Association of RNF213 polymorphism and cortical hyperintensity sign on fluid-attenuated inversion recovery images after revascularization surgery for moyamoya disease: possible involvement of intrinsic vascular vulnerability

A cortical hyperintensity on fluid-attenuated inversion recovery images (FLAIR cortical hyperintensity (FCH)) is an abnormal finding after revascularization surgery for moyamoya disease. This study aimed to investigate the pathophysiology of FCH through genetic analyses of RNF213 p.R4810K polymorphism and perioperative hemodynamic studies using single-photon emission computed tomography. We studied 96 hemispheres in 65 adults and 47 hemispheres in 27 children, who underwent combined direct and indirect revascularization. Early or late FCH was defined when it was observed on postoperative days 0-2 and 6-9, respectively. FCH scores (range: 0-6) were evaluated according to the extent of FCH in the operated hemisphere. FCHs were significantly more prevalent in adult patients than pediatric patients (early: 94% vs. 78%; late: 97% vs. 59%). In pediatric patients, FCH scores were significantly improved from the early to late phase regardless of the RNF213 genotype (mutant median [IQR]: 2 [1-5] vs. 1 [0-2]; wild-type median: 4 [0.5-6] vs. 0.5 [0-1.75]). In adults, FCH scores were significantly improved in patients with the wild-type RNF213 allele (median: 4 [2-5.25] vs. 2 [2, 3]); however, they showed no significant improvement in patients with the RNF213 mutation. FCH scores were significantly higher in patients with symptomatic cerebral hyperperfusion than those without it (early median: 5 [4, 5] vs. 4 [2-5]; late median: 4 [3-5] vs. 3 [2-4]). In conclusion, the RNF213 p.R4810K polymorphism was associated with prolonged FCH, and extensive FCH was associated with symptomatic cerebral hyperperfusion in adult patients with moyamoya disease.

Impact of RNF213 c.14576G>A Variant on the Development of Direct and Indirect Revascularization in Pediatric Moyamoya Disease

BACKGROUND

Superficial temporal artery (direct) and encephalomyosynangiosis (indirect) revascularization may develop after combined bypass surgery in pediatric patients with moyamoya disease (MMD). However, arterial development varies widely among patients, and the underlying mechanisms remain unknown.

OBJECTIVES

We evaluated the relationship between the development of donor arteries after bypass surgery in pediatric patients with MMD and the MMD-susceptibility gene variant c.14576G>A of ring finger protein (RNF) 213.

METHODS

The data of pediatric patients with MMD (age <16 years at the time of surgery) treated with combined bypass surgery between September 2013 and April 2019 were consecutively analyzed. Quantitative measurements of the superficial temporal artery (STA), deep temporal artery (DTA), and middle meningeal artery (MMA) diameters with magnetic resonance angiography (MRA) source imaging were performed preoperatively and at 6-12 months postoperatively. The postoperative caliber change ratios (CCRs) were calculated. The relationship between CCRs and RNF213 c.14576G>A status was examined.

RESULTS

Forty-eight hemispheres from 28 pediatric patients with MMD were examined. Three hemispheres belonged to patients with the AA genotype; 33 to patients with the AG genotype (AA/AG group); and 12 to patients with the GG genotype (GG group; wild type). The CCRs for the DTA were significantly higher in patients with RNF213 variant (AA/AG group; 2.5 ± 0.1) than in the GG group (2.0 ± 0.2) (p = 0.03), whereas the CCRs for the STA were significantly higher in the GG (1.6 ± 0.1) than in the AA/AG group (1.3 ± 0.6) (p = 0.02). There was no significant difference in the CCRs for the MMA and basilar artery between the groups. Other factors, including sex, age, and MRA grading, were not associated with the development of specific bypass development.

CONCLUSIONS

The extent of collateral development associated with direct or indirect bypass was found to differ between the genotypes of the RNF213 c.14576G>A associated with pediatric MMD. This genetic variant correlates with the development of the disease and affects revascularization after bypass surgery in pediatric patients with MMD.

Outcomes of Combined Revascularization Surgery for Moyamoya Disease without Preoperative Cerebral Angiography

OBJECTIVE

Cerebral angiography is the gold standard for diagnosing moyamoya disease (MMD), whereas magnetic resonance (MR) imaging/angiography is becoming more popular in the field of cerebrovascular disease due to its low invasiveness. Although there are concerns about using only MR imaging/angiography for preoperative analysis of MMD, considering the underestimation of pre-existing transdural collateral circulations and dangerous collaterals related to the risk of hemorrhage, we retrospectively reviewed our 10-year experience of MR imaging-first diagnosis and analyzed the perioperative outcomes.

