Outcomes of Bypass Surgery in Adult Moyamoya Disease by Onset Type.

Importance: Moyamoya disease (MMD) is a rare chronic cerebrovascular disease, and the outcomes of bypass management in adult patients remain controversial. Objective: To categorize adult MMD based on asymptomatic, ischemic, and hemorrhagic onset and compare the outcomes (death, hemorrhagic stroke [HS], and ischemic stroke [IS]) of bypass surgery (direct or indirect) with those of conservative management. Design, Setting, and Participants: This retrospective, nationwide, population-based longitudinal cohort study used Korean National Health Insurance Research data to identify adults (aged ≥15 years) with MMD who were diagnosed between January 1, 2008, and December 31, 2020, and followed up until December 31, 2021 (median follow-up, 5.74 [IQR, 2.95-9.42] years). A total of 19 700 participants (3194 with hemorrhagic, 517 with ischemic, and 15 989 with asymptomatic MMD) were included. Data were analyzed from January 2 to April 1, 2023. Exposures: Bypass surgery and conservative management. Main Outcomes and Measures: Death constituted the primary outcome; secondary outcomes consisted of HS or IS. Kaplan-Meier survival curve and Cox proportional hazards regression analysis were applied. The propensity score-matching and stratified analyses were performed to control covariate effects. Results: A total of 19 700 patients (mean [SD] age, 45.43 [14.98] years; 12 766 [64.8%] female) were included. Compared with conservative management, bypass was associated with a reduced risk of death (adjusted hazard ratio [AHR], 0.50 [95% CI, 0.41-0.61]; P < .001) and HS (AHR, 0.36 [0.30-0.40]; P < .001) in hemorrhagic MMD; reduced risk of IS (AHR, 0.55 [95% CI, 0.37-0.81]; P = .002) in ischemic MMD; and reduced risk of death (AHR, 0.74 [95% CI, 0.66-0.84]; P < .001) in asymptomatic MMD. However, bypass was associated with an increased risk of HS (AHR, 1.76 [95% CI, 1.56-2.00]; P < .001) in asymptomatic MMD. Both direct and indirect bypass demonstrated similar effects in hemorrhagic and asymptomatic MMD, except only direct bypass was associated with a reduced risk of IS (AHR, 0.52 [95% CI, 0.33- 0.83]; P = .01) in ischemic MMD. After stratification, bypass was associated with a reduced risk of death in patients younger than 55 years with ischemic (AHR, 0.34 [95% CI, 0.13- 0.88]; P = .03) and asymptomatic (AHR, 0.69 [95% CI, 0.60-0.79]; P < .001) MMD, but an increased risk of HS in patients 55 years or older with ischemic MMD (AHR, 2.13 [95% CI, 1.1-4.16]; P = .03). Conclusions and Relevance: The findings of this cohort study of bypass outcomes for patients with MMD emphasize the importance of tailoring management strategies in adult patients based on onset types.

How I do it: operative nuances of the Encephalo-Duro-Mio-Synangiosis (EDMS) technique for pediatric moyamoya disease and syndrome.

BACKGROUND: Moyamoya disease, a progressive occlusive arteriopathy mainly affecting the supraclinoid internal carotid artery, leads to abnormal "Moyamoya vessels" and ischemic events in children due to decreased cerebral blood flow. Surgery, especially indirect revascularization, is suggested for pediatric Moyamoya cases. METHOD: We present the Encephalo-Duro-Mio-Synangiosis (EDMS) technique, illustrated with figures and videos, based on 14 years' experience performing 71 surgeries by the senior author (SGJ) and the Moyamoya Interdisciplinary Workteam at "Prof. Dr. J. P. Garrahan" Pediatric Hospital. CONCLUSION: EDMS is a simple and effective treatment for Moyamoya disease, enhancing procedure precision and safety, reducing associated risks, complications, and improving clinical outcomes.

Spontaneous occlusion of ruptured microaneurysm formed on postoperative transosseous anastomosis after indirect revascularization in a patient with moyamoya disease.

