Intra-Arterial MR Perfusion Imaging of Meningiomas: Comparison to Digital Subtraction Angiography and Intravenous MR Perfusion Imaging.

BACKGROUND AND PURPOSE: To evaluate the ability of IA MR perfusion to characterize meningioma blood supply. METHODS: Studies were performed in a suite comprised of an x-ray angiography unit and 1.5T MR scanner that permitted intraprocedural patient movement between the imaging modalities. Patients underwent intra-arterial (IA) and intravenous (IV) T2* dynamic susceptibility MR perfusion immediately prior to meningioma embolization. Regional tumor arterial supply was characterized by digital subtraction angiography and classified as external carotid artery (ECA) dural, internal carotid artery (ICA) dural, or pial. MR perfusion data regions of interest (ROIs) were analyzed in regions with different vascular supply to extract peak height, full-width at half-maximum (FWHM), relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), and mean transit time (MTT). Linear mixed modeling was used to identify perfusion curve parameter differences for each ROI for IA and IV MR imaging techniques. IA vs. IV perfusion parameters were also directly compared for each ROI using linear mixed modeling. RESULTS: 18 ROIs were analyzed in 12 patients. Arterial supply was identified as ECA dural (n = 11), ICA dural (n = 4), or pial (n = 3). FWHM, rCBV, and rCBF showed statistically significant differences between ROIs for IA MR perfusion. Peak Height and FWHM showed statistically significant differences between ROIs for IV MR perfusion. RCBV and MTT were significantly lower for IA perfusion in the Dural ECA compared to IV perfusion. Relative CBF in IA MR was found to be significantly higher in the Dural ICA region and MTT significantly lower compared to IV perfusion.

Pediatric intracranial dural arteriovenous fistulas: age-related differences in clinical features, angioarchitecture, and treatment outcomes.

OBJECTIVE Intracranial dural arteriovenous fistulas (DAVFs) are rare in children. This study sought to better characterize DAVF presentation, angioarchitecture, and treatment outcomes. METHODS Children with intracranial DAVFs between 1986 and 2013 were retrospectively identified from the neurointerventional database at the authors' institution. Demographics, clinical presentation, lesion angioarchitecture, treatment approaches, angiographic outcomes, and clinical outcomes were assessed. RESULTS DAVFs constituted 5.7% (22/423) of pediatric intracranial arteriovenous shunting lesions. Twelve boys and 10 girls presented between 1 day and 18 years of age; boys presented at a median of 1.3 years and girls presented at a median of 4.9 years. Four of 8 patients ≤ 1 year of age presented with congestive heart failure compared with 0/14 patients > 1 year of age (p = 0.01). Five of 8 patients ≤ 1 year old presented with respiratory distress compared with 0/14 patients > 1 year old (p = 0.0021). Ten of 14 patients > 1 year old presented with focal neurological deficits compared with 0/8 patients ≤ 1 year old (p = 0.0017). At initial angiography, 16 patients harbored a single intracranial DAVF and 6 patients had 2-6 DAVFs. Eight patients (38%) experienced DAVF obliteration by the end of treatment. Good clinical outcome (modified Rankin Scale score 0-2) was documented in 77% of patients > 1 year old at presentation compared with 57% of patients ≤ 1 year old at presentation. Six patients (27%) died. CONCLUSIONS Young children with DAVFs presented predominantly with cardiopulmonary symptoms, while older children presented with focal neurological deficits. Compared with other pediatric vascular shunts, DAVFs had lower rates of angiographic obliteration and poorer clinical outcomes.

New-Generation Laser-lithographed Dual-Axis Magnetically Assisted Remote-controlled Endovascular Catheter for Interventional MR Imaging: In Vitro Multiplanar Navigation at 1.5 T and 3 T versus X-ray Fluoroscopy.

