Moyamoya Vasculopathy and Moyamoya-Related Systemic Vasculopathy: A Review With Histopathological and Genetic Viewpoints

Systemic vasculopathy has occasionally been reported in cases of moyamoya disease (MMD). Since the pathological relationship between moyamoya vasculopathy (MMV) and moyamoya-related systemic vasculopathy (MMRSV) remains unclear, it was examined herein by a review of histopathologic studies in consideration of clinicopathological and genetic viewpoints. Although luminal stenosis was a common finding in MMV and MMRSV, histopathologic findings of vascular remodeling markedly differed. MMV showed intimal hyperplasia, marked medial atrophy, and redundant tortuosity of the internal elastic lamina, with outer diameter narrowing called negative remodeling. MMRSV showed hyperplasia, mainly in the intima and sometimes in the media, with disrupted stratification of the internal elastic lamina. Systemic vasculopathy has also been observed in patients with non-MMD carrying the RNF213 (ring finger protein 213) mutation, leading to the concept of RNF213 vasculopathy. RNF213 vasculopathy in patients with non-MMD was histopathologically similar to MMRSV. Cases of MMRSV have sometimes been diagnosed with fibromuscular dysplasia. Fibromuscular dysplasia is similar to MMD not only in the histopathologic findings of MMRSV but also from clinicopathological and genetic viewpoints. The significant histopathologic difference between MMV and MMRSV may be attributed to a difference in the original vascular wall structure and its resistance to pathological stress between the intracranial and systemic arteries. To understand the pathogeneses of MMD and MMRSV, a broader perspective that includes RNF213 vasculopathy and fibromuscular dysplasia as well as an examination of the 2- or multiple-hit theory consisting of genetic factors, vascular structural conditions, and vascular environmental factors, such as blood immune cells and hemodynamics, are needed.

Neuroprotective effects of a hemoglobin-based oxygen carrier (stroma-free hemoglobin nanoparticle) on ischemia reperfusion injury

The application of hemoglobin (Hb)-based oxygen carriers (HBOCs) to the treatment of cerebral ischemia has been investigated. A cluster of 1 Hb and 3 human serum albumins (Hb-HSA3) was found to exert neuroprotective effects on ischemia/reperfusion injury. Stroma-free hemoglobin nanoparticles (SFHbNP), a subsequently developed HBOC consisting of a spherical polymerized stroma-free Hb core with a HSA shell, contains the natural antioxidant enzyme catalase and, thus, is expected to exert additive effects. We herein investigated whether SFHbNP exerted enhanced neuroprotective effects in a rat transient middle cerebral artery occlusion (tMCAO) model. Rats were subjected to 2-hour tMCAO and divided into the following 3 groups with the intravenous administration of the respective reagents: (1) phosphate-buffered saline (PBS), as a vehicle (2) Hb-HSA3, and (3) SFHbNP. After 24-hour reperfusion, infarct and edema volumes decreased in the order of the PBS, Hb-HSA3, and SFHbNP groups, with a significant difference (p < 0.05) between the PBS and SFHbNP groups. Similar reductions were observed in oxidative stress, leukocyte recruitment, and blood-brain barrier disruption in the order of the PBS, Hb-HSA3, and SFHbNP groups. In the early phase of reperfusion within 6 h, microvascular HBOC perfusion and cerebral blood flow were maintained at high levels during the reperfusion period in the Hb-HSA3 and SFHbNP groups. However, a difference was observed in tissue oxygen partial pressure levels, which significantly decreased after 6-hour reperfusion in the Hb-HSA3 group, but remained high in the SFHbNP group. A superior oxygen transport ability appears to be related to the enhanced neuroprotective effects of SFHbNP.

The Pathogenetic Mechanism for Moyamoya Vasculopathy Including a Possible Trigger Effect of Increased Flow Velocity

Moyamoya disease (MMD), which commonly exhibits moyamoya vasculopathy characterized by chronic progressive steno-occlusive lesions in the circle of Willis with "moyamoya" collateral vessels, has been well known for its unique demographic and clinical features. Although the discovery of the susceptibility gene RNF213 for MMD revealed the factor for its predominance in East Asians, the mechanisms underlying other predominant conditions (females, children, young to middle-aged adults, and anterior circulation) and lesion formation are yet to be determined. As MMD and moyamoya syndrome (MMS), which secondarily produces moyamoya vasculopathy due to pre-existing diseases, have the same vascular lesions despite differences in their original pathogenesis, they may share a common trigger for the development of vascular lesions. Thus, we herein consider a common trigger from a novel perspective on blood flow dynamics. Increased flow velocity in the middle cerebral arteries is an established predictor of stroke in sickle cell disease, which is often complicated by MMS. Flow velocity is also increased in other diseases complicated by MMS (Down syndrome, Graves' disease, irradiation, and meningitis). In addition, increased flow velocity occurs under the predominant conditions of MMD (females, children, young to middle-aged adults, and anterior circulation), suggesting a relationship between flow velocity and susceptibility to moyamoya vasculopathy. Increased flow velocity has also been detected in the non-stenotic intracranial arteries of MMD patients. In a pathogenetic overview of chronic progressive steno-occlusive lesions, a novel perspective including the trigger effect of increased flow velocity may provide insights into the mechanisms underlying their predominant conditions and lesion formation.

Neuroprotective effects of combination therapy of regional cold perfusion and hemoglobin-based oxygen carrier administration on rat transient cerebral ischemia

Regional cold perfusion and hemoglobin-based oxygen carrier administration both exert neuroprotective effects against cerebral ischemia reperfusion injury. We herein investigated whether the combination of these two therapies leads to stronger neuroprotective effects. Combination therapy was performed with the regional perfusion of cold HemoAct, a core-shell structured hemoglobin-albumin cluster, in a rat transient middle cerebral artery occlusion model. The effects of combination therapy, the intra-arterial administration of 10 °C HemoAct (10H) initiated at the onset of reperfusion, were compared with those of monotherapies, the intra-arterial administration of 10 °C saline (10S) and 37 °C HemoAct (37H), and an untreated control under the condition of 2-hour ischemia/24-hour reperfusion. The durability of therapeutic effects and the therapeutic time window of combination therapy were assessed based on comparisons with the 10H and control groups. Significantly better neurological findings and smaller infarct volumes were observed in the three treated (10S, 37H, and 10H) groups than in the control group. Among the 3 treated groups, only the 10H group showed significant improvements over the control group in the other items examined, including cerebral blood flow reduction, brain edema, and protein extravasation. The significant therapeutic effects of combination therapy on neurological disabilities and infarct volumes were confirmed at least until 7 days after reperfusion. Furthermore, combination therapy ameliorated neurological disabilities and hemorrhagic transformation in rats subjected to 4- and 5-hour ischemia/24-hour reperfusion. Since therapeutic effects may be expected until at least 5 h of complete ischemia and reperfusion, this combination therapy is a promising neuroprotective strategy against severe ischemic stroke.

[Successful Total Resection with Preceding Arterial Coil Embolization of Intradural Extramedullary Tumor at Craniovertebral Junction Encasing Dominant-side Vertebral Artery]

OBJECTIVE

The surgical resection of craniovertebral junction(CVJ)meningioma is challenging because of the neighboring brainstem, lower cranial nerves, and vertebral artery(VA). Moreover, encasement of the VA by the tumor can raise the risk of complications and require cautious manipulation during surgery.

CASE

A 46-year-old woman presented with a one-year history of neck pain. She had temporal hemiplegia and numbness on her left side. Magnetic resonance imaging(MRI)showed a CVJ meningioma pushing the brainstem from the right vertebral side and encasing the right VA. Digital subtraction angiography(DSA)showed two feeding arteries arising from the right VA and a sunburst sign. The right VA was the dominant side but did not have the right posterior inferior cerebellar artery(PICA). The anterior spinal artery(ASA)was dominant in the left VA. We performed a balloon test occlusion(BTO)for 20 min and it did not cause any complications;therefore, we occluded the VA using endovascular coils. After 4 days, we removed the meningioma in the prone position, using a far-lateral approach and C1-laminectomy. The laterally located meningioma pushed the brainstem. After detaching the tumor from the dura, we cut the encased VA and the tumor was resected safely(Simpson grade II). Postoperatively, she developed temporal thermal hypoalgesia on the left side of her body. Magnetic resonance imaging showed a microinfarction in the medulla.

CONCLUSION

If the VA test occlusion provides a clear result, pre-operative endovascular sacrifice of the VA encased by CVJ meningioma is a feasible treatment strategy.

Abstract WP547: FTY720 (Fingolimod) Ameliorates Ischemia Reperfusion Injury in Experimental Stroke Model

Background: Fingolimod (FTY720), a widely known sphingosine-1-phosphate (S1P) receptor agonist, was approved as a treatment for multiple sclerosis due to its strong anti-inflammatory effect.

Methods: In-vivo study, FTY720 was injected intraperitoneally just before reperfusion. Neurological score and infarct volume were evaluated at Day0, 1, 3, 5, and 7 after MCAO. Evans Blue analysis and immunohistochemistry were conducted at day1 and day7. [18F]DPA-714 PET was performed 2 and 9 days after MCAO. In vitro study, in order to perform OGD, Bovine Brain Microvascular Endothelial Cells (BBMVECs) were incubated in a glucose-free medium under 1% oxygen condition, and then reperfused for 4 hours. In vitro models of ischemia/reperfusion injury were exposed to FTY720, FTY720-P, S1P and SEW (100 nM) immediately after reperfusion. The effects of FTY720 on the blood brain barrier were examined by real-time PCR analysis and immunofluorescence staining.

