Contrast extravasation on computed tomographic angiography mimicking a basilar artery aneurysm in angiogram-negative subarachnoid hemorrhage: report of 2 cases.

BACKGROUND AND IMPORTANCE: Contrast extravasation on computed tomography angiography (CTA) is becoming more common, with increasing use of CTA for myriad intracranial vascular pathologies. This article describes the first 2 documented cases of contrast extravasation from a nonaneurysmal basilar artery source seen on CTA and discusses possible pathophysiologic mechanisms. CLINICAL PRESENTATION: We present 2 cases of diffuse atraumatic subarachnoid hemorrhage in which the CTA showed an abnormality in association with the basilar artery highly suggestive of a ruptured aneurysm. Follow-up digital subtraction angiography, however, was completely negative. Subsequent repeat digital subtraction angiography failed to reveal a vascular lesion. Both patients were treated for complications associated with SAH, but given the negative digital subtraction angiography, no intervention was performed. CONCLUSION: Because of the frequent use of CTA, contrast extravasation is an increasingly common observation. Physicians should be aware that basilar artery extravasation can mimic the appearance of an aneurysm.

Clinical utility of quantitative magnetic resonance angiography in the assessment of the underlying pathophysiology in a variety of cerebrovascular disorders.

BACKGROUND: Quantitative MRA (qMRA) is a relatively new technique that uses traditional time-of-flight and phase-contrast MRI to visualize extracranial and intracranial vascular anatomy and measure volumetric blood flow. We aimed to assess the clinical utility of qMRA in assessing the hypothesized pathophysiology (HP) in a range of cerebrovascular diseases. Moreover, we postulated that evaluation of the arterial waveforms, can improve the evaluation of the hypothesized pathophysiology by qMRA. METHODS: We reviewed studies from 10 patients who underwent qMRA examinations before and after their treatments. Two reviewers assessed the anatomy, volumetric flow rates and arterial waveforms for each vessel sampled and reached a consensus as to whether the above parameters supported the clinical diagnosis/hypothesized pathophysiology and the subsequent management. FINDINGS: All 20 qMRA studies were technically adequate. qMRA supported the HP in all 10 patients as determined by abnormal volumetric flow values in the affected vessels before treatment and by the correction of these abnormal values in the patients whose treatment was successful. Each of our five patients with occlusive disease/vasoconstriction demonstrated evidence of dampening of the arterial waveforms distally to the narrowed artery (parvus-tardus phenomenon). The parvus-tardus effect disappeared after treatment. CONCLUSION: qMRA is unique in combining time-of-flight MRA in a complementary manner with phase-contrast MRA to obtain volumetric flow values and potentially important physiologic information from arterial waveform analysis in patients with a range of cerebrovascular diseases during the course of a single MR examination.

The ARUBA trial: current status, future hopes.

BACKGROUND AND PURPOSE: Report on the status of an on-going National Institutes of Neurological Disorders and Stroke (NINDS)-supported clinical trial of management of unbled brain arteriovenous malformations. SUMMARY OF REVIEW: Begun in April 2007 with 3 centers, the trial has grown to 65 centers, and has randomized 124 patients through mid-June 2010 en route to the planned 400. The current literature continues to support the rationale for the trial. CONCLUSIONS: ARUBA is steadily approaching its monthly randomization goals and has already reached the number needed to test the maximum published interventional complication rates against the minimum hemorrhage rates for natural history.

De novo formation of large arteriovenous shunting and a vascular nidus mimicking an arteriovenous malformation within an anaplastic oligodendroglioma: treatment with embolization and resection.

The authors report the de novo occurrence and treatment of an arteriovenous lesion within an anaplastic oligodendroglioma in a patient with previously unremarkable brain imaging. Intracranial arteriovenous malformations (AVMs) are believed to be congenitally acquired lesions, and their association with brain neoplasms is extremely rare. Diagnostic imaging revealed a mass lesion with large arteriovenous shunts and a vascular nidus mimicking a true AVM. Histological and immunohistochemical testing showed an anaplastic oligodendroglioma mixed with an AVM. The clinical, radiological, and operative data are reviewed, as are the histopathological findings. To the authors' knowledge this is the first case of de novo occurrence of an arteriovenous lesion with large shunts and a vascular nidus within an anaplastic oligodendroglioma.

Aneurysmal rupture during coiling: low incidence and good outcomes at a single large volume center.

