Neurologic complications of cerebral angiography in childhood moyamoya syndrome

Comparison of CBF Measured with Combined Velocity-Selective Arterial Spin-Labeling and Pulsed Arterial Spin-Labeling to Blood Flow Patterns Assessed by Conventional Angiography in Pediatric Moyamoya

BACKGROUND AND PURPOSE

Imaging CBF is important for managing pediatric moyamoya. Traditional arterial spin-labeling MR imaging detects delayed transit thorough diseased arteries but is inaccurate for measuring perfusion because of these delays. Velocity-selective arterial spin-labeling is insensitive to transit delay and well-suited for imaging Moyamoya perfusion. This study assesses the accuracy of a combined velocity-selective arterial spin-labeling and traditional pulsed arterial spin-labeling CBF approach in pediatric moyamoya, with comparison to blood flow patterns on conventional angiography.

MATERIALS AND METHODS

Twenty-two neurologically stable pediatric patients with moyamoya and 5 asymptomatic siblings without frank moyamoya were imaged with velocity-selective arterial spin-labeling, pulsed arterial spin-labeling, and DSA (patients). Qualitative comparison was performed, followed by a systematic comparison using ASPECTS-based scoring. Quantitative pulsed arterial spin-labeling CBF and velocity-selective arterial spin-labeling CBF for the middle cerebral artery, anterior cerebral artery, and posterior cerebral artery territories were also compared.

RESULTS

Qualitatively, velocity-selective arterial spin-labeling perfusion maps reflect the DSA parenchymal phase, regardless of postinjection timing. Conversely, pulsed arterial spin-labeling maps reflect the DSA appearance at postinjection times closer to the arterial spin-labeling postlabeling delay, regardless of vascular phase. ASPECTS comparison showed excellent agreement (88%, κ = 0.77, P < .001) between arterial spin-labeling and DSA, suggesting velocity-selective arterial spin-labeling and pulsed arterial spin-labeling capture key perfusion and transit delay information, respectively. CBF coefficient of variation, a marker of perfusion variability, was similar for velocity-selective arterial spin-labeling in patient regions of delayed-but-preserved perfusion compared to healthy asymptomatic sibling regions (coefficient of variation = 0.30 versus 0.26, respectively, Δcoefficient of variation = 0.04), but it was significantly different for pulsed arterial spin-labeling (coefficient of variation = 0.64 versus 0.34, Δcoefficient of variation = 0.30, P < .001).

CONCLUSIONS

Velocity-selective arterial spin-labeling offers a powerful approach to image perfusion in pediatric moyamoya due to transit delay insensitivity. Coupled with pulsed arterial spin-labeling for transit delay information, a volumetric MR imaging approach capturing key DSA information is introduced.

Thrombosis and spontaneous recanalization of a giant intracranial aneurysm: diagnostic and management pearls in a pediatric patient

The authors present the case of a boy who was successfully managed through the spontaneous thrombosis of a cavernous internal carotid artery (ICA) aneurysm, the subsequent occlusion of the ICA, its recanalization, and ultimate endovascular sacrifice, using only two angiograms because of the diagnostic capability of CT angiography. Spontaneous recanalization of the ICA following occlusion in the setting of a giant aneurysm has not been previously reported.

Anesthesia for interventional radiology

Pediatric patients in the neurointerventional radiology setting pose the dual challenges of caring for relatively sick patients in the outfield environment. For safe and successful practice, the anesthesiologist must not only understand the nuances of pediatric anesthesia and the physiologic demands of the cerebral lesions. They must also help maintain a team-based approach to safe, compassionate care of the child in this challenging setting. In this review article, we summarize key aspects of success for several of these topics.

Challenges in pediatric neuroanesthesia: awake craniotomy, intraoperative magnetic resonance imaging, and interventional neuroradiology

This article gives a review of 3 challenges in caring for children undergoing neurosurgical and neurointerventional procedures. Anesthesiologists may have experience with certain aspects of these situations but may not have extensive experience with each clinical setting. This review addresses issues with awake craniotomy, intraoperative magnetic resonance imaging, and neurointerventional procedures in children with neurologic disease. Familiarization with these complex clinical scenarios and their unique considerations allows the anesthesiologist to deliver optimal care and helps facilitate the best possible outcome for these patients.

