzed. Results: Our case series consists of 4 males and 5 females, ranging from 5 weeks to 11 months of age. All cases of SSFC developed spontaneously over a period of days, and the infants had no history of injuries or hair manipulation. Six patients had a remote history of forceps or vacuum-assisted births. One patient experienced fluctuating fluid collection size over 4 months, but in all the cases, the collections resolved spontaneously without structural or infectious complications. Conclusions: This is the largest series describing SSFC to date, and summarizes the experience of a large academic neurosurgical center. SSFCs develop spontaneously without immediate preceding trauma, and an extensive hematology or child abuse workup is not necessary. A conservative approach with outpatient follow-up is advocated.

Background: The Spinal Instability Neoplastic Score (SINS) is used to assess mechanical instability based on radiographic and clinical factors. We conducted this study to evaluate the clinical utility of SINS in surgical decision-making in spinal metastasis and its association with metastatic epidural spinal cord compression (MESCC). Methods: We allocated 285 patients with spinal metastatic disease through a retrospective review. SINS was calculated using good-quality computed tomography. The degree of MESCC was assessed using 0 to 3 grading system. Results: Based on SINS, patients were categorized into stable (35.1%), potentially unstable (52.3%) and unstable (12.6%) groups. In the surgical intervention group, there was 69.5% treated with decompression and instrumented fusion, 17% with decompression alone, 8.5% with percutaneous vertebral augmentation and 5% with instrumented vertebral augmentation. A significantly higher proportion of patients with stable SINS (63.6%) were treated surgically without instrumentation (X2=10.6, P=0.005), whereas instrumentation was utilized in 87.5% of patients with unstable SINS. Grade 3 MESCC occurred in 65.5% of patients with unstable SINS, whereas 71.4% of patients with stable SINS had grade 0 MESCC (X2=42.1, P<0.001). Conclusions: SINS is associated with higher degrees of MESCC and plays an important role in surgical decision-making, facilitating assessment and recognition of spinal instability in need of urgent appropriate surgical interventions.

Background: This study aims to provide epidemiological data concerning spinal instability and patterns of metastatic invasion of the spine based on tumor histology. Methods: We allocated 285 patients with spinal metastatic disease through a retrospective review. SINS was calculated using good-quality computed tomography (CT) imaging studies. Spinal metastases were also grouped into intracompartmental, extracompartmental or multiple metastases. Results: Esophageal cancer was the least likely to be associated with instability with about 64% of cases being stable. The highest rate of instability scores was observed in breast carcinoma with 18% of cases graded as unstable. Renal cell carcinoma was associated with lytic spinal metastases whereas blastic metastases mostly occurred in prostate carcinoma (P<0.001). Whereas 68.1% of cases represented multiple metastases, the remainder was associated with either intracompartmental (13.3%) or extracompartmental (18.6%) disease. The highest degrees of spinal instability (intermediate and unstable categories) were associated with extra-compartmental metastatic disease (P<0.001). Conclusions: This study sheds light on the patterns of spinal metastatic disease and mechanical instability on the basis of tumor histology, utilizing standardized scoring systems. The utilization of such scoring systems allows for a standardized approach towards description and analysis of spinal metastasis facilitating clinical research in this avenue.

Background: The management of central cord syndrome (CCS) is controversial. There is a perception that CCS patients tend to improve without the need for surgical intervention. The purpose of this study was to compare the clinical improvements of patients with traumatic SCI, both with and without CCS. Methods: Nova Scotia Provincial Trauma Registry was retrospectively reviewed from 2005-2010. Improvement in the American Spinal Injury Association (ASIA) Impairment Scale (AIS) was determined after mean 5 months follow-up. Results: The study population comprised 96 cases with SCI, subdivided into cases with AIS grade A, non-CCS cases with AIS grades B-D and CCS cases. 88% of the non-CCS and 65% of the CCS patients underwent surgical decompression, with mean operative times being 71.6±137.8 and 102.9±144.6 post injury (p=0.45). The mean improvements in the mean ASIA motor scores for the three groups were 1.3±6.5 and 15.6±35.0 and 22.5±14.6 (p=0.004) respectively, with a statistically significant difference only between the CCS and AIS grade A groups (p<0.001). 20%, 54% and 10% of the patients respectively, underwent an improvement of ≥ one AIS grades (p=0.018, c2=8.0). Conclusions: This retrospective review investigates the natural history of CCS and explores the role of surgical intervention on optimizing patient outcome.

Background: Lumbar fusion for degenerative indications is associated with a great degree of practice variation. We summarize the current evidence on the comparative safety and efficacy of lumbar fusion, decompression alone, or non-operative care for degenerative indications. Methods: Literature search of electronic bibliographic databases was conducted. Comparative studies reporting validated measures of safety or efficacy were included. Treatments effects were calculated through DerSimonian and Laird random effects models. Results: We retrieved 62 studies (17 randomized controlled, 15 prospective, 15 retrospective, and 15 registries), enrolling a total 302,347 adult patients. Disability, pain, and patient satisfaction following fusion, decompression alone, or non-operative care were dependent on surgical indications and study methodology. Relative to decompression alone, the risk of reoperation following fusion was increased for spinal stenosis (relative risk [RR] 1.17, 95% CI 1.06 to 1.30, p<0.004) and decreased for spondylolisthesis (RR 0.71, 95% CI 0.59 to 0.84, p<0.001). In all indications, complications were more frequent following fusion (RR 1.88, 95% CI 1.37 to 2.58, p<0.001). Mortality and treatment modality were not associated. Conclusions: Improvements were greatest in patients undergoing fusion for spondylolisthesis while complications limited the role of fusion for spinal stenosis. The relative safety and efficacy of fusion for chronic low back pain suggested careful patient selection is required.