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Background: Clazosentan has been explored worldwide for the prophylaxis of cerebral vasospasm after aneurysmal subarachnoid hemorrhage (aSAH). In a dose-finding trial (CONSCIOUS-1) conducted in Israel, Europe, and North America, clazosentan (1, 5, and 15 mg/h) significantly reduced the incidence of cerebral vasospasm, but its efficacy in Japanese and Korean patients was unknown. We conducted a double-blind comparative study to evaluate the occurrence of cerebral vasospasm in Japanese and Korean patients with aSAH. Methods: The aim of this multicenter, double- blind, randomized, placebo-controlled, dose-finding phase 2 clinical trial, was to evaluate the efficacy, pharmacokinetics, and safety of clazosentan (5 and 10 mg/h) against cerebral vasospasm after clipping surgery in Japanese and Korean patients with aSAH. Patients aged between 20 and 75 years were administered the study drug within 56 h after the aneurysm rupture and up to day 14 post-aSAH. The inci- dence of vasospasm, defined as an inner artery diameter reduction of major intracranial arteries ≥ 34% based on catheter angiography, was compared between each treatment group. Cerebral infarction due to vasospasm at 6 weeks and patients' outcome at 3 months was also compared. Results: Among 181 enrolled patients, 158 completed the study and were analyzed. The incidence of vasospasm up to day 14 after aSAH onset was 80.0% in the placebo group (95% CI 67.0- 89.6), 38.5% in the 5 mg/h clazosentan group (95% CI 25.3- 53.0), and 35.3% in the 10 mg/h clazosentan group (95% CI 22.4-49.9), indicating that the incidence of vasospasm was significantly reduced by clazosentan treatment (placebo vs. 5 mg/h clazosentan, p < 0.0001; placebo vs. 10 mg/h clazosentan, p < 0.0001). The occurrence of cerebral infarction due to vasospasm was 20.8% in the placebo group (95% CI 10.8- 34.1), 3.8% in the 5 mg/h clazosentan group (95% CI 0.5- 13.2), and 4.2% in the 10 mg/h clazosentan group (95% CI 0.5-14.3), indicating that clazosentan significantly reduced the occurrence of cerebral infarctions caused by vasospasm (placebo vs. 5 mg/h clazosentan, p = 0.0151; placebo vs. 10 mg/h clazosentan, p = 0.0165). The overall incidence of allcause death and/or vasospasm-related morbidity/mortality was significantly reduced in the 10 mg/h clazosentan group compared with the placebo group ( p = 0.0003). Conclusion: These results suggest that clazosentan prevents cerebral vasospasm and subsequent cerebral infarction, and could thereby improve outcomes after performing a clipping surgery for aSAH in Japanese and Korean patients. [ABSTRACT FROM AUTHOR]

Background/Aims: To enable the diagnosis of moyamoya disease (MMD), detection of distal internal carotid artery stenosis and hazy network of basal collaterals (BCs) are required. This study aimed at evaluating the factors that could determine the degree of BCs in patients with angiographically confirmed MMD. Methods: We analyzed 146 consecutive patients with MMD (age 26.2 ± 19.6, range 1–75). The degree of BCs (%) was measured based on conventional angiography. Factors associated with the degree of BCs, including clinico-radiological and genetic factors (p.Arg4810Lys variant), were analyzed. Results: The degree of BCs varied among MMD patients and significantly decreased with an increase in the age of diagnosis of MMD (coefficient –1.55; p < 0.001). Although the degree of BC development depends on the MMD stage (Suzuki stage), it is less prominent in adult-onset (>18 years) MMD compared to childhood MMD. The presence of p.Arg4810Lys variant, types of MMD (bilateral vs. unilateral) and stroke (ischemic, hemorrhagic, or asymptomatic), shrinkage (outer diameter) of intracranial vessels, external carotid collateral status, and cortical neovascularization were not associated with the degree of BCs. Conclusion: Although prominent BCs are required for diagnosis of MMD, BCs are decreased with aging, suggesting that angiogenic capacity is altered in adult onset MMD compared to childhood MMD. [ABSTRACT FROM AUTHOR]

Background: Contrary to deeply located brain arteriovenous malformations (AVMs), superficially located AVMs are more likely to have transdural arterial communications (TACs). However, the clinical and radiologic characteristics of patients presenting with AVMs and TACs are poorly understood. The purpose of this study is to determine whether clinicoradiological features of cerebral AVMs differ according to TAC. Methods: Between 2002 and 2012, 438 consecutive patients with a brain AVM were treated in our hospital. Among them were 124 patients with superficially located brain AVMs who met the inclusion and exclusion criteria of our study. We retrospectively reviewed the clinicoradiological features of their TACs to explore the variation in characteristics. Results: Thirty-two of the 124 patients with a superficially located AVM (25.8%) had TAC. Radiologic findings of brain AVM images with TAC showed that TAC occurred significantly more frequently among larger AVMs (with vs. without TAC, 11.2 vs. 4.0 ml) and among diffuse AVMs (56.3 vs. 28.3%, p = 0.004). Clinical findings indicate that TAC was associated with chronic headache (43.8 vs. 12.0%, p < 0.001)and older age (43.1 vs. 36.6 years, p = 0.037). Conclusions: Brain AVM with TAC seems to be accompanied by distinctive clinical features, such as chronic headache and older age. Larger size and diffuseness of the AVM were also associated with TAC. Findings from this study and the prognostic significance of TAC should be further explored in a large prospective study. [ABSTRACT FROM AUTHOR]

