Association of Genetic Variants with Postoperative Donor Artery Development in Moyamoya Disease: RNF213 and Other Moyamoya Angiopathy-Related Gene Analysis.

Robust postoperative bypass development is a characteristic of moyamoya disease (MMD); however, genetic factors mediating this phenomenon remain incompletely understood. Therefore, we aimed to elucidate the relationship between postoperative donor artery development and genetic variants. We retrospectively enrolled 63 patients (79 hemispheres) who underwent combined revascularization surgery. Postoperative development of the superficial temporal artery (STA), middle meningeal artery, and deep temporal artery (DTA) was assessed using the caliber-change ratio determined from magnetic resonance angiography measurements. We analyzed RNF213 and 36 other moyamoya angiopathy-related genes by whole-exome sequencing and extracted rare or damaging variants. Thirty-five participants carried RNF213 p.Arg4810Lys (all heterozygotes), whereas 5 had RNF213 rare variants (RVs). p.Arg4810Lys was significantly associated with postoperative DTA development, while age at surgery, hypertension, and hyperlipidemia were inversely associated. Multiple regression analysis revealed that age and p.Arg4810Lys held statistical significance (P = 0.044, coefficient - 0.015, 95% confidence interval (CI) - 0.029 to 0.000 and P = 0.001, coefficient 0.670, 95% CI 0.269 to 1.072, respectively). Those with RNF213 RV without p.Arg4810Lys exhibited a significant trend toward poor DTA development (P = 0.001). Hypertension demonstrated a significant positive association with STA development, which remained significant even after multiple regression analysis (P = 0.001, coefficient 0.303, 95% CI 0.123 to 0.482). Following Bonferroni correction for multiple comparisons, targeted analyses of RNF213 and 36 moyamoya angiopathy-related genes showed a significant association of only RNF213 p.Arg4810Lys with favorable DTA development (P = 0.001). A comprehensive analysis of RNF213, considering both p.Arg4810Lys and RVs, may provide a clearer prediction of postoperative DTA development.

A bibliometric analysis of the 100 most-cited clinical articles in the research of intracranial artery stenosis and intracranial atherosclerosis.

Background: Intracranial arterial stenosis (ICAS), caused by intracranial atherosclerosis, is one of the major causes of ischemic stroke. This study identified the top 100 most-cited publications on ICAS through a bibliometric analysis. Methods: Two independent authors conducted a search in the Web of Science database for clinical articles on ICAS published between 1993 and 2022. The top 100 most-cited articles were then extracted. For each article, the analysis covered the title, author, country of origin/affiliation, journal, total number of citations, number of citations per year, and type of study. Results: The top 100 most-cited papers in the ICAS were authored by 565 authors from 12 countries and published in 29 journals. In terms of the 5-year trend, the largest number of papers were published between 2003 and 2007 (n = 31). The median number of citations for the 100 papers was 161 (range 109-1,115). The journal with the highest proportion of the 100 most published articles was Stroke, accounting for 41% of articles and 37% of the citations. According to country of origin, the United States of America accounted for the largest number of articles, followed by China, Japan, and South Korea, with these four countries together accounting for 81% of the total number of articles and 88% of the citations. Trends in the past five years included the use of terms such as acute ischemic stroke and mechanical thrombectomy. Conclusion: The findings of this study provide novel insight into this field and will facilitate future research endeavors.

Stroke events and risk factors in older patients with moyamoya disease.