Results: In this study, we observed that FTY720 reduced infarction size and improved neurological score after MCAO. [18F]DPA-714 PET showed a high standardized uptake value (SUV) around the ischemic area 2 days after MCAO. Although SUV was increased further 9 days after MCAO in both treatment groups, the increase was significantly inhibited in 1.5mg/kg group. In addition, FTY720 recovered the integrity of blood brain barrier which has been disrupted by ischemia/reperfusion injury. However, we observed that FTY720 can improve the integrity of blood brain barrier by inducing the translocation of tight junction and adherins junction, but FTY720 cannot ameliorate the expression of tight junction and adherins junction.

Conclusions: The present results suggest that FTY720 improves neurological score, reduces infarction size, inflammatory activation and neuronal apoptosis. Especially ameliorates the integrity of Blood-Brain Barrier by inducing the translocation of tight junction and adherins junction after transient MCAO.

Decreased Plasma Tissue Factor Pathway Inhibitor Activity in Ischemic Stroke Patients

Although tissue factor pathway inhibitor (TFPI) plays an essential role in the regulation of blood coagulation, the quantitative changes in its levels in thrombotic disease are still undefined. We compared TFPI activity in ischemic stroke patients and control subjects matched for age and cholesterol level to determine whether TFPI activity is changed in the disease. TFPI activity was significantly lower in the stroke patients (1.01 ± 0.24 U/ml) than in the control subjects (1.10 ± 0.16 U/ml). In relation to clinical subtypes of stroke, TFPI activity in atherothrombotic infarction (0.93 ± 0.19 U/ml) and lacunar infarction (0.99 ± 0.23 U/ml) was significantly lower than in the control subjects, whereas the level in cardioembolic infarction (1.16 ± 0.31 U/ml) was not. No relationship could be established between TFPI activity and other haemostatic parameters reflecting the production of thrombin/fibrin and the activation of fibrinolysis. These results may suggest that the moderately lower TFPI activity in stroke patients could be due to atherosclerotic changes rather than to consumptive coagulopathy.

[18F]DPA-714 PET imaging shows immunomodulatory effect of intravenous administration of bone marrow stromal cells after transient focal ischemia

Background

The potential application of bone marrow stromal cell (BMSC) therapy in stroke has been anticipated due to its immunomodulatory effects. Recently, positron emission tomography (PET) with [¹⁸F]DPA-714, a translocator protein (TSPO) ligand, has become available for use as a neural inflammatory indicator. We aimed to evaluate the effects of BMSC administration after transient middle cerebral artery occlusion (MCAO) using [¹⁸F]DPA-714 PET.

The BMSCs or vehicle were administered intravenously to rat MCAO models at 3 h after the insult. Neurological deficits, body weight, infarct volume, and histology were analyzed. [¹⁸F]DPA-714 PET was performed 3 and 10 days after MCAO.

Results

Rats had severe neurological deficits and body weight loss after MCAO. Cell administration ameliorated these effects as well as the infarct volume. Although weight loss occurred in the spleen and thymus, cell administration suppressed it. In both vehicle and BMSC groups, [¹⁸F]DPA-714 PET showed a high standardized uptake value (SUV) around the ischemic area 3 days after MCAO. Although SUV was increased further 10 days after MCAO in both groups, the increase was inhibited in the BMSC group, significantly. Histological analysis showed that an inflammatory reaction occurred in the lymphoid organs and brain after MCAO, which was suppressed in the BMSC group.

Conclusions

The present results suggest that BMSC therapy could be effective in ischemic stroke due to modulation of systemic inflammatory responses. The [¹⁸F]DPA-714 PET/CT system can accurately demonstrate brain inflammation and evaluate the BMSC therapeutic effect in an imaging context. It has great potential for clinical application.

Research on advanced intervention using novel bone marrOW stem cell (RAINBOW): a study protocol for a phase I, open-label, uncontrolled, dose-response trial of autologous bone marrow stromal cell transplantation in patients with acute ischemic stroke

Background

Stroke is a leading cause of death and disability, and despite intensive research, few treatment options exist. However, a recent breakthrough in cell therapy is expected to reverse the neurological sequelae of stroke. Although some pioneer studies on the use of cell therapy for treating stroke have been reported, certain problems remain unsolved. Recent studies have demonstrated that bone marrow stromal cells (BMSCs) have therapeutic potential against stroke. We investigated the use of autologous BMSC transplantation as a next-generation cell therapy for treating stroke. In this article, we introduce the protocol of a new clinical trial, the Research on Advanced Intervention using Novel Bone marrOW stem cell (RAINBOW).

Methods/design

RAINBOW is a phase 1, open-label, uncontrolled, dose-response study, with the primary aim to determine the safety of the autologous BMSC product HUNS001–01 when administered to patients with acute ischemic stroke. Estimated enrollment is 6–10 patients suffering from moderate to severe neurological deficits. Approximately 50 mL of the bone marrow is extracted from the iliac bone of each patient 15 days or later from the onset. BMSCs are cultured with allogeneic human platelet lysate (PL) as a substitute for fetal calf serum and are labeled with superparamagnetic iron oxide for cell tracking using magnetic resonance imaging (MRI). HUNS001–01 is stereotactically administered around the area of infarction in the subacute phase. Each patient will be administered a dose of 20 or 50 million cells. Neurological scoring, MRI for cell tracking, ¹⁸F–fuorodeoxyglucose positron emission tomography, and ¹²³I–Iomazenil single­photon emission computed tomography will be performed for 1 year after the administration.

Discussion

This is a first-in-human trial for HUNS001–01 to the patients with acute ischemic stroke. We expect that intraparenchymal injection can be a more favorable method for cell delivery to the lesion and improvement of the motor function than intravenous infusion. Moreover, it is expected that the bio-imaging techniques can clarify the therapeutic mechanisms.

Trial registration

The trial was registered at The University Hospital Medical Information Network on February 22, 2017 (UNIN ID: UMIN000026130). The findings of this trial will be disseminated to patients and through peer-reviewed publications and international presentations.

Regional transarterial hypothermic infusion in combination with endovascular thrombectomy in acute ischaemic stroke with cerebral main arterial occlusion: protocol to investigate safety of the clinical trial

INTRODUCTION

Acute cerebral ischaemia with main cerebral artery occlusion requires treatment with intravenous tissue plasminogen activator administration and/or endovascular thrombectomy. However, some patients fail to recover even after recanalisation because of ischaemia/reperfusion (I/R) injury. We hypothesised that regional transarterial hypothermic infusion would be effective for patients with I/R injury. The aim of this study is to validate the safety of this procedure.

METHODS AND ANALYSIS

This is a clinical exploratory study to evaluate safety of regional transarterial hypothermic infusion in combination with endovascular thrombectomy. Patients with acute ischaemic stroke and a National Institutes of Health Stroke Scale (NIHSS) score of 5-29 who require endovascular thrombectomy are eligible for the study. When no improvement in NIHSS score after the recanalisation is achieved by thrombectomy, cold saline (15°C) will be administered through a microcatheter located in the ipsilateral internal carotid artery. The primary endpoints of this study are mortality and morbidity. The secondary endpoint is deleterious effects on clinical data such as symptoms, radiographic findings and physiological data. The primary and secondary endpoints will be accumulated as case series because this study will be conducted on a small sample of seven patients.

ETHICS AND DISSEMINATION

All protocols and the informed consent form comply with the Ethics Guideline for Clinical Research (Japanese Ministry of Health, Labour and Welfare). Ethics review committees at the Hokkaido University Hospital approved the study protocols. The results of the study will be disseminated at several research conferences and also contributed to peer-reviewed journals. The study will be implemented and reported in line with the SPIRIT statement.

TRIAL REGISTRATION NUMBER

UMIN Clinical Trails Registry (UMIN000018255); pre-results.

Superior Microvascular Perfusion of Infused Liposome-Encapsulated Hemoglobin Prior to Reductions in Infarctions after Transient Focal Cerebral Ischemia

BACKGROUND

The development of cerebral infarction after transient ischemia is attributed to postischemic delayed hypoperfusion in the microvascular region. In the present study, we assessed the microvascular perfusion capacity of infused liposome-encapsulated hemoglobin (LEH) in a therapeutic approach for transient middle cerebral artery occlusion (tMCAO).

METHODS

Two-hour middle cerebral artery occlusion rats were immediately subjected to intra-arterial infusion of LEH (LEH group) or saline (vehicle group) or no treatment (control group), and then to recanalization. Neurological findings, infarct and edema progression, microvascular endothelial dysfunction, and inflammatory reactions were compared between the 3 groups after 24 hours of reperfusion. Microvascular perfusion in the early phase of reperfusion was evaluated by hemoglobin immunohistochemistry and transmission electron microscopy.

RESULTS

The LEH group achieved significantly better results in all items evaluated than the other groups. Hemoglobin immunohistochemistry revealed that the number of hemoglobin-positive microvessels was significantly greater in the LEH group than in the other groups (P < .01), with microvascular perfusion being more likely in narrow microvessels (≤5 µm in diameter). An electron microscopic examination revealed that microvessels in the control group were compressed and narrowed by swollen astrocyte end-feet, whereas those in the LEH group had a less deformed appearance and contained LEH particles and erythrocytes.

CONCLUSION

The results of the present study demonstrated that the infusion of LEH reduced infarctions after tMCAO with more hemoglobin-positive and less deformed microvessels at the early phase of reperfusion, suggesting that the superiority of the microvascular perfusion of LEH mediates its neuroprotective effects.