METHODS

We analyzed 160 consecutive direct/indirect combined revascularization procedures for MMD preoperatively assessed using MR imaging/angiography alone. Perioperative complications were assessed for up to 2 weeks after surgery. Locations of the lesions responsible for complications were further classified into the surgical field, the ipsilateral hemisphere outside the surgical field, and the contralateral hemisphere.

RESULTS

Sixty-four revascularization procedures were performed in 38 children, and 96 procedures were performed in 68 adults. There was no difference in the incidence of perioperative ischemic complications between adults (6.3%) and pediatric patients (4.7%), but hemorrhagic complications were more frequently observed in adults (7.3%) than in children (0%) (P < 0.05). There was no specific lesion deviation for ischemic complications; however, hemorrhagic complications predominantly occurred in the surgical field.

CONCLUSIONS

Direct/indirect combined revascularization surgery based on our preoperative diagnostic protocol with the MR-first strategy resulted in favorable outcomes in pediatric MMD patients with relatively low complication rates. However, the validity of the MR-first diagnostic protocol should be further evaluated in adult patients with MMD.

The mechanobiological theory: a unifying hypothesis on the pathogenesis of moyamoya disease based on a systematic review

OBJECTIVE

Moyamoya angiopathy (MMA) affects the distal internal carotid artery and is designated as moyamoya disease (MMD) when predisposing conditions are absent, or moyamoya syndrome (MMS) when it occurs secondary to other causes. The authors aimed to investigate the reason for this anatomical site predilection of MMA. There is compelling evidence to suggest that MMA is a phenomenon that occurs due to stereotyped mechanobiological processes. Literature regarding MMD and MMS was systematically reviewed to decipher a common pattern relating to the development of MMA.

METHODS

A systematic review was conducted to understand the pathogenesis of MMA in accordance with PRISMA guidelines. PubMed MEDLINE and Scopus were searched using "moyamoya" and "pathogenesis" as common keywords and specific keywords related to six identified key factors. Additionally, a literature search was performed for MMS using "moyamoya" and "pathogenesis" combined with reported associations. A progressive search of the literature was also performed using the keywords "matrix metalloprotease," "tissue inhibitor of matrix metalloprotease," "endothelial cell," "smooth muscle cell," "cytokines," "endothelin," and "transforming growth factor" to infer the missing links in molecular pathogenesis of MMA. Studies conforming to the inclusion criteria were reviewed.

RESULTS

The literature search yielded 44 published articles on MMD by using keywords classified under the six key factors, namely arterial tortuosity, vascular angles, wall shear stress, molecular factors, blood rheology/viscosity, and blood vessel wall strength, and 477 published articles on MMS associations. Information obtained from 51 articles that matched the inclusion criteria and additional information derived from the progressive search mentioned above were used to connect the key factors to derive a network pattern of pathogenesis.

CONCLUSIONS

Based on the available literature, the authors have proposed a unifying theory for the pathogenesis of MMA. The moyamoya phenomenon appears to be the culmination of an interplay of vascular anatomy, hemodynamics, rheology, blood vessel wall strength, and a plethora of intricately linked mechanobiological molecular mediators that ultimately results in the mechanical process of occlusion of the blood vessel, stimulating angiogenesis and collateral blood supply in an attempt to perfuse the compromised brain.

Efficacy of Carotid Artery Stenting Performed under General Anesthesia with Somatosensory Evoked Potential Monitoring

OBJECTIVES

During carotid artery stenting (CAS), hemodynamics may be affected by the carotid sinus reflex in some cases. Although general anesthesia has been reported to stabilize intraoperative hemodynamics, the patient's neurological condition must be assessed indirectly. Therefore, we investigated the changes in intraoperative hemodynamics and perioperative complications of CAS under general anesthesia and evaluated the efficacy of somatosensory evoked potential (SEP) monitoring in detecting a reduction in perfusion during CAS.

MATERIALS AND METHODS

From April 2011 to August 2016,57 consecutive patients who underwent CAS under general anesthesia were evaluated. The follow-up period ranged from 3 to 8 years. During CAS, anesthesiologists monitored and managed the hemodynamics. SEP monitoring was performed during the CAS procedure in all patients.

RESULTS

Intraoperative hypotension (systolic blood pressure ≤ 100 mmHg) was evident in 16 patients (28.1%), and 13 patients (22.8%) experienced intraoperative bradycardia; however, all of these cases were promptly managed under general anesthesia. None of the patients showed systolic blood pressure < 50 mmHg from baseline. Regarding perioperative complications, none of the patients exhibited myocardial infarction or postoperative hyperperfusion symptoms, and there was no mortality. Among 21 patients (36.8%) with a decrease in the intraoperative SEP, 3 (5.3%) exhibited transient ischemic symptoms and 1 (1.8%) had postoperative infarction.