BACKGROUND: We aimed to comprehensively analyze the epidemiology, natural history, stroke events and their risk factors, and the RNF213 p.Arg4810Lys variant in older patients with moyamoya disease (MMD). METHODS: We enrolled patients with MMD followed-up at our hospital between 2000 and 2023. Those who developed MMD at age ≥ 60 years or were diagnosed at a younger age and followed-up after age 60 years were included. Baseline characteristics, onset type, radiological features, and RNF213 p.Arg4810Lys variant status were investigated. RESULTS: Among 56 patients with 100 affected hemispheres, 62 were asymptomatic, 26 experienced ischemic onset, and 12 had hemorrhagic onset. A higher incidence of anterior choroidal artery (AchA) dilatation and lower proportion of favorable modified Rankin scale scores were detected in hemorrhagic onset, whereas greater prevalence of bypass surgery in ischemic onset. Of 76 asymptomatic hemispheres at the age of 60 years, subsequent stroke events occurred in 10 hemispheres, comprising eight hemorrhages and two ischemias. Risk factors for de novo hemorrhage in asymptomatic hemispheres included AchA dilatation and choroidal anastomosis. Comparison of the RNF213 p.Arg4810Lys variant status showed no significant differences in baseline characteristics, onset types, or imaging findings, except for a higher percentage of patients in the GA group with a family history of MMD. CONCLUSIONS: Hemorrhagic events were the most prevalent and prognostically deteriorating factors in older patients with MMD aged ≥60 years. AchA dilatation and choroidal anastomosis were predictors of de novo hemorrhage in asymptomatic nonsurgical hemispheres in older patients with MMD.

Iatrogenic vertebral artery injury during catheter ablation treated using coil embolization.

The internal jugular vein (IJV) is occasionally used for blood access during catheter ablation. Additionally, accidental injury of the vertebral artery during an IJV puncture is a rare complication that can result in catastrophic events, such as death. However, vascular access complications cannot be completely prevented despite the introduction of ultrasound-guided punctures. Here, we present a case of a patient with symptomatic paroxysmal atrial fibrillation that required catheter ablation.

Transarterial embolization with n-butyl-2-cyanoacrylate for a ruptured aneurysm at the artery of Davidoff and Schechter.

The artery of Davidoff and Schechter (ADS) is mostly identified in pathological conditions such as dural arteriovenous fistulas and brain tumors. Herein, we report a rare case of a ruptured aneurysm of the ADS, which was one of the feeders of a falcotentorial dural arteriovenous fistula. We performed endovascular embolization of the aneurysm and parent artery using n-butyl-2-cyanoacrylate. Complete occlusion of the fistula was achieved by another feeder after the acute phase. To our best knowledge, only a few reports on embolization of ruptured ADS aneurysms exist. Furthermore, this is the first report on the embolization of a ruptured ADS aneurysm using n-butyl-2-cyanoacrylate. This case highlights that endovascular n-butyl-2-cyanoacrylate embolization could be a useful treatment for a ruptured ADS aneurysm.

Safety evaluation of sinus patency after stereotactic radiosurgery for transverse-sigmoid sinus dural arteriovenous fistulas: implications of treatment options for patients with Borden type I fistulas.

OBJECTIVE: This study aimed to assess the efficacy and safety of stereotactic radiosurgery (SRS) in treating transverse-sigmoid sinus dural arteriovenous fistulas (TSS DAVFs), and to investigate post-SRS sinus patency, focusing on the risk factors associated with treated sinus occlusion. METHODS: Data from 34 patients treated with SRS between January 2006 and April 2023 were analyzed. Detailed angioarchitecture was confirmed using digital subtraction angiography before SRS. Angiography of the ipsilateral internal carotid artery and vertebral artery was performed to evaluate whether the involved side of the TSS was used for normal venous drainage. TSS stenosis was defined as sinus diameter < 50% of the normal proximal diameter. DAVF shunt obliteration, TSS occlusion, neurological status, and adverse events were also evaluated. RESULTS: Of the 34 patients, 21 had Borden type I and 14 had Borden type II DAVFs. The median age at SRS was 64 years (interquartile range 54-71 years), and the follow-up period was 31 months (interquartile range 15-94 months). Complete shunt obliteration was achieved in 24 (70.6%) patients. The cumulative 2-, 3-, and 5-year shunt obliteration rates were 49.6%, 71.2%, and 86.0%, respectively. Borden type I had higher obliteration rates (60.5%, 83.1%, and 94.4%, respectively) than Borden type II (41.7%, 51.4%, and 75.7%, respectively; p = 0.034). TSS occlusion occurred in 5 patients (14.7%). The cumulative 1-, 5-, and 10-year TSS occlusion rates were 2.9%, 8.3%, and 23.6%, respectively, across the entire cohort. All occlusions occurred exclusively in the sinuses that were not used for normal venous drainage. Cox proportional analyses revealed that TSS stenosis and the sinus not being used for normal venous drainage were significantly associated with a greater risk of TSS occlusion after SRS (HR 9.44, 95% CI 1.01-77.13; p = 0.049). CONCLUSIONS: SRS is effective and safe for TSS DAVF and results in favorable shunt obliteration, symptom improvement, and low complication rates. TSS occlusion after SRS is asymptomatic and is limited to sinuses that are not used for normal venous drainage.

