Two Postmortem Cases of Moyamoya Disease with Different RNF213 p.R4810K Variant Statuses.

Moyamoya disease (MMD) is characterized by distinct histopathological changes in intracranial arteries, such as narrowing of the arterial lumen due to thickening of the tunica intima, waving of the internal elastic membranes, and thinning of the tunica media. Ring finger protein 213 is a susceptibility gene for MMD that affects clinical outcomes. However, little is known about its relationship with histopathology.

Is initial unilateral revascularization acceptable in pediatric patients with bilateral moyamoya disease with mild contralateral hemodynamic disturbance?

Objective: Although asymmetrical vascular involvement between hemispheres is common in pediatric patients with bilateral moyamoya disease, whether hemispheres with mild vascular changes and hemodynamic impairment require immediate surgical revascularization or whether they can be observed until disease progression remains unclear. The authors evaluated the long-term outcomes of their strategy to initially perform unilateral surgery and withhold surgery to the contralateral hemispheres with mild vascular changes and hemodynamic impairment.

Methods: The authors retrospectively evaluated Japanese pediatric patients (onset age ≤ 15 years) diagnosed with bilateral sporadic moyamoya disease who underwent unilateral revascularization.

Intraoperative Telestration System in Endoscopic Transsphenoidal Surgery Contributes to Improved Surgical Safety and Efficient Surgical Education.

Objective: To evaluate the effectiveness of a "telestration" system in which the mentor annotates the view of the surgical field, for endoscopic transsphenoidal surgery (ETS).

Methods: The use of telestration was evaluated for sellar floor-opening during ETS and for a task performed using ETS simulation training. During ETS, the mentor outlined the opening area of the sella turcica on the monitor and then the trainee surgeon opened the sella, either with the telestration displayed (telestration (+) group, n = 8) or without (telestration (-) group, n = 7).

Spatial coefficient of variation of arterial spin labeling magnetic resonance imaging can predict decreased cerebrovascular reactivity measured by acetazolamide challenge single-photon emission tomography.

Purpose: The aim of this study was to investigate whether the spatial coefficient of variation of arterial spin labeling (ASL-CoV) acquired in clinical settings can be used to estimate decreased cerebrovascular reactivity (CVR) measured with single-photon emission computed tomography (SPECT) and acetazolamide challenge in patients with atherosclerotic stenosis of intra- or extracranial arteries.

Methods: We evaluated the data of 27 atherosclerotic stenosis patients who underwent pseudocontinuous ASL and SPECT. After spatial normalization, regional values were measured using the distributed middle cerebral artery territorial atlas of each patient.

Routine screening serum tests to detect underlying thyroid and autoimmune diseases in patients with moyamoya disease.

Background: Recent studies have revealed that thyroid and autoimmune diseases may be associated with sporadic moyamoya disease. However, whether routine screening serum tests to detect these underlying diseases are useful or not remains unclear.

Methods: We retrospectively evaluated 459 patients with moyamoya disease but without previous history of thyroid or autoimmune diseases who underwent the screening serum tests targeting thyroid and autoimmune diseases from 2016 to 2023 in our institute.

Stroke and Disease Progression During Long-Term Follow-Up of Patients with Moyamoya Disease Older Than 50 Years.

Objective: The long-term prognosis of elderly patients with moyamoya disease (MMD) is not fully understood and needs to be elucidated.

Methods: MMD patients who first visited our institute between 1999 and 2019, were ≥ 50 years of age, and were followed for ≥1 year were retrospectively included. Follow-up data such as stroke and disease progression on magnetic resonance angiography (MRA) were collected from medical records.

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.

Decreased diffusivity along the perivascular space and cerebral hemodynamic disturbance in adult moyamoya disease.

Moyamoya disease (MMD) causes cerebral arterial stenosis and hemodynamic disturbance, the latter of which may disrupt glymphatic system activity, the waste clearance system. We evaluated 46 adult patients with MMD and 33 age- and sex-matched controls using diffusivity along the perivascular space (ALPS) measured with diffusion tensor imaging (ALPS index), which may partly reflect glymphatic system activity, and multishell diffusion MRI to generate freewater maps. Twenty-three patients were also evaluated via O-gas positron emission tomography (PET), and all patients underwent cognitive tests.