PURPOSE: To assess the feasibility of multiplanar vascular navigation with a new magnetically assisted remote-controlled (MARC) catheter with real-time magnetic resonance (MR) imaging at 1.5 T and 3 T and to compare it with standard x-ray guidance in simulated endovascular catheterization procedures. MATERIALS AND METHODS: A 1.6-mm-diameter custom clinical-grade microcatheter prototype with lithographed double-saddle coils at the distal tip was deflected with real-time MR imaging. Two inexperienced operators and two experienced operators catheterized anteroposterior (celiac, superior mesenteric, and inferior mesenteric arteries) and mediolateral (renal arteries) branch vessels in a cryogel abdominal aortic phantom. This was repeated with conventional x-ray fluoroscopy by using clinical catheters and guidewires. Mean procedure times and percentage success data were analyzed with linear mixed-effects regression. RESULTS: The MARC catheter tip was visible at 1.5 T and 3 T. Among inexperienced operators, MARC MR imaging guidance was not statistically different from x-ray guidance at 1.5 T (67% successful vessel selection turns with MR imaging vs 76% with x-ray guidance, P = .157) and at 3 T (75% successful turns with MR imaging vs 76% with x-ray guidance, P = .869). Experienced operators were more successful in catheterizing vessels with x-ray guidance (98% success within 60 seconds) than with 1.5-T (65%, P < .001) or 3-T (75%) MR imaging. Among inexperienced operators, mean procedure time was nearly equivalent by using MR imaging (31 seconds) and x-ray guidance (34 seconds, P = .436). Among experienced operators, catheterization was faster with x-ray guidance (20 seconds) compared with 1.5-T MR imaging (42 seconds, P < .001), but MARC guidance improved at 3 T (31 seconds). MARC MR imaging guidance at 3 T was not significantly different from x-ray guidance for the celiac (P = .755), superior mesenteric (P = .358), and inferior mesenteric (P = .065) arteries. CONCLUSION: Multiplanar navigation with a new MARC catheter with real-time MR imaging at 1.5 T and 3 T is feasible and comparable to x-ray guidance for anteroposterior vessels at 3 T in a vascular phantom.

Extent of collateralization predicting symptomatic cerebral vasospasm among pediatric patients: correlations among angiography, transcranial Doppler ultrasonography, and clinical findings.

OBJECT: Although the development and prevalence of cerebral vasospasm (CV) has been extensively investigated in adults, little data exist on the development of CV in children. The authors hypothesized that even though children have highly vasoreactive arteries, because of a robust cerebral collateral blood flow, they rarely develop symptomatic CV. METHODS: The authors retrospectively reviewed their university hospital's neurointerventional database for children (that is, patients ≤ 18 years) who were examined or treated for aneurysmal or traumatic subarachnoid hemorrhage (SAH) during the period 1990-2013. Images from digital subtraction angiography (DSA) were analyzed for the extent of CV and collateralization of the cerebral circulation. Results from transcranial Doppler (TCD) ultrasonography were correlated with those from DSA. Cerebral vasospasm on TCD ultrasonography was defined according to criteria developed for adults. Clinical outcomes of CV were assessed with the pediatric modified Rankin Scale (mRS). RESULTS: Among 37 children (21 boys and 16 girls ranging in age from 8 months to 18 years) showing symptoms of an aneurysmal SAH (comprising 32 aneurysms and 5 traumatic pseudoaneurysms), 17 (46%) had CV confirmed by DSA; CV was mild in 21% of these children, moderate in 50%, and severe in 29%. Only 3 children exhibited symptomatic CV, all of whom had poor collateralization of cerebral vessels. Among the 14 asymptomatic children, 10 (71%) showed some degree of vessel collateralization. Among 16 children for whom TCD data were available that could be correlated with the DSA findings, 13 (81%) had CV according to TCD criteria. The sensitivity and specificity of TCD ultrasonography for diagnosing CV were 95% and 59%, respectively. The time to CV onset detected by TCD ultrasonography was 5 ± 3 days (range 2-10 days). Twenty-five (68%) of the children had good long-term outcomes (that is, had mRS scores of 0-2). CONCLUSIONS: Children have a relatively high incidence of angiographically detectable, moderate-to-severe CV. Children rarely develop symptomatic CV and have good long-term outcomes, perhaps due to robust cerebral collateral blood flow. Criteria developed for detecting CV with TCD ultrasonography in adults overestimate the prevalence of CV in children. Larger studies are needed to define TCD ultrasonography-based CV criteria for children.

Density of thrombus on admission CT predicts revascularization efficacy in large vessel occlusion acute ischemic stroke.