High-Temperature and High-Electron Mobility Metal-Oxide-Semiconductor Field-Effect Transistors Based on N-Type Diamond.

Diamond holds the highest figure-of-merits among all the known semiconductors for next-generation electronic devices far beyond the performance of conventional semiconductor silicon. To realize diamond integrated circuits, both n- and p-channel conductivity are required for the development of diamond complementary metal-oxide-semiconductor (CMOS) devices, as those established for semiconductor silicon. However, diamond CMOS has never been achieved due to the challenge in n-type channel MOS field-effect transistors (MOSFETs). Here, electronic-grade phosphorus-doped n-type diamond epilayer with an atomically flat surface based on step-flow nucleation mode is fabricated. Consequently, n-channel diamond MOSFETs are demonstrated. The n-type diamond MOSFETs exhibit a high field-effect mobility around 150 cm2 V-1 s-1 at 573 K, which is the highest among all the n-channel MOSFETs based on wide-bandgap semiconductors. This work enables the development of energy-efficient and high-reliability CMOS integrated circuits for high-power electronics, integrated spintronics, and extreme sensors under harsh environments.

Elective Cholecystectomy After Endoscopic Gallbladder Stenting for Acute Cholecystitis: A Propensity Score Matching Analysis.

OBJECTIVE: To investigate the influence of endoscopic gallbladder stenting (EGBS) on subsequent cholecystectomy. We retrospectively compared the surgical outcomes of EGBS, followed by elective cholecystectomy with those of immediate cholecystectomy (IC). PATIENTS AND METHODS: A total of 503 patients were included in this study. Patients who underwent EGBS as initial treatment for acute cholecystitis, followed by elective cholecystectomy, were included in the EGBS group and patients who underwent IC during hospitalization were included in the IC group. Propensity score matching analysis was used to compare the surgical outcomes. In addition, the factors that increased the amount of bleeding were examined by multivariate analysis after matching. RESULTS: Fifty-seven matched pairs were obtained after propensity matching the EGBS group and the IC group. The rate of laparoscopic cholecystectomy in the EGBS versus IC groups was 91.2% versus 49.1% ( P < 0.001). The amount of bleeding was 5 mL in the EGBS versus 188 mL in the IC group ( P < 0.001). In the EGBS and IC groups, multivariate analysis of factors associated with more blood loss revealed IC (odds ratio: 4.76, 95% CI: 1.25-20.76, P = 0.022) as an independent risk factor. CONCLUSION: EGBS as the initial treatment for acute cholecystitis and subsequent elective cholecystectomy after the inflammation has disappeared can be performed in minimally invasive procedures and safely.

Trans-Distal Radial Artery Carotid Revascularization with Forearm Flow Reversal: An Alternative Option of CAS in the TCAR Era.

