[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.

Abstract 77: Circulating miRNome in Moyamoya Discordant MZ Twins - Implications for Endothelial Biofunctions

Objective: We aim to investigate circulating genome-wide microRNA (miRNome) profiles in Moyamoya disease-discordant monozygotic (MZ) twins with the RNF213 founder mutation (rs112735431), since the etiology remains unclear even after the identification of RNF213.

Methods: Circulating miRNome was screened in a pair of Moyamoya-discordant MZ twins and a validation cohort (unrelated 9 cases and 8 normal controls) using microarray and validated by quantitative real-time PCR. Differential plasma microRNAs were quantified in endothelial cells differentiated from iPS cell line (iPSECs) derived from unrelated 3 cases and 3 controls. Gene expressions targeted by the significant microRNAs in iPSECs was studied using published iPSEC-transcriptome and bioinformatics tool.

Results: A total of 537 circulating microRNAs were detected in the Moyamoya-discordant MZ twins and the validation cohort. Unsupervised cluster analysis demonstrated 2 discrete miRNome, predominantly by disease, but the MZ twins showed similar miRNome profiles, regardless of phenotypic discordance (Fig. 1A). Across the 143 and 98 differential microRNAs in the MZ twins and validation cohort, 23 microRNAs were overlapped (Fig. 1B). A cluster of plasma hsa-miR-6722-3p/-328-3p/150-5p was significantly up-regulated in patients in the validation cohort (p < 0.05) (Fig. 1C). In iPSECs, hsa-miR-6722-3p/-328-3p cluster was up-regulated with a greater than 3.0-fold change in patients. Bioinformatics analysis revealed that 94 target genes involving organismal injuries and cell survival/maintenance were significantly down-regulated in Moyamoya-iPSECs (p < 0.05, q < 0.1), suggesting the regulatory role of the miR-6722/-328 cluster in endothelial gene expression (Fig. 1D).

Conclusions: Differential plasma-miRNAs in Moyamoya-discordant MZ twins may potentially serve as a diagnostic biomarker in Moyamoya disease and regulate endothelial gene expression.

Novel insights into symptomatology of moyamoya disease in pediatric patients: survey of symptoms suggestive of orthostatic intolerance

OBJECTIVE A specific population of young patients with moyamoya disease (MMD) persistently experience physical symptoms not attributable to focal ischemia. These symptoms, highly suggestive of orthostatic intolerance (also termed "orthostatic dysregulation"), were investigated and reported as potential determinants of quality of life in young MMD patients. METHODS Forty-six patients (6-30 years of age) were selected from a group of 122 patients who were diagnosed with MMD before 18 years of age. The authors administered a structured questionnaire consisting of 11 items based on screening checklists published in the Japanese clinical guidelines for juvenile orthostatic dysregulation in young patients. The results were tabulated, and correlations with clinical data were explored. RESULTS Thirty-seven (80%) patients (mean age 15.9 years) responded to the questionnaire. Frequent headache, vertigo/dizziness on standing, fatigue, difficulty with getting out of bed, and motion sickness were the top 5 symptoms, resulting in 57% of patients being unable to attend school. Forty-three percent of the patients demonstrated multiple symptoms suggestive of orthostatic intolerance, even as long as 5 years after revascularization surgery. The number of symptoms was inversely associated with the number of years after surgery (p = 0.028). The number of symptoms was not associated with a history of surgery, clinical presentations, vascular involvement, cerebral perfusion, brain lesions, or history of transient ischemic attacks. CONCLUSIONS The present study provided novel insight into the symptomatology of young patients with MMD. Failure to notice nonfocal physical symptoms can significantly impair quality of life in young patients with MMD even years after successful revascularization surgery. These symptoms may serve as independent clinical markers used to assess disease outcome, although the underlying mechanisms of this disease are, as of yet, unclear.

Accessibility to Tertiary Stroke Centers in Hokkaido, Japan: Use of Novel Metrics to Assess Acute Stroke Care Quality

BACKGROUND

Both the accessibility and availability of stroke specialists are major determinants of patient outcomes following acute ischemic stroke (AIS). The purpose of this study was to implement novel metrics to assess the accessibility of tertiary stroke centers as well as to evaluate regional disparities in stroke specialists.