BACKGROUND AND PURPOSE: Can lysability of large vessel thrombi in acute ischemic stroke be predicted by measuring clot density on admission nonenhanced CT (NECT), postcontrast enhanced CT, or CT angiogram (CTA)? METHODS: We retrospectively studied 90 patients with acute large vessel ischemic strokes treated with intravenous (IV) tPA, intra-arterial (IA) tPA, and/or mechanical thrombectomy devices. Clot density [in Hounsfield unit (HU)] was measured on NECT, postcontrast enhanced CT, and CTA. Recanalization was assessed by the Thrombolysis in Cerebral Infarction grading system (TICI) on digital subtraction angiography. RESULTS: Thrombus density on preintervention NECT correlated with postintervention TICI grade regardless of pharmacological (IV tPA r=0.69, IA tPA r=0.72, P<0.0001) or mechanical treatment (r=0.73, P<0.0001). Patients with TICI≥2 demonstrated higher HU on NECT (mean corrected HU IV tPA=1.58, IA tPA=1.66, mechanical treatment=1.7) compared with patients with TICI<2 (IV tPA=1.39, IA tPA=1.4, mechanical treatment=1.3) (P=0.01, 0.006, <0.0001 respectively). There was no association between recanalization and age, sex, baseline National Institute of Health Stroke Scale, treatment method, time to treatment, or clot volume. CONCLUSIONS: Thrombi with lower HU on NECT appear to be more resistant to pharmacological lysis and mechanical thrombectomy. Measuring thrombus density on admission NECT provides a rapid method to analyze clot composition, a potentially useful discriminator in selecting the most appropriate reperfusion strategy for an individual patient.

Vascular myelopathies.

Vascular abnormalities of the spinal cord are an important cause of myelopathy. Clinicians need to be aware of these disorders as they can present with a variety of neurologic symptoms ranging from acute spinal neurologic emergencies, relapsing/remitting spells to gradually progressive dysfunction. The unique topography and vascular anatomy of the spinal cord lends to the variety of clinical presentations. Both ischemic and hemorrhagic insults can occur. Increased clinical suspicion, better detection with newer imaging modalities and early treatment can often impact outcomes. The authors review clinical diagnoses, novel imaging, and advanced treatment modalities for the most common causes of vascular myelopathy.

Spinal dural arteriovenous fistulas and intrathecal venous drainage: correlation between digital subtraction angiography, magnetic resonance imaging, and clinical findings.

OBJECT: Spinal dural arteriovenous fistulas (SDAVFs) cause myelopathy through arterialization of the perimedullary venous plexus and venous congestion of the spinal cord. The authors hypothesized that the craniocaudal extent of engorgement of intrathecal draining veins between the fistula site and the point of drainage out of the thecal sac correlates with the degree of myelopathy. METHODS: A retrospective review of the authors' institution's radiology databases identified 31 patients with SDAVFs who had undergone digital subtraction angiography (DSA) and MRI examinations of the spine. The authors counted the number of vertebral body levels of spinal cord enhancement and intrathecal vessel enhancement on T1-weighted postcontrast MRI studies. They also counted the number of levels of cord hyperintensity and intrathecal flow voids on T2-weighted MRI studies. On DSA, the authors identified the number of vertebral body levels of dilated intrathecal draining veins and outflow points from intrathecal veins to epidural veins. Functional status of the patients at the time of diagnosis was assessed using the Aminoff-Logue scale (ALS). RESULTS: Enlargement of the intrathecal draining veins averaged 10 ± 7.7 spinal levels on DSA. Patients with enlarged draining veins extending 10 or more spinal levels on DSA had worse ALS scores (mean gait 3.4, mean micturition 1.5) than patients with draining veins extending fewer than 10 levels (mean gait 1.8, mean micturition 0.6; p = 0.009 and 0.02, respectively). The number of vertebral body levels of enlarged draining veins correlated with the ALS score (gait r = 0.42, p = 0.009; and micturition r = 0.55, p = 0.0006). More extensive enlarged draining veins were associated with more spinal cord T2 hyperintensity, T2 intrathecal flow voids, and T1 vessel enhancement but not cord enhancement. CONCLUSIONS: The craniocaudal extent of enlarged intrathecal veins draining SDAVF correlates with patient functional status, providing further insight into the pathophysiology of venous hypertensive myelopathy.