A 40-year-old female with a history of ischemic moyamoya disease treated with indirect revascularization at ages 12 and 25 years presented with a sudden severe headache. Imaging studies revealed focal parenchymal hemorrhage and acute subdural hematoma, confirming a microaneurysm formed on the postoperative transosseous vascular network as the source of bleeding. Conservative management was performed, and no hemorrhage recurred during the 6-month follow-up period. Interestingly, follow-up imaging revealed spontaneous occlusion of the microaneurysm. However, due to the rarity of this presentation, the efficacy of conservative treatment remains unclear. Further research on similar cases is warranted.

Vascular risk profile and changes of arterial hypertension after surgical revascularization in adult Moyamoya patients.

Moyamoya disease (MMD) is a rare stenoocclusive cerebral vasculopathy often treated by neurosurgical revascularization using extracranial-intracranial bypasses to prevent ischemic or hemorrhagic events. Little is known about the vascular risk profile of adult MMD patients compared to the general population. We therefore analyzed 133 adult MMD patients and compared them with data from more than 22,000 patients from the German Health Update database. Patients with MMD showed an age- and sex-adjusted increased prevalence of arterial hypertension, especially in women between 30 and 44 years and in patients of both sexes between 45 and 64 years. Diabetes mellitus was diagnosed significantly more frequently in MMD patients with increasing age, whereas the vascular risk profile in terms of obesity, nicotine and alcohol consumption was similar to that of the general population. Antihypertensive medication was changed one year after surgical revascularization in 67.5% of patients with a tendency towards dose reduction in 43.2% of all patients. After revascularization, physicians need to be aware of a high likelihood of changes in arterial hypertension and should adjust all other modifiable systemic vascular risk factors to achieve the best treatment possible.

Natural course of hemodynamically stable hemispheres contralateral to operated hemispheres in adult patients with ischemic moyamoya diseases.

The necessity of bilateral bypass in adult moyamoya disease (MMD) remains unclear despite its recommendation for pediatric and hemorrhagic cases. We aimed to investigate the natural course of hemodynamically stable unoperated hemispheres after bypass surgery for symptomatic and hemodynamically unstable hemispheres in adult patients with ischemic MMD. Among 288 patients, the mean age at the first operation of the unstable hemispheres was 40.8 ± 12.2 years. The mean follow-up period was 62.9 ± 46.5 months. 45 patients (15.6%) experienced stroke events in the unoperated hemisphere, consisting of hemorrhagic stroke in 8 (2.8%) and ischemic stroke in 37 (12.8%), including progressive transient ischemic attack in 25 (8.7%) and infarction in 12 (4.2%). Among them, 39 patients (13.5%) underwent bypass surgery. The annual risk of total stroke is 3.0%/patient-year, with 2.5% for ischemic stroke and 0.5% for hemorrhagic stroke. The 5- and 10-year cumulative risks of ischemic stroke were 13.4% and 18.3%, respectively, and those of hemorrhagic stroke were each 3.2%. The natural course of hemodynamically stable hemispheres contralateral to the operated ones appeared fairly good. Additional bypass surgery on the unoperated hemispheres should be considered for symptomatic and hemodynamically unstable hemispheres in adult patients with ischemic MMD during the follow-up.

Predictive value of the hemispheric magnetic resonance angiography score on the development of indirect pial synangiosis after combined revascularization surgery for adult moyamoya disease.

PURPOSE: It is difficult to precisely predict indirect bypass development in the context of combined bypass procedures in moyamoya disease (MMD). We aimed to investigate the predictive value of magnetic resonance angiography (MRA) signal intensity in the peripheral portion of the major cerebral arteries for indirect bypass development in adult patients with MMD. METHODS: We studied 93 hemispheres from 62 adult patients who underwent combined direct and indirect revascularization between 2005 and 2019 and genetic analysis for RNF213 p.R4810K. The signal intensity of the peripheral portion of the major intracranial arteries during preoperative MRA was graded as a hemispheric MRA score (0-3 in the middle cerebral artery and 0-2 in the anterior cerebral and posterior cerebral arteries, with a high score representing low visibility) according to each vessel's visibility. Postoperative bypass development was qualitatively evaluated using MRA, and we evaluated the correlation between preoperative factors, including the hemispheric MRA score and bypass development, using univariate and multivariate analyses. RESULTS: A good indirect bypass was observed in 70% of the hemispheres. Hemispheric MRA scores were significantly higher in hemispheres with good indirect bypass development than in those with poor indirect bypass development (median: 3 vs. 1; p < 0.0001). Multiple logistic regression analysis revealed hemispheric MRA score as an independent predictor of good indirect bypass development (odds ratio, 2.1; 95% confidence interval, 1.3-3.6; p < 0.01). The low hemispheric MRA score (< 2) and wild-type RNF213 predicted poor indirect bypass development with a specificity of 0.92. CONCLUSION: Hemispheric MRA score was a predictive factor for indirect bypass development in adult patients who underwent a combined bypass procedure for MMD. Predicting poor indirect bypass development may lead to future tailored bypass surgeries for MMD.