BACKGROUND: Transcarotid artery revascularization (TCAR) has emerged as an alternative to carotid artery stenting (CAS). TCAR demonstrated its superiority by avoiding femoral artery puncture and establishing proximal protection without crossing the stenotic lesion. In the TCAR era, we focused on the possibility of a trans-distal radial approach (DRA). A balloon-guide catheter was navigated via DRA to establish proximal protection before lesion crossing. The forearm subcutaneous vein was used as the flow-reversal circuit. METHODS: Six internal carotid artery stenosis patients underwent CAS using "the forearm flow reversal technique." Every procedure was performed under continuous flow reversal from the common carotid artery to the forearm cephalic vein. RESULTS: Successful revascularization was achieved without ischemic or access-site complications. The distal radial artery was patent at discharge in all cases. CONCLUSIONS: Trans-distal radial CAS with forearm flow reversal is a feasible and less invasive technical option.

Custom shaping of distal access catheter for navigation of microcatheter into inferolateral and meningohypophyseal trunk feeders.

OBJECTIVE: Navigating a microcatheter to tiny feeding arteries such as the inferolateral trunk (ILT) and meningohypophyseal trunk (MHT) of the internal carotid artery (ICA) is technically challenging because of the anatomical features of steep angulation, small diameter, and significant caliber difference from the ICA. To guide the microcatheter to these ICA side branch feeders, the authors thought that a custom shaping of the intermediate catheter would be helpful to determine the direction of the microcatheter and strongly back it up. The aim of this study was to report the detailed methodology and clinical outcomes of patients who had undergone the embolization of ILT and MHT feeders using this method. METHODS: This was a retrospective study of consecutive patients with intracranial tumors and dural arteriovenous fistulas (DAVFs) who had undergone endovascular embolization. The details of the embolization procedures were examined, especially the technique of guiding a low-profile microcatheter supported by the thermoformed intermediate catheter. The authors assessed the patient background, procedural outcomes, and postoperative complications. RESULTS: Between October 2013 and June 2022, 43 patients with intracranial tumors and 45 with DAVFs underwent embolization at the authors' institutions. Among these cases, embolization of the ICA side branch feeder was attempted in 10 intracranial tumors and 2 DAVFs. Of these 12 patients, the microcatheter was guided deep enough for successful embolization in 11 cases (92%). Two asymptomatic arteriovenous fistulas were complicated during guidewire manipulation deep in the feeder. Yet, both disappeared completely after glue injection into the feeding artery. No spasm or dissection of the parent artery occurred during the procedure. Postoperative radiological evaluation showed no intracranial hematoma or symptomatic cerebral infarction. One patient (9%) developed permanent postoperative cranial neuropathy that gradually improved after embolization. CONCLUSIONS: This study revealed that custom shaping of distal access catheters is an effective technique that enabled the embolization of ILT and MHT feeders with a success rate of more than 90%.

Clinical Characteristics of Immediate Contralateral Ischemia Subsequent to Revascularization for Moyamoya Disease.

BACKGROUND: Moyamoya disease is a bilateral steno-occlusive disease involving the cerebral vasculature. While some patients are affected by procedure-related ipsilateral ischemia, ischemic complications contralateral to the revascularization are rarely observed. METHODS: We retrospectively investigated 135 hemispheres (103 patients) that underwent revascularization in our institution between April 2006 and September 2022. Revascularization surgery comprised single superficial temporal artery-middle cerebral artery anastomosis and encephalo-myo-synangiosis. Certain patients aged under 10 years underwent indirect revascularization. Bilateral revascularization was performed with an interval of >3 months. Medical records and neuroimages were reviewed, and patients with contralateral ischemic complications were identified. Some cases underwent genetic analysis. RESULTS: The mean age was 34.5 (range: 5-71) years, and 95 cases (70.4%) were in women. Of the 102 cases examined for the RNF213 c.14429 G > A (p.Arg4810Lys) variant, 33 (32.4%) and 69 (67.6%) showed the GG and GA genotype, respectively. Three cases (2.2%, all female, age range 44-71 years) were complicated with contralateral infarction. The infarcted area distributions of the 2 cases with RNF213 c.14429 G > A variant were patchy and peripheral. The other case showed on magnetic resonance imaging (MRI) angiography total occlusion of the internal carotid artery where patency had been confirmed preoperatively. CONCLUSIONS: Contralateral ischemia after revascularization occurred in 2.2% of cases. We classified them into peripheral and central types: peripheral type, an infarction owing to hemodynamic insufficiency or intracranial blood flow redistribution; central type, total occlusion of the contralateral internal carotid artery. Intensive preoperative management can minimize the risk of peripheral types, and neurosurgeons should beware of severe central types.