OBJECTIVE: To study the incidence and clinical outcomes of intraoperative aneurysm rupture (IOR) during endovascular coil embolization at a single large volume center and to review the literature on this subject to determine whether IOR rupture rate and mortality correlate with volume of aneurysms treated at a given center and years since the institution of Guglielmi detachable coils as a treatment modality. METHODS: We reviewed the aneurysm database at the Center for Endovascular Surgery since its inception (1997-2003) and reviewed 600 consecutively treated intracranial aneurysms in which coiling was attempted. All patients who sustained an IOR were studied. Procedural and follow-up angiograms as well as clinical outcomes were retrospectively reviewed. A literature review was conducted. RESULTS: Six patients (1.0%) experienced IOR (1.4% in acutely ruptured lesions, 0% in unruptured). All six had presented with diffuse subarachnoid hemorrhage (Fisher Grade 3) and in good clinical grade (Hunt & Hess Grades 1-3). One patient was rendered permanently disabled secondary to delay in controlling the IOR. All others were neurologically unchanged. A review of the literature revealed a trend in correlation between volume of aneurysms treated and IOR rate; no statistically significant correlation was found between volume of aneurysms treated or years since the introduction of GDC technology and IOR rates or mortality. CONCLUSION: IOR remains a serious risk of endosaccular coiling of intracranial aneurysms, with aneurysms presenting with subarachnoid hemorrhage at greater risk for this complication. This risk can be minimized with very low associated morbidity and mortality (incidence 1%, 17% morbidity, 0% mortality at our institution).

Wingspan stenting of symptomatic extracranial vertebral artery stenosis and perioperative evaluation using quantitative magnetic resonance angiography: report of two cases.

The best management strategy for symptomatic vertebrobasilar ischemia is currently not well-defined. Noninvasive Optimal Vessel Analysis (NOVA, VasSol, Inc.) is computer software that, using quantitative magnetic resonance (MR) angiography technology, represents the only commercially available means of noninvasively measuring blood flow within the human vasculature. The author used quantitative MR angiography to study cerebral blood flow in 2 patients who underwent angioplasty and stenting for medically refractory extracranial cervical vertebral artery (VA) stenosis using the recently Food and Drug Administration-approved WingSpan stent (Boston Scientific, Target). WingSpan stents were successfully placed after balloon angioplasty in both patients without complications. At the 5-month clinical follow-up examination, 1 patient was symptom free and the other had had a possible transient ischemic attack without sequelae. The WingSpan stent may represent an alternative management scheme for symptomatic vertebrobasilar ischemia from extracranial VA stenosis. Quantitative MR angiography can readily measure blood flow in the vertebrobasilar system, and these values correlated with the angiographic outcomes in the 2 patients treated in the present study.

Endovascular treatment of acute ischaemic stroke.

The emphasis of treatments for acute ischaemic stroke during the past two decades has been on revascularisation. Endovascular treatment is a promising alternative for patients who are ineligible for standard intravenous thrombolytic therapy; however, its use is limited by the few randomised trials reported and the small number of practising neurointerventionalists. Although data are still being collected, important progress has been made. In this Review, we summarise the findings of the major clinical trials of endovascular treatment, and show that endovascular treatment of acute ischaemic stroke is a therapeutic option for patients who are disqualified from or do not improve on treatment with intravenous alteplase. Moreover, the American Heart Association has expanded its guidelines to include endovascular stroke therapies as a treatment option.

Neurointerventional treatment of vasospasm.

OBJECTIVES: To review the historical development and current status of endovascular techniques used in the treatment of symptomatic vasospasm following aneurysmal subarachnoid hemorrhage. METHODS: This article summarizes the relevant literature on neurointerventional therapy for vasospasm, namely instillation of intraarterial medication (papaverine, nicardipine, verapamil) and transluminal balloon angioplasty. The authors synthesize the available literature with their own experience using the various endovascular modalities to treat vasospasm at high volume cerebrovascular centers. TECHNIQUE: Indications for the use of neurointerventional therapy as well as a summary of the technique for transluminal angioplasty to treat vasospasm as employed by the authors is described. DISCUSSION: Neurointerventional treatment of vasospasm following aneurysmal hemorrhage has been proven to be a safe and successful technique for those patients suffering symptomatic vasospasm refractory to medical management. The techniques contunue to undergo refinement as endovascular technology advances. We currently favor the use of balloon angioplasty over intraarterial antispasmotics due to the increased durability and long-lasting effects of the former and lower risk profile.