[Imaging risk factors for postoperative cerebral infarction in adults with ischemic Moyamoya disease].

Objective: To investigate the imaging factors associated with postoperative cerebral infarction in adult patients aged 18 and above with ischemic Moyamoya disease. Methods: The clinical data of adult patients who underwent surgeries for ischemic Moyamoya disease in the Department of Neurosurgery at Peking University International Hospital from October 2015 to October 2020 were retrospectively analyzed. Of the 239 patients, 120 were male and 119 were female, with ages ranging from 18 to 63 (41.7±10.3) years. A total of 239 patients(290 cases) underwent direct and indirect combined revascularization (CR).Gender, age, surgical side, preoperative transient ischemic attack (TIA), presence of old cerebral infarction, and imaging features were compared between the patients with (48 cases) and without (242 cases) cerebral infarction within 1 week after surgery. Multivariate logistic binary regression model was used to analyze the imaging risk factors of postoperative cerebral infarction. Results: Cerebral infarction occurred in 48 cases(16.5%) among the 290 CR group within 1 week after surgery. The proportion of patients with TIA, old cerebral infarction, ICA stenosis, A1 segment stenosis, M1 segment stenosis, abnormal posterior cerebral artery (PCA), and unstable compensation before CR in the cerebral infarction group was higher than that in the non-cerebral infarction group (P<0.05).Preoperative TIA (OR=4.514, 95%CI: 1.920-10.611), old cerebral infarction (OR=2.856,95%CI:1.176-6.936), A1 stenosis (OR=7.027,95%CI:1.877-26.308), M1 stenosis (OR=6.968,95%CI:2.162-22.459), abnormal PCA (OR=4.114,95%CI:1.330-12.728)and unstable compensation (OR=4.488,95%CI:1.194-16.865) were risk factors for cerebral infarction after CR surgery (all P<0.05). Conclusion: Among the imaging factors, TIA, old cerebral infarction, A1 stenosis, M1 stenosis, abnormal PCA and unstable compensation were risk factors for cerebral infarction in adult patients with ischemic Moyamoya disease treated by combined revascularization.

[Various Bypass Surgery:Preoperative Simulation for STA-MCA Bypass].

In STA-MCA bypass surgery, it is important to select the optimal recipient using preoperative simulation to avoid complications. We report a preoperative simulation for STA-MCA bypass using the Brain LAB iPLAN platform®BRAIN LAB)and the 3DCG simulation software GRID®Kompath). Here, we introduce the basics and applications of preoperative simulation for occlusive atherosclerotic lesions and present a target bypass for periventricular anastomosis and peripheral vessels of aneurysms in Moyamoya disease. By creating and visualizing 3D fusion images, the optimal donor and recipient can be selected. Determining the skin incision and extent of craniotomy according to the case is also applicable to the minimally invasive STA-MCA bypass. Preoperative simulations enable accurate pinpoint bypass surgery and prevent complications.

Development of the external carotid artery system including the middle temporal artery after direct-indirect revascularization surgery for moyamoya disease.