Surgically treated intracranial arteriovenous fistulas with hemorrhage, resulting in complete obliteration: illustrative cases.

BACKGROUND: Intracranial arteriovenous fistula (AVF) is a rare disease, defined as anastomoses between cerebral or meningeal arteries and dural venous sinuses or cortical veins. With the development of new agents and devices, endovascular embolization has been considered safe and effective in a majority of cases. However, cases that require direct surgery do exist. Herein, the authors present 3 cases of intracranial AVFs that presented with hemorrhage and were treated with direct surgery, achieving complete obliteration and favorable outcomes. OBSERVATIONS: Intracranial AVFs that present with hemorrhage require immediate and complete obliteration. When AVFs involve the dural sinus, transvenous embolization is usually the first choice of treatment. AVFs with single cortical venous drainage are best treated with interruption of the draining vein close to the fistula. Transarterial embolization can be a curative treatment if there are no branches supplying cranial nerves or an association with pial feeders. In cases in which endovascular treatment is technically challenging or has resulted in incomplete occlusion, surgical treatment is indicated. LESSONS: Despite the recent rise in endovascular treatment, it is important to recognize situations in which such treatment is not suitable for intracranial AVFs. Direct surgery is effective in such cases to offer the best possible outcome.

Hypertensive disorders of pregnancy in moyamoya disease: A single institution experience.

OBJECTIVE: The characteristics of pregnancy and delivery in patients with moyamoya disease (MMD) remain unclear. We retrospectively investigated perinatal outcomes in patients with MMD to evaluate the risks associated to this condition. MATERIALS AND METHODS: Clinical data of women with MMD who delivered at the University of Tokyo Hospital between 2000 and 2021 were collected. Maternal characteristics including genetic data, obstetric complications, method of delivery and anesthesia, neonatal outcomes, neurological events during pregnancy, delivery, and postpartum course, were reviewed. RESULTS: Thirteen pregnancies with MMD were identified. The median maternal age was 30 years. The initial clinical symptoms were identified as transient ischemic attack, infarction, and headache. Eight patients had a history of bypass surgery. The median gestational age at delivery was 37 weeks. DNA samples were collected from five patients, responsible for six pregnancies. Of these six cases, five had the RNF213 c.14429G > A (p.Arg4810Lys) heterozygous variant. Of the 13 pregnancies, seven had hypertensive disorder of pregnancy (HDP). Additionally, three of five pregnancy cases with RNF213 p.Arg4810Lys heterozygous variant presented with HDP. Nine patients underwent cesarean section, and four delivered vaginally with epidural anesthesia. One case of ischemic stroke was confirmed during the postpartum period. Regarding newborns, neither Apgar scores lower than 7 nor neonatal intensive care unit admissions were reported. CONCLUSIONS: This study suggests that the frequency of HDP is higher in patients with MMD compared to those with normal pregnancies. Strict blood pressure control should be performed in patients with MMD during pregnancy and postpartum period.

Double-catheter technique for the embolization of recurrent cerebral aneurysms: A single-center experience.