Spontaneous occlusion of the circle of Willis in children: pediatric moyamoya summary with proposed evidence-based practice guidelines. A review

Moyamoya is a progressive arteriopathy of unknown origin affecting the branches of the internal carotid artery (ICA). The arteriopathy can present as an isolated medical condition, affecting both sides of the brain ("moyamoya disease") or can be unilateral or found in association with systemic disorders ("moyamoya syndrome"). The ischemia resulting from luminal narrowing predisposes children to transient ischemic attacks and stroke-the primary presentations of affected patients. Although it is rare-affecting 1 in 1 million children in the US-moyamoya is implicated in 6% of all childhood strokes. Diagnosis is defined by characteristic findings on arteriograms, including stenosis of the branches of the ICA and a pathognomonic spray of small collateral vessels in this region, descriptively likened to a "puff of smoke" ("moyamoya" in Japanese). Treatment is predicated on restoration of cerebral blood flow by surgical revascularization. The rarity of this disorder has limited research and the development of evidence-based clinical management. While acknowledging these limitations, in this article the authors aim to summarize current studies of pediatric moyamoya, with the objective of providing a framework for construction of evidence-based guidelines for treatment. The compilation of current data in these guidelines should serve as a resource to aid pediatric neurosurgeons in their role as advocates for providing appropriate care to affected children.

Moyamoya syndrome precipitated by cranial irradiation for craniopharyngioma in children

Recently, combination of surgery and radiation therapy (RT) has been recommended in the treatment of craniopharyngioma. RT could be associated with late complications, including vasculopathy. We report two cases of the moyamoya syndrome seen in children with craniopharyngioma who received RT after surgical resection. Thirty-five patients in pediatric age with craniopharyngioma were surgically treated. Fifteen out of 35 patients underwent surgical resection followed by RT or gamma knife surgery. Two of the 15 were found to have symptoms of transient ischemic attack and were diagnosed as moyamoya syndrome through the cerebral angiography. Age at RT was 4 and 13 years, respectively. The latent period for development of the moyamoya syndrome was 27 months and 3 years, respectively, after RT. The RT dose of both patients was 54 Gy. These two patients received bilateral encephaloduroarteriosynangiosis procedures. We report here these two cases of radiation-induced moyamoya syndrome in pediatric craniopharyngioma. Pediatric patients with craniopharyngioma who received RT should be reminded, during follow-up, about the risk of development of the moyamoya syndrome.

The role of imaging studies for evaluation of stroke in children

Stroke is a major cause of morbidity and mortality in children and long-term neurological deficits. Although cerebrovascular disorders occur less often in children than in adults, recognition of stroke in children has probably increased because of the widespread application of noninvasive diagnostic studies such as magnetic resonance imaging and computed tomography.Computed tomography (CT) should be the first imaging choice in the emergency setting when stroke is suspected. It will show the presence of hemorrhage (eg, bleeding from arteriovenous malformation). It is often normal within the first hours in arterial ischemic stroke. As in adults, magnetic resonance imaging is the neuroimaging modality to confirm the clinical diagnosis of ischemic stroke. In children, however, magnetic resonance imaging requires sedation and may not be as readily available as CT. Perfusion imaging demonstrates flow within the brain and can detect areas that are at risk of ischemia; however, further studies in the pediatric population need to be validated for this technique in children. Angiography detects arterial disease (eg, aneurysm); however, its use has been largely superseded by better magnetic resonance angiography, which is sensitive enough to visualize lesions in the proximal anterior cerebral artery, middle cerebral artery, and distal internal carotid artery (ICA). Magnetic resonance imaging using diffusion- weighted imaging is the most versatile and sensitive imaging technique for identifying ischemic lesions. In the future, we need to identify the pediatric patient presenting to the emergency department with an acute stroke and develop a pathway for the use of particular imaging techniques (eg, CT vs magnetic resonance imaging).