Clinical features and treatment outcomes in patients in their twenties with ischemic moyamoya disease.

INTRODUCTION: Revascularization surgery is recommended for all pediatric patients with moyamoya disease (MMD) with ischemic symptoms because the brains of such patients are still developing. By contrast, no clear guidelines for selective revascularization surgery in adult patients (30 years or more) with ischemic presentation have been established. Regarding the age of initial onset of ischemic MMD, patients in their 20s are at the bottom of the distribution and this age group may share features with both adult and pediatric patients. The present prospective study aimed to clarify the clinical features and treatment outcomes of patients in their 20s (younger patients) with ischemic MMD compared with patients aged 30-60 years (older patients). METHODS: While patients with misery perfusion in the symptomatic cerebral hemisphere on 15O-positron emission tomography underwent combined surgery including direct and indirect revascularizations in the first study period and indirect revascularization alone in the second study period, patients without misery perfusion in that hemisphere received pharmacotherapy alone through the two study periods. Cerebral angiography via arterial catheterization and neuropsychological testing were performed before and after surgery. RESULTS: During 12 years, 12 younger patients were included and comprised 6% of all adult patients (194 patients). The incidence of misery perfusion in the affected hemisphere was significantly higher in younger (12/12 [100%]) than in older patients (57/182 [31%]) (p < 0.0001). No difference in the incidence of cerebral hyperperfusion syndrome and postoperatively declined cognition was seen between younger (2/5 [40%] and 2/5 [40%], respectively) and older (11/36 [31%] and 15/36 [42%], respectively) cerebral hemispheres undergoing combined revascularization surgery. No difference in the incidence of postoperatively formed collateral flows feeding more than one-third of the middle cerebral artery cortical territory on angiograms and postoperatively improved cognition was seen between younger (9/10 [90%] and 6/10 [60%], respectively) and older (18/22 [83%] and 14/22 [64%], respectively) cerebral hemispheres undergoing indirect revascularization surgery alone. CONCLUSION: Patients in their 20s with ischemic MMD always exhibit misery perfusion in the affected hemisphere, unlike older patients, and sometimes develop cerebral hyperperfusion syndrome after combined revascularization surgery, leading to cognitive decline, similar to older patients. Moreover, indirect revascularization surgery alone forms sufficient collateral circulation and restores cognitive function in patients in their 20s, similar to older patients.

Impact of postoperative cerebral hyperperfusion on 2-year cognitive outcomes of patients undergoing carotid endarterectomy.

OBJECTIVE: In 10% of patients undergoing carotid endarterectomy (CEA), the cognitive function declines postoperatively, primarily in association with postoperative cerebral hyperperfusion. In contrast, in the majority of patients undergoing CEA, long-term cognitive outcomes remain unclear. Furthermore, it is not known whether the decline in cognition due to cerebral hyperperfusion recovers on a long-term basis. This study aimed to understand how postoperative cerebral hyperperfusion affects the cognitive outcomes of patients who undergo CEA. METHODS: The participants in this prospective observational study were patients with internal carotid artery stenosis who underwent CEA. Cerebral hyperperfusion syndrome or asymptomatic cerebral hyperperfusion following CEA was determined based on brain perfusion SPECT scans and symptomatology before and after surgery. Neuropsychological testing was performed preoperatively, at 1-2 months postoperatively, and at 2 years postoperatively to investigate cognitive decline. RESULTS: A logistic regression analysis revealed that asymptomatic cerebral hyperperfusion (95% CI 13.0-84.5, p < 0.0001) and cerebral hyperperfusion syndrome (95% CI 449.7-14,237.4, p < 0.0001) were significantly associated with cognitive decline at 1-2 months postoperatively. The incidence of cognitive decline was significantly decreased at 2 years postoperatively (7%) in comparison to 1-2 months postoperatively (11%) (p = 0.0461). A logistic regression analysis also revealed that asymptomatic cerebral hyperperfusion (95% CI 3.7-36.7, p < 0.0001), cerebral hyperperfusion syndrome (95% CI 128.0-6183.6, p < 0.0001), and further strokes during the 2-year follow-up period (95% CI 1.5-78.7, p = 0.0167) were significantly associated with cognitive decline at 2 years postoperatively. The incidence of cognitive decline at 1-2 months postoperatively was significantly higher in patients with cerebral hyperperfusion syndrome (100%) than in those with asymptomatic cerebral hyperperfusion (44%) (p < 0.0001). No significant difference in incidence was observed in the former patients at 2 years postoperatively (88%), but significant reduction was found in patients with asymptomatic cerebral hyperperfusion and cognitive decline between the timepoints of 1-2 months postoperatively (100%) and 2 years postoperatively (39%) (p = 0.0001). CONCLUSIONS: Postoperative cerebral hyperperfusion causes prolonged cognitive decline at 2 years postoperatively in patients undergoing CEA.