A paradigm for awake intraoperative memory mapping during forniceal stimulation.

A case report is presented detailing the successful use of awake intraoperative memory testing while using white matter stimulation in order to isolate the fornix tracks involved in memory function. The identification of the white matter tracks of the fornix that were involved in memory function was used to tailor the neurosurgical resection of a third ventricle tumor that was impinging on the fornix in order to successfully preserve memory functioning in the patient.

Aquaporin expression in the brains of patients with or without cerebral amyloid angiopathy.

Aquaporins have recently been identified as protein channels involved in water transport. These channels may play a role in the edema formation and alterations in microvascular function observed in Alzheimer disease (AD) and cerebral amyloid angiopathy (CAA). We investigated the expression of aquaporin 1 (AQP1) and aquaporin 4 (AQP4) in 24 human autopsy brains consisting of 18 with AD and varying degrees of CAA and 6 with no pathologic abnormalities using immunohistochemistry. In cases of AD and CAA, there was enhanced AQP4 expression compared with the age- and sex-matched controls. Aquaporin 4 immunoreactivity was prominent at the cerebrospinal fluid and brain interfaces, including subpial, subependymal, pericapillary, and periarteriolar spaces. Aquaporin 1 expression in AD and CAA cases was not different from that in age- and sex-matched controls. Double labeling studies demonstrated that both AQP1 and 4 were localized to astrocytes. Both enhanced AQP4 expression and its unique staining pattern suggest that these proteins may be important in the impaired water transport observed in AD and CAA.

Advances in the biology of cerebral cavernous malformations.

OBJECT: To provide a review of current, high-impact scientific findings pertaining to the biology of cerebral cavernous malformations (CCMs). METHODS: A comprehensive literature review was conducted using PubMed to examine the current literature regarding the molecular biology and pathophysiology of CCMs. RESULTS: In this literature review, a comprehensive approach is taken to review the current scientific status of CCMs. This includes discussion of molecular biology and animal models, ultrastructure and angioarchitectural features and immunological methods and hypotheses. CONCLUSIONS: Studies examining the molecular biology of CCMs have shown that genes involved in angiogenesis, blood-brain barrier formation, cell size regulation, vascular permeability and apoptosis play critical roles in the ontogeny of this disease. In vivo work suggests the likelihood of a "two-hit mechanism" resulting in somatic mosaicism and biallelic loss of angiogenic genes. The etiological effects of angioarchitecture and immune response within these lesions further complicate the pathophysiology. Future treatment endeavors will necessitate exploitation of the multiple facets of CCM formation to maximize success at CCM prevention or obliteration.

Moyamoya disease in children with congenital dwarfing conditions.

Congenital dwarfisms can be associated with a variety of vascular anomalies. Here, we describe 2 patients with congenital dwarfisms who presented with moyamoya syndrome and underwent indirect intracranial revascularization. The pathogenesis of moyamoya syndrome in this population is not well understood, but it is a major cause of stroke and early death in these patients, making their timely diagnosis and management critical.

Spontaneous thrombosis of neonatal vein of Galen malformation.

Vein of Galen malformations are rare congenital intracranial vascular malformations. Based on reports in the literature, spontaneous thrombosis or regression of these lesions is rare. Patients have variable outcomes from an asymptomatic course to death. The reasons behind spontaneous thrombosis are not entirely understood. Here the authors present a case of an infant diagnosed with a vein of Galen malformation in utero that subsequently went on to thrombose or regress. A review of the published cases on this phenomenon and the potential causality are discussed.

Cerebral arteriovenous malformations. Part 1: cellular and molecular biology.

OBJECT: The scientific understanding of the nature of arteriovenous malformations (AVMs) in the brain is evolving. It is clear from current work that AVMs can undergo a variety of phenomena, including growth, remodeling, and/or regression-and the responsible processes are both molecular and physiological. A review of these complex processes is critical to directing future therapeutic approaches. The authors performed a comprehensive review of the literature to evaluate current information regarding the genetics, pathophysiology, and behavior of AVMs. METHODS: A comprehensive literature review was conducted using PubMed to reveal the molecular biology of AVMs as it relates to their complex growth and behavior patterns. RESULTS: Growth factors involved in AVMs include vascular endothelial growth factor, fibroblast growth factor, transforming growth factor beta, angiopoietins, fibronectin, laminin, integrin, and matrix metalloproteinases. Conclusions Understanding the complicated molecular milieu of developing AVMs is essential for defining their natural history. Growth factors, extracellular matrix proteins, and other molecular markers will be the key to unlocking novel targeted drug treatments for these brain malformations.