Mapping altered brain connectivity and its clinical associations in adult moyamoya disease: A resting-state functional MRI study

Detection of subtle ischemic injuries in moyamoya disease may enable optimization of timing of revascularization surgery, and could potentially improve functional outcomes. Resting-state functional magnetic resonance imaging (rs-fMRI) is widely used to study functional organization of the brain, but it remains unclear whether rs-fMRI could elucidate distinct characteristics in moyamoya disease. Here, we aimed to determine changes in a conventional rs-fMRI measure and analyze any associations with clinical symptoms and cerebral hemodynamics. Thirty-one adults with moyamoya disease and 25 adult controls underwent rs-fMRI, in which we measured brain connectivity via temporal correlations of low-frequency BOLD signals. We identified the extent of between-group differences with multivoxel pattern analysis. Seed-based analysis was performed to determine associations with vascular lesions, symptoms, and regional cerebral blood flow (rCBF). There was significantly altered connectivity in the precentral gyrus, operculo-insular region, precuneus, cingulate cortex, and middle frontal gyrus in moyamoya disease. There was reduced connectivity in the left insula, left precuneus, right precentral, and right middle frontal regions, which form part of the salience, default mode, motor, and central executive networks, respectively. Patients with ischemic motor-related symptoms showed significantly decreased connectivity in precentral homotopic regions compared with those without, while there were no differences in vascular lesions or rCBF. Connectivity between the right occipital and left hippocampus was significantly associated with cognitive performance and posterior cerebral artery involvement. Our results demonstrate distinct alterations in the temporal correlations of low-frequency BOLD signals, predominantly in resting-state networks in moyamoya disease. Additionally, rs-fMRI measures were associated with ischemic motor-related symptoms and cognitive performance in the patients. Thus, rs-fMRI may offer a useful non-invasive method of acquiring additional information beyond cerebral perfusion as part of clinical investigations in patients with moyamoya disease.

Abstract WP99: Neuroprotective Therapy for Ischemia-Reperfusion Injury by Hemoglobin-albumin-cluster(Hemoact Tm )

Background: A hemoglobin-albumin cluster designated as “HemoAct” was developed as a red blood cell substitute. It is composed of one core hemoglobin center wrapped covalently by three albumin shells. Since its particle size with a diameter of 10 nm is far smaller than red blood cell, it is expected to maintain good perfusion in the cerebral microvessels, leading to neuroprotective effects on ischemia-reperfusion (I/R) injury.

Purpose: We aim to examine whether HemoAct have neuroprotective effects in rat transient middle cerebral artery occlusion (tMCAO) model, without toxic effects of hemoglobin, by administering it though the recanalized artery just before the onset of reperfusion.

Subjects and Methods: Male Sprague-Dawley rats were subjected to 2-hour tMCAO by suture occlusion and then divided into four groups with respective treatments: (1) control group; no infusion, (2) vehicle group; infusion of PBS as the solvent (3) 0.5х HemoAct group; infusion of one-half diluted HemoAct (4) HemoAct group; infusion of undiluted HemoAct. Physical and neurological states, infarct and edema volumes, reactive oxygen species (ROS) and protease immunoblot levels were compared between the four groups after 24 hours of reperfusion. Microvascular hemoglobin perfusion and morphological states were compared between the control and HemoAct groups with immunohistochemical technique.

Results: No significant changes were observed in blood pressure, pH, and blood gas after HemoAct infusion. Neurological symptoms were significantly less severe in the HemoAct group than in the other groups. Infarct and edema volumes were significantly smaller in the 0.5х HemoAct group (27.1%/15.2%) and the HemoAct group (20.2%/14.1%) than in the control group (55.2%/26.4%) and the vehicle group (53.2%/27.1%). ROS (4-HNE) and protease (MMP-9) immunoblot levels were significantly reduced in HemoAct group compared with the control and vehicle groups. Microvascular hemoglobin perfusion was more and microvascular narrowing changes was less in the HemoAct group than in the control group.

Conclusion: HemoAct exhibited strong neuroprotective effects on I/R injury without toxic effects of hemoglobin. Superior microvascular perfusion of HemoAct may be a possible neuroprotective mechanism.

Abstract TP99: Inflammatory Changes in Brain and Lymphoid Organs After Ischemic Stroke: PET Imaging for Cell Therapy

Recently, bone marrow stromal cell (BMSC) therapy for stroke is expected due to the immunomodulation effect. Here, we use PET and other detecting method to investigate the inflammatory changes of brain and lymphoid organs in rat stroke model. In this study, F344 rats were used as transient MCAO models. One part of rats were serially monitored by small-animal PET/CT system with new neuroinflammatory ligand [ 18 F]DPA-714. The brains were removed and sliced subsequently for autoradiograph (ARG) and TTC staining. The rest of rats were sacrificed, their brains and lymphoid organs were taken out, weighed, stained, etc. In histology, cytotoxic T cell (CD8α), macrophage (Iba1 and CD68), apoptosis (TUNEL) and proliferation (ki67) antibodies were chosen and analyzed. PET and ARG represented high concentration in the ischemic area which had been confirmed by TTC. In body imaging, no significant change was found. With the increase of ischemic severity, the size of lymphoid organs have a significantly decrease as well as the body weight. Histological assay showed cd8α + and ki67 + cells decreased in the lymphoid organs and increased in brain. Besides macrophages and apoptosis cells increased all the time in liver, in other organs, the rate of cells reached peak and gradually decreased more or less. In summary, [ 18 F]DPA-714 PET has a great potential for evaluating brain damage. Inflammatory responses in brain and lymphoid organs are distinct after stroke. Based on these results, we will continue the study for evaluating immunomodulation effect of BMSC transplantation therapy.

Surgical Outcome of Cerebral Aneurysm Clipping Treated with Immunosuppressants: Report of 11 Cases and Review of the Literature

There are no reports on the outcomes of clippings in patients who receive immunosuppressants, for example, due to connective tissue diseases or following organ transplantation. We thoroughly reviewed these cases focusing on the perioperative management phase. The study included 11 patients with intracranial aneurysms who were taking immunosuppressants; between 2007 and 2014. We performed 12 clipping surgeries. Their clinical records were reviewed for age and gender, aneurysms' location and size, perioperative management of the immunosuppressive drugs, and surgical complications. The study included nine females and two males, aged between 52 and 71 years (mean 60.1 ± 8.5 years). The clinical presentation in five cases was subarachnoid hemorrhage (SAH); the aneurysm was incidentally diagnosed in six patients (7 aneurysms). The reasons for taking immunosuppressants were autoimmune disorder in nine patients and liver transplantation in two patients. Daily intake of oral immunosuppressants for the patients with liver transplantation was discontinued for 2-4 days, and no infectious complications were evidenced. The weekly course of immunosuppressive drugs for the patients with autoimmune disorder was continued in eight of nine patients. Caution must be exercised when considering the suitability of clipping for patients taking immunosuppressants, but surgery outcomes are generally favorable; when operative treatment is required, we believe it to be comparatively safe, if the perioperative management is conducted in close collaboration with the relevant departments.

Ultrasound-guided Femoral Artery Access for Minimally Invasive Neuro-intervention and Risk Factors for Access Site Hematoma

Although ultrasound (US) guidance for venous access is becoming the “standard of care” for preventing access site complications, its feasibility for arterial access has not been fully investigated, especially in the neuro-interventional population. We conducted the first prospective cohort study on US-guided femoral artery access during neuro-interventional procedure. This study included 64 consecutive patients who underwent US-guided femoral artery access through 66 arterial access sites for diagnostic and/or neuro-interventional purposes. The number of attempts required for both the sheath insertion and the success of anterior wall puncture were recorded. In addition, the occurrence of major complications and hematoma formation on the arterial access site examined by US were statistically analyzed. The median number of attempts was 1 (1–2) and first-pass success rate was 63.6%. Anterior wall puncture was achieved in 98.5%. In one case (1.5%), a pseudoaneurysm was observed. In all cases, US clearly depicted a common femoral artery (CFA) and its bifurcation. Post-procedural hematoma was detected in 13 cases (19.7%), most of which were “tiny” or “moderate” in size. Low body mass index and antiplatelet therapy were the independent risk factors for access site hematoma. The US-guided CFA access was feasible even in neuro-interventional procedure. The method was particularly helpful in the patients with un-palpable pulsation of femoral arteries. To prevent arterial access site hematoma, special care should be taken in patients with low body mass index and who are on antiplatelet therapy.

Transarterial regional hypothermia provides robust neuroprotection in a rat model of permanent middle cerebral artery occlusion with transient collateral hypoperfusion

The robust neuroprotective effects of transarterial regional hypothermia have been demonstrated in the typical transient middle cerebral artery occlusion (tMCAO) model, but have not yet been tested in other ischemic stroke models, even though clinical ischemic conditions are diverse. In order to clarify these effects in a different ischemic stroke model, we employed a rat model of permanent MCAO (pMCAO) with transient collateral hypoperfusion (tCHP), which was achieved by direct MCA ligation through craniotomy and 1-h bilateral common carotid artery occlusion at the beginning of pMCAO. The infusion of 20ml/kg of 4°C cold saline (CS) or 37°C warm saline (WS) into the ipsilateral internal carotid artery (ICA) was performed for 15min in intra- or post-tCHP. Neurological scores, infarct/edema volumes, and neuronal apoptosis and reactive gliosis were compared between the CS and WS groups and a non-infusion control group after 48h of reperfusion. Although brain temperatures were only reduced by 2-3°C for 15min, the CS group had significantly better neurological scores, smaller infarct/edema volumes, and less penumbral neuronal apoptosis and reactive gliosis than the control and WS groups. The post-tCHP CS group exhibited prominent neuroprotective effects, even though infarct volumes and neuronal apoptosis were reduced less than those in the intra-tCHP CS group. In conclusion, we demonstrated the neuroprotective effects of transarterial regional hypothermia in an ischemic model of pMCAO with tCHP. Even though MCAO is persistent, cold infusion via the ICA is neuroprotective for the penumbra, suggesting the wider therapeutic application of this therapy.