Diagnostic accuracy of preoperative quantitative susceptibility mapping for detecting histologic intraplaque hemorrhage in cervical ICA stenosis in patients undergoing carotid endarterectomy.

BACKGROUND AND PURPOSE: Quantitative susceptibility mapping (QSM) has been proposed to assess intraplaque hemorrhage (IPH) in the carotid artery. The purpose of this study was to compare the diagnostic accuracy of preoperative QSM with that of the conventional T1-weighed (T1W) three-dimensional (3D)-FSE sequence for detecting IPH in cervical ICA stenosis in patients undergoing carotid endarterectomy (CEA) using histology as the reference standard. MATERIALS AND METHODS: Carotid T1W 3D-FSE and QSM images were obtained from 16 patients with cervical ICA stenosis before CEA. Relative signal intensity (RSI) and susceptibility of the ICA were measured on three axial images including the location of most severe stenosis on T1W 3D-FSE and QSM images, respectively. Three transverse sections of carotid plaques excised by CEA, which corresponded with images on MRI, were stained with H&E, antibody against glycophorin A and Prussian blue, and the relative area (RA) of histologic IPH was calculated. RESULTS: The correlation coefficient was significantly greater between susceptibility and RA-histologic IPH (ρ = 0.691) than between RSI and RA-histologic IPH (ρ = 0.413; P = .0259). The areas under the receiver operating characteristic curves for detecting histologic sections consisting primarily of IPH (RA-histologic IPH > 40.7%) tended to be greater for susceptibility (0.964) than for T1WI FSE-RSI (0.811). Marginal homogeneity was observed between susceptibility and histologic sections consisting primarily of IPH (P = .0412) but not between T1W FSE-RSI and histologic sections consisting primarily of IPH (P = .1824). CONCLUSIONS: Pre-CEA QSM detects histologic IPH in cervical ICA stenosis more accurately than preoperative T1W 3D-FSE imaging. ABBREVIATIONS: QSM = quantitative susceptibility mapping; IPH = intraplaque hemorrhage; T1W = T1-weighed; 3D = three-dimensional; CEA = carotid endarterectomy; RSI = relative signal intensity; RA = relative area.

Association between preoperative cortical magnetic susceptibility and postoperative changes in the cerebral blood flow on cognitive improvement following carotid endarterectomy.

INTRODUCTION: While patients who experience improved cognition following carotid endarterectomy (CEA) typically demonstrate restored brain perfusion after the procedure, it is worth noting that less than 50% of patients in whom postoperative cerebral blood flow (CBF) restoration is achieved actually show improved cognition after postoperatively. This suggests that factors beyond the mere restoration of CBF may play a role in postoperative cognitive improvement. Increased iron deposition in the cerebral cortex may cause neural damage, and quantitative susceptibility mapping (QSM) obtained using magnetic resonance imaging (MRI) quantifies magnetic susceptibility in the cerebral cortex, allowing for the assessment of iron deposition in vivo. The purpose of the present study was to determine whether preoperative cortical magnetic susceptibility as well as postoperative changes in CBF are associated with cognitive improvement after CEA. METHODS: Brain MRI with a three-dimensional gradient echo sequence was preoperatively performed in 53 patients undergoing CEA for ipsilateral internal carotid artery stenosis (≥70%), and QSM with brain surface correction and vein removal was obtained. Cortical magnetic susceptibility was measured in the cerebral hemisphere ipsilateral to surgery on QSM. Preoperatively and at two months after the surgery, brain perfusion single-photon emission computed tomography (SPECT) and neuropsychological assessments were conducted. Using these collected data, we evaluated alterations in CBF within the affected hemisphere and assessed cognitive improvements following the operation. RESULTS: A logistic regression analysis showed that a postoperative greater increase in CBF (95% confidence interval [CI], 1.06-1.90; p = 0.0186) and preoperative lower cortical magnetic susceptibility (95% CI, 0.03-0.74; p = 0.0201) were significantly associated with postoperatively improved cognition. Although sensitivity, specificity, and positive- and negative-predictive values with the cutoff value lying closest to the upper left corner of a receiver operating characteristic curve for the prediction of postoperatively improved cognition did not differ between postoperative changes in CBF and preoperative cortical magnetic susceptibility, the specificity and the positive-predictive value were significantly greater for the combination of postoperative changes in CBF and preoperative cortical magnetic susceptibility (specificity, 95% CI, 93-100%; positive-predictive value 95% CI, 68-100%) than for the former parameter alone (specificity, 95% CI, 63-88%; positive-predictive value 95% CI, 20-64%). CONCLUSION: Preoperative cortical magnetic susceptibility as well as postoperative changes in CBF are associated with cognitive improvement after CEA.