BACKGROUND: The aim of this study was to clarify when and from which blood vessels indirect revascularization develops after combined revascularization surgery for moyamoya disease and how the donor vessels that undergo direct revascularization change in the medium to long term. In particular, we focused on the middle temporal artery (MTA), which has not received much attention in indirect revascularization surgery for moyamoya disease until now. METHODS: We targeted 20 sides that were suitable for evaluating the diameter of the external carotid artery system involved in combined revascularization surgery among moyamoya disease patients who underwent a composite revascularization procedure utilizing a 'U'-shaped skin incision encircling the parietal branch of the superficial temporal artery (STA) at our institution from 2018 to 2023. We identified the STA parietal branch, MMA, DTA, and MTA in the TOF source MR images acquired preoperatively and three and six months after surgery; measured the long and short diameters of each blood vessel; approximated the blood vessel shape as an ellipse, and calculated its cross-sectional area. RESULTS: The cross-sectional areas of the MMA, DTA, and MTA involved in indirect revascularization significantly increased compared to presurgery three months after surgery, and this trend continued six months after surgery, but no significant change was observed between three and six months after surgery. There were no cases in which the MTA was clearly confirmed before surgery in the TOF reconstructed images, but the MTA was clearly confirmed in 55% (11/20 cases) of hemispheres three months after surgery and in 85% (17/20 cases) of hemispheres six months after surgery. The crosssectional area of the STA parietal branch, which was the donor for direct revascularization, had increased by more than 150% compared to before surgery in 55% (11/20 cases) of hemispheres three months after surgery. CONCLUSIONS: Indirect revascularization can be expected three months after combined revascularization surgery for moyamoya disease. The MTA, which has not received much attention in terms of indirect revascularization for moyamoya disease patients thus far, was found to be a useful blood flow source for indirect revascularization in combined revascularization surgery for patients with moyamoya disease. Whether or not the cross-sectional area of the superficial temporal artery used as a donor for direct revascularization increased in the medium to long term varied on a case-by-case basis.

[Moyamoya disease in adults: treatment methods in modern era]. / Sovremennyi podkhod k lecheniyu angiopatii moyamoya u vzroslykh.

Moyamoya angiopathy is a chronic progressive cerebrovascular disease characterized by stenosis and occlusion of the distal segments of the internal carotid arteries and/or proximal segments of the middle and anterior cerebral arteries, with a gradual compensatory restructuring of the cerebral circulation to the system of the external carotid arteries. Today, the main treatment method for Moyamoya angiopathy is surgical revascularization of the brain. A search and analysis of publications on the treatment of adult patients with Moyamoya angiopathy was carried out in the PubMed and Medscape databases over the past 10 years. We present a case of an adult female patient with a hemorrhagic form of Moyamoya angiopathy stage IV according to J. Suzuki, who underwent staged combined revascularization of both cerebral hemispheres. Surgical revascularization included the creation of a low-flow extra-intracranial shunt combined with a combination of indirect synangiosis. The combination of direct and indirect methods of surgical revascularization enables to achieve the development of an extensive network of collaterals and fully compensate for cerebral circulatory disorders both in the early and late postoperative periods, which is confirmed by instrumental diagnostic data. Combined revascularization is the most effective modern method of treating patients with Moyamoya angiopathy due to the complementary influence of direct and indirect components of revascularization.

Risk Factors for Specific Postoperative Ischemic Complications in Patients with Moyamoya Disease: A Single-Center Retrospective Study.

AIM: To evaluate and compare postoperative ischemic complications to determine the risk factors for ischemic complications following revascularization surgery for Moyamoya disease (MMD). MATERIAL AND METHODS: This single-center retrospective study included 266 procedures between 2016 and 2021. Three types of revascularization approaches including direct bypass, indirect bypass, and combined bypass were performed. To identify risk factors for postoperative ischemic complications and contralateral cerebral infarction, preoperative clinical characteristics and radiographic features were examined using multivariate and ordinal logistic regression analyses. RESULTS: Postoperative ischemic complications occurred in 103 (6.6%) procedures. Ischemic presentation (p=0.001, odds ratios [OR] 5.59, 95% confidence interval [CI] 2.05-15.23), hypertension (p=0.030, OR 2.75, 95%CI 1.11- 6.83), advanced Suzuki stage (p=0.006, OR 3.19, 95%CI 1.40-7.26), and collateral circulation (p=0.001 OR 0.17, 95%CI 0.06-0.47) were risk factors for postoperative ischemic complications. Ordinal regression analysis revealed that unilateral involvement (p=0.043, OR 2.70, 95%CI 0.09-5.31), hemorrhagic presentation (p=0.013, OR 3.45, 95%CI 0.72-6.18), surgical approach (p=0.032, OR -1.38, 95%CI -2.65, -0.12), and collateral circulation [p=0.043, OR -1 .27, 95%CI -2.51, -0.04)] were associated with the type of ischemic complications. History of hypertension (p=0.031) and contralateral computed tomography (CT) perfusion stage (p=0.045) were associated with contralateral infarction. CONCLUSION: Inability of cerebral vessels to withstand changes in blood pressure induced by revascularization-related hemodynamic instability might be associated with postoperative complications in patients with Moyamoya disease.