Background: Recurrent cerebral aneurysms have complex shapes and are often technically challenging to treat with a single microcatheter. This study evaluates the clinical characteristics and treatment outcomes of patients who received double-catheter coil embolization for recurrent cerebral aneurysms. Methods: Patients who underwent double-catheter coil embolization at our institution between April 2011 and March 2022 for recurrent aneurysms were included in the study. Baseline characteristics, course to recurrence, details of the procedures, and outcomes after endovascular treatment were retrospectively analyzed based on past medical records. Results: Eight patients with recurrent aneurysms were treated with the double-catheter technique. One patient had a subarachnoid hemorrhage due to a rupture of a recurrent aneurysm and the others had radiological recurrence during follow-up. The initial treatment for the aneurysm was clipping in one case and coiling in seven cases. All the aneurysms were located at bifurcation sites. During retreatment, balloon remodeling technique was used in five cases. Angiographic features immediately after the treatment included complete occlusion in one case, neck remnant in three cases, and dome filling in four cases. There were no procedure-related severe complications, besides preexisting oculomotor nerve palsy due to the mass effect of the aneurysm worsened in one patient. The mean follow-up period after retreatment was 4.3 years. There was one case of recurrence after retreatment in which additional endovascular coiling was necessary. Conclusion: This study demonstrated that the double-catheter technique could be a safe and useful treatment option for patients with recurrent aneurysms at bifurcation sites.

Cerebrovascular Events During Treatment for Systemic Malignant Tumors in Patients with Moyamoya Disease.

OBJECTIVE: With the increasing incidence of malignancies, the importance of cancer-associated stroke is emphasized. Although moyamoya disease is a leading cause of stroke, no reports have documented cancer-associated stroke in patients with this condition. We aimed to investigate cerebrovascular events during malignancy treatments in patients with moyamoya disease. METHODS: A total of 405 patients with moyamoya disease who visited our hospital between January 2000 and March 2022 were retrospectively examined. We evaluated the management of moyamoya disease, presence of the ring finger protein 213 p.Arg4810Lys variant, treatments for malignant tumors, presence of cerebrovascular events during treatment, and follow-up periods and outcomes. RESULTS: Among the 405 patients, 17 patients with moyamoya disease (4.2%) were diagnosed with malignancies. Among patients aged 60 years and over, 7 out of 67 (10.4%) had malignancies. Of the 17 patients, 11 (64.7%) were symptomatic, and 7 (41.2%) had revascularization surgery. 9 patients were treated with oral antiplatelet drugs. There was no significant difference between the groups with and without malignancy regarding the presence of the ring finger protein 213 p.Arg4810Lys variant (80.0% vs. 62.7%, P = 0.33). All patients underwent surgical treatment, and 7 (41.2%) received chemotherapy. One death due to tumor progression was reported. No cerebrovascular event was observed during malignancy treatments and follow-up periods, which had a mean duration of 6 years. CONCLUSIONS: In our cohort, malignancy treatments in patients with moyamoya disease were safely conducted without cerebrovascular events. However, it is advisable to avoid hypotension, dehydration, hyperventilation, and long-term discontinuation of antiplatelet drugs during the treatment of malignant tumors.

Aneurysmal Inflow Rate Coefficient Predicts Ultra-early Rebleeding in Ruptured Intracranial Aneurysms: Preliminary Report of a Computational Fluid Dynamics Study.