Feasibility of Diffusion-weighted Imaging (DWI) for Assessing Cerebrospinal Fluid Dynamics: DWI-fluidography in the Brains of Healthy Subjects.

PURPOSE: The present study aimed to investigate whether diffusion-weighted imaging (DWI) can qualify and quantify cerebrospinal fluid (CSF) dynamics in the brains of healthy subjects. For this purpose, we developed new DWI-based fluidography and compared the CSF dynamics seen on the fluidography with two apparent diffusion coefficients obtained with different DWI signal models at anatomical spaces filled by CSF. METHODS: DWI with multiple b values was performed for 10 subjects using a 7T MRI scanner. DWI-fluidography based on the DWI signal variations in different motion probing gradient directions was developed for visualizing the CSF dynamics voxel-by-voxel. DWI signals were measured using an ROI in the representative CSF-filled anatomical spaces in the brain. For the multiple DWI signals, the mono-exponential and kurtosis models were fitted and two kinds of apparent diffusion coefficients (ADCC and ADCK) were estimated in each space using the Gaussian and non-Gaussian diffusion models, respectively. RESULTS: DWI-fluidography could qualitatively represent the features of CSF dynamics in each anatomical space. ADCs indicated that the motions at the foramen of Monro, the cistern of the velum interpositum, the quadrigeminal cistern, the Sylvian cisterns, and the fourth ventricle were more drastic than those at the subarachnoid space and anterior horns of the lateral ventricle. Those results seen in ADCs were identical to the findings on DWI-fluidography. CONCLUSION: DWI-fluidography based on the features of DWI signals could show differences of CSF dynamics among anatomical spaces.

Association between preoperative white matter hyperintensities and postoperative new ischemic lesions on magnetic resonance imaging in patients with cognitive decline after carotid endarterectomy.

Although cognitive decline after carotid endarterectomy (CEA) is mainly related to postoperative cerebral hyperperfusion, approximately 30% of patients with cognitive decline do not have postoperative cerebral hyperperfusion. In patients with acute ischemic events, the development of cognitive decline after such events is associated with the presence of chronic cerebral white matter hyperintensities (WMHs). The present prospective observational study aimed to determine whether preoperative WMHs and postoperative new ischemic lesions (PNILs) are associated with cognitive decline after CEA in patients without cerebral hyperperfusion after CEA. Brain magnetic resonance imaging (MRI) was performed preoperatively, and WMHs were graded according to the Fazekas scale in patients undergoing CEA for severe stenosis of the ipsilateral internal carotid. Diffusion-weighted MRI was performed before and after CEA to determine the development of PNILs. Neuropsychological testing was performed preoperatively and at 2 months postoperatively to determine the development of postoperative cognitive decline (PCD). In 142 patients without postoperative cerebral hyperperfusion, logistic regression analysis revealed that preoperative Fazekas scale of periventricular WMHs (PVWMHs) (95% confidence interval [CI]: 1.78-28.10; P = 0.0055) and PNILs in the eloquent areas (95% CI: 7.42-571.89; P = 0.0002) were significantly associated with PCD. The specificity and positive-predictive value for the prediction of PCD were significantly greater for the combination of preoperative Fazekas scale 2 or 3 of PVWMHs and PNILs in the eloquent areas than for each individually. Preoperative PVWMHs, PNILs in the eloquent areas, and the combination of both were associated with PCD in patients without cerebral hyperperfusion after CEA.

Correlation Between Low-Density Hematoma at 1-Week Post-Middle Meningeal Artery Embolization and Rapid Resolution of Chronic Subdural Hematoma.