Nonalcoholic fatty liver disease is an independent risk factor for ischemic stroke after revascularization in patients with Moyamoya disease: a prospective cohort study.

BACKGROUND: The study aimed to investigate the association between nonalcoholic fatty liver disease (NAFLD) and ischemic stroke events after revascularization in patients with Moyamoya disease (MMD). METHODS: This study prospectively enrolled 275 MMD patients from September 2020 to December 2021. Patients with alcoholism and other liver diseases were excluded. NAFLD was confirmed by CT imaging or abdominal ultrasonography. Stroke events and modified Rankin Scale (mRS) scores at the latest follow-up were compared between the two groups. RESULTS: A total of 275 patients were enrolled in the study, among which 65 were diagnosed with NAFLD. Univariate logistic regression analysis showed that NAFLD (P = 0.029) was related to stroke events. Multivariate logistic regression analysis showed that NAFLD is a predictor of postoperative stroke in MMD patients (OR = 27.145, 95% CI = 2.031-362.81, P = 0.013). Kaplan-Meier analysis showed that compared with MMD patients with NAFLD, patients in the control group had a longer stroke-free time (P = 0.004). Univariate Cox analysis showed that NAFLD (P = 0.016) was associated with ischemic stroke during follow-up in patients with MMD. Multivariate Cox analysis showed that NAFLD was an independent risk factor for stroke in patients with MMD (HR = 10.815, 95% CI = 1.259-92.881, P = 0.030). Furthermore, fewer patients in the NAFLD group had good neurologic status (mRS score ≤ 2) than the control group (P = 0.005). CONCLUSION: NAFLD was an independent risk factor for stroke in patients with MMD after revascularization and worse neurological function outcomes.

Safety of antiplatelet therapy during the perioperative period of revascularization surgery for moyamoya disease patients with ischemic onset.

For patients with moyamoya disease, antiplatelet agents are often used during the perioperative periods of revascularization surgeries to prevent ischemic events. However, antiplatelet therapy is associated with the risk of hemorrhagic complications. Further, the influence of antiplatelet therapy on perioperative ischemic or hemorrhagic complications has not been investigated. This study aimed to determine the impact of antiplatelet agents on adult moyamoya disease patients with ischemic onset during the perioperative period. From January 2016 to December 2020, 183 consecutive combined (direct and indirect) revascularization surgeries for moyamoya disease patients were performed. Among these surgeries, 96 consecutive combined revascularization surgeries for adult moyamoya disease patients with ischemic onset were analyzed and perioperative ischemic and hemorrhagic complications were reviewed. Antiplatelet agents were continued during the perioperative period including on the day of surgery and the day after the surgery. Among 96 surgeries, no hemorrhagic complications occurred postoperatively. Infarction occurred in five cases (5.2%). Among the five cases, neurological deficits persisted in two cases and improved in three. The median value of bleeding volume was 112.5 mL (interquartile range, 80.0 - 200.0). Twenty-five cases (26.0%) needed blood transfusion. The modified Rankin Scale score deteriorated in two cases due to cerebral infarction. The incidence of hemorrhagic and ischemic complications after combined revascularization surgery in patients with ischemic moyamoya disease under antiplatelet therapy was low, indicating the safety of continued antiplatelet therapy.

Ultrasonography monitoring with Superb Microvascular Imaging during cerebrovascular surgery.

