abbreviatioNs AHA = American Heart Association; CAS = carotid artery stenting; CEA = carotid endarterectomy; CEUS = contrast-enhanced ultrasonography; CTA = CT angiography; DCE = dynamic contrast-enhanced; DSCT = dual-source CT; FDG = fluorodeoxyglucose; FSE = fast spin echo; Gd = gadolinium; HU = Hounsfield units; IPH = intraplaque hemorrhage; LRNC = lipid-rich necrotic core; MDCT = multidetector-row CT; MDCTA = MDCT angiography; MES = microembolic signal; MMP-9 = matrix metalloproteinase-9; MRA = MR angiography; PDW = proton density-weighted; SUV = standardized uptake value; SUVmax = maximal SUV; TBR = target-to-background ratio; TCD = transcranial Doppler ultrasonography; TIA = transient ischemic attack; TOF = time of flight; USPIO = ultrasmall superparamagnetic iron oxide. Carotid artery stenosis is a well-established risk factor of ischemic stroke, contributing to up to 10%-20% of strokes or transient ischemic attacks. Many clinical trials over the last 20 years have used measurements of carotid artery stenosis as a means to risk stratify patients. However, with improvements in vascular imaging techniques such as CT angiography and MR angiography, ultrasonography, and PET/CT, it is now possible to risk stratify patients, not just on the degree of carotid artery stenosis but also on how vulnerable the plaque is to rupture, resulting in ischemic stroke. These imaging techniques are ushering in an emerging paradigm shift that allows for risk stratifications based on the presence of imaging features such as intraplaque hemorrhage (IPH), plaque ulceration, plaque neovascularity, fibrous cap thickness, and presence of a lipid-rich necrotic core (LRNC). It is important for the neurosurgeon to be aware of these new imaging techniques that allow for improved patient risk stratification and outcomes. For example, a patient with a low-grade stenosis but an ulcerated plaque may benefit more from a revascularization procedure than a patient with a stable 70% asymptomatic stenosis with a thick fibrous cap. This review summarizes the current state-of-the-art advances in carotid plaque imaging. Currently, MRI is the gold standard in carotid plaque imaging, with its high resolution and high sensitivity for identifying IPH, ulceration, LRNC, and inflammation. However, MRI is limited due to time constraints. CT also allows for high-resolution imaging and can accurately detect ulceration and calcification, but cannot reliably differentiate LRNC from IPH. PET/CT is an effective technique to identify active inflammation within the plaque, but it does not allow for assessment of anatomy, ulceration, IPH, or LRNC. Ultrasonography, with the aid of contrast enhancement, is a cost-effective technique to assess plaque morphology and characteristics, but it is limited in sensitivity and specificity for detecting LRNC, plaque hemorrhage, and ulceration compared with MRI. Also summarized is how these advanced imaging techniques are being used in clinical practice to risk stratify patients with low- and high-grade carotid artery stenosis....

BackgroundCancer and ischemic stroke are two of the most common causes of death among the elderly, and associations between them have been reported. However, the main pathomechanisms of stroke in cancer patients are not well known, and can only be established based on accurate knowledge of the characteristics of cancer-related strokes. We review herein recent studies concerning the clinical, laboratory, and radiological features of patients with cancer-related stroke.Main ContentsThis review covers the epidemiology, underlying mechanisms, and acute and preventive treatments for cancer-related stroke. First, the characteristics of stroke (clinical and radiological features) and systemic cancer (type and extent) in patients with cancer-specific stroke are discussed. Second, the role of laboratory tests in the early identification of patients with cancer-specific stroke is discussed. Specifically, serum D-dimer levels (as a marker of a hypercoagulable state) and embolic signals on transcranial Doppler (suggestive of embolic origin) may provide clues regarding changes in the levels of coagulopathy related to cancer and anticoagulation. Finally, strategies for stroke treatment in cancer patients are discussed, emphasizing the importance of preventive strategies (i.e., the use of anticoagulants) over acute revascularization therapy in cancer-related stroke.ConclusionRecent studies have revealed that the characteristics of cancer-related stroke are distinct from those of conventional stroke. Our understanding of the characteristics of cancer-related stroke is essential to the correct management of these patients. The studies presented in this review highlight the importance of a personalized approach in treating stroke patients with cancer.

Background and Purpose-An optimal strategy for management of symptomatic intracranial atherosclerotic stenosis (ICAS) has not yet been established. We compared the efficacy of 2 combinations of antiplatelets, aspirin plus cilostazol (cilostazol group) verus aspirin plus clopidogrel (clopidogrel group), on the progression of ICAS, which is known to be associated with clinical stroke recurrence. Methods-In this investigator-initiated double-blind trial, 457 patients with acute symptomatic stenosis in the M1 segment of the middle cerebral artery or the basilar artery were randomly allocated into either a cilostazol group or a clopidogrel group. After 7 months of treatment, follow-up MR angiogram and MRI were performed. The primary end point was the progression of ICAS in comparison with stenosis on the baseline MR angiogram. Secondary end points included the occurrence of new ischemic lesions on MRI, composite of cardiovascular events, and major bleeding complications. Results-Cardiovascular events occurred in 15 of 232 patients (6.4%) in the cilostazol group and 10 of 225 (4.4%) in the clopidogrel group (Pϭ0.312). Cilostazol did not reduce the progression of symptomatic ICAS (20 of 202) compared to clopidogrel (32 of 207) (odds ratio, 0.61; Pϭ0.092), although favorable changes in serum lipoproteins were observed in the cilostazol group. There were no significant differences between the 2 groups with respect to new ischemic lesions (18.7% versus 12.0%; Pϭ0.078) and major hemorrhagic complications (0.9% versus 2.6%; Pϭ0.163). Conclusions-This trial failed to show significant difference in preventing progression of ICAS and new ischemic lesions between the 2 combination antiplatelet therapies in the patients with symptomatic ICAS. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT00130039.