BACKGROUND: Temporal changes in the volume of chronic subdural hematoma (CSDH) following middle meningeal artery (MMA) embolization vary. We aimed to determine whether CSDH density on computed tomography is related to hematoma resolution following particle MMA embolization. METHODS: Patients who underwent MMA embolization for CSDH were enrolled. The CSDHs were quantitatively divided into 2 hematoma groups based on the hematoma density at 1-week postembolization: low-density or high-density. The temporal change in the volume of CSDHs was then analyzed between the groups. RESULTS: Thirty patients were enrolled in this study. Three patients with high-density hematomas required rescue surgery. The hematoma volume was significantly lower in low-density hematomas than in high-density hematoma at 1-week (P = 0.006), 1-month (P = 0.003), and 2-month (P = 0.004) postembolization; although the volume converged to a similar value at 3-month (P > 0.05). There was a positive correlation between hematoma density at 1-week postembolization and percentage hematoma volume at 1-week and 1-month postembolization (P = 0.004 and P < 0.001, respectively), but no correlation was observed between hematoma density before MMA embolization and percentage hematoma volume at 1-week and 1-month postembolization (P = 0.54 and P = 0.17, respectively). CONCLUSIONS: Rapid resolution of CSDH following MMA embolization was associated with low hematoma density at 1-week postembolization. Based on hematoma density on computed tomography at 1-week postembolization, a 1-month follow-up would be sufficient in cases of low density, but a 3-month follow-up would be required in cases of high-density hematoma. Larger studies and clinical trials are needed to confirm our findings.

Assessment of magnetic field interactions and heating for cerebral aneurysm flow diverters during 7T MRI.

Flow diverters (FDs) are utilized for a wide range of aneurysms, but show safety issues such as adverse interactions with static magnetic fields (displacement force and torque) and radiofrequency-induced heating during magnetic resonance imaging (MRI). The present study aimed to assess these adverse interactions in a 7-tesla (7T) static magnetic field and radiofrequency-induced heating during a 7T MRI for two types of FD. Displacement force and magnetically induced torque were assessed using the deflection angle method and low friction surface method, respectively. To assess heating, each FD was set in a phantom filled with gelled-saline mixed with polyacrylic acid and underwent a 7T MRI using a three-dimensional fast spin echo method. Displacement force and magnetically induced torque in the 7T static magnetic field were undetectable, and radiofrequency-induced heating during 7T MRI remained ≤ 0.6 °C for both types of FD, suggesting that magnetic field interactions and heating on FDs during a 7T MRI are acceptable from a safety perspective.

Influence of atherosclerotic burden on adult patients with ischemic moyamoya disease: combined analysis of two prospective cohorts.

OBJECTIVE: This study aimed to determine the influence of atherosclerotic risk factors on initial and further cerebrovascular events in adult patients with moyamoya disease (MMD) by combined analysis of two prospective cohorts in which patients received pharmacotherapy alone and were prospectively followed-up for 5 years. METHODS: In 71 patients, smoking status, home blood pressure, hemoglobin (Hb)A1c and low-density lipoprotein cholesterol (LDL-chol) were checked at inclusion and at further cerebrovascular event or at the end of 5-year follow-up. When a patient had daily smoking, increased HbA1c, increased LDL-chol, increased systolic blood pressure, or increased diastolic blood pressure, the patient was categorized as showing atherosclerotic burden. Angiographic disease progression was determined using changes on magnetic resonance angiography. RESULTS: Eleven patients showed angiographic disease progression and seven of these 11 patients experienced further cerebrovascular events during the follow-up period. The remaining 60 patients did not exhibit either condition. At inclusion, the incidence of atherosclerotic burden was significantly greater in patients without angiographic disease progression (80%) than in those with such progression (45%; p = 0.0249). For patients without angiographic disease progression, values or incidence of almost all variables showed significant interval decreases at the end of 5-year follow-up (p < 0.05). CONCLUSIONS: Adult patients with ischemic MMD who do not exhibit angiographic disease progression appear more strongly affected by atherosclerotic burden at the initial onset of cerebrovascular events than those exhibiting angiographic disease progression. A reduction in atherosclerotic burden by medical treatments for the former patients prevents further cerebrovascular events.

Symptomatic subdural hemorrhage following heart valve surgery: a retrospective cohort study.