CONCLUSIONS

CAS under general anesthesia is a safe and effective management option in terms of intraoperative hemodynamic stability. In addition, our findings indicate that SEP monitoring could be helpful in evaluating transient postoperative cerebral ischemia or cerebral infarction after CAS.

Immersive 3-Dimensional Virtual Reality Modeling for Case-Specific Presurgical Discussions in Cerebrovascular Neurosurgery

BACKGROUND

Adequate surgical planning includes a precise understanding of patient-specific anatomy and is a necessity for neurosurgeons. Although the use of virtual reality (VR) technology is emerging in surgical planning and education, few studies have examined the effectiveness of immersive VR during surgical planning using a modern head-mounted display.

OBJECTIVE

To investigate if and how immersive VR aids presurgical discussions of cerebrovascular surgery.

METHODS

A multiuser immersive VR system, BananaVisionTM, was developed and used during presurgical discussions in a prospective patient cohort undergoing cerebrovascular surgery. A questionnaire/interview was administered to multiple surgeons after the surgeries to evaluate the effectiveness of the VR system compared to conventional imaging modalities. An objective assessment of the surgeon's knowledge of patient-specific anatomy was also conducted by rating surgeons' hand-drawn presurgical illustrations.

RESULTS

The VR session effectively enhanced surgeons' understanding of patient-specific anatomy in the majority of cases (83.3%). An objective assessment of surgeons' presurgical illustrations was consistent with this result. The VR session also effectively improved the decision-making process regarding minor surgical techniques in 61.1% of cases and even aided surgeons in making critical surgical decisions about cases involving complex and challenging anatomy. The utility of the VR system was rated significantly higher by trainees than by experts.

CONCLUSION

Although rated as more useful by trainees than by experts, immersive 3D VR modeling increased surgeons' understanding of patient-specific anatomy and improved surgical strategy in certain cases involving challenging anatomy.

Use of magnetic resonance venography for inferior petrosal sinus sampling

BACKGROUND

Inferior petrosal sinus (IPS) sampling (IPSS) is a transvenous interventional procedure performed to diagnose Cushing's disease. The reported IPSS failure rate is approximately 10% because IPS catheter delivery is conducted blindly and is challenging because of IPS anatomical variations. This study aimed to evaluate the usefulness of preprocedural magnetic resonance venography (MRV) for assessing IPS access routes before IPSS.

METHODS

Nineteen consecutive patients who underwent IPSS at a single university hospital in Japan were retrospectively studied. A preprocedural MRV protocol optimized to visualize the IPS before IPSS was established and utilized in the eight most recent cases. An IPSS procedure was considered successful when bilateral IPS catheterization was accomplished. Patient demographics, IPSS success rate, and radiation dose required during IPSS were compared between two groups: MRV group (N = 8) and no-MRV group (N = 11) before IPSS.

RESULTS

There were no significant differences in age, sex, and IPSS success rates between the groups. The average radiation dose was 663.6 ± 246.8 (SD) mGy and 981.7 ± 389.5 (SD) mGy in the MRV group and no-MRV group, respectively. Thus, there was a significant reduction in radiation exposure in the MRV group (p = 0.044). Catheterization of the left IPS was unsuccessful in only one patient in the MRV group owing to IPS hypoplasty, as found on the MRV.

CONCLUSIONS

Hypoplastic IPSs occur in patients and can complicate IPSS. Preprocedural MRV assessment is useful for understanding venous anatomy and preventing unnecessary intravenous catheter manipulation during IPSS, which involves blind manipulation around the IPS.

[Familial Mediterranean Fever-Associated Lenticulostriate Artery Aneurysm Presenting with Intracranial Hemorrhage and Disappearing Spontaneously: A Case Report]

Lenticulostriate artery (LSA) aneurysm is relatively rare, and the need for surgical intervention is controversial. Here, we report a case of ruptured LSA aneurysm which was accompanied by familial Mediterranean fever (FMF). A 45-year-old woman with a history of FMF presented with sudden onset of headache and vertigo. Computed tomography revealed hemorrhage in the right caudate nucleus and lateral ventricles. Digital subtraction angiography revealed a fusiform aneurysm (3mm) at the distal site of medial LSA. Observation was selected, and the aneurysm gradually decreased and eventually disappeared on the 105^th day from the onset. This was the first report describing an LSA aneurysm associated with FMF. It suggests that such aneurysms could be treated conservatively with close radiological follow-up.

Microsurgical Findings of Pial Arterial Feeders in Intracranial Dural Arteriovenous Fistulae: A Case Series

BACKGROUND

Pial arterial feeders in an intracranial dural arteriovenous fistula (dAVF) are risk factors for both ischemic and hemorrhagic complications during endovascular embolization. Microsurgery in dAVF with pial arterial feeders has rarely been reported.

