Background: Patients suffering from traumatic brain injury (TBI) are at increased risk of venous thromboembolism (VTE). However, initiation of chemoprophylaxis (VTEp) may cause further intracranial hemorrhage. We reviewed the literature to determine the post-injury time interval at which VTEp can be administered without risk of TBI evolution and hematoma expansion. Methods: MEDLINE and EMBASE databases were searched. Inclusion criteria were: studies investigating timing and safety of VTEp in TBI patients not previously on oral anticoagulation. Two investigators extracted data and graded the papers based on levels of evidence. Results: A total of 408 studies were screened. Forty-five studies were reviewed in-entirety and 21 were included in the systematic review. There were 2 prospective randomized trials and 19 comparative studies. Eighteen total studies demonstrated that VTEp post injury in patients with stable head computed tomography scan does not lead to TBI progression. Fourteen studies demonstrated that VTEp administration specifically 24–72 hours post injury is safe in patients with stable injury. Four studies suggested that administering VTEp within 24 hours of injury in patients with stable TBI does not lead to progressive ICH. Conclusions: Literature suggests that administering VTEp 48 hours post-injury may be safe for patients with low-hemorrhagic risk TBIs and stable injury on repeat imaging.

Background: Multiple myeloma (MM) as a cause of spontaneous intracranial hemorrhage has not been well established. Methods: We report a patient who developed a spontaneous intracerebral hemorrhage secondary to MM and conduct a systematic review of the literature. In addition, we discuss the underlying pathophysiology. Results: A 67-year-old relatively healthy female with a recent history of low back pain presented with an altered level of consciousness and left sided hemiplegia. CT demonstrated a large right temporal intracerebral hemorrhage. CT angiogram ruled out a vascular abnormality; however, multiple abnormal bony lesions were incidentally noted. Other causes for intracranial bleed were ruled out. She underwent a craniotomy for hematoma evacuation. Intra-operatively, the skull was noted to be abnormal and hematoma was not associated with a mass lesion. In addition, serum and urine electrophoresis were found to be positive for monoclonal free kappa light chains. Subsequent bone biopsy confirmed the diagnosis of MM. Our literature search identified 2 reported cases of spontaneous subdural hematomas and 2 patients with spontaneous intracerebral hematomas secondary to MM. Moreover, only 4 reports in the literature document intracranial hemorrhage secondary to a mass developed from MM. Conclusions: Multiple myeloma is perhaps an under-reported possible cause for spontaneous intracerebral hematoma.

Background: In 1963, Ayub Ommaya proposed a surgical technique for placement of a subcutaneous reservoir and pump to allow access to intraventricular cerebrospinal fluid (CSF). Currently, the most common indication for Ommaya reservoir insertion in adults is for patients with hematologic or leptomeningeal disorders who require repeated injection of chemotherapy into the CSF space. Historically, the intraventricular catheter has been inserted blindly based on anatomical landmarks. The purpose of this study was to determine short-term complication rates from Ommaya reservoir placement in the image-guidance era. Methods: We retrospectively evaluated all operative cases of image-guided Ommaya reservoir insertion from 2004-2014 by the senior author (JFM). Patient demographic data and peri-operative complications were collected. Results: We identified 28 patients over the study period (43.3+/-17.3 years; 64.3% male). Indications for placement included acute lymphoblastic leukemia, diffuse large B-cell lymphoma, and leptomeningeal carcinomatosis. There was one asymptomatic peri-operative intracranial hemorrhage (3.6%), and one early infection (3.6%). All catheters were well-positioned and functional. Conclusions: In our retrospective single-centre case series, all catheters were placed accurately. Our results support routine use of intra-operative image guidance for proximal catheter insertion in elective Ommaya reservoir placement for intraventricular chemotherapy.

Background: The etiology and treatment of pulsatile tinnitus is difficult and there are different causes for it. To our knowledge, an obstruction of the transverse sinus due to tentorial meningioma has not been reported. Methods: A 66 year old female presented a year ago with a sudden onset of a hissing sound in her ear which has persisted since. Neurologically she was intact. She was seen by otolaryngology who identified no cause for her tinnitus. A CT scan and MRI showed a tentorial meningioma on the right side with partial obstruction of the transverse sinus with evidence of partial chronic thrombus. Results: Removal of the meningioma with decompression of the transverse sinus resulted in immediate disappearance of the pulsatile tinnitus. Conclusions: This report can be added to the etiology of the difficult entity of pulsatile tinnitus particularly as it relates to its management.