Rebleeding from a ruptured intracranial aneurysm has poor outcomes. Although numerous factors are associated with rebleeding, studies on computational fluid dynamics (CFD) on hemodynamic parameters associated with early rebleeding are scarce. In particular, no report of rebleeding in ultra-early phase exists. We aimed to elucidate the specific hemodynamic parameters associated with ultra-early rebleeding using CFD. In this study, the rebleeding group included patients with aneurysmal subarachnoid hemorrhage (aSAH) that rebled within 6 h from the onset. The control group included patients without rebleeding, observed for >10 h following the initial rupture. Clinical images after initial rupture and before rebleeding were used to build 3D vessel models for hemodynamic analysis focusing on the following parameters: time-averaged wall shear stress (WSS), normalized WSS, low shear area, oscillatory shear index, relative residence time, pressure loss coefficient, and aneurysmal inflow rate coefficient (AIRC). Five and 15 patients in the rebleeding and control groups, respectively, met the inclusion criteria. The World Federation of Neurosurgical Surgeons grade was significantly higher in the rebleeding group (p = 0.0088). Hemodynamic analysis showed significantly higher AIRC in the rebleeding group (p = 0.042). The other parameters were not significantly different between groups. There were no significant differences or correlations between SAH severity and AIRC. AIRC was identified as a hemodynamic parameter associated with ultra-early rebleeding of ruptured intracranial aneurysms. Thus, AIRC calculation may enable the prediction of ultra-early rebleeding.

Bypass Surgery for Adult-Onset Hemorrhagic Moyamoya Disease: Analysis Classified by Site of Initial Bleeding.

OBJECTIVE: Prevention of rebleeding events is crucial for patients with hemorrhagic moyamoya disease (MMD), as these increase the risk of mortality. Bypass surgery is effective in preventing subsequent hemorrhage, particularly in patients with posterior hemorrhage, but its efficacy in those with anterior hemorrhage remains unclear. We analyzed the effects of surgical intervention, stroke risk factors, and radiological features on rebleeding events. METHODS: Patients with hemorrhagic-onset MMD who were followed at our institution between 2000 and 2022 were included (41 adult patients, 45 hemispheres). Baseline characteristics and radiological features (anterior or posterior hemorrhagic site, Suzuki grade, posterior cerebral artery involvement, and periventricular anastomosis) were thoroughly reviewed. RESULTS: Of the 45 hemispheres, hemorrhage developed in 9 (20%) hemispheres, with a median duration until rebleeding of 38 (range: 1-44) months. Rebleeding rates were significantly lower in the surgical group than in the nonsurgical group (odds ratio: 0.09; 95% confidence interval [CI]: 0.01-0.79; P = 0.011), and Kaplan-Meier analysis revealed a significantly longer interval between bleeding events in the surgical group (1.3%/y vs. 5.3%/y; P = 0.002), especially in the anterior hemorrhage group (1.3%/y vs. 5.1%/y; P = 0.019). The hazard ratio of surgical intervention for rebleeding with initial anterior hemorrhage was 0.11 (95% CI: 0.01-0.98; P = 0.048). In the nonsurgical group, the presence of hypertension shortened the time to subsequent hemorrhage (P = 0.004). CONCLUSIONS: Surgical intervention may decrease the risk of rebleeding in hemorrhagic onset MMD patients, even in those presenting with anterior hemorrhage. Hypertension was a significant risk factor for rebleeding in nonsurgical patients.

Complete Recanalization in Mechanical Thrombectomy Is Associated with Favorable Functional Outcome for M2 Occlusions.

Objective: There are insufficient coherent reports on mechanical thrombectomy (MT) for occlusion of the second segment of the middle cerebral artery (M2 occlusion) in a real-world clinical setting. We evaluated the efficacy and safety of MT for M2 occlusions and compared the primary thrombectomy strategies (stent retriever, aspiration catheter, and combined technique) to analyze factors predicting good functional outcomes. Methods: We evaluated background factors, preprocedural factors, procedural factors, and procedural time for patients who underwent MT for M2 occlusions from our retrospective cohort. According to the modified Rankin Scale (mRS) score three months after MT, patients were divided into good (mRS ≤2) and poor (mRS ≥3) prognosis groups. Results: A total of 29 patients (median age, 78 years; 11 [37.9%] females) were included in the study. In this cohort, rates of successful reperfusion, thrombolysis in cerebral infarction (TICI) 3, postprocedural hemorrhage (PPH), and symptomatic PPH were 82.8, 34.5, 31.0, and 0%, respectively. Good prognoses were achieved in 13 (45%) cases. A prognostic factor of MT for M2 occlusions is TICI 3 from multivariate analysis (OR, 11.7; 95% CI, 1.003-136; p = 0.0497). There was no statistically significant difference in the functional outcome three months after MT based on the choice of the primary thrombectomy strategy. Conclusion: MT for M2 occlusions is a reliable and relatively safe procedure. The presence of TICI 3 was a prognostic factor in this cohort. Future studies are warranted to investigate the optimal thrombectomy strategy for medium vessel occlusion.