OBJECTIVE

To assess our original experience with microsurgery for dAVF with pial arterial feeders by investigating surgical findings and outcomes.

METHODS

In 40 patients with intracranial dAVF who underwent microsurgery, we found 8 patients who had pial arterial feeders. A retrospective review was conducted.

RESULTS

The locations of the dAVFs were as follows: tentorium, 2 patients; Galenic system, 1; straight sinus, 1; torcula, 1; transverse sinus, 1; ethmoid, 1; and convexity, 1. Preoperative angiography revealed that the pial arterial feeders originated from the middle cerebral artery in 2 patients, the anterior cerebral artery in 1, the posterior cerebral artery in 2, and the posterior medial choroidal artery in 1. Of note, in 2 patients (6.7%), feeders from the superior cerebellar artery were determined to be angiographically occult during preoperative examination and were detected through careful intraoperative observation and arachnoid dissection. In 5 cases, the additional obliteration of the pial arterial feeders and/or more distal cortical venous drainers after the simple disconnection of proximal cortical drainers was necessary to cure the dAVF. Finally, all shunts were cured with only 1 minor complication.

CONCLUSION

Although microsurgical results were acceptable, the surgeon should be aware of the presence of pial arterial feeders even after the simple disconnection of cortical venous drainage. Angiographically occult feeders may also exist.

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.

Vascular Smooth Muscle Cell Derived from IPS Cell of Moyamoya Disease - Comparative Characterization with Endothelial Cell Transcriptome

BACKGROUND

Moyamoya disease (MMD) is an occlusive cerebrovascular disease, causing stroke in children and young adults with unknown etiology. The fundamental pathology is fibrocellular intimal thickening of cerebral arteries, in which vascular smooth muscle cells (VSMCs) are observed as one of the major cell types. Although the characteristics of circulating smooth muscle progenitor cells have been previously reported, the VSMCs are poorly characterized in MMD. We aimed to characterize VSMCs in MMD using induced pluripotent stem cell (iPSC)-technology.

METHODS

We differentiated VSMCs from neural crest stem cells (NCSCs) using peripheral blood mononuclear cell-derived iPSCs and compared biological and transcriptome features under naïve culture conditions between three independent healthy control (HC) subjects and three MMD patients. VSMC transcriptome profiles were also compared to those of endothelial cells (ECs) differentiated from the same iPSCs.

RESULTS

Homogeneous spindle-shaped cells differentiated from iPSCs exhibited smooth muscle cell marker expressions, including α-smooth muscle actin (αSMA, 82.3 ± 6.7% and 81.0 ± 6.7%); calponin (91.3 ± 2.1% and 90.9 ± 1.3%); myosin heavy chain-11 (MYH11, 96.9 ± 0.7% and 97.1 ± 0.3%) without significance of differences between the two groups. Real-time PCR showed few PECAM1 and CD34 gene expressions in both groups, indicating features of differentiated VSMCs. There were no significant differences in cellular proliferation (p = 0.45), migration (p = 0.60), and contractile abilities (p = 0.96) between the two groups. Transcriptome analysis demonstrated similar gene expression profiles of VSMCs in HC subjects and MMD patients with six differentially expressed genes (DEGs); while ECs showed a distinct transcriptome profile in MMD patients with 120 DEGs. The Wnt-signaling pathway was a significant pathway in VSMCs.

CONCLUSIONS

This is the first study that established VSMCs from NCSCs using MMD patient-derived iPSCs and demonstrated similar biological function and transcriptome profile of iPSC-derived VMSCs in MMD patients and HC subjects under naïve single culture condition. Comparative transcriptome features between iPSC-derived VSMCs and ECs, displaying distinct transcriptome in the ECs, suggested that pathological traits can be driven by naïve ECs predominantly and VSMCs may require specific environmental factors in MMD, which provides novel insight into the pathophysiology of MMD. Our iPSC derived VSMC model can contribute to further investigations of diagnostic and therapeutic target of MMD in addition to the current iPSC derived EC model.

Combined structural and diffusion tensor imaging detection of ischemic injury in moyamoya disease: relation to disease advancement and cerebral hypoperfusion

OBJECTIVE

The microstructural integrity of gray and white matter is decreased in adult moyamoya disease, suggesting covert ischemic injury as a mechanism of cognitive dysfunction. Establishing a microstructural brain imaging marker is critical for monitoring cognitive outcomes following surgical interventions. The authors of the present study determined the pathophysiological basis of altered microstructural brain injury in relation to advanced arterial occlusion, cerebral hypoperfusion, and cognitive function.

