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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. [ABSTRACT FROM AUTHOR]

Head CT, which includes the facial region, can visualize faces using 3D reconstruction, raising concern that individuals may be identified. We developed a new de-identification technique that distorts the faces of head CT images. Head CT images that were distorted were labeled as "original images" and the others as "reference images." Reconstructed face models of both were created, with 400 control points on the facial surfaces. All voxel positions in the original image were moved and deformed according to the deformation vectors required to move to corresponding control points on the reference image. Three face detection and identification programs were used to determine face detection rates and match confidence scores. Intracranial volume equivalence tests were performed before and after deformation, and correlation coefficients between intracranial pixel value histograms were calculated. Output accuracy of the deep learning model for intracranial segmentation was determined using Dice Similarity Coefficient before and after deformation. The face detection rate was 100%, and match confidence scores were < 90. Equivalence testing of the intracranial volume revealed statistical equivalence before and after deformation. The median correlation coefficient between intracranial pixel value histograms before and after deformation was 0.9965, indicating high similarity. Dice Similarity Coefficient values of original and deformed images were statistically equivalent. We developed a technique to de-identify head CT images while maintaining the accuracy of deep-learning models. The technique involves deforming images to prevent face identification, with minimal changes to the original information. [ABSTRACT FROM AUTHOR]

Background: Vestibular schwannomas (VS) present at variable size with heterogeneous symptomatology. Modern treatment paradigms for large VS include gross total resection, subtotal resection (STR) in combination with observation, and/or radiation to achieve optimal function preservation, whereas treatment is felt to be both easier and safer for small VS. The objective is to better characterize the presentation and surgical outcomes of large and small VS. Methods: We collected data of patients who had surgically treated VS with a posterior fossa diameter of 4.0 cm or larger (large tumor group, LTG) and smaller than 1.0 cm in cisternal diameter (small tumor group, STG). Statistical significance was defined as p < 0.05. Results: LTG included 48 patients (average tumor size: 44.9 mm) and STG 38 (7.9 mm). Patients in STG presented more frequently with tinnitus and sudden hearing loss. Patients in LTG underwent more STR than STG (50.0% vs. 2.6%, p < 0.0001). LTG had more complications (31.3% vs. 13.2%, p = 0.049). Postoperative facial nerve function in STG was significantly better than LTG. STG had better hearing preoperatively (p < 0.0001) and postoperatively than LTG (p = 0.0002). Postoperative headache was more common in STG (13.2% vs. 2.1%, p = 0.045). The rate of recurrence/progression needing treatment was not statistically different between the groups (12.5% in LTG vs. 7.9% in STG, p = 0.49). Those patients who required periprocedural cerebrospinal fluid diversion had higher risk of infection (20.8% vs 4.8%, p = 0.022). Conclusion: Large and small VS present differently. LTG showed more unsatisfactory outcomes in facial nerve function and postoperative hearing despite maximal efforts undertaken toward function-preservation strategy; however, similar tumor control was achieved. [ABSTRACT FROM AUTHOR]

Distal anterior cerebral artery (DACA) aneurysms are rare, accounting for 1–9% of all intracranial aneurysms. Previous systematic reviews have highlighted that given the markedly increased incidence of major complications after endovascular treatment, microsurgical clipping is the more attractive treatment option with generally excellent clinical outcomes. Subcallosal DACA aneurysms constitute a rare subset of these aneurysms, requiring special anatomic considerations—particularly with regard to the approach. The aim of this study is to review the technical nuances of microsurgical treatment of subcallosal DACA aneurysms, including review of contemporary techniques through presentation of a microneurosurgical operative video. This is a retrospective case series and intraoperative microsurgical videos review. Three subcallosal DACA aneurysms were identified via retrospective query of our institutional neurosurgical database from December 2017 to May 2018. Two were female; median age was 74 years (range 70–83); all 3 underwent bifrontal craniotomy via bicoronal skin incision for aneurysm clipping. Aneurysms were located in left pericallosal–callosomarginal artery junction, bifurcation of azygos A2, and pericallosal artery related with azygos A2, and the anterior interhemispheric approach was used in all 3 operations. No acute stroke, hemorrhage, or major complications occurred, and all patients remained neurologically intact at the time of last follow-up (median 3 months, range 1–6). Although DACA aneurysms are rare, they represent an important variant for cerebrovascular neurosurgeons where microsurgical clipping can have better angiographic outcomes than endovascular treatment. Detail-oriented anterior interhemispheric arachnoid dissection through bifrontal craniotomy with its lower margin sitting at the superior orbital rim maximizes safe and effective clipping of subcallosal DACA aneurysms. [ABSTRACT FROM AUTHOR]