Topographic changes in cerebral blood flow and reduced white matter integrity in the first 2 weeks following revascularization surgery in adult moyamoya disease

OBJECTIVE After revascularization surgery, hyperperfusion and ischemia are associated with morbidity and mortality in adult moyamoya disease (MMD). However, structural changes within the brain following revascularization surgery, especially in the early postsurgical period, have not been thoroughly studied. Such knowledge may enable improved monitoring and clinical management of hyperperfusion and ischemia in MMD. Thus, the objective of this study was to investigate the topographic and temporal profiles of cerebral perfusion and related white matter microstructural changes following revascularization surgery in adult MMD. METHODS The authors analyzed 20 consecutive surgeries performed in 17 adults. Diffusion imaging in parallel with serial measurements of regional cerebral blood flow (rCBF) using SPECT was performed. Both voxel-based and region-of-interest analyses were performed, comparing neuroimaging parameters of postoperative hemispheres with those of preoperative hemispheres at 4 different time points within 2 weeks after surgery. RESULTS Voxel-based analysis showed a distinct topographic pattern of cerebral perfusion, characterized by increased rCBF in the basal ganglia for the first several days and gradually increased rCBF in the lateral prefrontal cortex over 1 week (p < 0.001). Decreased rCBF was also observed in the lateral prefrontal cortex, occipital lobe, and cerebellum contralateral to the surgical hemisphere (p < 0.001). Reduced fractional anisotropy (FA) and axial diffusivity (AD), as well as increased radial diffusivity (RD), were demonstrated in both the anterior and posterior limbs of the internal capsule (p < 0.001). Diffusion parameters demonstrated the greatest changes in both FA and RD on Days 1-2 and in AD on Days 3-6; FA, RD, and AD recovered to preoperative levels on Day 14. Patients with transient neurological deteriorations (TNDs), as compared with those without, demonstrated greater increases in rCBF in both the lateral prefrontal cortex and striatum as well as smaller FAs in the posterior limb of the internal capsule (p < 0.05). CONCLUSIONS The excessively increased rCBF and the recovery process were heterogeneous across brain regions, demonstrating a distinct topographic pattern during the initial 2 weeks following revascularization surgery in MMD. Temporary impairments in the deep white matter tract and immediate postoperative ischemia were also identified. The study results characterized postoperative brain perfusion as well as the impact of revascularization surgery on the brain microstructure. Notably, rCBF and white matter changes correlated to TNDs, suggesting that these changes represent potential neuroimaging markers for tracking tissue structural changes associated with hyperperfusion during the acute postoperative period following revascularization surgery for MMD.

Increased Blood Viscosity in Ischemic Stroke Patients with Small Artery Occlusion Measured by an Electromagnetic Spinning Sphere Viscometer

BACKGROUND AND PURPOSE

High blood viscosity causes blood stagnation and subsequent pathological thrombotic events, resulting in the development of ischemic stroke. We hypothesize that the contribution of blood viscosity may differ among ischemic stroke subtypes based on specific pathological conditions. We tried to verify this hypothesis by measuring blood viscosity in acute ischemic stroke patients using a newly developed electromagnetic spinning sphere (EMS) viscometer.

METHODS

Measurements in acute ischemic stroke patients were performed 4 times during admission and data were compared with those obtained from 100 healthy outpatient volunteers.

RESULTS

We enrolled 92 patients (cardioembolism: 25, large artery atherosclerosis: 42, and small artery occlusion [SAO]: 25) in this study. Comparisons of blood viscosity between the ischemic stroke subgroups and control group revealed that blood viscosity at the date of admission was significantly higher in the SAO group (5.37 ± 1.11 mPa⋅s) than in the control group (4.66 ± .72 mPa⋅s) (P < .01). Among all subtype groups showing a reduction in blood viscosity after 2 weeks, the SAO group showed the highest and most significant reduction, indicating that SAO patients had the most concentrated blood at the onset.

CONCLUSIONS

Blood viscosity was significantly increased in the SAO group at the date of admission, which indicated the contribution of dehydration to the onset of ischemic stroke. The importance of dehydration needs to be emphasized more in the pathogenesis of SAO. The clinical application of the EMS viscometer is promising for understanding and differentiating the pathogenesis of ischemic stroke.

Characteristics of Diffusional Kurtosis in Chronic Ischemia of Adult Moyamoya Disease: Comparing Diffusional Kurtosis and Diffusion Tensor Imaging

BACKGROUND AND PURPOSE

Detecting microstructural changes due to chronic ischemia potentially enables early identification of patients at risk of cognitive impairment. In this study, diffusional kurtosis imaging and diffusion tensor imaging were used to investigate whether the former provides additional information regarding microstructural changes in the gray and white matter of adult patients with Moyamoya disease.

MATERIALS AND METHODS

MR imaging (diffusional kurtosis imaging and DTI) was performed in 23 adult patients with Moyamoya disease and 23 age-matched controls. Three parameters were extracted from diffusional kurtosis imaging (mean kurtosis, axial kurtosis, and radial kurtosis), and 4, from DTI (fractional anisotropy, radial diffusivity, mean diffusivity, and axial diffusivity). Voxelwise analysis for these parameters was performed in the normal-appearing brain parenchyma. The association of these parameters with neuropsychological performance was also evaluated.

RESULTS

Voxelwise analysis revealed the greatest differences in fractional anisotropy, followed, in order, by radial diffusivity, mean diffusivity, and mean kurtosis. In patients, diffusional kurtosis imaging parameters were decreased in the dorsal deep white matter such as the corona radiata and superior longitudinal fasciculus (P < .01), including areas without DTI abnormality. Superior longitudinal fasciculus fiber-crossing areas showed weak correlations between diffusional kurtosis imaging and DTI parameters compared with tissues with a single-fiber direction (eg, the corpus callosum). Diffusional kurtosis imaging parameters were associated with general intelligence and frontal lobe performance.

CONCLUSIONS

Although DTI revealed extensive white matter changes, diffusional kurtosis imaging additionally demonstrated microstructural changes in ischemia-prone deep white matter with abundant fiber crossings. Thus, diffusional kurtosis imaging may be a useful adjunct for detecting subtle chronic ischemic injuries.

Cardiovascular events occur independently of high on-aspirin platelet reactivity and residual COX-1 activity in stable cardiovascular patients

Several studies have indicated that approximately 25 % of patients treated with aspirin exhibit high on-treatment platelet reactivity (HTPR), which is potentially associated with cardiovascular events (CVEs). However, this association is still controversial, since the mechanisms by which HTPR contributes to CVEs remain unclear and a no standardised definition of HTPR has been established. To determine whether HTPR is associated with CVE recurrence and what type of assay would best predict CVE recurrence, we conducted a multicentre prospective cohort study of 592 stable cardiovascular outpatients treated with aspirin monotherapy for secondary prevention. Their HTPR was determined by arachidonic acid- or collagen-induced aggregation assays using two different agonist concentrations. Residual cyclooxygenase (COX)-1 activity was assessed by measuring serum thromboxane (TX)B2 or urinary 11-dehydro TXB2. Shear-induced platelet thrombus formation was also examined. We followed all patients for two years to evaluate how these seven indexes were related to the recurrence of CVEs (cerebral infarction, transient ischaemic attack, myocardial infarction, unstable angina, revascularisation, other arterial thrombosis, or cardiovascular death). Of 583 patients eligible for the analysis, CVEs occurred in 69 (11.8 %). A Cox regression model identified several classical risk factors associated with CVEs. However, neither HTPR nor high residual COX-1 activity was significantly associated with CVEs, even by applying cut-off values suggested in previous reports or a receiver-operating characteristic analysis. In conclusion, recurrence of CVEs occurred independently of HTPR and residual COX-1 activity. Thus, our findings do not support the use of platelet or COX-1 functional testing for predicting clinical outcomes in stable cardiovascular patients.

De novo arteriovenous malformation in a patient with hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant systemic disorder characterized by the enlargement of capillaries, recurrent nosebleeds, and multiple arteriovenous malformations (AVMs). Although cerebral AVMs are traditionally considered to be congenital lesions, some reports have described de novo AVMs, which suggests that the authors believed them to be dynamic conditions. In this article, the authors describe the case of a 5-year-old boy with HHT in whom a de novo cerebral AVM was detected after a negative MRI result at 5 months. To the authors' knowledge, this is the first report of a de novo AVM in a patient with HHT. In patients with a family history of HHT, de novo AVMs are possible, even when no lesions are detected at the first screening. Therefore, regular screenings need to be performed, and the family should be informed that AVMs could still develop despite normal MRI results.

Abstract 9: A Novel Large Cerebral Aneurysm Model in Rats with Intraperitoneal Administration of Beta-AminoPropioNitril-Fumarate

Introduction: Mechanisms of formation, enlargement, and rupture of cerebral aneurysm (CA) are not fully understood. Unveiling the mechanisms lead to the prevention of a life-threatening subarachnoid hemorrhage. Although several CA models in rats have been reported, most of CAs in the models are immature and insufficient for the close investigation into the mechanisms of enlargement and rupture. The establishment of a large CA model is required for full disclosure of the mechanisms.