INTRODUCTION: Ultrasonography (US) is used as a real-time dynamic imaging modality during neurosurgery. A novel Doppler US technique, Superb Microvascular Imaging (SMI), can be used to visualize low-velocity flow of small vessels at high resolution with high frame rates. We visualized vessel flow using this US SMI technique and contrast agent during cerebrovascular surgery. METHODS: Forty-three patients with an unruptured cerebral aneurysm (control), ischemic and hemorrhagic moyamoya disease, carotid artery stenosis, hemangioblastoma, severe stenosis of the middle cerebral artery, venous angioma, and intracerebral hemorrhage (ICH) underwent neurosurgery with US SMI monitoring using a contrast agent. The diameter, length, and number of penetrating vessels were analyzed in patients with an unruptured cerebral aneurysm (control), moyamoya disease, and ICH. RESULTS: Diameter and length of cerebral penetrating vessels were significantly increased in patients with moyamoya disease and ICH compared to control patients. The number of penetrating vessels was increased in moyamoya disease patients compared to control and ICH patients. In hemorrhagic moyamoya disease, flow in the penetrating vessels originated from a deep periventricular point and extended to the cerebral surface. Pulsatile cerebral aneurysms during clipping surgery and carotid artery stenosis during carotid endarterectomy were easily identified by SMI. Drastically increased vessel flow in patients with a hemangioblastoma or a venous angioma was observed. CONCLUSION: Using the US SMI technique and contrast agent, we obtained useful flow information of the vascular disease structure and intracerebral deep small vessels during cerebrovascular surgery. Further quantitative analysis will be informative and helpful for cerebrovascular surgery.

Effect of revascularization surgery on cerebral hemodynamics in adult moyamoya disease.

OBJECTIVE: Few studies have reported local hemodynamic changes after revascularization surgery. This study aimed to identify regional hemodynamic changes after combined revascularization surgery for moyamoya disease using single-photon emission computed tomography with N-isopropyl-p-123I-iodoamphetamine. METHODS: A total of 46 adults with moyamoya disease who underwent combined revascularization surgery from August 2009 to July 2021 at our facility were enrolled. The combined bypass procedure comprised a single direct bypass to the motor area and encephalo-duro-arterio-myo-synangiosis. The preoperative and postoperative cerebral blood flow (CBF) and cerebral vascular reserve (CVR) in the genu; precentral, central, parietal, angular, temporal, and posterior regions; splenium; hippocampus; and cerebellum were measured. To modify the examination variability, the cerebral-to-cerebellar activity ratio (CCR) was calculated by dividing the counts in the region by those in the cerebellum (CBF-CCR and CVR-CCR). RESULTS: Postoperatively, asymptomatic cerebral infarction occurred in three (6.5%) patients. The CBF-CCR and CVR-CCR improved in the precentral, parietal, and temporal regions and in the overall middle cerebral artery (MCA) territory. Sub-analysis of anterior cerebral artery (ACA) and posterior cerebral artery (PCA) territory hemodynamics revealed that patients with normal preoperative hemodynamics showed no changes in the CBF-CCR and CVR-CCR postoperatively, whereas patients with preoperative perfusion impairment exhibited improved CVR-CCR in the ACA territory (0.13-0.3, p=0.019) and CBF-CCR in the PCA territory (0.93-0.96, p=0.0039). CONCLUSION: Combined revascularization surgery with single bypass to the motor area improved hemodynamics in the primary targeted MCA territory and in the ACA and PCA territories among patients with preoperative hemodynamic impairment.

Evaluation of the contribution of individual arteries to the cerebral blood supply in patients with Moyamoya angiopathy: comparison of vessel-encoded arterial spin labeling and digital subtraction angiography.

PURPOSE: Vessel-encoded arterial spin labeling (VE-ASL) is able to provide noninvasive information about the contribution of individual arteries to the cerebral perfusion. The aim of this study was to compare VE-ASL to the diagnostic standard digital subtraction angiography (DSA) with respect to its ability to visualize vascular territories. METHODS: In total, 20 VE-ASL and DSA data sets of 17 patients with Moyamoya angiopathy with and without revascularization surgery were retrospectively analyzed. Two neuroradiologists independently assessed the agreement between VE-ASL and DSA using a 4-point Likert scale (no- very high agreement). Additionally, grading of the vascular supply of subterritories (A1-A2, M1-M6) on the VE-ASL images and angiograms was performed. The intermodal agreement was calculated for all subterritories in total and for the subdivision into without and after revascularization (direct or indirect bypass). RESULTS: There was a very high agreement between the VE-ASL and the DSA data sets (median = 1, modus = 1) with a substantial inter-rater agreement (kw = 0.762 (95% CI 0.561-0.963)). The inter-modality agreement between VE-ASL and DSA in vascular subterritories was almost perfect for all subterritories (k = 0.899 (0.865-0.945)), in the subgroup of direct revascularized subterritories (k = 0.827 (0.738-0.915)), in the subgroup of indirect revascularized subterritories (k = 0.843 (0.683-1.003)), and in the subgroup of never revascularized subterritories (k = 0.958 (0.899-1.017)). CONCLUSION: Vessel-encoded ASL seems to be a promising non-invasive method to depict the contributions of individual arteries to the cerebral perfusion before and after revascularization surgery.