METHODS

The authors examined 58 patients without apparent brain lesions and 30 healthy controls by using structural MRI, as well as diffusion tensor imaging (DTI). Arterial occlusion in each hemisphere was classified as early or advanced stage based on MRA and posterior cerebral artery (PCA) involvement. Regional cerebral blood flow (rCBF) was measured with N-isopropyl-p-[123I]-iodoamphetamine SPECT. Furthermore, cognitive performance was examined using the Wechsler Adult Intelligence Scale, Third Edition and the Trail Making Test (TMT). Both voxel- and region of interest-based analyses were performed for groupwise comparisons, as well as correlation analysis, using parameters such as cognitive test scores; gray matter volume; fractional anisotropy (FA) of association fiber tracts, including the inferior frontooccipital fasciculus (IFOF) and superior longitudinal fasciculus (SLF); PCA involvement; and rCBF.

RESULTS

Compared to the early stages, advanced stages of arterial occlusion in the left hemisphere were associated with a lower Performance IQ (p = 0.031), decreased anterior cingulate volumes (p = 0.0001, uncorrected), and lower FA in the IFOF, cingulum, and forceps major (all p < 0.01, all uncorrected). There was no significant difference in rCBF between the early and the advanced stage. In patients with an advanced stage, PCA involvement was correlated with a significantly lower Full Scale IQ (p = 0.036), cingulate volume (p < 0.01, uncorrected), and FA of the left SLF (p = 0.0002, uncorrected) compared to those with an intact PCA. The rCBF was positively correlated with FA of the SLF, IFOF, and forceps major (r > 0.34, p < 0.05). Global gray matter volumes were moderately correlated with TMT part A (r = 0.40, p = 0.003). FA values in the left SLF were moderately associated with processing speed (r = 0.40, p = 0.002).

CONCLUSIONS

Although hemodynamic compensation may mask cerebral ischemia in advanced stages of adult moyamoya disease, the disease progression is detrimental to gray and white matter microstructure as well as cognition. In particular, additional PCA involvement in advanced disease stages may impair key neural substrates such as the cingulum and SLF. Thus, combined structural MRI and DTI are potentially useful for tracking the neural integrity of key neural substrates associated with cognitive function and detecting subtle anatomical changes associated with persistent ischemia, as well as disease progression.

Crossed cerebellar diaschisis as an indicator of severe cerebral hyperperfusion after direct bypass for moyamoya disease

Cerebral hyperperfusion (HP) complicates the postoperative course of patients with moyamoya disease (MMD) after direct revascularization surgery. Crossed cerebellar diaschisis (CCD) has been considered to be rarely associated with HP after revascularization surgery. This study aimed to describe the clinical features and factors associated with CCD secondary to cerebral HP after revascularization surgery for MMD. We analyzed 150 consecutive hemispheres including 101 in adults and 49 in pediatric patients who underwent combined direct and indirect bypass for MMD. Using single-photon emission computed tomography (SPECT), serial cerebral blood flow (CBF) was measured immediately after the surgery and on postoperative days 2 and 7. Pre- and postoperative voxel-based analysis of SPECT findings was performed to compare the changes in regional CBF. Multivariate logistic regression analysis was performed to test the effect of multiple variables on CCD. Asymptomatic and symptomatic HP was observed in 41.3% (62/150) and 16.7% (25/150) of the operated hemispheres, respectively. CCD was observed in 18.4% (16/87) of these hemispheres with radiological HP. Multivariate analysis revealed that the occurrence of CCD was significantly associated with symptomatic HP (p = 0.0015). Voxel-based analysis showed that the CBF increase in the operated frontal cortex, and the CBF reduction in the contralateral cerebellar hemisphere on day 7 were significantly larger in symptomatic HP than in asymptomatic HP (median 11.3% vs 7.5%; - 6.0% vs - 1.7%, respectively). CCD secondary to postoperative HP is more common than anticipated in MMD. CCD could potentially be used as an indicator of severe postoperative HP in patients with MMD.

Abstract WP180: Measuring Tissue Motion During Carotid Endarterectomy Using Video-based Analyses

Background: During carotid endarterectomies (CEA), perioperative stroke and cranial or cervical nerve injuries are the most common major complications. Many experts have emphasized the importance of careful and gentle manipulation around carotid plaques. However, there have been no methodological assessments that quantitatively measure ‘gentleness’. This study was aimed to propose a novel metric for gentle surgical maneuvers during CEA.

Methods: Using surgical video-based motion software, the motion of the carotid artery around plaque was analyzed and quantified during a CEA. Kinematic parameters (minimum and maximum acceleration, and maximum and mean velocity) were compared among the surgical tasks and techniques, as well as between novice and expert surgeons.

Results: The surgical tasks of dissecting the common carotid artery, passing the proximal vessel loops, and ligating vessels showed the highest absolute values of kinematic parameters. Dissections perpendicular to the line of the internal carotid artery tended to show higher kinematic parameters than those in the parallel direction, with blunt dissections typically higher than sharp dissections. The kinematic parameters of novice surgeons were significantly higher than those of experts, and receiver operating curve analysis showed a strong discriminative power. The kinematic parameters in the case of postoperative ischemic stroke also showed the highest absolute values.