Successful emergent angioplasty of neurosarcoid vasculitis presenting with strokes.

BACKGROUND: Sarcoidosis is a systemic disease with neurologic involvement in approximately 5% of cases. Ischemic events related to neurosarcoid vasculitis are rare. We report the successful treatment of symptomatic neurosarcoid vasculitis with angioplasty. CASE DESCRIPTION: A 41-year-old African American with a diagnosis of neurosarcoid presented with aphasia and right-sided weakness. He was treated medically with antiplatelet agents, heparinization, and hypertensive therapy. Despite this treatment, he experienced clinical worsening and radiographic extension of his infarcts. He underwent successful angioplasty of a severe focal stenosis of the left middle cerebral artery. After the procedure, he experienced marked improvement in his symptoms and at follow-up continues to improve. CONCLUSIONS: We report the angiographic demonstration of neurosarcoidosis with large vessel changes and resultant strokes and its successful treatment with balloon angioplasty.

Transarterial embolization of vein of Galen malformations: the use of magnetic resonance imaging noninvasive optimal vessel analysis to quantify shunt reduction. Report of two cases.

In patients with vein of Galen malformations, high-flow shunting decreases cerebral perfusion. By reducing or eliminating these shunts, transarterial embolization can improve cerebral perfusion and clinical outcomes. Quantifying pre- and postembolization shunt blood flow may help determine the optimal timing and efficacy of embolization and may provide prognostic information. The authors used magnetic resonance imaging noninvasive optimal vessel analysis as a novel modality to measure volumetric blood flow through vein of Galen malformation shunts in a neonate and an infant before and after transarterial embolization.

Cystic dilation of the conus ventriculus terminalis presenting as an acute cauda equina syndrome relieved by decompression and cyst drainage: case report.

OBJECTIVE AND IMPORTANCE: The ventriculus terminalis of the conus, or "fifth ventricle" refers to the ependymal-lined space in the middle of the conus that is present in childhood and whose persistence into adulthood is rare. A number of cases of cystic dilatation of the ventriculus terminalis have been described in adulthood. Patients tend to present with either pain alone or gradually progressive conus or cauda equina syndromes with varying degrees of recovery after cyst drainage. Presentation with an acute cauda equina syndrome and its successful surgical management has not been previously reported. CLINICAL PRESENTATION: A 57-year-old woman experienced back pain and bilateral sciatica ascribed to diabetic neuropathy for 2 years. Over a 24-hour period she developed bilateral lower extremity weakness, saddle anesthesia, and bowel and bladder incontinence. Lumbosacral magnetic resonance imaging demonstrated a large cystic dilatation of the ventriculus terminalis. INTERVENTION: She was taken for emergency surgical decompression and cyst drainage. Immediately after surgery, she experienced significant increase in lower extremity strength and has since regained continence. CONCLUSION: Cystic dilation of the ventriculus terminalis should be part of the differential diagnosis for a cauda equina syndrome; surgical decompression with simple cyst drainage can result in excellent clinical results.

Aneurysmal rupture during coiling: low incidence and good outcomes at a single large volume center.

OBJECTIVE: To study the incidence and clinical outcomes of intraoperative aneurysm rupture (IOR) during endovascular coil embolization at a single large volume center and to review the literature on this subject to determine whether IOR rupture rate and mortality correlate with volume of aneurysms treated at a given center and years since the institution of Guglielmi detachable coils as a treatment modality. METHODS: We reviewed the aneurysm database at the Center for Endovascular Surgery since its inception (1997-2003) and reviewed 600 consecutively treated intracranial aneurysms in which coiling was attempted. All patients who sustained an IOR were studied. Procedural and follow-up angiograms as well as clinical outcomes were retrospectively reviewed. A literature review was conducted. RESULTS: Six patients (1.0%) experienced IOR (1.4% in acutely ruptured lesions, 0% in unruptured). All six had presented with diffuse subarachnoid hemorrhage (Fisher Grade 3) and in good clinical grade (Hunt & Hess Grades 1-3). One patient was rendered permanently disabled secondary to delay in controlling the IOR. All others were neurologically unchanged. A review of the literature revealed a trend in correlation between volume of aneurysms treated and IOR rate; no statistically significant correlation was found between volume of aneurysms treated or years since the introduction of GDC technology and IOR rates or mortality. CONCLUSION: IOR remains a serious risk of endosaccular coiling of intracranial aneurysms, with aneurysms presenting with subarachnoid hemorrhage at greater risk for this complication. This risk can be minimized with very low associated morbidity and mortality (incidence 1%, 17% morbidity, 0% mortality at our institution).