OBJECTIVE: Subdural hemorrhage (SDH) has been reported to be the most frequent intracranial hemorrhagic complication following open heart surgery; however, its clinical features and pathophysiology remain unclear. The aim of this retrospective study was to elucidate the incidence, clinical course, and factors associated with the development of symptomatic SDH following heart valve surgery. METHODS: A retrospective review of medical records on the development of symptomatic SDH after heart valve surgery involving cardiopulmonary bypass (CPB) from April 2011 to March 2016 was performed. Patients who had undergone preoperative cranial computed tomography (CT) or brain magnetic resonance imaging (MRI) were included in this study, and factors associated with SDH following heart valve surgery were analyzed. When neurological symptoms developed after heart valve surgery, cranial CT or brain MRI was performed. RESULTS: A total of 556 patients who had undergone heart valve surgery were analyzed. Among these patients, symptomatic SDH occurred in 11 (2.0%). The mean duration of symptomatic onset was 10.1 days (range 2-37 days). Ten of 11 patients (90.9%) developed SDH in the posterior fossa or occipital convexity. Logistic regression analysis revealed longer aortic clamp time (95% CI 1.00-1.10, p = 0.04), higher dose of heparin after surgery (95% CI 1.00-1.02, p = 0.001), and higher pulmonary artery pressure (PAP) just before disconnection of the CPB (95% CI 1.01-1.37, p = 0.04) as significantly associated with the development of SDH. CONCLUSIONS: The incidence of symptomatic SDH following heart valve surgery was 2.0%. Symptoms due to SDH usually developed a few days to 1 month after surgery. Surprisingly, most SDHs developed in the posterior fossa or occipital convexity following heart valve surgery. A longer aortic clamp time, higher dose of heparin after surgery, and higher PAP just before disconnection of the CPB were related to the development of symptomatic SDH following heart valve surgery.

Effect of the addition of 123I-iomazenil single-photon emission computed tomography to brain perfusion single-photon emission computed tomography on the detection accuracy of misery perfusion in adult patients with ischemic moyamoya disease.

OBJECTIVE: The present prospective study aimed to determine whether the addition of 123I-iomazenil (IMZ) single-photon emission computed tomography (SPECT) to brain perfusion SPECT could improve the detection accuracy of misery perfusion on positron emission tomography (PET) in adult patients with ischemic moyamoya disease (MMD). METHODS: Oxygen extraction fraction (OEF) and brain perfusion were assessed using 15O gas PET and N-isopropyl-p-[123I]-iodoamphetamine (IMP) SPECT, respectively, in 137 patients. IMZ SPECT was also performed. Regions of interest (ROIs) were automatically placed in the five middle cerebral artery (MCA) territories ipsilateral to the symptomatic cerebral hemisphere and in the contralateral posterior cerebral artery territory using a three-dimensional stereotaxic ROI template. The radioactive count of the MCA ROI to the contralateral posterior cerebral artery ROI was calculated on IMP SPECT (relative SPECT-IMP uptake) and IMZ SPECT (relative SPECT-IMZ uptake). The relative SPECT-IMZ uptake to the relative SPECT-IMP uptake was also calculated (relative SPECT-IMZ/IMP uptake). Of the five MCA ROIs in the symptomatic cerebral hemisphere in each patient, the ROI with the highest PET-OEF value (one ROI per patient) was selected for analysis. RESULTS: Significant correlations were observed between the PET-OEF and relative SPECT-IMP uptake (correlation coefficient, - 0.683) and relative SPECT-IMZ/IMP uptake (correlation coefficient, 0.875). The area under the receiver operating characteristic curve for detecting misery perfusion (PET-OEF > 51.3%) was significantly greater for the relative SPECT-IMZ/IMP uptake than for the relative SPECT-IMP uptake (difference between areas, 0.080; p = 0.0004). The sensitivity, specificity, and positive- and negative-predictive values for the relative SPECT-IMZ/IMP uptake for detecting misery perfusion were 100%, 92%, 81%, and 100%, respectively. The specificity and positive-predictive value were significantly greater for the relative SPECT-IMZ/IMP uptake than for the relative SPECT-IMP uptake. CONCLUSIONS: The addition of IMZ SPECT to brain perfusion SPECT improves the detection accuracy of misery perfusion on PET in adult patients with ischemic MMD.

Prediction of cerebral hyperperfusion following carotid endarterectomy using intravoxel incoherent motion magnetic resonance imaging.