Cerebral arteriovenous malformations. Part 2: physiology.

OBJECT: The scientific understanding of the nature of arteriovenous malformations (AVMs) in the brain is evolving. It is clear from current work that AVMs can undergo a variety of phenomena, including growth, remodeling, and/or regression-and the responsible processes are both molecular and physiological. A review of these complex processes is critical to directing future therapeutic approaches. The authors performed a comprehensive review of the literature to evaluate current information regarding the genetics, pathophysiology, and behavior of AVMs. METHODS: A comprehensive literature review was conducted using PubMed to reveal the angioarchitecture and cerebral hemodynamics of AVMS as they relate to lesion development. RESULTS: Feeding artery pressures, brain AVM compartmentalization, venous drainage, flow phenomena, and vascular steal are discussed. CONCLUSIONS: The dynamic nature of brain AVMs is at least in part attributable to hemodynamic and flow-related phenomena. These forces acting on an evolving structure are critical to understanding the challenges in endovascular and surgical therapy. As knowledge in this field continues to progress, the natural history and predicted behavior of these AVMs will become more clearly elucidated.

Fibromatosis presenting as a sacrococcygeal mass.

Most children older than a year who present with a sacrococcygeal mass have a malignant tumor. We describe an 8-year-old child with of a sacrococcygeal soft tissue mass that was completely resected with histologic findings consistent with fibromatosis. Fibromatosis is a deep-seated, musculoaponeurotic, borderline tumor that is rare in childhood and has a high incidence of local recurrence even after margin-free resection. We review and discuss management strategies for treatment of fibromatosis in children. This case represents the first report of fibromatosis presenting as a sacrococcygeal mass.

Intra-arterial calcium channel blocker infusion for treatment of severe vasospasm in traumatic brain injury: case report.

OBJECTIVE: The authors describe a case of severe traumatic arterial vasospasm and its subsequent management using angiography and multiple infusions of calcium channel blockers. CLINICAL PRESENTATION: A 26-year-old man presented with subarachnoid hemorrhage and an initial Glasgow Coma Scale score of 4 after a motor vehicle accident. The patient underwent a bifrontal craniotomy and right frontal decompressive craniectomy for bilateral frontal epidural and subdural hematomas secondary to subarachnoid hemorrhage. INTERVENTION: While the patient was in the intensive care unit, severe vasospasm developed, as documented by transcranial Doppler ultrasonography, cerebral blood flow monitoring, and angiography. The patient was treated on 3 separate days with either nicardipine or verapamil infusions during angiography. After each infusion, the middle cerebral artery diameter improved (diameter increased 23.1-60.5%). The arterial vasospasm eventually resolved after 22 days, and the patient was discharged to acute rehabilitation. Four months after discharge, the patient had a Barthel index of 90 and has relatively slow speech but was able to ambulate without assistance and follow complex commands. CONCLUSION: To our knowledge, this is the first reported case of multiple intra-arterial calcium channel blocker infusions for severe posttraumatic vasospasm, as assessed by transcranial Doppler ultrasonography, cerebral blood flow monitoring, and angiography. This case reinforces that arterial vasospasm does occur in response to traumatic brain injury and further demonstrates that treatment with calcium channel blocker infusions is associated with angiographic changes and a subsequent reversal of ischemic blood flow.

Long-term survival in a child with a central nervous system medulloepithelioma.

Central nervous system medulloepitheliomas are extremely rare and malignant (World Health Organization Grade IV) primitive neuroectodermal tumors (PNETs) that arise in childhood. Unlike other PNETs, medulloepitheliomas have a dismal prognosis, with only 2 reported cases in the literature in which the patient survived beyond 5 years after treatment. The authors report on the third known case of a child who survived longer than 5 years. A review of all the published cases of medulloepithelioma is also presented, and alternative treatment strategies for PNET tumors, including high-dose chemotherapy with stem-cell rescue, are discussed.

