Sophia Shakur

Sophia Shakur
Mills-Peninsula Health Services

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59
Publications
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Publications

Publications (59)
Article
BACKGROUND AND IMPORTANCE Extracranial-intracranial (EC-IC) bypass anastomosis-associated aneurysms are rare sequelae of cerebral revascularization surgery. Although treatment paradigms are not well defined, clipping, trapping with revision bypass, and donor vessel ligation represent the most common microsurgical approaches. CLINICAL PRESENTATION...
Article
Surgical resection is considered to be the treatment of choice for carotid body tumors. However, surgery can be complicated by intraoperative bleeding, injury to the internal carotid artery, and cerebral ischemia. Consequently, preoperative endovascular strategies including transarterial or percutaneous embolization or covered carotid stenting may...
Article
Onyx (ethylene vinyl alcohol, ev3, Irvine, California, USA) is commonly used to treat dural arteriovenous fistulas (DAVFs) and presents several advantages over n-butyl cyanoacrylate glue (Codman Neurovascular Inc, Raynham, Massachusetts, USA) including slower, more controlled injections and better penetration via radial casting. However, Onyx is no...
Article
Flow diversion technology has revolutionized the treatment of complex anterior circulation cerebral aneurysms. However, vessel tortuosity and atherosclerotic disease may hamper the standard transfemoral access used in these procedures. Percutaneous direct carotid puncture is a viable alternative, but adequate carotid closure must be achieved. Here,...
Chapter
Over years, neurosurgical training is changing: sophisticated clinical skills to learn are challenged by catastrophic consequences in case of surgical mistakes, and patient safety and procedure efficacy have a higher priority than educational training. Practice, though, is the mainstay for surgical learning and skills improvement, and simulation mo...
Article
OBJECTIVE The pathogenesis of cerebral aneurysms in patients with internal carotid artery (ICA) occlusion is hypothesized to be hemodynamic. For the first time, the authors quantify the hemodynamic characteristics associated with aneurysm formation in patients with ICA occlusion. METHODS Records of patients with unilateral ICA stenosis or occlusio...
Article
Objective Pipeline embolization devices (PED) are commonly used for endovascular treatment of cerebral aneurysms but changes in intracranial hemodynamics after PED deployment are poorly understood. Here, we assess middle cerebral artery (MCA) and systemic blood pressure before and after PED treatment. Methods Records of patients with cerebral aneu...
Article
Objective: The pathogenesis of venous intimal hyperplasia and venous outflow stenosis associated with cerebral arteriovenous malformation (AVM) draining veins is poorly understood. We sought to determine the relationship between venous stenosis and age. Methods: All patients with an AVM seen at our institution between 1990-2016 who underwent a d...
Article
Background Pipeline embolization devices (PEDs) are used for endovascular treatment of cerebral aneurysms but can be associated with delayed ipsilateral intraparenchymal hemorrhage (DIPH). Changes in intracranial hemodynamics after PED are poorly understood. Objective Here, we assess hemodynamic changes after PED in patients and compare these chan...
Article
Objective The pathogenesis of venous outflow stenosis associated with cerebral arteriovenous malformation (AVM) draining veins is poorly understood. We sought to determine the relationship between venous stenosis and atherosclerotic risk factors. Materials and methods All patients with an AVM seen at our institution between 1990 and 2016 were retr...
Article
Background: and Purpose Digital subtraction angiography (DSA) provides an excellent anatomic characterization of cerebral vasculature, but hemodynamic assessment is often qualitative and subjective. Various clinical algorithms have been produced to semi-quantify flow from data obtained from DSA, but few have tested these against reliable flow valu...
Article
Background: The relationship between cerebral aneurysm size and risk of rupture is well documented, but the impact of aneurysms on distal intracranial hemodynamics is unknown. Objective: To examine the relationship between aneurysm size and distal intracranial hemodynamics prior to treatment. Methods: Patients seen at our institution between 2...
Article
Background: Digital subtraction angiography (DSA) currently provides angioarchitectural features of cerebral arteriovenous malformations (AVMs) but its role in the hemodynamic evaluation of AVMs is poorly understood. Objective: To assess contrast time-density time (TT) on DSA relative to AVM flow measured using quantitative magnetic resonance an...