OBJECTIVES: One of the risk factors for cerebral hyperperfusion following carotid endarterectomy (CEA) is a chronic reduction in cerebral perfusion pressure due to internal carotid artery (ICA) stenosis, which is clinically detected as increased cerebral blood volume (CBV). The perfusion fraction (f) is one of the intra-voxel incoherent motion (IVIM) parameters obtained using magnetic resonance (MR) imaging that theoretically reflects CBV. The present study aimed to determine whether preoperative IVIM-f on MR imaging predicts development of cerebral hyperperfusion following CEA. MATERIALS AND METHODS: Sixty-eight patients with unilateral ICA stenosis (≥ 70%) underwent preoperative diffusion-weighted 3-T MR imaging, and IVIM-f maps were generated from these data. Quantitative brain perfusion single-photon emission computed tomography (SPECT) was performed before and immediately after CEA. Regions-of-interest (ROIs) were automatically placed in the bilateral middle cerebral artery territories in all images using a three-dimensional stereotactic ROI template, and affected-to-contralateral ratios in the ROIs were calculated on IVIM-f maps. RESULTS: Nine patients (13%) exhibited postoperative hyperperfusion (cerebral blood flow increases of ≥ 100% compared with preoperative values in the ROIs on brain perfusion SPECT). Only high IVIM-f ratios were significantly associated with the occurrence of postoperative hyperperfusion (95% confidence interval, 253.8-6774.2; p = 0.0031) on logistic regression analysis. The sensitivity, specificity, and positive and negative predictive values of the IVIM-f ratio to predict the occurrence of postoperative hyperperfusion were 100%, 81%, 45%, and 100%, respectively. CONCLUSIONS: Preoperative IVIM-f on MR imaging can predict development of cerebral hyperperfusion following CEA.

Feasibility of Preoperative Magnetic Resonance Angiography/Black-Blood Magnetic Resonance Imaging/Computed Tomography Fusion Imaging Without Contrast Agent for Carotid Endarterectomy.

BACKGROUND: Preoperative identification of the carotid bifurcation (CB) location and plaque and stenosis distal end of the cervical internal carotid artery in relation to bony structures is essential for carotid endarterectomy (CEA). However, for patients with contrast contraindications, cervical 3-dimensional computed tomography angiography (3D-CTA) is unavailable. In this study, we created fusion images of magnetic resonance angiography (MRA), black-blood (BB) magnetic resonance imaging (MRI), and CT to determine if these noncontrast agent images are superior to 3D-CTA for preoperative CEA planning. METHODS: The fusion images showed vascular structures obtained by MRA, plaque observed by BB-MRI, and bone structures shown by CT. Spatial localization accuracy was verified by directly overlaying contrast-enhanced 3D-CTA images on the fusion images. We validated this technique in 50 patients with unilateral ICA stenosis, 28 of whom underwent CEA. The 2D-distance CB MRA-CTA (the 2D distance difference between CB MRA and CB CTA perpendicular to the long axis of the carotid artery) was measured. We also compared the findings of the fusion image regarding the CB location and plaque distal end with the operative findings. RESULTS: The median 2D distance CB MRA-CTA was 1 mm. CB MRA was located distal and proximal to CB CTA in 21and 29 patients, respectively. The CB location and fusion-image plaque were consistent with the intraoperative findings in all CEA patients. CONCLUSIONS: Fusion images created from MRA, BB-MRI, and noncontrast CT were feasible as an alternative to 3D-CTA for patients with contrast contraindications.

Changes in periventricular anastomosis after indirect revascularization surgery alone for adult patients with misery perfusion due to ischemic moyamoya disease.

Periventricular anastomosis in moyamoya disease (MMD) is an unusual angiographic finding that arises from perforating arteries such as the lenticulostriate artery (LSA), thalamic artery (THA), and anterior choroidal artery (AChA). This anastomosis is associated with increased hemorrhagic risk in MMD and can be corrected by direct revascularization surgery. The present supplementary analysis on a prospective cohort aimed to elucidate changes in periventricular anastomosis after indirect revascularization surgery alone for adult patients with misery perfusion due to ischemic MMD. Twenty-two patients with misery perfusion in the symptomatic cerebral hemisphere who underwent indirect revascularization surgery alone also underwent six-vessel cerebral angiography via arterial catheterization before and at 6 months after surgery. Before surgery, two patients (9%) had positive periventricular anastomosis from the LSA and another (5%) from the AChA; all three of these periventricular anastomoses regressed after surgery, but these changes were not statistically significant (p = 0.0833). The degree of formation of collateral vessels from the LSA significantly decreased after surgery (p = 0.0143), but the degree of collateral vessels from the THA or AChA did not differ between pre- and postoperative conditions. Eight patients with postoperative regression of the collateral vessels from any perforating artery exhibited postoperative rich collateral flow from indirect revascularization. Periventricular anastomosis tended to regress after indirect revascularization surgery alone for adult patients with misery perfusion due to ischemic MMD. Collateral vessels formed from the LSA likely regressed after indirect revascularization surgery alone for such patients, but those vessels from the THA or AChA seldom changed.

Small Sphenoid Ridge as a Factor Associated with Laterally Deviated Proximal Sylvian Fissure in Patients Undergoing Pterional Craniotomy.