METHODS

Using network analysis in a geographic information system, we calculated areas within 30- and 60-minute travel times to facilities providing intravenous recombinant tissue-type plasminogen activator and mechanical thrombectomy. We further evaluated the accessibility for the proportion of the population aged 65 years or older that resided outside of these areas. Uniformity in the geographical distribution of stroke specialists was then evaluated using optimal statistical analysis.

RESULTS

Accessibility varied widely from region to region, with low accessibility being concentrated in rural areas with low population density. Accessibility to facilities providing mechanical thrombectomy was especially low, and 17.8% of elderly individuals lived ≥60 minutes from treatment facilities. In addition, the distribution of stroke specialists was uneven compared with the distribution of hospital beds and full-time medical doctors.

CONCLUSION

The results of this study revealed regional disparities in the spatial accessibility to treatment facilities, as well as in the distribution of stroke specialists in Hokkaido. These findings provide useful information that could be employed to appropriately allocate resources toward the formation of a medical supply system for patients with AIS.

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.

Proposal for a Prospective Registry for Moyamoya Disease in Japan

The number of clinical research papers published worldwide on moyamoya disease (MMD) has increased recently. However, the majority of the literature comprises retrospective single-center studies collecting data on small numbers of patients. Several multi-center studies are ongoing in Japan; however, the current data are insufficient for comprehensively outlining the various characteristics of MMD. To enhance our knowledge on epidemiologic, vascular, and genetic aspects of MMD, a prospective multicenter registry will be established in Japan that will help to streamline clinical research as well as improve clinical treatments and long-term outcomes. Patients with MMD or secondary moyamoya syndrome referred to the participating centers will be invited to the registry. Demographic and physiological parameters, along with neuroimaging data will be collected chronologically. Clinical events, including neurological, medical, and surgical interventions will be recorded. Whole blood samples will be collected. Extra- and intracranial vascular tissue, and/or cerebrospinal fluid will also be collected from patients who undergo surgical revascularization. These biospecimens will be stored at the repositories and utilized for genome-wide association studies for identifying genetic variants, as well as tissue-specific proteomic, and/or molecular analyses. Ethics approval will be obtained at all facilities collecting biospecimens. The registry will provide descriptive statistics on functional outcomes, surgical techniques used, medications, and neurological events stratified according to patients’ clinical characteristics. We expect this study to provide novel insights in the management of MMD patients and design better therapies.

Abstract TP448: Genome-wide CNV Array Analysis Following Post-hoc Targeted Amplicon Sequencing Revealed Genetic Anticipation in Parent-offspring Pairs with Moyamoya Disease

Introduction: Molecular mechanisms underlying clinical observation of progressively earlier age of onset of Moyamoya disease (MMD) as it is passed on to the next generation, as known as clinical anticipation, is still obscure. This study investigates copy number variation (CNV) in parent-offspring pairs with MMD with and without clinical anticipation using genome-wide CNV array following high-throughput DNA sequencing.

Methods: Fifteen out of 25 consecutive Japanese parent-offspring pairs with MMD treated at our institute since 1980 were enrolled. Demographics, inheritance pattern, angiographical stage, disease type at onset were reviewed. Using genomic DNA from whole blood, rs112735431 in RNF213 gene was genotyped, then genome-wide CNV analysis was conducted using a 2.6 M oligonucleotide array to compare CNV profile in parent-offspring pairs with and without clinical anticipation. Amplicon Sequencing was further conducted using Miseq.

Results: Clinical anticipation was observed in 10 pairs (67%) and was not in 5 pairs (33%). In clinical anticipation group, mean age at onset was significantly lower in the offsprings than in the parents (p<0.001). There were no significant differences in other clinical and genetic backgrounds, including the genotype in RNF213 between the generations and between the groups with and without clinical anticipation. Genome-wide CNV profiling revealed that 10 CNV in chr7q, 8p, 9q, 14q, 16p, 19p, 20q, and 22q were overlapped for more than 3 individuals in the whole studied population. Of these CNV, copy number was different only in chr16p13.3 between the generations in clinical anticipation group (P=0.06). Fourteen genes were observed in this locus, including GNPTG gene, whose mutation is known to be associated with mucolipidosis. Amplicon sequence targeting these 14 genes revealed significant copy number loss at GNPTG gene locus, in the offsprings compared to their parent (P = 0.02, copy number = 1.8 and 2.0, respectively).