Background: Both basal collaterals (BC) and cortical microvascularization (CM) on angiography have been suggested as moyamoya disease (MMD)-specific findings; however, it is unknown whether the vascular network represents compensatory mechanisms for vascular occlusion or aberrant active neovascularization. Methods: We investigated the grade of antegrade MCA flow, the degree of BC, and the presence of CM on conventional angiography in relation to disease severity in pediatric MMD. CM was defined as enlarged and winding distal cortical arteries and categorized into anterior or posterior CM depending on their sources. Findings from basal and acetazolamide stress brain perfusion SPECT studies were also evaluated. Results: A total of 172 pediatric patients with MMD were enrolled in this study. As the severity of MMD increased, the grade of antegrade MCA flow gradually diminished. While the degree of BC peaked at Suzuki stage 3-4, CM was frequently observed at early MMD stages. About two-thirds of hemispheres with normal antegrade MCA flow on angiography and normal perfusion status on SPECT had anterior and/or posterior CM. Both anterior and posterior CM gradually decreased with the advancement of MMD. Conclusion: Our findings from a large cohort of angiographically confirmed pediatric MMD patients indicate that neovascularization may occur before significant hemodynamic impairment in MMD. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: As regular medical check-ups are becoming more common, the prevalence of asymptomatic moyamoya disease (MMD) is increasing. However, the definition and clinical features are still unclear. The lack of precision has hampered the establishment of guidelines for the management of asymptomatic MMD. The purpose of this study was to define and clarify the clinical characteristics of asymptomatic MMD in adults. Methods: We identified all adults (aged ≥18 years) with MMD who underwent digital subtraction angiography or magnetic resonance angiography at our institution from 1995 through 2010. The authors defined asymptomatic MMD as asymptomatic or nonspecific symptom without any infarction or ischemia on magnetic resonance imaging. In our MMD registry, 40 patients (74 hemispheres) were identified and enrolled in this retrospective cohort study. Their demographic, radiological and clinical findings were evaluated. The log-rank test was used to assess prognostic factors. Pearson's correlation test and the Mann-Whitney U test were used to identify correlation angiographic staging and age or perfusion status. Results: Overall, 6 patients underwent indirect bypass surgery and 36 received antiplatelet medication. On initial single positron emission tomography (35 patients, 67 affected hemispheres), basal and acetazolamide stress brain perfusion were decreased in 19 (28.4%) and 22 (32.8%) hemispheres, respectively. Among 70 angiographically evaluated hemispheres, 6 were unilateral MMD; 27 of 64 affected hemispheres (42.2%) had transdural collateral at evaluation. Age (p = 0.309, Pearson's correlation test) and hemodynamic impairment (p = 0.614, Mann-Whitney U test) did not correlate with angiographic staging. During a median 32-month (range 6-203) clinical follow-up, 3 nonsurgically treated patients had a transient ischemic attack, which was associated with decreased vascular reserve (p < 0.001, log-rank test) and smoking (p = 0.017). Other variables did not show a significant association with clinical progression. During a median 24-month (range 12-108) radiological follow-up, 3 patients displayed angiographic progression and 3 displayed new hemodynamic abnormalities. Radiological progressions were related to hypertension only (p = 0.022). In this case series, there was no case of ischemic or hemorrhagic stroke. Conclusion: The findings suggest that asymptomatic MMD in adults is not a stable disease in our definition. However, stroke rate (0%) was lower than previous reports. Lifestyle modification, stroke risk factor control and/or antiplatelet medication seem to be appropriate initial treatments for patients with normal cerebrovascular reserve. A clear definition of asymptomatic MMD and further clarification of its clinical course are needed to set precise treatment guidelines. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Statins suppress expression of pro-inflammatory cytokines in endothelial cells, whereas they enhance it in immune cells. Pro-inflammatory cytokines and lipopolysaccharide (LPS) induce matrix metalloproteinase (MMP)-9 gene expression in macrophages, which has been linked to progress of various inflammatory diseases. The aim of this study was to identify effects of various statins on LPS-induced MMP-9 gene expression in macrophages and microglia. MMP-9 expression was analyzed by real-time PCR or zymography. Effect of statins on activation of signaling pathways was analyzed by time-dependent phosphorylation of signaling molecules. Atorvastatin and simvastatin, but not pravastatin, up-regulated LPS-induced MMP-9 expression in murine RAW 264.7 macrophages and BV2 microglia. The phosphorylation duration of extracellular signal regulated kinases was extended by simvastatin, but not by atorvastatin or pravastatin. The up-regulation of LPS-induced MMP-9 gene expression by the statins was dependent on extracellular calcium ions and mediated by enhancing phosphorylation of cAMP-responsive element binding protein. Geranylgeranyl pyrophosphate, a precursor for cholesterol synthesis, could suppress up-regulation of LPS-mediated MMP-9 gene expression by atorvastatin and simvastatin. Atorvastatin and simvastatin-mediated up-regulation of LPS-induced MMP-9 gene expression in macrophages and microglia in vitro raises an important concern about use of the widely-prescribed statins in certain inflammatory conditions that are mediated by LPS. Copyright © 2012 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]