RNF213 p.Arg4810Lys Wild Type is Associated with De Novo Hemorrhage in Asymptomatic Hemispheres with Moyamoya Disease.

Clinical implications of RNF213 genetic variants, other than p.Arg4810Lys, in moyamoya disease (MMD), remain unclear. This study aimed to investigate the association of RNF213 variants with clinical phenotypes in MMD. This retrospective cohort study collected data regarding the clinical characteristics of 139 patients with MMD and evaluated the angioarchitectures of 253 hemispheres using digital subtraction angiography at diagnosis. All RNF213 exons were sequenced, and the associations of clinical characteristics and angiographical findings with p.Arg4810Lys, p.Ala4399Thr, and other rare variants (RVs) were examined. Among 139 patients, 100 (71.9%) had p.Arg4810Lys heterozygote (GA) and 39 (28.1%) had the wild type (GG). Fourteen RVs were identified and detetcted in 15/139 (10.8%) patients, and p.Ala4399Thr was detected in 17/139 (12.2%) patients. Hemispheres with GG and p.Ala4399Thr presented with significantly less ischemic events and more hemorrhagic events at diagnosis (p = 0.001 and p = 0.028, respectively). In asymptomatic hemispheres, those with GG were more susceptible to de novo hemorrhage than those with GA (adjusted hazard ratio [aHR] 5.36) with an increased risk when accompanied by p.Ala4399Thr or RVs (aHR 15.22 and 16.60, respectively). Within the choroidal anastomosis-positive hemispheres, GG exhibited a higher incidence of de novo hemorrhage than GA (p = 0.004). The GG of p. Arg4810Lys was a risk factor for de novo hemorrhage in asymptomatic MMD hemispheres. This risk increased with certain other variants and is observed in choroidal anastomosis-positive hemispheres. A comprehensive evaluation of RNF213 variants and angioarchitectures is essential for predicting the phenotype of asymptomatic hemispheres in MMD.

White epidermoid cyst transformation after stereotactic radiosurgery: illustrative case.

BACKGROUND: White epidermoid cysts (WECs) are a rare type of epidermoid cyst with atypical radiological features. The epidemiological aspects and mechanisms of their onset remain unknown. Herein, the authors report a unique case of WEC transformation from a typical epidermoid cyst after stereotactic radiosurgery (SRS), confirmed by radiological and pathological findings. OBSERVATIONS: The case involved a 78-year-old man with a history of 2 surgeries for a left cerebellopontine angle typical epidermoid cyst 23 years earlier and SRS using the CyberKnife for recurrent trigeminal neuralgia (TN) 14 years earlier. The tumor with high intensity on T1-weighted imaging, low intensity on T2-weighted imaging, without restriction on diffusion-weighted imaging had gradually enlarged after SRS. Therefore, a salvage surgery was performed via a left suboccipital craniotomy, and the intraoperative findings showed a cyst with a brown, viscous liquid component, consistent with those of WECs. Histopathologically, keratin calcification and hemorrhage were identified, leading to a diagnosis of WEC. The postoperative course was uneventful, and the TN resolved. No tumor recurrence was recorded at 2 years postoperatively. LESSONS: To the best of the authors' knowledge, this is the first world case of WEC transformation from a typical epidermoid cyst after SRS, confirmed by radiological and pathological findings. Radiation effects could have been involved in this transformation.