Loss of methylthioadenosine phosphorylase immunoreactivity correlates with poor prognosis and elevated uptake of C-methionine in IDH-mutant astrocytoma.

Purpose: The proximate localization of MTAP, which encodes methylthioadenosine phosphorylase, and CDKN2A/B on Chromosome 9q21 has allowed the loss of MTAP expression as a surrogate for homozygous deletion of CDKN2A/B. This study aimed to determine whether MTAP status correlates with clinical outcomes and C-methionine uptake in astrocytomas with IDH mutations.

Methods: We conducted immunohistochemistry for MTAP in 30 patients with astrocytoma, IDH-mutant who underwent C-methionine positron emission tomography scans prior to surgical resection.

Impact of [C]methionine PET with Bayesian penalized likelihood reconstruction on glioma grades based on new WHO 2021 classification.

Objective: The uptake of [C]methionine in positron emission tomography (PET) imaging overlapped in earlier images of tumors. Bayesian penalized likelihood (BPL) reconstruction increases the quantitative values of tumors compared with conventional ordered subset-expectation maximization (OSEM). The present study aimed to grade glioma malignancy based on the new WHO 2021 classification using [C]methionine PET images reconstructed using BPL.

Synergistic Interaction of Thyroid Autoantibodies and Ring Finger Protein 213 Variant in Moyamoya Disease.

Recently, thyroid autoantibodies were found to be associated with moyamoya disease (MMD). The ring finger protein 213 (RNF213) p.R4810K variant represents the most important susceptibility genotype of this disease, but its relationship with thyroid autoantibodies remains to be elucidated.

Long-term prognosis of 452 moyamoya disease patients with and without revascularization under perfusion-based indications.

Objectives: To evaluate the long-term outcomes of patients treated under our perfusion-based strategy and assess whether conservative treatment without surgical treatment under our strategy is acceptable.

Materials And Methods: A total of 315 adult and 137 pediatric MMD patients (follow-up period ≥ 3 years from 2001 to 2020) were included. Follow-up events in each patient group (pediatric or adult, surgically treated or conservatively treated) were evaluated and compared to each other using a log-rank test.

Regression of periventricular anastomosis after indirect revascularization in pediatric patients with moyamoya disease.

Objective: The aim of this study was to evaluate whether indirect revascularization in pediatric patients with moyamoya disease leads to periventricular anastomosis (PVA) regression, which is markedly developed in moyamoya vessels and is regarded as a risk factor for hemorrhage.

Methods: Pediatric patients with moyamoya disease treated with indirect revascularization from 2011 to 2021 were included in this study. Magnetic resonance angiography and arterial spin labeling images acquired before and 1 year after surgery were assessed to obtain a visual scale of postoperative collateral artery formation, moyamoya vessels, PVA, and quantitative values of cerebral blood flow (CBF).

T2-FLAIR mismatch sign correlates with C-methionine uptake in lower-grade diffuse gliomas.

Purpose: The T2-FLAIR mismatch sign is recognized as an imaging finding highly suggestive of IDH-mutant astrocytomas. This study was designed to determine whether the T2-FLAIR mismatch sign correlates with uptake of C-methionine in lower-grade gliomas.

Methods: We included 78 histopathologically verified lower-grade gliomas (grade 2: 31 cases, grade 3: 47 cases) in this study.

Increased Parenchymal Free Water May Be Decreased by Revascularization Surgery in Patients with Moyamoya Disease.

Purpose: Moyamoya disease (MMD) is a cerebrovascular disease associated with steno-occlusive changes in the arteries of the circle of Willis and with hemodynamic impairment. Previous studies have reported that parenchymal extracellular free water levels may be increased and the number of neurites may be decreased in patients with MMD. The aim of the present study was to investigate the postoperative changes in parenchymal free water and neurites and their relationship with cognitive improvement.

Encephalo-Duro-Pericranio-Synangiosis for the Treatment of Moyamoya Disease with Posterior Cerebral Artery Lesions.