Background: The infratemporal fossa is an anatomically complex region. Lesions that arise in the infratemporal fossa are uncommon; however, their surgical resection remain challenging. Here we present a modified preauricular subtemporal approach initially described by Obwegeser et al. used in four patients with large skull base lesions. Methods: Retrospective case series of 4 patients Results: Four patients with various lesions of the infratemporal fossa (aneurysmal bone cyst, giant cell tumor of the bone, recurrent melanoma and recurrent clival chordoma) underwent surgical resection using the modified Obwegeser approach. A multidisciplinary team cared for patients consisting of maxillofacial surgery, otolaryngology and neurosurgery. After either nasotracheal intubation or tracheostomy, the patient’s jaw was temporarily wired shut. A curvilinear incision was fashioned and the root of zygoma was exposed (masseter attached) and osteotomized followed by inferior mobilization. The mandibular condyle is osteomized next and TMJ disarticulated with temporalis muscle still attached and reflected superiorly. Surgical resection of tumor then proceeded centered around the region bridging the temporal and infratemporal fossae. Reconstruction was carried out using plates and screws. Conclusions: The modified Obwegeser approach can provide safe and direct access to certain infratemporal fossa lesions with good cosmesis and functional outcome for patients without substantially increasing OR time.

Background: CAS is reported to have higher complication rates in elderly compared to younger patients. This effect may be a surrogate for unfavourable anatomy (tortuosity, arch/access vessel atheroma burden) for endovascular treatment. We report our experience with 42 highly selected patients with favourable anatomy in spite of age. Methods: From a cohort of 217 consecutive patients undergoing CAS at St Michael’s Hospital from 2010-2016, stroke and a composite outcome of stroke, MI or death at 30 days post procedure was recorded. We compared outcomes in patients below and above the age of 75. Results: In 217 patients, 175 (80.7%) were below and 42 (19.3%) were above age 75 years. The stroke rate was 1.7% (n=3) and 2.4% (n=1), for patients below and above age 75 years respectively (p=0.58). The composite outcome rate was 4.0% (n=7) and 4.8% (n=2) for patients below and above age 75 years respectively (p=0.69). Conclusions: Patients without high-risk anatomic features were selected for CAS treatment. In this selected group, outcomes for those older than 75 years are comparable to the younger age category. Complication rates were comparable to the results in major randomized symptomatic carotid trials.

Background: The CREST trial remains the most influential study regarding choice of treatment modality for carotid revascularization in the modern era. The effect of the CREST trial on patient outcomes and changes to clinical practice are yet to be fully elucidated. Methods: We report a cohort of 217 consecutive symptomatic average risk patients undergoing CAS at St. Michael’s Hospital, between 2010 and 2016. Outcome measures were stroke, MI and death at 30 days post procedure. Of the 217 patients, 42 were above the age of 75 (19%). Results: The 30-day combined stroke, MI and death outcome for all patients was 4.1%. One death occurred (0.46%) in a patient who suffered an MI. One disabling stroke (0.46%) and 3 mild strokes (1.38%) with full recovery by 6 months occurred. Overall 4 patients suffered an MI (1.84%). Conclusions: As a result of the CREST trial in our single institutional experience there has been a clear migration to treating average risk patients using CAS, a treatment previously reserved for high risk patients. In this average risk cohort we report favourable outcomes when compared to the CREST trial as well as the firmly established benchmarks for CEA complications derived from the NASCET trial.

Background: Abciximab is used for the treatment of thromboembolism occuring during endovascular procedures, however the experience with intra-arterial infusion is limited. The objective is to evaluate its safety and effectiveness during coiling complications. Methods: From an aneurysm coiling database, patients treated with intra-arterial abciximab due to thrombotic complications were selected. Patient were classified either as non-ruptured aneurysm for elective coiling or presenting with subarachnoid hemorrhage. They all had preand post-procedure cerebral angiography performed at our institution as part of routine work-up. Success rate was based on recanalization seen on cerebral angiography. Complications of using abciximab were reported. Results: 35 of 441 coiling patients had a thrombotic complication. 13 of them were treated using intra-arterial infusion of abciximab. 2 patients were male, median age 59. 6 patients presented with sub-arachnoid haemorrhage. 84 % of patients had at least partial recanalization, while 38 % experienced complete recanalization of the parent vessel. 45 % of patients had complications, none severe. 2 patients had aneurysm recanalization, 3 distal migration of thrombus and 1 had haemorrhage (non ruptured aneurysm). Conclusions: Inspite of being considered a safer alternative, use of intrarterial abciximab has potential risks, including hemorrhage, distal thromboembolism and aneurysm recanalization.