Conclusion: These data suggest clinical anticipation of MMD in Japanese population can be observed regardless of the RNF213 genotype. This is the first genome-wide CNV profiling, suggesting the CNV in chr16p13.3 might be underlying mechanism for anticipation in familial MMD by reducing gene dosage.

Abstract TP133: Interactive Development of Direct and Indirect Bypass After Combined Revascularization for Moyamoya Disease: The Significance of Indirect Bypass

Background & Purpose: The additional effects of indirect bypass on combined revascularization surgery in moyamoya disease (MMD) remain unclear. Our purpose in this study is to evaluate how direct and indirect bypass in combined revascularization change through long term follow up and to analyze the clinical factors or hemodynamic parameters involved in these changes.

Methods: A retrospective survey was conducted with a sample size of 97 hemispheres from 69 consecutive patients (43 adults and 26 children) with MMD treated by combined revascularization. We used magnetic resonance angiography (MRA) to evaluate bypass development with the diameters of superior temporal artery (STA) for the direct bypass and middle meningeal artery (MMA) and deep temporal artery (DTA) for the indirect bypass. A multivariate logistic regression analysis was used to study the related multiple variables on bypass development.

Results: Good indirect bypass indicated by MMA development was seen 78% of the adult hemispheres and 95% of the pediatric ones. Dual development of direct and indirect bypasses was most frequently observed (47% and 56% of the adult and pediatric hemispheres, respectively). When indirect bypasses developed, 28% of the STAs reduced in diameter reciprocally from the acute to the chronic phases after surgery. The development of indirect bypass was significantly better in the adult hemispheres at Suzuki stage 4 or greater ( P =0.02; odds ratio 7.4, 95% confidence interval, 1.4-39.4). The disease onset type and the hemodynamic parameters were not associated with the development of surgical revascularization.

Conclusions: Indirect bypass developed effectively in both adult and pediatric patients, even in the presence of direct bypass. The universal application of indirect bypass is considered an optimal surgical strategy to maximize revascularization in MMD.

Abstract TP447: Edaravone Reduces Hyperperfusion-related Neurological Deficits After Direct Bypass in Adult Moyamoya Disease

Background and Purpose: Postoperative hyperperfusion-related transient neurological deficits (TNDs) are frequently observed in adult patients with moyamoya disease (MMD) who undergo direct bypass procedures. The present study evaluated the effect of the free radical scavenger edaravone on postoperative hyperperfusion in adult MMD.

Methods: This study included 92 hemispheres in 72 adult patients who underwent direct bypass for MMD. Serial measurements of cerebral blood flow were conducted immediately after surgery and on postoperative days 2 and 7. In 40 hemispheres in 36 patients, edaravone (60 mg/day) was administered from the day of surgery until postsurgical day 7. The incidence of postoperative hyperperfusion and associated TNDs were compared with a control group that included 52 hemispheres in 36 patients.

Results: Radiological hyperperfusion was observed in 28/40 (70.0%) and 39/52 (75.0%) hemispheres in the edaravone and control groups, respectively (P = 0.30). Hyperperfusion-related TNDs incidences were significantly lower in the edaravone group compared with the control group (12.5% vs. 32.7%, P = 0.024). Multivariate analysis demonstrated that edaravone administration (P = 0.009) and left-sided surgery (P = 0.037) were significantly correlated with hyperperfusion-related TNDs (odds ratios, 0.3 and 4.2, respectively).

Conclusions: Perioperative administration of edaravone reduced the incidence of hyperperfusion-related TNDs after direct bypass procedures in adult patients with MMD.

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.

Synergistic Interactions Between Direct and Indirect Bypasses in Combined Procedures: The Significance of Indirect Bypasses in Moyamoya Disease

BACKGROUND: Whether additional indirect bypasses effectively contribute to revascularization in combined procedures remains unclear in patients with moyamoya disease.

OBJECTIVE: To evaluate the longitudinal changes associated with combined procedures while following up pediatric and adult patients long term and to assess whether any other clinical factors or hemodynamic parameters affected these changes to determine an optimal surgical strategy.

METHODS: We studied 58 hemispheres in 43 adults and 39 hemispheres in 26 children who underwent combined revascularization for moyamoya disease. To evaluate bypass development, we assessed the sizes of the superficial temporal artery and middle meningeal artery using magnetic resonance angiography. Multivariate analysis determined the effects of multiple variables on bypass development.