Methods: A new CA model in rats was designed by modifying the Hashimoto model in that high-dose β-aminopropionitril fumarate (BAPN-F) was administrated intraperitoneally. Seven-week-old male Sprague-Dawley rats were deeply anesthetized, the left common carotid artery was dissected and the bilateral posterior branches of the renal artery were ligated. After the operation, rats were fed food with 8% sodium chloride and divided into 4 groups according to the weekly dose amount of BAPN-F as well as the breeding periods (group 1: n=31, 400mg/kg for 4weeks, group 2: n=31, 400mg/kg for 8weeks, group 3: n=27, 2800mg/kg for 8weeks, group 4: n=13, 2800mg/kg for 12weeks). We then investigated aneurysmal development pathologically along with calculating CA induction rate and mortality rate in each group.

Results: Continuous hypertension were induced in all groups. CA induction rate was 19.4%, 29%, 85.2%, and 84.6% while mortality was 12.9%, 16.1%, 7.4% and 30.1% in the group 1, 2, 3, and 4, respectively. Group 3 has statistically significant differences in both the induction rate (p=0.018) and mortality (p=0.027). Among 4 groups, CAs were located at anterior cerebral artery - ophthalmic artery bifurcation, anterior communicating artery (Acom A), and posterior communication artery (Pcom A). We defined the large CA as over one and a half times the size of its parent artery. Large CAs were predominantly detected at Acom A and Pcom A in the group 3 (22.2%) and 4 (23.1%). In addition, all large CAs were morphologically and histologically similar to that of human.

Conclusions: Intraperitoneal administration of 2800mg/kg BAPN-F enabled us to induce large CAs with 20% induction rate and low mortality. A further investigation of this model should be promising for full disclosure of the CAs mechanisms.

Abstract WP110: The Next Generation of Autologous Bone Marrow Stromal Cell Transplantation Against Stroke

Background and purpose: Recent studies have elucidated that the bone marrow stromal cells (BMSCs) have therapeutic potential against stroke. Some clinical trials have been starting up in practice. We aimed to evolve the autologous BMSC transplantation for stroke into the next generation.

Materials and methods: Human BMSCs were cultured with human platelet lysate (hPL) instead of fetal calf serum (FCS). They were labeled with superparamagnetic iron oxide (SPIO). Rat ischemic stroke models were made and 5x105 cells were injected into the ipsilateral striatum stereotactically 7 days post-insult. Behavioral analysis, MRI for cell tracking, (18)F-FDG PET, and (123)I-Iomazenil SPECT were performed. The animals were sacrificed 5 to 8 weeks post-transplantation and histological analysis was performed.

Results: There was no difference in the surface markers and cell proliferation between hPL and FCS. Although rotarod test showed that motor function deteriorated in rats suffered from permanent MCAo, BMSC-hPL transplantation enhanced recovery of the motor function, significantly. MRI demonstrated that SPIO-BMSCs aggressively migrated towards the lesion. Moreover, (18)F-FDG PET and (123)I-Iomazenil SPECT showed that BMSC transplantation promoted recovery of the glucose utilization and the binding potential of iomazenil in the peri-infarct area, respectively. Histological analysis supported the findings on MRI and showed the inclination for neural differentiation of donor cells.

Conclusion: The hPL may be valuable and safe in expanding BMSCs. The application of bio-imaging techniques is also valuable for BMSC transplantation for stroke. Now we prepare the novel clinical trial against stroke, Research on Advanced Intervention using Novel Bone marrOW stem cell (RAINBOW) study. The present results are translated into the optimal design of the trial.

Abstract TP234: New Clinical Application of Measurement of Blood Viscosity With an Electromagnetically Spinning Sphere Viscometer in Acute Ischemic Stroke Patients

Introduction: Blood viscosity (BV) is an important blood property for determining the hemodynamic status. High BV causes blood stagnation and subsequent thrombotic reactions leading to cerebral infarction. However, clinical application of the measurement of BV is out of fashion due to the stereotype that the measurement results are within expectations with less clinical value.

Hypothesis: Since the importance of BV remains unchanged in the pathogenesis of vascular diseases, BV values should still contain important information. We hypothesize that BV values may differ among stroke subtypes based on pathological condition.

Methods: A new type of viscometer was recently developed using an electromagnetically spinning sphere (EMS) method, which enable us to measure small amount of samples quickly and sequentially in non-contact disposable manner. We measured BV in 100 healthy outpatients and 67 acute ischemic stroke patients (atherothrombotic: 28, lacunar: 23, and cardioembolic: 16) with EMS viscometer. The relationships between BV and hematological parameters were analyzed. The measurements in the acute stroke patients were performed a total of 4 times (Day0, Day2, Day7, and Day14 from the admission).

Results: BV values in the healthy outpatients correlated more strongly with the total count of red blood cells and platelets (R2=0.6957) than with the hematocrit (R2=0.6435) in an exponential approximation. Compared with BV values in the healthy outpatients (4.57±0.76 mPa·s), Day0 BV values in the lacunar patients (5.37±1.11 mPa·s) were significantly higher (p<0.01), but those in the atherothrombotic patients (4.82±0.98 mPa·s) and in the cardioembolic patients (4.66±0.93 mPa·s) were not significantly different. In comparison between the values at Day 0 and Day 14, the lacunar patients alone showed a significant decrease from Day0 to Day14, suggesting that the lacunar patients suffered from dehydration at the onset.

Conclusion: BV values at Day0 of lacunar infarction were significantly increased, which indicated contribution of dehydration to the onset of lacunar infarction. These measurements were performed with only 0.3ml of blood quickly and sequentially; therefore, the clinical application of the EMS viscometer appears to be promising.

Abstract WP112: Trans-arterial Regional Hypothermia Provides Robust Neuroprotection in Rat Permanent Middle Cerebral Artery Occlusion Model

Background and Purpose: We previously reported the neuroprotective effects of trans-arterial regional hypothermia in rat transient middle cerebral artery occlusion (tMCAO) model (ISC 2014, ISC 2015). The tMCAO model is representative of the clinical setting of successful recanalization in acute ischemic stroke. However, it is not always possible to achieve successful recanalization. Herein, we investigated the neuroprotective effects of trans-arterial regional hypothermia in permanent MCAO (pMCAO) model as well.

Methods: Three groups were provided to investigate the neuroprotective effects. Regional hypothermia group had a single infusion of 20ml/kg 10°C cold saline via the ipsilateral internal carotid artery for 15 min at 0 hr or 1 hr after the onset of pMCAO. Vehicle group had a 37°C warm saline infusion in the same manner. Control group had no infusion after pMCAO. The rats were tested for neurological score after 48-hour pMCAO and then sacrificed to evaluate infarction size and pathological condition. Immunohistochemical analysis was performed to investigate the neuronal apoptosis (NeuN, cleaved caspase 3), glial reaction (GFAP), and microglial activation (Iba-1).

Results: The regional hypothermia group showed significantly better neurological score compared with the other groups (p<0.01). Infarct volume was significantly smaller in the regional hypothermia group (8.1±4.7% at 0 hr and 15.7±5.9% at 1 hr) than in the vehicle group (35.8±5.6% at 0 hr and 34.0±3.6% at 1 hr) and also in the control group (35.1±8.9%) (p<0.01). Neuronal apoptosis (p<0.01), reactive gliosis (p<0.01), and microglial activation (p<0.05) in the peri-infarct area were significantly inhibited in the regional hypothermia group compared with the other groups. The degree of the inhibition was somewhat more evident at 0 hr than at 1 hr.

Conclusions: Our result demonstrated that trans-arterial regional hypothermia provided robust neuroprotection in pMCAO model as well as tMCAO model, suggesting that this therapy may have a wide clinical application in ischemic stroke treatment.

[Efficacy of Stent-Assisted Coil Embolization for a Dissecting Aneurysm of the Cervical Internal Carotid Artery Caused by a Systemic Vascular Disease: A Case Report]

Systemic vascular diseases such as fibromuscular dysplasia, Ehlers-Danlos syndrome, Marfan syndrome, and Behçet's disease are known to cause spontaneous dissecting aneurysms of the cervical internal carotid artery. These diseases are generally associated with vascular fragility; therefore, invasive treatments are avoided in many cases of dissecting aneurysms, and a conservative approach is used for the primary disease. Surgical or intravascular treatment may be chosen when aneurysms are progressive or are associated with a high risk of hemorrhage; however, there is no consensus on which treatment is better. We report a case of a dissecting aneurysm of the cervical internal carotid artery in a patient with suspected Behçet's disease, which was treated using stent-assisted coil embolization. A man in his 40's, with suspected Behçet's disease, presented with an enlarged dissecting aneurysm of the right cervical internal carotid artery. The lesion was present for approximately 10 years. We performed stent-assisted coil embolization for the lesion. Post-surgery, no aneurysms were detected with carotid artery echography. Our case report suggests that stent-assisted coil embolization is a promising treatment for dissecting aneurysms of the cervical internal carotid artery. In addition, the procedure demonstrates the utility of carotid artery echograms for examining recanalization after stent-assisted coil embolization.

Localized reversible high signal intensities on diffusion-weighted MRI in hypoglycemia: A study of 70 cases

INTRODUCTION

It is well-known that localized reversible high signal intensities in the splenium of the corpus callosum or the basal ganglia appear on diffusion-weighted MRI in the presence of hypoglycemia. The aim of this study was to clarify the incidence and significance of such high signal intensity lesions.