Conclusions: This study shows that tissue motion parameters could be a novel and feasible surrogate marker for the objective assessment on the ‘gentleness’ of surgical performance in CEA. Such an objective measurement might be applicable towards enhancing surgical education and risk management.

Reversible Cerebral Angiopathy after Viral Infection in a Pediatric Patient with Genetic Variant of RNF213

Ring finger protein (RNF) 213 is known as a susceptibility gene for moyamoya disease (MMD), which is characterized by bilateral carotid folk stenosis. Cerebral angiopathy after viral infection has been known to present angiographical appearance resembling MMD, however its pathogenesis and genetic background are not well known. We report a case of reversible cerebral angiopathy after viral infection in a pediatric patient with genetic variant of RNF213 mutation. The patient had developed a severe headache after hand, foot, and mouth disease. Magnetic resonance imaging and magnetic resonance angiography (MRA) performed 2-3 weeks after disease onset revealed bilateral carotid folk stenosis and an old cerebral infarction in the left putamen. The patient's headache spontaneously resolved and the follow-up MRA showed a complete spontaneous resolution of the arterial stenosis after 9 months. We were able to determine genetic predisposition to angiopathy by identifying the RNF213 c.14576G>A (rs112735431, p.R4859K) mutation. Based on the present case, we hypothesize that an RNF213 variant might play an important role for the onset of postviral cerebral angiopathy.

Association of cognitive function with cerebral blood flow in children with moyamoya disease

OBJECTIVE

The cognitive effects of main cerebral artery occlusive lesions are unclear in children with moyamoya disease (MMD). The authors aimed to investigate cognitive function in the presurgical phase of pediatric patients with MMD with no apparent brain lesions.

METHODS

In this prospective, observational, single-center study, 21 children (mean age 10 ± 3.0 years, range 5-14 years) diagnosed with MMD at Hokkaido University Hospital between 2012 and 2018 were enrolled. A cross-sectional evaluation of intellectual ability was performed using the Wechsler Intelligence Scale for Children-Fourth Edition at the initial diagnosis. rCBF was measured using [123I] N-isopropyl p-iodoamphetamine/SPECT. The associations among clinical factors, disease severity, regional cerebral blood flow (rCBF), and intelligence test scores were also examined.

RESULTS

The mean full-scale intelligence quotient (FIQ) was 101.8 ± 12.5 (range 76-125) in children with no apparent brain lesions. A significant difference in the intelligence scale index score was observed, most frequently (42.9%) between working memory index (WMI) and verbal comprehension index (VCI; VCI - WMI > 11 points). Regional CBF was significantly reduced both in the left and right medial frontal cortices (left: 61.3 ± 5.3 ml/100 g/min, right 65.3 ± 5.3 ml/100 g/min; p < 0.001) compared to the cerebellum (77.8 ± 6.8 ml/100 g/min). There was a significant association of rCBF in the left dorsolateral prefrontal cortex (DLPFC) with FIQ (r = 0.46, p = 0.034), perceptual reasoning index (PRI; r = 0.44, p = 0.045), and processing speed index (PSI; r = 0.44, p = 0.045). There was an association between rCBF of the left medial frontal cortex and PSI (r = 0.49, p = 0.026). Age of onset, family history, ischemic symptoms, and angiographic severity were not associated with poor cognitive performance.

CONCLUSIONS

Although average intellectual ability was not reduced in children with MMD, the association of reduced rCBF in the left DLPFC and medial frontal cortex with FIQ, PRI, and PSI suggests mild cognitive dysfunction due to cerebral hypoperfusion.

Characteristics of Moyamoya Disease Based on National Registry Data in Japan

Background and Purpose—

A public registration system for intractable diseases was started in Japan in 1972 to investigate the etiology and pathogenesis of intractable diseases while reducing out-of-pocket medical expenses on patients. The goal of this study was to investigate the epidemiology and clinical characteristics of Moyamoya disease using data from applications submitted to this system between 2004 and 2008.

Methods—

In addition to demographic factors such as onset age and family history, we evaluated clinical presentation type, imaging findings, clinical symptoms, and functioning in activities of daily living (ADL).