Osseous and vascular anatomical variations within the C1-C2 complex: a radiographical study using computed tomography angiography.

BACKGROUND: One of the limiting factors of C1-C2 fixation is the location of the vertebral artery (VA). The authors sought to assess the potential variations in atlanto-axial VA anatomy using computed tomography angiography (CTA). METHODS: Detailed measurements were made on digital images of 106 patients undergoing CTA at our institution (54 males, 52 females; mean age 56, range 20-86). Distances, diameters and angles of osseous and vascular elements of the atlanto-axial complex were measured. RESULTS: Optimal C1 and C2 screw trajectories demonstrated wide variations among patients. The size of the VA groove or foramen was not predictive of exact arterial location or size. CONCLUSIONS: The size, location and path of the VA cannot be precisely predicted by the appearance of osseous structures such as the transverse foramina and/or the VA groove. CTA provides additional information regarding the atlanto-axial complex, and should be considered as a useful adjunct in the preoperative evaluation of select patients.

Surgical outcomes of elderly patients with cervical spondylotic myelopathy.

BACKGROUND: Cervical spondylotic myelopathy is a potentially serious neurologic disorder that commonly presents with gait difficulty and hand dysfunction. Because the development of CSM is in large part related to advanced spondylosis and degenerative disk disease, elderly patients appear to be at an increased risk to develop this condition. The surgical outcomes of this patient population have been understudied; the authors seek to report their clinical results in a series of patients with CSM older than 75 years who underwent surgical treatment. METHODS: This report is composed of a cohort of 36 elderly patients (older than 75 years) and 34 younger patients (younger than 65 years) who underwent decompressive surgery for CSM at one institution between 2001 and 2005. The patients' functional status was evaluated preoperatively and postoperatively using the mJOA disability scale. RESULTS: The mean follow-up time in the elderly group was 24 months, with a range from 12 to 48 months. There was a statistically significant improvement between mean preoperative (11.3) and postoperative (14.4) mJOA scores (P< .0001). The younger group had a higher neurologic recovery rate (71%) than the elderly group (59%); however, this was not statistically significant (P= .29). The postoperative complication rate in the elderly population (38%) was higher than in the younger group (6%; P= .002). CONCLUSION: Elderly patients with CSM are likely to obtain neurologic improvement after decompressive surgery. Their postoperative complication rate is higher than that of younger patients, yet most complications appear to be self limiting and do not adversely affect neurologic outcome.

Endonasal microscopic removal of clival chordomas.

INTRODUCTION: Clival chordomas have traditionally been removed using a variety of anterior and lateral skull base approaches. Herein, we evaluate the outcomes of patients who underwent an extended endonasal transsphenoidal removal of a clival chordoma. METHOD: All consecutive patients with a clival chordoma treated using an endonasal microscope approach were identified. In 8 cases, frameless surgical navigation was used, and in 4 cases, endoscopic assistance was used. Patients treated with prior radiotherapy were excluded. RESULT: Over 5 years, 18 procedures were performed on 14 patients (7 females; mean age, 47 years). Patients were followed from 3 to 58 months (median, 20 months). Mean tumor diameter was 32 +/- 17 mm; 7 (50%) patients had intradural extension. Postoperative MRIs after the initial operation showed gross total, near-total (>90%), and subtotal resection in 43%, 43%, and 14% of patients, respectively. Use of the endoscope was associated with gross total or near-total tumor removal in 4 of 4 cases. Tumor regrowth occurred in 2 (14%) cases 10 and 12 months after the initial surgery and before radiotherapy. Two patients had multiple operations, in one as a planned staged operation, and in the other, 3 additional debulkings were performed despite an initial gross total removal. Nine patients, all with CS invasion, had subsequent stereotactic radiation. Of 10 patients with cranial neuropathy, 80% improved or resolved including 75% and 67% of sixth and fifth CN palsies, respectively. Complications included one each of adrenal insufficiency and chemical meningitis. There were no CSF leaks or new neurological deficits. CONCLUSION: In this small series with relatively short follow-up, endonasal microscopic removal of clival chordomas proved safe and elfective with gross total or near-total removal in 86% of patients and improvement of cranial neuropathy in 80% of patients. Endoscopy for aiding tumor removal and assessing completeness of resection, as well as surgical navigation, are recommended for all cases.