Objective: We describe our experience performing encephalo-duro-pericranio synangiosis for the parieto-occipital region (EDPS-p) as a treatment for moyamoya disease (MMD) with hemodynamic disturbances caused by lesions of the posterior cerebral artery.

Methods: From 2004 to 2020, 60 hemispheres of 50 patients with MMD (38/50 females, age 1-55 years) underwent EDPS-p as a treatment for hemodynamic disturbances in the parieto-occipital region. A skin incision was made on the parieto-occipital area to avoid the major skin arteries, and the pedicle flap was created by attaching the pericranium to the dura mater under the craniotomy with multiple small incisions.

Changes in the clinical spectrum of pediatric moyamoya disease over 40 years.

Objective: To investigate the chronological changes in the clinical presentation and long-term prognosis of pediatric-onset moyamoya disease in our institute over 40 years.

Methods: We evaluated 282 pediatric-onset (≤ 15 years old) moyamoya disease patients who visited our institute from 1981 to 2020 (divided into the former period, 1981-2000, and the latter period, 2001-2020). Differences in the clinical presentation and the long-term outcome were compared between the periods.

[Indirect Revascularization Surgery for Chronic Ischemia in Moyamoya Disease].

Indirect revascularization is a surgical procedure to reduce cerebral ischemia, using subcutaneous tissues or dura mater supplied by extracranial arteries as grafts. The perfusion pressure gradient between the cortex and the graft, if present, induces arteriogenesis and develops extracranial-intracranial anastomoses to supply blood flow to the cerebral cortex underneath the graft. Therefore, it is essential to perform the craniotomy over the site of the cerebral ischemia to induce functional anastomoses.

Correlation of Intraoperative 5-ALA-Induced Fluorescence Intensity and Preoperative C-Methionine PET Uptake in Glioma Surgery.

Background: 5-Aminolevulinic acid (5-ALA) is widely employed to assist fluorescence-guided surgery for malignant brain tumors. Positron emission tomography with C-methionine (MET-PET) represents the activity of brain tumors with precise boundaries but is not readily available. We hypothesized that quantitative 5-ALA-induced fluorescence intensity might correlate with MET-PET uptake in gliomas.

Effect of Temporal Sampling Rate on Estimates of the Perfusion Parameters for Patients with Moyamoya Disease Assessed with Simultaneous Multislice Dynamic Susceptibility Contrast-enhanced MR Imaging.

Purpose: The effect of temporal sampling rate (TSR) on perfusion parameters has not been fully investigated in Moyamoya disease (MMD); therefore, this study evaluated the influence of different TSRs on perfusion parameters quantitatively and qualitatively by applying simultaneous multi-slice (SMS) dynamic susceptibility contrast-enhanced MR imaging (DSC-MRI).

Methods: DSC-MRI datasets were acquired from 28 patients with MMD with a TSR of 0.5 s.

Differences in cerebral blood flow measurement using arterial spin labeling MRI between patients with moyamoya disease and patients with arteriosclerotic cerebrovascular disease.

Background: It is unclear whether the accuracy of arterial spin labeling (ASL) magnetic resonance imaging (MRI) is the same between moyamoya disease (MMD), which is known to have markedly elevated cerebral blood volume (CBV), and atherosclerotic intracranial arterial stenosis (AS), which has relatively less elevated CBV.

Purpose: To investigate how the differences in hemodynamics affect measurement of ASL-cerebral blood flow (CBF) using ASL for patients with MMD and AS.

Material And Methods: Fourteen MMD and ten AS patients were evaluated with ASL-MRI, magnetic resonance angiography (MRA), and O-gas positron emission computed tomography (PET).

Absence of the RNF213 p.R4810K variant may indicate a severe form of pediatric moyamoya disease in Japanese patients.

Objective: The authors' objective was to investigate the influence of the RNF213 p.R4810K variant on the clinical presentation and outcomes of Japanese pediatric patients with moyamoya disease.

Methods: A total of 129 Japanese patients with pediatric-onset moyamoya disease (onset age ≤ 15 years) who visited the authors' department from 2012 to 2020 participated in this study.