RESULTS

We analyzed 70 cases of hypoglycemia with consciousness disturbance referred to our outpatient office. Localized reversible high signal intensities on diffusion-weighted MRI were noted in 6 cases (8.6%). They were at the splenium of the corpus callosum in four cases (5.7%), and right frontal cortex and bilateral frontal white matter in one each. Convulsions were noted in five cases, and right hemiparesis was noted in three. None of the three cases of hemiparesis showed localized reversible high signal intensities on diffusion-weighted MRI. These lesions are reversible if the patients undergo treatment without delay.

CONCLUSION

The significance of these lesions is still unclear. However, when a high signal intensity lesion that is not reasonable for the symptom is detected on diffusion-weighted MRI, an immediate check of the blood sugar level is mandatory.

Surgical Outcomes for Cervical Carotid Artery Stenosis: Treatment Strategy for Bilateral Cervical Carotid Artery Stenosis

BACKGROUND

Carotid endarterectomy (CEA) and carotid stenting (CAS) are beneficial procedures for patients with high-grade cervical carotid stenosis. However, it is sometimes difficult to manage patients with bilateral carotid stenosis. To decide the treatment strategy, one of the most important questions is whether contralateral stenosis increases the risk of patients undergoing CEA.

METHODS

This retrospective study included 201 patients with carotid stenosis who underwent a total of 219 consecutive procedures (CEA 189/CAS 30). We retrospectively analyzed outcomes in patients with carotid stenosis who were treated with either CEA or CAS and evaluated whether or not contralateral lesions increases the risk of patients undergoing CEA or CAS. Furthermore, we retrospectively verified our treatment strategy for bilateral carotid stenosis.

RESULTS

The incidences of perioperative complications were 5.3% in the CEA patients and 6.7% in the CAS patients, respectively. There was no significant difference between these 2 groups. The existences of contralateral occlusion and/or contralateral stenosis were not associated with perioperative complications in both the groups. There were 32 patients with bilateral severe carotid stenosis (>50%). Of those, 13 patients underwent bilateral revascularizations; CEA followed by CEA in 8, CEA followed by CAS in 3, CAS followed by CEA + coronary artery bpass grafting in 1, and CAS followed by CAS in 1.

CONCLUSIONS

Our date showed that the existence of contralateral carotid lesion was not associated with perioperative complications, and most of our cases with bilateral carotid stenosis initially underwent CEA.

Abstract T MP55: Utility of 4D-MRA to Measure Blood Flow Velocity in Cerebral Major Arteries

Transcranial Doppler is widely used clinically to measure blood flow velocity (BFV) in cerebral major arteries. This method, however, has a limitation in that its successful measurement depends on the accessibility of patients’ cranial window and the technical ability of operators. We therefore developed a novel method to measure BFV in cerebral major arteries with 4D-MRA, which was less susceptible to patients and the conditions of the operators.

Methods: 4D-MRA was performed with a 3T MR unit (Achieva TX; Philips Medical Systems) using arterial spin labeling methods. The blood flow through the internal carotid arteries (ICA) and the basilar artery (BA) within imaging range was visualized by using look-locker readout methods. BFV was calculated by dividing the flow distance traveled in the arteries by the time elapsed. BFV of 34 patients (non-vascular disease:11, ICA stenotic disease:6, moyamoya disease:9, and cerebral aneurysm:8) were measured using the 4D-MRA method and the 2D phase contrast method.

Results: In the case of patients with non-vascular diseases, mean BFV of the right ICA, the left ICA, and the BA was 24.5±7.0, 23.3±6.9, and 17.2±5.1 cm/sec, respectively. Correlation between BFV values from the 4D-MRA method and those from the 2D phase contrast method was statistically significant (r=0.78, p<0.01). In the case of patients with ICA severe stenosis (more than 90%), BFV of the stenotic ICA was decreased to 9~11cm/sec (40~50% of BFV of the contralateral ICA). In the case of patients with advanced-stage moyamoya disease, BFV of the ICA was decreased to 9~16cm/sec (30~50% of BFV of the BA). The BFV decreases were related to CBF reduction in some cases if the development of the collateral circulation was insufficient. In the patients with aneurysm, BFV of the artery proximal to aneurysm tended to be increased except for the decrease in cavernous ICA giant aneurysm.

Conclusions: We could steadily obtain BFV in all patients by using the 4D-MRA method without any operational difficulties. In this preliminary study, we observed BFV decrease in ICA stenotic disease and moyamoya disease, and BFV increase in cerebral aneurysm. This novel 4D-MRA method to measure BFV may become a promising tool for pathophysiological evaluation of cerebrovascular diseases.

Abstract W P97: Post-ischemic Trans-arterial Regional Hypothermia Therapy Attenuates Microvascular Narrowing due to Astrocyte End-feet Swelling and Inhibits Subsequent Inflammatory Reactions in Ischemia Reperfusion Injury

Background and Purpose: We previously presented the robust neuroprotective effects of post-ischemic trans-arterial regional hypothermia therapy in I/R injury model rats (ISC 2014, San Diego). This treatment showed a significant suppression of infarct volume and inflammatory reaction at 24hrs after reperfusion. To characterize the neuroprotective effects in terms of microvascular integrity, we investigated microvascular morphological changes and inflammatory reactions by a time course analysis within 24hrs.

Methods: At reperfusion onset, 2hr-MCAO rats were divided into cold saline group (10°C, 20ml/kg of trans-arterial infusion from the recanalized artery for 15mins), warm saline group (37°C, in the same manner as cold saline group), and control group (recanalization only). Microvascular morphological changes were examined by vWF Immunohistochemistry (IHC) and transmission electron microscopy (TEM), and inflammatory reactions were examined by Western blotting and IHC at the time point of 0hr, 2hrs, 6hrs, and 24hrs of reperfusion.

Results: IHC analysis and TEM observation revealed that astrocyte end-feet swelling occurred at 2hrs and progressed to 6hrs, and microvascular narrowing due to the swelling occurred at 6hrs in control group. This microvascular morphological change was attenuated in cold saline group. While endothelial ICAM1 overexpression started at 6hrs in control group, MPO, MMP9, and Iba-1 overexpression occurred only at 24hrs in the same group. These inflammatory reactions were also inhibited in cold saline group.

Conclusions: Post-ischemic trans-arterial regional hypothermia therapy attenuated astrocyte end-feet swelling from 2hrs and the swelling induced microvascular narrowing at 6hrs. The treatment also inhibited endothelial ICAM-1 overexpression at 6hrs, and subsequently inhibited inflammatory reactions at 24hrs. The maintenance of microvascular morphological and functional integrity may be the primary cause of the neuroprotective effects by the regional hypothermia.

Abstract W P73: Inside Intramural Thrombus Formation with Inflammatory Reactions Is Relevant to the Rupture of Cerebral Aneurysms

Background and Purpose: Although recent researches on cerebral aneurysms (CAs) have been performed with the hydrodynamic or the molecular biological technique, the mechanisms of rupture are not fully understood. The aim of this study is to assess the mechanism by a comparison between ruptured and un-ruptured CAs with histopathological and electron-microscopic analysis.

Methods: We analyzed 33 CAs (24 ruptured, 9 un-ruptured) collected surgically after neck clipping. As for the ruptured CAs, we operated them within 24 hours from the onset. HE staining, Elastica Masson staining, PTAH staining, and CD68 immunohistochemical staining were performed with paraffin sections. Morphological analysis with Scanning Electron Microscopy (SEM) was performed with 6 CAs (3 ruptured, 3 un-ruptured).

Results: The common histopathological finding in both ruptured and un-ruptured CAs was that the aneurysmal wall consisted mostly of thick collagen layer without normal internal elastic lamina and media. The characteristic histopathological finding in ruptured CAs was inside intramural thrombus formation with infiltration of CD68 positive cells at the rupture point. The common SEM finding in both ruptured and un-ruptured CAs was the denudation of endothelial cells and the exposure of a subendothelial amorphous or a fibrous surface. The characteristic SEM finding in ruptured CAs was the cluster formation of thick fibrin fibers with incorporation of macrophages and platelets.

Conclusions: While the endothelial denudation, the disappearance of internal elastic lamina and media, and the predominance of collagen layer in the aneurysmal wall were common in both ruptured and un-ruptured CAs, inside intramural thrombus formation with inflammatory reactions was characteristic only in ruptured CAs. This result suggests that thrombo-inflammatory reactions in CAs may act as a trigger for ruptures.