RESULTS: Indirect bypass (middle meningeal artery) development occurred in 95% and 78% of the pediatric and adult hemispheres, respectively. Of these, dual development of direct and indirect bypasses occurred in 54% of the pediatric hemispheres and in 47% of the adult hemispheres. Reciprocal superficial temporal artery regression occurred in 28% of the hemispheres during the transition from the postoperative acute phase to the chronic phase during indirect bypass development. Good indirect bypass development was associated with adult hemispheres at Suzuki stage 4 or greater (odds ratio, 7.4; 95% confidence interval, 1.4-39.4; P = .02). Disease onset type and preoperative hemodynamic parameters were not considered predictors for the development of surgical revascularization.

CONCLUSION: Simultaneous direct and indirect bypass development was most frequently observed, regardless of patient age and hemodynamic status. Applying indirect bypass as an adjunct to direct bypass could maximize revascularization in adults and children.

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.

Direct Anastomosis Using Occipital Artery for Additional Revascularization in Moyamoya Disease After Combined Superficial Temporal Artery–Middle Cerebral Artery and Indirect Bypass

BACKGROUND: The posterior cerebral artery (PCA) is involved in approximately 30% of moyamoya disease (MMD) cases. However, there have been insufficient reports describing revascularization techniques in the posterior portion of the brain, particularly of direct anastomosis.

OBJECTIVE: To perform a technical assessment in patients with MMD who underwent either occipital artery (OA)–PCA bypass or OA–middle cerebral artery (MCA) bypass.

METHODS: A total of 428 revascularization procedures in 368 patients were retrospectively assessed by reviewing clinical charts and radiological data.

RESULTS: Ten patients (3.5%) were treated with direct bypass after the anterior revascularization with a median interval of 30 months (range, 5 months-16 years). Seven patients were &lt; 18 years of age (average age, 17.5 ± 15.6 years). Preoperative symptoms included transient motor deficits involving the lower extremities (n = 5), visual disturbances (n = 6), and cerebral infarctions (n = 6). A favorable outcome (modified Rankin Scale score &lt; 3) was achieved in 9 of these 10 patients. Direct anastomosis was performed in 3 hemispheres with an OA-MCA bypass and in 8 hemispheres with an OA-PCA bypass. Patency of the direct bypass was confirmed on angiogram in 7 of 7 patients who underwent conventional angiogram performed within 1 year after the surgery. None of the 10 patients demonstrated cerebral infarctions after the posterior revascularization.

CONCLUSION: In MMD, symptomatic PCA regression after anterior revascularization was found predominantly in children and young adults. Direct anastomosis in the posterior portion of the brain can be successfully achieved and is effective in preventing ischemic events.

Edaravone Reduces Hyperperfusion-Related Neurological Deficits in Adult Moyamoya Disease

Background and Purpose—

Postoperative hyperperfusion-related transient neurological deficits (TNDs) are frequently observed in adult patients with moyamoya disease who undergo direct bypass procedures. The present study evaluated the effect of the free radical scavenger edaravone on postoperative hyperperfusion in adult moyamoya disease.

Methods—

This study included 92 hemispheres in 72 adult patients who underwent direct bypass for moyamoya disease. Serial measurements of cerebral blood flow were conducted immediately after surgery and on postoperative days 2 and 7. In 40 hemispheres for 36 patients, edaravone (60 mg/d) was administered from the day of surgery to postsurgical day 7. The incidence of postoperative hyperperfusion and associated TNDs were compared with a control group that included 52 hemispheres in 36 patients.

Results—

Radiological hyperperfusion was observed in 28 of 40 (70.0%) and 39 of 52 (75.0%) hemispheres in the edaravone and control groups, respectively ( P =0.30). Hyperperfusion-related TND incidences were significantly lower in the edaravone group compared with the control group (12.5% versus 32.7%; P =0.024). Multivariate analysis demonstrated that edaravone administration ( P =0.009) and left-sided surgery ( P =0.037) were significantly correlated with hyperperfusion-related TNDs (odds ratios, 0.3 and 4.2, respectively).

Conclusions—

Perioperative administration of edaravone reduced the incidence of hyperperfusion-related TNDs after direct bypass procedures in adult patients with moyamoya disease.