Results—

Of 3859 cases for which applications were submitted, 2545 were confirmed to meet the diagnostic criteria after data cleansing. Onset age showed a bimodal distribution, and Moyamoya disease had a higher incidence in women than in men. The presence of occlusion and infarction in the proximal region of the anterior cerebral artery was more frequent in pediatric cases than adult cases. Our findings also indicated that 23% of patients required assistance with ADL. Cerebral infarction (odds ratio [OR], 12.5; 95% CI, 3.55–44.66), seizure (OR, 7.44; 95% CI, 1.29–42.96), and sensory disorders (OR, 5.23; 95% CI, 1.15–23.75) were identified as significant predictors of impaired ADL in pediatric cases 3 years after the initial application. Moderate ADL function (OR, 11.59; 95% CI, 5.29–25.39) and intellectual disabilities (OR, 4.38; 95% CI, 1.58–12.17) at the time of the application were identified as significant prognostic factors in adults.

Conclusions—

The results of this study indicated that characteristics of Moyamoya disease such as onset type, symptoms, and imaging abnormalities differ with onset age. Prognostic analyses suggested that pediatric cases with good ADL but with infarct type onset, seizure, or sensory disorders might have a subsequent decline in ADL.

Brain Structure, Connectivity, and Cognitive Changes Following Revascularization Surgery in Adult Moyamoya Disease

BACKGROUND

The effect of the combined direct/indirect revascularization surgery in Moyamoya disease has not been evaluated sufficiently with regard to cognitive function, brain microstructure, and connectivity.

OBJECTIVE

To investigate structural and functional changes following revascularization surgery in patients with moyamoya disease (MMD) through a combined analysis of brain morphology, microstructure, connectivity, and neurobehavioral data.

METHODS

Neurobehavioral and neuroimaging examinations were performed in 25 adults with MMD prior to and >12 mo after revascularization surgery. Cognitive function was investigated using the Wechsler Adult Intelligence Scale-III, Trail-Making Test, Wisconsin Card Sorting Test, Continuous Performance Test, Stroop test, and Wechsler Memory Scale. We assessed white matter integrity using diffusion tensor imaging, brain morphometry using magnetization-prepared rapid gradient-echo sequences, and brain connectivity using resting-state functional magnetic resonance imaging (MRI).

RESULTS

Cognitive examinations revealed significant changes in the full-scale intelligence quotient (IQ), performance IQ (PIQ), perceptual organization (PO), processing speed, and Stroop test scores after surgery (P < .05). Enlargement of the lateral ventricle, volume reductions in the corpus callosum and subcortical nuclei, and cortical thinning in the prefrontal cortex were also observed (P < .05). Fractional anisotropy in the white matter tracts, including the superior longitudinal fasciculus, increased 2 to 4 yr after surgery, relative to that observed in the presurgical state (P < .05). Resting-state brain connectivity was increased predominantly in the fronto-cerebellar circuit and was positively correlated with improvements in PIQ and PO (P < .05).

CONCLUSION

Revascularization surgery may improve processing speed and attention in adult patients with MMD. Further, multimodal MRI may be useful for detecting subtle postsurgical brain structural changes, reorganization of white matter tracts, and brain connectivity alterations.

Contrecoup Injury-Induced Middle Meningeal Arteriovenous Fistula Detected by Time-of-Flight Magnetic Resonance Angiography and Magnetic Resonance Arterial Spin Labeling: Case Report and Review of the Literature

BACKGROUND

Middle meningeal arteriovenous fistula (MM-AVF) is rare; however, it will sometimes be followed by intracranial hemorrhage or progressive symptoms caused by abnormal shunt flow. Radiological examination and endovascular treatment of this condition have recently advanced; thus, we have described the pathogenesis, clinical features, and appropriate diagnostic and therapeutic management of MM-AVF. We also reviewed the reported data of the past 35 years, including 30 cases of MM-AVF.

CASE DESCRIPTION

We report the case of 24-year-old man who had presented with right tinnitus who had experienced previous head trauma on the opposite side to the tinnitus ear. Time-of-flight magnetic resonance angiography and magnetic resonance arterial spin labeling findings were suggestive of MM-AVF, and catheter angiography confirmed MM-AVF with shunt flow draining into the cavernous sinus. Endovascular transarterial embolization was performed, and the MM-AVF was embolized successfully using detachable coils and n-butyl-2-cyanoacrylate. The tinnitus disappeared completely immediately after the treatment.

CONCLUSIONS

MM-AVF is caused, not only by coup injury, but also by contrecoup injury. Time-of-flight magnetic resonance angiography and magnetic resonance arterial spin labeling are useful for detecting MM-AVF. Endovascular transarterial embolization is an effective and safe treatment.

Efficacy of ‘drive and retrieve’ as a cooperative method for prompt endovascular treatment for acute ischemic stroke

Background

Outcomes of endovascular treatment for acute ischemic stroke depend on the time interval from onset to reperfusion. Although the centralized ‘mothership’ method is considered preferable, the required transportation time increases the risk that a patient with a stroke may not receive intravenous or endovascular therapy. In contrast, ‘drive and retrieve’ describes a system wherein doctors from comprehensive stroke centers travel to primary stroke centers and provide endovascular treatment for acute ischemic stroke.