Abstract T P226: Cilostazol Can Attenuate Oxidative Stress by Suppressing Nox2 on Neurons in Mice Permanent Focal Ischemia

It has been reported that phosphodiesterase (PDE) 3 inhibitor cilostazol, which is used as an antiplatelet drug, could ameliorate ischemic brain injury. We aimed to investigate how cilostazol affected permanent focal ischemia. Male Balb/c mice were subjected to permanent middle cerebral artery occlusion. They were treated with cilostazol (10- mg/kg or 20-mg/kg) or vehicle 30 min and 24 h post-ischemia, and the infarct volume was assessed 48 h post-ischemia. The animals treated with 20-mg/kg cilostazol or vehicle were sacrificed 6 h or 24 h post-ischemia, and then the immunohistochemistry was performed to the brain sections. We demonstrated that the treatment with 20- mg/kg cilostazol significantly reduced infarct volume (70.1% vs. vehicle group). Immunohistochemistry against 8-hydroxydeoxyguanosine (OHdG) showed that some neurons suffered from oxidative stress in peri-infarct 6 h post-ischemia. The treatment with cilostazol reduced the number of 8-OHdG-positive neurons significantly (65.8 ± 33.5% in vehicle group and 21.3 ± 9.9% in cilostazol group). Moreover, the number of NADPH oxidase (NOX) 2-positive neurons was also reduced significantly (57.0 ± 13.6% in vehicle group and 26.5 ± 16.7% in cilostazol group). On the other hand, immunohistochemistry against phosphorylated cyclic-AMP response element binding protein (pCREB) showed that the number of the pCREB-positive neurons in peri-infarct of the cilostazol-treated animals was significantly higher than in vehicle-treated ones 24 h post-ischemia. These findings suggested that cilostazol could have multi-mechanisms to ameliorate the tissue damage, one was to attenuate oxidative stress by suppressing NOX2 on ischemic neurons, and another was anti-apoptotic effect through the pathway of Akt/pCREB.

Short-, middle- and long-term safety of superparamagnetic iron oxide-labeled allogeneic bone marrow stromal cell transplantation in rat model of lacunar infarction

Recently, both basic and clinical studies demonstrated that bone marrow stromal cell (BMSC) transplantation therapy can promote functional recovery of patients with CNS disorders. A non-invasive method for cell tracking using MRI and superparamagnetic iron oxide (SPIO)-based labeling agents has been applied to elucidate the behavior of transplanted cells. However, the long-term safety of SPIO-labeled BMSCs still remains unclear. The aim of this study was to investigate the short-, middle- and long-term safety of the SPIO-labeled allogeneic BMSC transplantation. For this purpose, BMSCs were isolated from transgenic rats expressing green fluorescent protein (GFP) and were labeled with SPIO. The Na/K ATPase pump inhibitor ouabain or vehicle was stereotactically injected into the right striatum of wild-type rats to induce a lacunar lesion (n = 22). Seven days after the insult, either BMSCs or SPIO solution were stereotactically injected into the left striatum. A 7.0-Tesla MRI was performed to serially monitor the behavior of BMSCs in the host brain. The animals were sacrificed after 7 days (n = 7), 6 weeks (n = 6) or 10 months (n = 9) after the transplantation. MRI demonstrated that BMSCs migrated to the damage area through the corpus callosum. Histological analysis showed that activated microglia were present around the bolus of donor cells 7 days after the allogeneic cell transplantation, although an immunosuppressive drug was administered. The SPIO-labeled BMSCs resided and started to proliferate around the route of the cell transplantation. Within 6 weeks, large numbers of SPIO-labeled BMSCs reached the lacunar infarction area from the transplantation region through the corpus callosum. Some SPIO nanoparticles were phagocytized by microglia. After 10 months, the number of SPIO-positive cells was lower compared with the 7-day and 6-week groups. There was no tumorigenesis or severe injury observed in any of the animals. These findings suggest that BMSCs are safe after cell transplantation for the treatment of stroke.

Abstract W P84: Post-ischemic Intra-arterial Infusion of Liposome-encapsulated Hemoglobin Suppresses Endothelial and Neutrophil Inflammatory Activation Accompanied by Maintaining Microvascular Perfusion in Rat Cerebral Ischemia Reperfusion Model

Background: Liposome-encapsulated hemoglobin (LEH) containing human hemoglobin (Hb) is an artificial oxygen carrier with 1/40th the size of erythrocytes. We previously demonstrated that post-ischemic intra-arterial (IA) infusion of LEH for 2 hours can reduce ischemia reperfusion (I/R) injury in the rat transient MCAO model (2013, ISC Honolulu). In the present study we examine whether short-time (15-minute) infusion of LEH can also have the same effect on I/R injury and explore the mechanism of the effect.

Methods: Male SD rats were subjected to 2-hour MCAO and then were divided into three groups: 1) LEH group (n=9) infused with LEH (20 ml/kg) through the recanalized internal carotid artery for 15 minutes, 2) vehicle group (n=8) infused with saline (20 ml/kg) in the same manner as the LEH group, and 3) control group subjected to recanalization only (n=8).

Results: Compared with the control and vehicle groups, the LEH group showed significantly better neurological score, smaller infarction and brain edema, and less Evans blue leakage (p<0.01). MPO expression, MMP-9 expression and activity, and ICAM-1 expression in the LEH group were also significantly lower than those in the control and vehicle groups (p<0.01). LEH visualized by immunostaining with anti-human Hb antibody in the LEH group was distributed in significantly more microvessels (p<0.01) compared with rat erythrocyte visualized by immunostaining with anti-rat Hb antibody in the control group (Figure).

Conclusions: Short-time IA infusion of LEH can reduce I/R injury like long-time infusion. This therapeutic approach is likely to suppress endothelial and neutrophil inflammatory activation accompanied by maintaining microvascular perfusion because of LEH’s small size compared with erythrocyte.

Abstract T P217: Neuroprotective Effects of Cilostazol through the Multi-mechanisms in Mice Permanent Focal Ischemia

Background and Purpose: It has been reported that Cilostazol, which is phosphodiesterase (PDE) 3 inhibitor clinically used as an antiplatelet drug, could ameliorate ischemic brain injury, but the mechanisms were not clarified. We aimed to investigate how Cilostazol affected mice permanent focal ischemia model.

Methods: Male Balb/c mice were subjected to permanent middle cerebral artery (MCA) occlusion. They were treated with Cilostazol (10- mg/kg or 20- mg/kg) or vehicle 30 min and 24 h post-ischemia. Infarct volume was assessed by 2,3,5-triphenyltetrazolium chloride (TTC) method after 48 h (n=8 in each group). In histological analysis, the animals were sacrificed 6 h or 24 h post-ischemia (n=5 in each group), and then the immunohistochemistry was performed to the brain sections.

Results: We showed that the treatment with Cilostazol salvaged the tissue damage in the infarct rim in a dose-dependent manner, and 20- mg/kg Cilostazol significantly reduced infarct volume to 70.1±24.4% of the control (P<0.05). Immunoreaction for 8-Hydroxydeoxyguanosine (OHdG), an oxidative stress marker, showed the neuronal damage by oxidative stress in peri-infarct, and the treatment with Cilostazol reduced the ratio of the damaged neurons 6 h post-ischemia (65.8±33.5% in vehicle-treated animals, 21.3±9.9% in Cilostazol-treated ones, P<0.05). Double staining for 8-OHdG and von Willebrand factor also showed that Cilostazol attenuated oxidative stress on the endothelial cells in peri-infarct 24 h post-ischemia, significantly (P<0.01). On the other hand, the immunostaining for phosphorylated cAMP response element binding protein (pCREB) showed that Cilostazol increased the ratio of the pCREB-positive neurons in peri-infarct 24 h post-ischemia significantly (74.5±8.0% in vehicle-treated animals, 93.6±2.9% in Cilostazol-treated ones, P<0.01).

Conclusions: These findings suggested that Cilostazol could have multi-mechanisms to ameliorate tissue damage due to permanent focal cerebral ischemia. Thus, one is to attenuate oxidative stress on neurnons and endothelial cells in the infarct rim, and another is to protect neural damage with anti-apoptotic effect through the pathway of Akt/pCREB.

Abstract W P87: Focal Hypothermia Induced by Post-Ischemic Intra-arterial Infusion of Cold Saline Has a Neuroprotective Effect on Cerebral Ischemia Reperfusion Injury

Background and Purpose: Although the neuroprotective effect of hypothermia on cerebral ischemia is well known, the clinical application of systemic hypothermia is limited because of management problems and complications. We examined whether focal hypothermia induced by post-ischemic intra-arterial infusion of cold saline attenuates cerebral ischemia reperfusion (I/R) injury in the rat transient middle cerebral artery occlusion (MCAO) model.

Methods: Male Sprague-Dawley rats were subjected to 2-hour MCAO and then were divided into three groups: 1) cold saline group (n=7) infused with 10°C saline (20ml/kg) through the recanalized internal carotid artery for 15 minutes, 2) warm saline group (n=7) infused with 37°C warm saline in the same manner as the cold saline group, and 3) control group subjected to recanalization only (n=7). After 24-hour reperfusion, all rats were tested for neurological score and then sacrificed to examine infarction, brain edema, and Evans blue leakage.

Results: In the cold saline group, brain temperature at basal ganglia rapidly decreased from 37.7±0.8°C to 35.4±0.7°C and remained significantly lower than pretreatment temperatures (p<0.05) until 30 minutes after the infusion. The cold saline group showed significantly better neurological score compared with the other groups (p<0.01). Infarct volume of cold saline group (13.7±11.3%) was significantly less than that of control (42.5±8.1%) and warm saline (36.4±8.8%) group (p<0.01). Brain edema and Evans blue leakage of cold saline group was also significantly less than those of the other groups (p<0.01).

Conclusions: The results of the present study suggest that focal hypothermia induced by post-ischemic intra-arterial infusion of cold saline has a neuroprotective effect on I/R injury. This therapeutic strategy is promising because of its feasibility in the clinical situation of endovascular approach.

Abstract W P207: Association of Increased Expression of NOX4 With Susceptibility to Hypoxia-Induced ROS Overproduction and ICAM-1 and VCAM-1 Upregulation in Brain Microvascular Endothelial Cells

Background and Purpose: NADPH oxidase 4 (NOX4) is the predominant source of reactive oxygen species (ROS) in the endothelial cells. It has been demonstrated that brain microvascular endothelial cells (BMECs) is more susceptible to stress-induced cellular responses compared with endothelial cells from other larger vessels. The aim of this study is to examine susceptibility to hypoxia-induced cellular reactions in BMECs compared with aortic endothelial cells (AECs) in terms of association of NOX4 expression with ROS production.