Background: We evaluated the effects of stents on carotid plaque and the arterial wall using carotid ultrasound in carotid stenting patients Methods: From a carotid stent database, 30 consecutive patients were selected. All had Doppler ultrasound performed pre and post-stenting. The diameters of the lumen at the level of stenotic plaque pre and post stenting, the dorsal and ventral plaque thickness, and of the outer arterial wall diameter were measured. Plaque thickness was measured at the level of maximal stenosis.Non parametric tests were used to determine whether the stent effect and luminal enlargement were based on wall remodeling or on total arterial expansion. Results: Patient was followed for an average of 22 months. 18 patients were male, average age 70 years. 87% were symptomatic ipsilateral to the side of stenosis. The luminal diameter increased post stenting in the region of severe stenosis. Plaque thickness, both ventrally, as well as dorsally decreased post stenting, with no significant difference between the ventral and dorsal plaque effects. The measured lumen in the stent increased over time post-stenting. Conclusions: Self-expanding nitinol stents alter the baseline ventral and dorsal plaque to a significant degree, and do not significantly affect the native arterial wall and the overall arterial diameter.

Background: Tri-axial systems are frequently employed in stroke interventions. In addition to more support, the distal access catheter can provide suction aspiration during a stent retrieval. We have recently adopted the 5F SOFIA as part of a tri-axial system for acute stroke interventions, and believe it has improved efficient recanalization. Methods: This is a retrospective case series of acute stroke interventions utilizing the 5 F SOFIA 125 cm distal access catheter. Cases were evaluated for distal location of the catheter, number of stent-triever passes, and final TICI score. We describe our angiographic technique. Results: Nine acute stroke cases were performed using the SOFIA catheter. LVOs were in the M1(6), M2 (2), distal basilar (1). The 5F SOFIA catheter was advanced into the M1 or Basilar artery in all cases. No dissections or spasm was seen in the catheterized intracranial artery. Mean stent-triever passes was 2 (1-4). Final angiographic results were TICI 3 (6), TICI 2b (2), and TICI 0 (1). Conclusions: Efficient thrombectomy is a key part of successful stroke recanalization. We report on our experience with a specific distal access catheter which has reduced the number of stent passes required to restore flow.

Background: Closed cell carotid stent fracture is rare. From our literature review, we present the first reported case in English literature of a carotid stent fracture post angioplasty for an in-stent stenosis. Methods: Case Report Results: 72-year-old male underwent left carotid stenting for symptomatic ulcerated stenosis of the proximal aspect of left ICA (71% stenosis with post-stenting 55% residual stenosis). His right ICA and right vertebral artery were occluded. 2 months later, he presented with TIA’s and severe in-stent stenosis in the proximal left ICA measuring 1 mm in diameter. Satisfactory balloon (5×40 mm) angioplasty was done with residual stenosis measuring 2.5 mm in diameter. 8 months later he presented with symptoms of compromised cerebral perfusion. Workup showed a stent fracture distally at the site of severe ICA stenosis secondary to atherosclerotic calcified plaque causing blood flow changes. His PSV (peak systolic velocity) in the left ICA was 383 m/s. As such he underwent left ICA re-stenting for symptomatic severe left ICA stenosis of 70% with 40% residual stenosis following stent deployment. Conclusions: Carotid stent fracture post balloon angioplasty for recurrent stenosis is rare but of paramount importance. We demonstrate re-stenting as a viable treatment modality when patient profile is not amenable to a surgical revascularization procedure.