Article
BACKGROUND Giant aneurysms are very high-risk lesions both in terms of natural history and treatment. Bypass with distal occlusion is thought to be a safe treatment option for these aneurysms. Here, we report two cases of aneurysm rupture after bypass and distal occlusion, review the literature, and discuss the possible underlying mechanisms, in th...
Article
Background: Subarachnoid hemorrhage cases with multiple cerebral aneurysms frequently demonstrate a hemorrhage pattern that does not definitively delineate the source aneurysm. In these cases, rupture site is ascertained from angiographic features of the aneurysm such as size, morphology, and location. Objective: To examine the frequency with wh...
Article
Objective: Pipeline Embolization Devices (PED) are commonly used for endovascular treatment of cerebral aneurysms but can be associated with delayed ipsilateral intraparenchymal hemorrhage (DIPH). The role that altered intracranial hemodynamics may play in the pathophysiology of DIPH is poorly understood. We assess middle cerebral artery (MCA) flo...
Article
Orbital lesions are challenging to access due to their location amidst critical anatomical structures. Here, we demonstrate direct transorbital cannulation of an orbital venous varix using image guidance. A 36-year-old male was diagnosed to have a left orbital venous varix approximately 5 years ago at an outside institution. He subsequently underwe...
Article
Balloon angioplasty is often performed for symptomatic vasospasm following aneurysmal subarachnoid hemorrhage. Angioplasty of the anterior cerebral artery (ACA), however, is perceived to be a challenging endeavor and not routinely performed due to technical and safety concerns. Here, we evaluate the safety and efficacy of balloon angioplasty of the...
Article
Background The hemodynamic evaluation of cerebral arteriovenous malformations (AVMs) using DSA has not been validated against true flow measurements. Objective To validate AVM hemodynamics assessed by DSA using quantitative magnetic resonance angiography (QMRA). Materials and methods Patients seen at our institution between 2007 and 2016 with a s...
Article
Background and purpose: The pathogenesis of venous intimal hyperplasia and venous outflow stenosis associated with cerebral arteriovenous malformation (AVM) draining veins is poorly understood. We sought to determine the relationship between maximum vein wall thickness and AVM flow. Methods: Patients who underwent AVM surgical resection and had...
Article
Introduction: Digital subtraction angiography (DSA) currently provides angioarchitectural features of cerebral arteriovenous malformations (AVMs) but its role in the hemodynamic evaluation of AVMs is poorly understood. Here, we assess transit time (TT) of contrast on DSA relative to AVM flow measured using quantitative magnetic resonance angiograph...
Article
Introduction: Digital subtraction angiography (DSA) has traditionally been used to provide high-resolution anatomical imaging but is not readily used to assess cerebral hemodynamics. Here we examine the relationship between time density transit time (TT) on DSA, vessel cross-sectional area and flow obtained from QMRA of the same artery. Methods: Pa...
Article
Introduction: The impact of aneurysms on distal cerebral hemodynamics is unknown. Here we examine the relationship between aneurysm size and distal hemodynamics prior to treatment. Methods: Patients seen at our institution between 2006-2015 with aneurysms within the cavernous or supraclinoid ICA segment (proximal to ICA terminus) were retrospective...
Article
It is postulated that hemodynamic changes occur in the distal vascular bed post deployment of Pipeline Embolization Devices (PED). In this paper, we evaluate changes in the contrast transit times (TT) on digital subtraction angiography (DSA) post PED interventions. DSA films were analyzed using custom-made software for the time-density relationsh...
Article
Objectives: Embolization reduces flow in cerebral arteriovenous malformations (AVMs) before surgical resection, but changes in pulsatility and resistance indices (PI, RI) are unknown. Here, we measure PI, RI in AVM arterial feeders before and after embolization/surgery. Methods: Records of patients who underwent AVM embolization and surgical res...
Article
BACKGROUND: Pipeline embolization devices (PEDs) are commonly used for endovascular treatment of cerebral aneurysms but can be associated with delayed ipsilateral intraparenchymal hemorrhage. Although intra-aneurysmal hemodynamic changes have been studied, parent vessel and intracranial hemodynamics after PED use are unknown. We examine the impact...