BACKGROUND: During the pterional-transsylvian approach, we sometimes encounter the proximal Sylvian fissure (SF) deviating laterally beyond the fold of the sphenoidal ridge (SR) and experience difficulty dissecting the SF due to the deep and oblique dissection plane. In the present study, we explored the association between the height of the SR and lateral deviation of the SF during the pterional-transsylvian approach. METHODS: The association between the height of the SR on axial computed tomography and the presence of a laterally deviated SF was evaluated by reviewing patients who had undergone pterional craniotomy. RESULTS: Among the 52 patients included, lateral deviation of the SF was observed in 8 patients (13.4%). The median height of the SR was significantly smaller in patients with laterally deviated SF (6.0 mm) than in patients with non-deviating SF (13.4 mm; P < 0.0001). The oculomotor nerves and middle fossa were observed at the edge of the dissection plane of the SF in all patients with a laterally deviating SF, while medial structures such as the internal carotid artery or optic nerve were observed in patients with non-deviating SF. CONCLUSIONS: Small SR was associated with lateral deviation of the proximal SF.

Development of cerebral microbleeds and its impact on cognitive function in adult patients receiving medical management alone for ischemic moyamoya disease: supplementary analysis of a 5-year prospective cohort.

OBJECTIVE: De novo cerebral microbleeds (CMBs) on T2*-weighted magnetic resonance imaging (MRI) develop over time in adult moyamoya disease (MMD) and are generally associated with a decline in global cognitive function. The present supplementary analysis of a 5-year prospective cohort aimed to elucidate the incidence of an interval increase in CMBs in adult patients receiving medical management alone for ischemic MMD and its impact on cognitive function. METHODS: Sixty-four patients without misery perfusion in the symptomatic cerebral hemispheres at inclusion who did not experience any further ischemic symptoms or new hemorrhagic events during a 5-year follow-up period underwent T2*-weighted MRI and five kinds of neuropsychologic tests at inclusion and the end of the 5-year follow-up. RESULTS: When T2*-weighted MRI was compared between inclusion and the end of the 5-year follow-up, 10 patients (15%) had an interval increase in CMBs in the symptomatic cerebral hemisphere at inclusion. The scores from two kinds of neuropsychologic tests significantly deteriorated at the end of the 5-year follow-up compared with those at inclusion in patients with an interval increase in CMBs, whereas the scores of four kinds of neuropsychologic tests significantly improved at the end of the 5-year follow-up compared with those at inclusion in patients without interval increases in CMBs, asymptomatic ischemic lesions, or angiographic disease progression. CONCLUSIONS: The incidence of an interval increase in CMBs was 15% per 5 years in adult patients receiving medical management alone for ischemic MMD, and this increase was associated with a decline in cognitive decline.

Long-term outcomes, including the survival rate and period to death, in patients over 80 years old after ruptured cerebral aneurysm clipping.

OBJECTIVE: This study aimed to identify the long-term outcomes, including the survival rate, period to death, causes of death, and predictors of poor outcomes, in patients aged over 80 years who underwent surgical clipping for a ruptured anterior circulation aneurysm. MATERIALS AND METHODS: In this retrospective observational study, the medical records of patients from April 1, 1994, to June 30, 2019, were evaluated. All patients underwent surgical clipping within 72 h of subarachnoid hemorrhage (SAH) onset. Information on the patient, SAH, and outcomes were collected. RESULTS: The mean hospitalization and long-term follow-up periods for all patients were 54.5 days and 53.3 months, respectively. The period to death was significantly shorter in patients with modified Rankin scale (mRS) of 4-5 than for those with an mRS of 0-3 at discharge (p=0.001). The Kaplan-Meier method using the log-rank test demonstrated that patients with an mRS of 4-5 at discharge had a significantly lower survival rate compared to those with an mRS of 0-3 at discharge (p<0.05). Univariate analysis revealed that the proportion of patients with Hunt and Hess grade and presence of surgical complications were significantly larger in the group with an mRS of 4-5 than in that with an mRS of 0-3 at discharge (p=0.0013 and 0.011, respectively). Multivariate analysis demonstrated that presence of surgical complications was the only independent predictor of poor outcomes (p=0.043, odds ratio [OR] 7.937, 95% confidence interval [CI] 1.061-59.38). The Kaplan-Meier method using the log-rank test demonstrated that patients with surgical complications had a significantly lower survival rate compared to those with no surgical complications (p<0.05). CONCLUSIONS: Especially in patients aged over 80 years, those with H-H grade 2 and a good clinical condition can be candidates for surgical clipping, whereas avoiding surgical complications is essential for achieving good outcomes.