Pediatric nonvertebral paraspinal arteriovenous fistulas along the segmental nerve: clinical, imaging, and therapeutic considerations.

OBJECT: The authors characterize the clinical presentation and imaging features of paraspinal nonvertebral arteriovenous fistulas (AVFs) along the segmental nerve and describe their endovascular treatment. METHODS: The authors undertook a retrospective review of medical records, imaging, and treatment of patients with endovascular problems spanning the period from 1985 to 2003. Five pediatric patients (2-3 years of age) received diagnoses of nonvertebral paraspinal AVFs along the segmental nerve. All patients presented with an incidentally discovered continuous murmur over the paraspinal or parasternal regions. All patients were neurologically intact; two patients had cardiomegaly. The AVF was found in the midthoracic level in four patients and at L-3 in one patient. All AVFs were high-flow single-hole fistulas at the neural foramen with venous drainage into paraspinal and epidural veins but without intradural reflux. All fistulas were endovascularly occluded in the same session as diagnostic angiography took place. The fistula was completely occluded, with detachable coils in one case and with N-butyl-cyanoacrylate (NBCA) in four cases. Before NBCA injection, the flow through the fistula was decreased either by placing coils distal to the fistula or by inflating a balloon proximally. No signs of recanalization appeared on short-term follow-up magnetic resonance imaging in all patients. All patients remained neurologically intact at the last available follow-up session (mean 6 years). CONCLUSIONS: Nonvertebral paraspinal AVFs along the segmental nerve are specific disease entities seen in children presenting with bruit and cardiomegaly. Endovascular embolization should be the treatment of choice for this rare disease.

Multiple cerebral aneurysms in a neonate: occlusion and rupture.

Aneurysmal subarachnoid hemorrhage in a neonate is exceedingly uncommon. The authors report the case of a neonate with a large anterior communicating artery aneurysm, accessory left middle cerebral artery aneurysm, and left internal carotid artery (ICA) fusiform aneurysm. The neonate suffered from occlusion of the left ICA and aneurysm rupture. The large aneurysm was treated with detachable coils and the patient made a significant recovery. Of the 15 case reports of cerebral aneurysms in neonates that have been published, none has contained a description of multiple aneurysms or a discussion of endovascular treatment.

Breast adenocarcinoma metastatic to epidural cervical spine meningioma: case report and review of the literature.

While several cases of cancer metastatic to cranial meningiomas have been reported, metastasis to spinal meningioma has been reported only once, and a mechanism for such metastases has not been investigated. We report a case of breast carcinoma metastatic to an epidural cervical meningioma, summarize the literature on metastases to central nervous system meningiomas, and suggest a possible mechanism. Our patient, a 55-year-old woman, presented with difficulty walking, back pain, and quadriparesis. Magnetic resonance imaging revealed an enhancing C3-4 epidural lesion and an L4 compression fracture. Because of concern that the fracture and epidural lesion might represent metastases, we performed a metastatic work-up, which revealed a right breast mass. The patient underwent C3-C4 laminectomies and an epidural lesion was encountered. Intraoperative frozen section revealed mixed meningioma and breast adenocarcinoma. A gross total resection was achieved and the patient subsequently received spinal irradiation and hormonal therapy. Whereas a literature review revealed numerous reports of metastases to cranial meningiomas, this represents only the second reported case of such pathology in the spine. Mechanisms of this unusual process likely include meningiomas' vascularity, meningiomas' slow growth providing nutrient availability, and perhaps, as suggested by our analysis, E-cadherin expression by both meningiomas and breast cancer. Metastasis to meningioma must be considered in an epidural spinal lesion in all patients with a known malignancy, with surgical aggressiveness tailored to the intraoperative pathologic diagnosis.

Hyperacute neuropathological findings after proton beam radiosurgery of the rat hippocampus.