Objective

To describe the drive and retrieve system and verify the effects of this new collaboration on outcomes in patients with acute ischemic stroke among facilities.

Methods

This non-randomized, single-arm study retrospectively analyzed patients who met the inclusion criteria for endovascular treatment provided through a drive and retrieve system. Among the 122 patients treated by this system, we analyzed the time of onset to recanalization as the primary outcome. We also analyzed the efficacy of the drive and retrieve system using geographic information system analysis.

Results

The median time from onset to recanalization was 229 min (IQR 170–307 min, 95% CI 201 to 252 min). The upper limit of the 95% CI for the time from onset to recanalization was shorter than the median times reported in two previous trials. Geographic information system analysis revealed an upward trend in the population coverage rate in each secondary medical area after the drive and retrieve method was introduced.

Conclusion

The drive and retrieve method may be an effective form of cooperation between facilities located within 1 hour of a comprehensive stroke center.

Circulating miRNome profiling in Moyamoya disease-discordant monozygotic twins and endothelial microRNA expression analysis using iPS cell line

Background

Moyamoya disease (MMD) is characterized by progressive stenosis of intracranial arteries in the circle of Willis with unknown etiology even after the identification of a Moyamoya susceptible gene, RNF213. Recently, differences in epigenetic regulations have been investigated by a case-control study in MMD. Here, we employed a disease discordant monozygotic twin-based study design to unmask potential confounders.

Methods

Circulating genome-wide microRNA (miRNome) profiling was performed in MMD-discordant monozygotic twins, non-twin-MMD patients, and non-MMD healthy volunteers by microarray followed by qPCRvalidation, using blood samples. Differential plasma-microRNAs were further quantified in endothelial cells differentiated from iPS cell lines (iPSECs) derived from another independent non-twin cohort. Lastly, their target gene expression in the iPSECs was analyzed.

Results

Microarray detected 309 plasma-microRNAs in MMD-discordant monozygotic twins that were also detected in the non-twin cohort. Principal component analysis of the plasma-microRNA expression level demonstrated distinct 2 groups separated by MMD and healthy control in the twin- and non-twin cohorts. Of these, differential upregulations of hsa-miR-6722-3p/− 328-3p were validated in the plasma of MMD (absolute log2 expression fold change (logFC) > 0.26 for the twin cohort; absolute logFC > 0.26, p < 0.05, and q < 0.15 for the non-twin cohort). In MMD derived iPSECs, hsa-miR-6722-3p/− 328-3p showed a trend of up-regulation with a 3.0- or higher expression fold change. Bioinformatics analysis revealed that 41 target genes of miR-6722-3p/− 328-3p were significantly down-regulated in MMD derived iPSECs and were involved in STAT3, IGF-1-, and PTEN-signaling, suggesting a potential microRNA-gene expression interaction between circulating plasma and endothelial cells.

Conclusions

Our MMD-discordant monozygotic twin-based study confirmed a novel circulating microRNA signature in MMD as a potential diagnostic biomarker minimally confounded by genetic heterogeneity. The novel circulating microRNA signature can contribute for the future functional microRNA analysis to find new diagnostic and therapeutic target of MMD.

Electronic supplementary material

The online version of this article (10.1186/s12920-018-0385-3) contains supplementary material, which is available to authorized users.

Electrocardiogram-Triggered Angiography Non-Contrast-Enhanced (TRANCE) Imaging to Assess Access Route Before Diagnostic Cerebral Angiography

BACKGROUND

Electrocardiogram (ECG)-triggered angiography non-contrast-enhanced (TRANCE) imaging is useful for investigating peripheral vessel diseases; however, its efficacy for access route assessment in cerebral angiography has yet to be reported. Therefore we aimed to evaluate the efficacy of TRANCE imaging in the assessment of the access route before diagnostic subtraction angiography for cerebral vascular disorders.

METHODS

TRANCE imaging was performed in all patients undergoing catheter angiography for disease diagnosis at our institute between April 2014 and March 2015. This study included 31 patients (14 men, 17 women) and investigated potential changes in the planned puncture site before and during the procedure (including the reason for the change) as our main outcome.

RESULTS

TRANCE was successfully conducted in all of the patients recruited. TRANCE images led to an alteration in the approach vessel for 5 cases. The mean procedure time for angiography was <60 minutes. The median total number of catheters and guidewires used during catheter angiography was 1 (range: 1-3) and 1 (range: 1-2), respectively. There were no catheter angiography-related complications.

CONCLUSIONS

TRANCE imaging before diagnostic angiography is useful because it allows detailed assessment of the access route. This practice may reduce procedure time, thus resulting in fewer complications.

[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.