Rupture of Vertebral Artery Dissecting Aneurysm after mRNA Anti-COVID-19 Vaccination: A Report of Two Cases.

The coronavirus disease 2019 (COVID-19) pandemic continues to spread around the world, and widespread vaccination is considered the most effective way to end it. Although the efficacy of COVID-19 vaccines has been confirmed, their safety remains a concern. In this paper, we report two cases of ruptured vertebral artery dissecting aneurysm (VADA) immediately after messenger RNA (mRNA) anti-COVID-19 vaccination. In Case 1, a 60-year-old woman experienced sudden headache 3 weeks before her first dose of the Moderna mRNA-1273 COVID-19 vaccine. Magnetic resonance imaging showed dilatation of the right vertebral artery (VA) without intracranial hemorrhage. A day after the vaccination, she developed subarachnoid hemorrhage with pulmonary effusion due to a ruptured right VADA. She underwent endovascular internal trapping and parent artery occlusion under general anesthesia. In Case 2, a 72-year-old woman with a previous history of the left VA occlusion due to arterial dissection developed subarachnoid hemorrhage 7 days after the first dose of the Pfizer-BioNTech BNT162b2 COVID-19 mRNA vaccine due to a ruptured right VADA and underwent stent-assisted coil embolization under general anesthesia. The postoperative courses of these two cases were uneventful. The accumulation of more cases and further study are warranted to clarify the relationship between COVID-19 mRNA vaccination and ruptured intracranial dissecting aneurysms.

Recovery of Cortical Neurotransmitter Receptor Function and Its Impact on Cognitive Improvement after Indirect Revascularization Surgery Alone for Adult Patients with Ischemic Moyamoya Disease: 123I-Iomazenil Single-Photon Emission Computed Tomography Study.

OBJECTIVE: Brain 123I-iomazenil single-photon emission computed tomography (SPECT) can assess the distribution of the binding potential of central benzodiazepine receptors in the cerebral cortex. This binding potential may reflect neuronal function in viable tissues. The present prospective study using brain 123I-iomazenil SPECT aimed to determine whether improvements in cognitive function after indirect revascularization surgery alone are associated with postoperative recovery in neurotransmitter receptor function in the affected cerebral hemisphere among adult patients with moyamoya disease accompanied by ischemic presentation due to misery perfusion. METHODS: Twenty-two patients who underwent indirect revascularization surgery alone also underwent brain SPECT scanning at 180 minutes after 123I-iomazenil administration and neuropsychological testing before and at 6 months after surgery. The affected-to-contralateral cerebral hemispheric asymmetry of tracer uptake before and after surgery was then calculated. RESULTS: The asymmetry of tracer uptake was significantly increased after surgery (P < 0.0001). A significant difference between the preoperative and postoperative asymmetry of tracer uptake was seen in patients with improved cognition compared with those with unchanged cognition (P = 0.0001). The area under the receiver operating characteristic curve was 0.99 for the difference between the preoperative and postoperative asymmetry of tracer uptake to assess the ability to discriminate patients with improved cognition from those with unchanged cognition. CONCLUSIONS: Improvements in cognitive function after indirect revascularization surgery alone are associated with postoperative recovery in the binding potential of central benzodiazepine receptors in the affected cerebral hemisphere in adult patients with moyamoya disease accompanied by ischemic presentation due to misery perfusion.

Outcomes of Medical Management Alone for Adult Patients with Cerebral Misery Perfusion Due to Ischemic Moyamoya Disease.

OBJECTIVES: Although revascularization surgery is recommended for adult patients with moyamoya disease (MMD) who present with ischemic symptoms due to hemodynamic compromise, the clinical course of such patients who are treated with medical management alone remains unclear. Here, we report outcomes of adult patients with cerebral misery perfusion due to ischemic MMD who received medical management alone. MATERIALS AND METHODS: We prospectively followed up patients who showed misery perfusion in the symptomatic cerebral hemisphere on 15O gas positron emission tomography (PET) and received strict medical management alone after refusing revascularization surgery. RESULTS: Of 57 patients who showed symptomatic misery perfusion on 15O gas PET, three (5%) were included into the present study. Two of these patients suffered further ischemic events at 7 and 8 months after inclusion, after which, their modified Rankin disability scale scores deteriorated. In the remaining patient, fatal intracerebral hemorrhage developed at 10 months after inclusion. CONCLUSIONS: These findings suggest that receiving medical management alone is associated with considerably poor outcomes for adult patients with cerebral misery perfusion due to ischemic MMD.