Article
The role that hemodynamics plays in the pathophysiology of cerebral arteriovenous malformation (AVM) hemorrhage remains unclear. Here, we examine the relationship of pulsatility and resistance indices to AVM angioarchitectural features and hemorrhage. Records of patients with cerebral AVMs evaluated at our institution between 2007-2014 and with flo...
Poster
Introduction/purpose Histopathological changes in cerebral arteriovenous malformation (AVM) draining veins secondary to chronically high AVM inflow have not been clearly elucidated. Here, we examine the relationship between draining vein wall thickness and AVM flow rate. Materials and methods Records of patients with cerebral AVMs evaluated at our...
Article
Background and purpose: Impaired cerebrovascular reserve in chronic steno-occlusive disease has been shown to be associated with poor leptomeningeal collaterals (LMCs) on digital subtraction angiography and increased stroke risk. We examined the relationship between the degree of LMCs and the flow change with Diamox challenge measured using quanti...
Article
Introduction: Embolization reduces flow in cerebral arteriovenous malformations (AVMs) before surgical resection, but changes in pulsatility and resistance indices (PI, RI) are unknown. Here, we measure PI, RI in AVM arterial feeders pre- and post-embolization/surgery. Methods: Records of patients who underwent AVM embolization and surgical resecti...
Article
Intranidal vessel geometry and organization underlying flow within cerebral arteriovenous malformations (AVM) is poorly understood. We examine the relationship between intranidal vessel characteristics and AVM flow. Records of patients with AVM evaluated at our institution between 2007 and 2013 were retrospectively reviewed. Patients were included...
Article
Full-text available
Background: To determine the utility of digital subtraction angiography (DSA) in patients with unruptured intracranial aneurysms (UIA) detected on noninvasive imaging, such as magnetic resonance angiography (MRA) and computed tomography angiography (CTA). The follow-up of patients with untreated UIAs involves serial imaging; however, this diagnosi...
Article
Background: Graft selection in extracranial-intracranial bypass surgery for cerebral aneurysms has traditionally been based on clinical impression and operator preference. However, decision making can be optimized with a donor selection algorithm based on intraoperative flow data. Objective: To present long-term follow-up and quantitative assess...
Article
Pial arteriovenous malformations (AVMs) of the brain are vascular abnormalities located in the subpial space that consist of direct communications from artery to vein via intervening nidus. AVMs are the most common intracranial pathology and frequent cause of intracranial hemorrhage in children. Moreover, the epidemiology and clinical findings part...
Article
Simulation-based training may be incorporated into neurosurgery in the future. To assess the usefulness of a novel haptics-based virtual reality percutaneous trigeminal rhizotomy simulator. A real-time augmented reality simulator for percutaneous trigeminal rhizotomy was developed using the ImmersiveTouch platform. Ninety-two neurosurgery residents...
Article
The pathogenesis of aneurysms associated with cerebral arteriovenous malformation (AVM) feeder vessels is poorly understood. We sought to determine the hemodynamic characteristics of AVM feeder vessels with and without aneurysms. Patients with AVMs associated with feeder aneurysms who had flow, vessel diameter, and wall shear stress measured before...
Article
Wall shear stress (WSS) has been implicated as an important stimulus for vascular remodeling. The purpose of this study is to measure WSS in AVM arterial feeders using quantitative magnetic resonance angiography pre- and post-embolization/surgery. Records of patients who underwent AVM embolization and surgical resection at our institution between 2...
Article
Embolization reduces flow in arteriovenous malformations (AVMs) before surgical resection, but achievement of this goal is determined subjectively from angiograms. Here, we quantify effects of embolization on AVM flow. Records of patients who underwent AVM embolization at our institution between 2007 and 2013 and had flow rates obtained pre- and po...
Article
Carotid artery stenting is an endovascular treatment option for patients with extracranial carotid stenosis. However, intracranial blood flow changes following stenting have not been established. To determine the effects of stenting on intracranial blood flow. Records of patients who underwent stenting at our institution between 2004 and 2012 and h...