Background: Virtual reality simulators allow development of novel methods to analyze neurosurgical performance. Force pyramids provide visual and spatial analysis of 3 dimensional force application by any instrument used during simulated tumor resection. This study was designed to answer three questions: 1) Do study groups have distinct force pyramids? 2) Do handedness and ergonomics influence force pyramid structure? 3) Are force pyramids dependent on visual and haptic characteristics of simulated tumors? Methods: NeuroVR (formerly NeuroTouch), a virtual reality simulator, continually assessed simulated ultrasonic aspirator force application of neurosurgeon, resident and medical student groups during resection of 18 simulated brain tumors with different visual and haptic characteristics. Results: Sixteen neurosurgeons, 15 residents and 84 medical students participated. Neurosurgeon, resident and medical students groups displayed easily distinguishable 3 dimensional ‘force pyramid fingerprints’. Neurosurgeons had the lowest force pyramids, indicating application of the lowest forces, followed by resident and medical student groups. Handedness, ergonomics, visual and haptic tumor characteristics resulted in distinct well-defined 3 dimensional force pyramid patterns. Conclusions: ‘Force pyramid fingerprints’ provide 3 dimensional spatial assessment displays of instrument force application during simulated tumor resections. Neurosurgeon force utilization and ergonomics data form a basis for understanding and modulating resident force application and improving patient safety during tumor resection.

Background: Because glioblastoma is currently incurable, the goal of therapy is the optimization of the patient’s quality of life (QOL). Tumor location is critical in screening surgical candidates, yet the impact of tumor location on QOL has never been demonstrated. By using a novel computer-driven algorithm, we set out to investigate the impact of tumor location on QOL. Methods: The tumors of fourty consecutive glioblastoma patients were segmented and the Euclidian distance between 90 brain regions and each tumor’s margin was calculated and correlated to the patients’ self-reported QOL as measured by the SNAS questionnaire. Results: QOL was statistically associated with proximity to three areas: the right para-hypocampal gyrus, the right posterior cingulate cortex and the right postcentral gyrus. We postulate that the adverse relation between proximity to these areas and QOL results from disruption in large-scale networks involved in high-order functions such as visuospatial memory. While harder to detect with a bedside clinical examination, such deficits are likely more impactful on QOL than those related to the motor cortex or Broca’s area. Conclusions: Tumor proximity to right parietooccipital region are associated with decreased QOL. This should be considered in the management strategies of glioma patients.

Background: This study aims to evaluate the impact of pre-operative functional magnetic resonance imaging (fMRI) on low grade glioma (LGG) patients’ outcomes. Methods: In this retrospective matched cohort study (N =48) of a single surgeon’s patients, we are comparing two groups of LGG patients (WHO grade II) based on exposure to fMRI. A 1:2 propensity score match from a pool of 764 brain tumour patients was performed. Results: Within the group of 16 LGG patients who have undergone fMRI studies over a 12-year period, mean age was 40 years, and most presented with seizures (81%). Most lesions were left-sided (81%), and the lobes most commonly involved were frontal (75%) and temporal (31%). Patients underwent either craniotomy (50%), stereotactic biopsy (25%) or nonsurgically management (25%). In surgical patients, between presurgical assessment and eight week post-surgical follow-up, mean modified Rankin scale improved from 1.80±0.79 to 1.50±0.97. In our cohort, 5-year mortality was 12.5% (patients followed for a mean duration of 5.46 years). Conclusions: Data analysis is ongoing with plans to compare relevant demographics and outcomes via 1:2 propensity score matching of LGG patients who underwent fMRI against a control cohort.

Background: Glioblastoma is the most common primary malignant brain tumor. Primary Glioblastoma (PriGO) cells are key drivers of glioblastoma. Senescence is the irreversible growth arrest of cells with continued metabolic activity. Recently, I discovered PriGO cells undergo premature senescence in response to Fetal Bovine Serum (FBS). Determining the underlying molecular mechanisms may allow development of novel therapeutic strategies to decrease the malignant potential of glioblastoma. Methods: Global gene expression changes in PriGO cells treated with serum were analyzed and compared to untreated cells. Senescence was determined by the Senescence-Associated-Beta-Galactosidase (SA-B-Gal) assay. Results: PriGO cells treated with serum demonstrated increased expression of genes in the Transforming Growth Factor Beta (TGF-B) pathway, such as Thrombospondin 1 (TSP1), compared to untreated cells. TGF-B treatment of PriGO cells significantly increased senescence compared to untreated cells. Treatment of PriGO cells with serum and the TGF-B inhibitor SB431542 led to a decrease in senescence compared to serum only treated cells. Treatment of PriGO cells with serum and the TSP1 inhibitor LSKL led to a reduction in senescence compared to serum only treated cells. Conclusions: Our data identifies TGF-B as an important component of serum responsible for inducing senescence in PriGO cells. Furthermore, TGF-B induced senescence in PriGO cells is in part mediated by TSP1.

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.