OBJECTIVE: To study the hyperacute histological and immunohistochemical effects of stereotactic proton beam irradiation of the rat hippocampus. METHODS: Nine rats underwent proton beam radiosurgery of one hippocampus with nominal doses of cobalt-2, -12, and -60 Gray equivalents (n = 3 each). Control animals (n = 3) were not irradiated. Animals were killed 5 hours after irradiation and brain sections were stained for Nissl, silver degeneration, deoxyribonucleic acid (DNA) fragmentation (DNAF), and the activated form of two mitogen-activated protein kinases (MAPKs), phospho-Erk1/2 (P-Erk1/2) and p38. Stained cells in the hippocampus expressing DNAF and/or P-Erk1/2 were counted. Confocal microscopy with double immunofluorescent staining was used to examine cellular colocalization of DNAF and P-Erk1/2. RESULTS: Both DNAF and P-Erk1/2 showed quantitative dose-dependent increases in staining in the targeted hippocampus compared with the contralateral side and controls. This finding was restricted to the subgranular proliferative zone of the hippocampus. Both markers also were up-regulated on the contralateral side when compared with controls in a dose-dependent fashion. Simultaneous staining for DNAF and P-Erk1/2 was found in fewer than half of all cells. p38 was unchanged compared with controls. Although Nissl staining appeared normal, silver stain confirmed dose-dependent cellular degeneration. CONCLUSION: DNAF, a marker of cell death, was present in rat hippocampi within 5 hours of delivery of cobalt-2 Gray equivalents stereotactically focused irradiation, suggesting that even low-dose radiosurgery has hyperacute neurotoxic effects. Activated mitogen-activated protein kinase was incompletely colocalized with DNAF, suggesting that activation of this cascade is neither necessary nor sufficient to initiate acute cell death after irradiation.

Treatment options for wide-necked intracranial aneurysms using a self-expandable hydrophilic coil and a self-expandable stent combination.

The endovascular treatment of wide-necked intracranial aneurysms is evolving. We report our initial experience in treating seven wide-neck intracranial aneurysms by using a new self-expanding stent, the Neuroform, in combination with a new generation of coils that incorporate a self-expandable hydrophilic lining, the HydroCoil.

Simultaneous bilateral internal carotid artery 3D rotational angiography.

We simultaneously injected both internal carotid arteries (ICAs) during 3D rotational digital subtraction angiography in a patient with a ruptured anterior communicating artery (Acom) aneurysm and vasospasm. Shaded surface display (SSD) images from this acquisition provided more anatomic detail than did SSD images created from individual ICA 3D rotational digital subtraction angriography. In the evaluation of complex Acom aneurysms, this technique can facilitate the choice of optimal working projections for safer aneurysm coiling.

MRI changes in the rat hippocampus following proton radiosurgery.

PURPOSE: To define radiographic dose-response relationships for proton radiosurgery using a rat brain model. METHODS AND MATERIALS: A group of 23 rats was treated with Bragg peak proton beam irradiation involving the right hippocampus. Single doses of 5, 12, 20, 30, 60, 90 and 130 cobalt gray equivalents (CGE) were delivered to groups of 3 animals using single fraction technique. One extra animal was included at the 130- and 30-CGE doses. Animals were imaged using a standard 1.5-tesla GE Signa MRI. A 3-inch surface coil was employed to obtain T1-weighted sagittal images (TR 600 and TE 30) and dual echo T2-weighted coronal images (TR 3,000 and TE 30/90). Animals were imaged at 1.5, 3, 4.5, 6 and 9 months. Volumetric analysis with custom software was done to evaluate areas of increased signal on T2-weighted images, and signal change versus time curves were generated. Gadolinium-enhanced T1-weighted imaging was also done at the 9-month time point to further evaluate tissue injury. The development of hydrocephalus was also examined. RESULTS: Peak tissue injury was greater and occurred earlier with higher versus lower doses of radiation. Statistically significant differences were seen between the 130- and 90-CGE animals and between the 90- and 60-CGE animals (p < 0.0016) using ANOVA. Signal changes can be seen in at least 1 of the animals at 20 CGE. The largest volume of tissue enhancement at 9 months was seen in animals at 60 CGE, which may represent an intermediate zone of tissue injury and gliosis compared with greater tissue loss at higher doses and less injury at lower doses. Hydrocephalus developed first in the untreated hemisphere in 130- and 90-CGE animals as a result of mass effect while it occurred at a later time in the treated hemisphere in lower-dose animals. CONCLUSIONS: Following single-dose proton radiosurgery of rat hippocampus, serial MRIs show T2 signal changes in animals ranging from 130 down to 20 CGE as well as the development of hydrocephalus. Dose-effect relationships using proton radiosurgery in rats will be a helpful step in guiding further studies on radiation injury to brain tissue.