Article
Background and purpose: The hemodynamic effects of extracranial carotid stenosis on intracranial blood flow are not well characterized. We sought to determine the impact of degree of stenosis, stenosis length, and residual lumen on intracranial blood flow in patients with extracranial carotid stenosis. Methods: Carotid stenosis patients who had...
Article
Objectives: To determine the effects of extracranial carotid stenting on intracranial blood flow. Methods: Records of patients who underwent stenting for extracranial carotid stenosis at our institution between 2004-2012 and had flow rates obtained pre and post stenting using quantitative magnetic resonance angiography were retrospectively reviewed...
Article
Objectives: To determine the effects of degree of stenosis, stenosis length, and residual lumen on intracranial blood flow in patients with extracranial carotid stenosis. Methods: Records of patients who underwent stenting for extracranial carotid stenosis at our institution between 2004-2012 and had flow rates obtained using quantitative magnetic...
Article
Full-text available
Chordomas located primarily in the sellar region are uncommon, and may be misdiagnosed non-functioning pituitary adenoma. Furthermore, the association of a persistent primitive trigeminal artery (PPTA) with an intrasellar chordoma is extremely rare, and no similar cases have been reported in the literature to date. The coexistence of intrasellar ch...
Article
Neurocytomas are tumors or neuronal differentiation, typically located within the supratentorial ventricular system. The extraventricular location is uncommon. A limited number of cases involving the brainstem have been reported and may be misdiagnosed as brainstem gliomas. Furthermore, midbrain neurocytomas are extremely rare, and no similar cases...
Article
Background context: Spinal fibromatosis is a unique subset of fibromatosis that is only anecdotally described in the literature in sporadic case reports. According to our review of the literature, only 11 cases of spinal fibromatosis have been previously documented. This paucity of clinical data limits our understanding of its presentation and tre...
Article
Full-text available
Cerebral vasospasm is a well-known consequence of aneurysmal subarachnoid hemorrhage (SAH) triggered by blood breakdown products. Here, we present the first case of cerebral vasospasm with ischemia following a spontaneous spinal SAH. A 67-year-old woman, who was on Coumadin for atrial fibrillation, presented with chest pain radiating to the back ac...
Article
Full-text available
Glioblastoma (GBM) rarely presents as an infratentorial tumor in adults. The authors present a case of concomitant supratentorial and infratentorial GBM in an adult. A 72-year-old man presented with headache, nausea, vomiting, and lightheadedness. Initial MR images revealed enhancing masses in the right cerebellum and right posterior periventricula...
Article
Ocular melanoma is a rare type of malignant melanoma. Melanoma metastatic to the spine typically arises within the vertebral column, presents with back pain, and has a poor prognosis. We present a patient with a unique disease course: ocular melanoma metastasis occurred after an extended latency period of 14 years, attained a large size within the...
Article
Full-text available
The tyrosine kinase receptor epidermal growth factor receptor (EGFR) can be activated by several ligands, thus triggering downstream pathways regulating cell growth and survival. Its dysregula­tion is particularly important for the development and progression of astrocytomas. After the description of its role in glioblastomas (WHO grade IV astrocyt...
Article
The tyrosine kinase receptor epidermal growth factor receptor (EGFR) can be activated by several ligands, thus triggering downstream pathways regulating cell growth and survival. Its dysregula­tion is particularly important for the development and progression of astrocytomas. After the description of its role in glioblastomas (WHO grade IV astrocyt...
Article
The authors present the first case of spontaneous radiographic resolution and subsequent redemonstration of Gd enhancement of an untreated glioblastoma. They also review the literature on MR imaging enhancement patterns of high-grade gliomas and speculate that this phenomenon could be attributed to the dynamic biology of glioblastomas but could als...
Article
Vagus nerve stimulation (VNS) was introduced as a novel method for the treatment of patients with medically and/or surgically refractory epilepsy. VNS typically involves placement of the electrode on the left vagus nerve. However, there are some patients who cannot be implanted on this side because of complications related to the surgical procedure...
Article
Solitary primary melanocytic tumors of the central nervous system (CNS) represent a spectrum of lesions ranging from well-differentiated melanocytoma to melanoma. The association of a meningeal melanocytoma with an ipsilateral nevus of Ota is extremely rare, with only six cases reported in the literature to date. Only a minority of melanocytic tumo...

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