Methods: Cultured bovine BMECs and AECs were incubated in the modular incubator chamber pre-filled with anoxic gas (95%N 2 /5% CO 2 ) at 37°C. Time course changes of ROS production, cell death occurrence, and mRNA expression of NOX4, ICAM-1, VCAM-1, HIF-1α, VEGF and GAPDH were examined in BMECs and AECs until 4 hours after hypoxia. ROS production, cell death occurrence, and mRNA expression were evaluated with DHE staining, Live/Dead cell kit, and RT-PCR, respectively.

Results: Basal ROS production was significantly higher in BMECs than in AECs (p<0.01). After hypoxia ROS production and cell death were more prominently increased in BMECs compared with AECs with time. While expression levels and pattern of HIF-1α and VEGF were similar in the both cells, expression levels of NOX4, ICAM-1, and VCAM-1 were quite different in the both cells. While the expression levels of NOX4, ICAM-1, and VCAM-1 in AECs were very low at all the time points, those expression levels in BMECs were significantly higher at the basal condition (p<0.01) and were increased more at 2 hours and decreased at 4 hours after hypoxia.

Conclusions: It was demonstrated in BMECs but not in AECs that NOX4 expression was high and increased more after hypoxia, which is consistent with the increase of ROS production and ICAM-1 and VCAM-1 expression. Increased expression of NOX4 is likely associated with susceptibility to hypoxia-induced ROS overproduction and ICAM-1 and VCAM-1 upregulation in BMECs.

Abstract 98: Post-ischemic Intra-arterial Infusion of Liposome-encapsulated Hemoglobin Can Reduce Ischemic Reperfusion Injury

Background: We sometimes encounter severe brain edema and hemorrhagic transformation due to ischemic reperfusion (I/R) injury after thrombolysis and/or thromboectomy. The mechanism of I/R injury is thought to depend on blood-brain barrier disruption mediated by matrix metalloproteinase-9 (MMP-9) mainly produced by circulating neutrophils. We examined whether post-ischemic intra-arterial infusion of liposome-encapsulated hemoglobin (LEH), an efficient oxygen carrier without blood cells including neutrophils, can reduce I/R injury through reducing the effect of neutrophil MMP-9 in the rat transient middle cerebral artery occlusion (MCAO) model.

Methods: Male Sprague-Dawley rats were subjected to transient MCAO for 2 hours and then were divided into three groups: 1) LEH group infused with LEH (10ml/kg/h) through the recanalized internal carotid artery for 2 hours, 2) vehicle group infused with saline, and 3) control group subjected to recanalization only. After 24-hour reperfusion, all rats were tested for neurological score and then sacrificed to examine infarct and edema volumes, MMP-9 expression, MMP-9 activity and reactive oxygen species (ROS) production.

Results: Compared with the control group, the LEH group showed significantly better neurological score (p<0.05), smaller infarct and edema size (p<0.01, p<0.05 respectively). MMP-9 expression, activity and ROS production in the LEH group were lower than those in the control group (p<0.001, p<0.01 and p<0.05, respectively). There was no significant difference between the results in the vehicle group and those in the control group.

Conclusion: The results in the present study suggest that post-ischemic intra-arterial infusion of LEH can reduce I/R injury through reducing the effect of neutrophil MMP-9. LEH may be a promising candidate to prevent I/R injury.

[A case of combined glossopharyngeal and trigeminal neuralgia]

It is well-known that idiopathic neuralgias of the trigeminal and glossopharyngeal nerves are caused by vascular compression at the root entry zone of the cranial nerves. Because they are functional diseases, initial treatment is medical, especially with carbamazepine. However, if medical therapy fails to adequately manage the pain, microvascular decompression (MVD) is prescribed. Glossopharyngeal neuralgia is rare, and combined trigeminal and glossopharyngeal neuralgia is an extremely rare disorder. A 70-year-old woman presented herself to Hokkaido Neurosurgical Memorial Hospital because of paroxysms of lancinating pain in her left pharynx and another lancinating pain in her left cheek. Carbamazepine, which was prescribed at another hospital, favorably relieved the pain; however, drug eruption compelled her to discontinue the medication. The multi-volume method revealed that a root entry zone of the left glossopharyngeal nerve was compressed by the left posterior inferior cerebellar artery, and the left trigeminal artery was compressed by the left superior cerebellar artery. MVD for both nerves was performed employing a left lateral suboccipital craniotomy. She experienced complete relief of pain immediately after MVD. Combined trigeminal and glossopharyngeal neuralgia is extremely rare, but some groups noted a relatively high incidence of concurrent trigeminal neuralgia in patients with glossopharyngeal neuralgia up until the 1970's. Glossopharyngeal neuralgia includes pain near the gonion; therefore, there is an overlap of symptoms between glossopharyngeal and trigeminal neuralgias. By virtue of recent progress in imaging technology, minute preoperative evaluations of microvascular compression are possible. Until the 1970's, there might have been some misunderstanding regarding the overlap of symptoms because of lack of the concept of microvascular compression as a cause of neuralgia and rudimentary imaging technology. Minute evaluations of both symptoms and imaging are very important.

Spontaneous regression of an anterior skull base mass

Spontaneous regression of an intracranial mass is rare. We report a 77-year-old man with spontaneous regression of an anterior skull base mass suspected to be an inflammatory pseudotumor. The patient attended our outpatient department approximately once per month for a regular check-up following a brain stem infarction. A small mass was detected at the anterior skull base by MRI. The mass gradually grew to about 3 cm over a period of 5 years and then remained stable for 3 years. Thereafter, the mass showed spontaneous regression 8 years after it was first visible on MRI. 'Inflammatory pseudotumor' is a broad category and the natural history of these lesions is highly variable. Although the definition does include some types of malignant lesion, most masses are benign lesions that can regress spontaneously, as in our patient. A 'wait-and-see' policy is appropriate for such patients.

[A case of subarachnoid hemorrhage presenting with supplementary motor aphasia as an initial symptom]

Supplementary motor aphasia results from impairment of the supplementary motor area in the left mesial frontal cortex. We report a rare case of subarachnoid hemorrhage presenting with supplementary motor aphasia as an initial symptom. A 52-year-old woman was brought to our hospital by ambulance due to sudden severe headache and supplementary motor aphasia. CT demonstrated subarachnoid hemorrhage that appeared to be particularly thick in the pericallosal cistern. She had undergone neck clipping of a left vertebral artery aneurysm for subarachnoid hemorrhage 14 years earlier. At that time, she underwent neck clipping of a de novo anterior communicating artery aneurysm. The postoperative course was uneventful and supplementary motor aphasia had disappeared in 4 weeks. To our knowledge, this is the first reported case of subarachnoid hemorrhage presenting with supplementary motor aphasia as an initial symptom. In this case, adhesion of the arachnoid membrane resulting from old subarachnoid hemorrhage might have prevented new subarachnoid hemorrhage from spreading diffusely. Hematomas spread mainly into the pericallosal cistern from ruptured aneurysm of the anterior communicating artery. Therefore, thick hematoma in this cistern might have compressed the supplementary motor area, resulting in supplementary motor aphasia. Aphasia disappeared as pressure from the hematoma dissipated. Neurosurgeons may be likely to encounter a patient showing a transient consciousness disturbance after the use of the anterior interhemispheric approach or within a period of vascular spasm. Supplementary motor aphasia might also be included in such consciousness disturbance. Supplementary motor aphasia might be a reversible symptom if there is no irreversible damage to the supplementary motor area by infarction or intraparenchymal hemorrhage.

Susceptibility of brain microvascular endothelial cells to advanced glycation end products-induced tissue factor upregulation is associated with intracellular reactive oxygen species

There is accumulating evidence that advanced glycation end products (AGEs) are relevant to the formation of vascular complications in diabetes mellitus. The aim of this study was to investigate whether AGEs have a significant effect on tissue factor (TF) expression in brain microvascular endothelial cells compared with that in other arterial endothelial cells. Cultured bovine brain microvascular endothelial cells (BBMECs) and aortic endothelial cells (BAECs) were incubated in medium containing glyceraldehyde-derived AGE (glycer-AGE). TF mRNA expression, protein expression, and activity were measured at multiple time points after glycer-AGE incubation. Participation of reactive oxygen species (ROS) in the effect of glycer-AGE on TF expression was investigated by treatment with a free radical scavenger, edaravone, and intracellular ROS measurements with dihydroethidium (DHE). Basic TF mRNA expression was greater in BBMECs than in BAECs. Glycer-AGE significantly upregulated TF mRNA expression in both cells, and the upregulation was more prominent in BBMECs than in BAECs. TF protein expression and activity were also upregulated with a pattern of being greater in BBMECs than in BAECs. Edaravone significantly attenuated the AGE-induced upregulation of TF mRNA expression, protein expression, and activity. Intracellular ROS levels measured with DHE-stained fluorescent intensity were significantly upregulated by glycer-AGE with a pattern of being greater in BBMECs than in BAECs. AGE-induced ROS upregulation was attenuated by edaravone like AGE-induced TF upregulation. These results suggest that brain microvascular endothelial cells are more susceptible to AGE-induced TF upregulation than aortic endothelial cells, and that this susceptibility is associated with levels of intracellular ROS.