Cortical Spreading Depolarization in Moyamoya Vasculopathy: A Case Series.

BACKGROUND: Spreading depolarization describes a near-complete electrical discharge with altered local cerebral blood flow. It is described in association with acute and chronic diseases like hemorrhagic stroke or migraine. Moyamoya vasculopathy is a chronic, progressive cerebrovascular disorder leading to cerebral hypoperfusion, hemodynamically insufficient basal collateralization, and increased cortical microvascularization. METHODS: In a prospective case series, we monitored for spontaneous spreading depolarization activity by using intraoperative laser speckle imaging for real-time visualization and measurement of cortical perfusion and cerebrovascular reserve capacity during cerebral revascularization in 4 consecutive patients with moyamoya. RESULTS: Spontaneous spreading depolarization occurrence was documented in a patient with moyamoya before bypass grafting. Interestingly, this patient also exhibited a marked preoperative increase in angiographic collateral vessel formation. CONCLUSIONS: The spontaneous occurrence of SDs in moyamoya vasculopathy could potentially provide an explanation for localized cortical infarction and increased cortical microvascular density in these patients.

Persistent trigeminal artery in a patient with moyamoya disease:a case report and literature review.

BACKGROUNDS: Persistent trigeminal artery (PTA) is a rare anastomosis between internal carotid artery (ICA) and basilar artery. In rare conditions, the PTA could be combined with others cerebrovascular anomalies, moyamoya disease (MMD) is one of them. CASE PRESENTATION: Here, we reported one rare case of MMD associated with PTA, the patient admitted to our department for severe dizziness and headache, imaging examination suggested MMD combined with right PTA, which arising from the ipsilateral cavernous portion of ICA. The patient received phased bilaterral revascularization with no any complication. In the subsequent follow-up, the patient's symptoms and intracranial vascular condition gradually improved. Moreover, we conducted a literature review of coexistence of PTA and MMD, the results of a web of science regarding such condition, and a deep discussion providing brief insight into the status of co-occurrence of PTA and MMD, including its manifestation, treatment and outcome. CONCLUSIONS: The coexistence of PTA and MMD was rarely reported, the pathogenesis of such condition remains unknown. We found that the features of the coexistence of PTA and MMD were diverse, revascularization might be a feasible for such patient.

Functional and Neuropsychological Outcome After Surgical Treatment of Moyamoya Disease.

BACKGROUND: Moyamoya disease (MMD) is a rare cerebrovascular disease characterized by progressive stenosis of the supraclinoid internal carotid artery. As a result of chronically decreased brain perfusion, eloquent areas of the brain become hypoperfused, leading to cognitive changes in patients. Repeated infarcts and bleeds produce clinically apparent neurologic deficits. OBJECTIVES: 1) To study the functional and neuropsychological outcome in MMD after revascularization surgery. 2) To find postrevascularization correlation between functional and neuropsychological improvement and radiologic improvement. METHODS: A single-center prospective and analytic study was carried out including 21 patients with MMD during the study period from March 2021 to December 2022. Patients were evaluated and compared before and after revascularization for functional, neuropsychological, and radiologic status. RESULTS: Postoperative functional outcome in terms of modified Rankin Scale score showed improvement in 33.33% of cases (P = 0.0769). An overall improving trend was observed in different neuropsychological domains in both adult and pediatric age groups. However, the trend of neuropsychological improvement was better in adults compared with pediatric patients. Radiologic outcome in the form of the Angiographic Outcome Score (AOS) significantly improved after revascularization (P = 0.0001). There was a trend toward improvement in magnetic resonance imaging (MRI) perfusion in the middle cerebral artery and anterior cerebral artery territories, 4.7% (P = 0.075) and 9.33% (P = 0.058) respectively, compared with preoperative MRI perfusion. CONCLUSIONS: After revascularization, significant improvement occurred in functional and neuropsychological status. This result was also shown radiologically as evidenced by improvement in MRI perfusion and cerebral angiography.