Purpose: Cavernous sinus syndrome is a rare phenomenon, characterized by simultaneous neuropathies of cranial nerves III-VI. Various pathological processes have been reported as precipitating etiologies, including infection, inflammation, vascular lesions, and neoplasms.Purpose: We report a unique case series of cavernous sinus syndrome attributable to prolonged Trendelenburg or prone positioning during non-cranial procedures and review the pertinent literature to enlighten on this rare but catastrophic phenomenon.Methods: Retrospective case series.Results: In the past year we encountered two patients who presented with acute cavernous sinus syndrome upon awakening from non-cranial operations. One patient underwent an extensive urologic resection of a bladder malignancy positioned in Trendelenburg for approximately 4 h. The second patient underwent a lumbar laminectomy and discectomy in prone position. Both patients were discovered to have infarcted large pituitary macroadenomas as the etiology of their acute ophthalmoplegias, and transnasal, transsphenoidal resection was performed acutely to decompress the cavernous sinus contents. Pathologic analysis of the resected specimens in each case confirmed necrotic, infarcted pituitary adenoma. Both patients made a complete recovery with no evidence of residual or recurrent tumor in short term follow-up.Conclusion: We report a brief case series of acute cavernous sinus syndrome resulting from dependent positioning during non-cranial operations in patients with pituitary macroadenoma. Although rare, this highlights a potential danger of “head down” positioning in patients with intracranial pathology—particularly in or around the sella and cavernous sinus. Despite multiple cranial neuropathies upon presentation, both patients made complete recovery following surgical decompression of the cavernous sinuses. [ABSTRACT FROM AUTHOR]

Background: The frontal bridging vein, which is the venous drainage route of the frontal cortex into the superior sagittal sinus (SSS), sometimes poses an obstacle in the anterior interhemispheric approach during surgery for anterior cerebral artery aneurysms. Although severe complications including venous infarction or edema due to damage to the bridging vein are well known, only a few reports have discussed how to avoid venous injury when we must sacrifice the bridging vein to obtain an appropriate surgical field. This report describes a microvascular technique performed in two patients who underwent rerouting of the bridging vein to obtain an appropriate anterior interhemispheric surgical corridor to treat a ruptured anterior cerebral artery aneurysm. The hindering bridging vein was resected from the entrance to the SSS and anastomosed toward the adjacent cortical vein. Methods: A 65-year-old male and a 43-year-old male were admitted to our hospital for sudden headache. Computed tomography, magnetic resonance angiogram, or digital subtraction angiography demonstrated a subarachnoid hemorrhage and an anterior cerebral artery aneurysm in both patients. In both cases, a relatively robust bridging vein, which appeared problematic to sacrifice, was draining into the SSS, resulting in a limited surgical corridor. Thus, we performed cortical vein reconstruction, and the aneurysms were successfully clipped under a wider surgical view. Results: We confirmed completed clipping without postoperative venous complications. One patient demonstrated patency of reconstructed venous flow by digital subtraction angiography. No apparent cognitive impairment was seen in either patient. Conclusions: This technique may be useful for obtaining an appropriate surgical corridor when the frontal bridging vein may be damaged. [ABSTRACT FROM AUTHOR]

Background: Acute extracranial internal carotid artery (ICA) occlusion by a huge cardiogenic embolus is rare, but can be catastrophic. Methods: Seven patients with acute ischemic stroke due to embolic occlusion of extracranial ICA who underwent emergent cervical surgical embolectomy were retrospectively reviewed. Diagnosis was made in six patients with magnetic resonance imaging (MRI) with optional digital subtraction angiography (DSA), while computed tomography (CT) and DSA were used in one patient with an implanted pacemaker. Clinical outcomes, including recanalization rate, recanalization time, complications, modified Rankin scale (mRS) at 3 months, and National Institute of Health Stroke Scale (NIHSS) score improvement at 1 month were evaluated. Results: Complete recanalization was obtained in seven patients (100 %). Median recanalization time from symptom onset and from start of surgery was 402 and 40 min, respectively. All seven patients showed severe left ventricular hypertrophy (LVH) according to an increased cardiothoracic ratio (CTR) ≥50 %. Complications included recurrence of cardioembolic stroke with the right middle cerebral artery occlusion, minimal expansion of infarction, and aggravation of heart failure, each in one patient, respectively. Four (57.1 %) patients had a history or postoperative recurrence of cardioembolic stroke. Median NIHSS at 1 month was 2 (range, 0-30). Median mRS at 3 months was 2 (range, 0-5). Five patients (71.4 %) had a favorable outcome (mRS2). Conclusions: Cervical surgical embolectomy for acute extracranial ICA occlusion resulted in a high complete recanalization rate with an acceptable safety profile. A possible association between severe cardiac illness and huge embolus occluding proximal large artery was suggested. [ABSTRACT FROM AUTHOR]

Background: Executive functions are complex cognitive control functions that include cognitive flexibility, inhibition (self-control, self-regulation), and working memory. Bilateral frontal lobe ischemia is associated with cognitive impairment, especially in the context of dysexecutive syndrome. This report describes two patients who underwent bilateral anterior cerebral artery (ACA) reconstruction by A3-A3 anastomosis in conjunction with superficial temporal artery (STA)-radial artery (RA) graft-A3 bypass to treat bilateral ACA steno-occlusive hemodynamic ischemia accompanying cognitive and executive dysfunction. Method: A 74-year-old woman and a 73-year-old woman were admitted to our hospital for unilateral cerebral infarction in the frontal lobe. Magnetic resonance angiogram (MRA) demonstrated severe bilateral ACA steno-occlusive pathology in both patients. Considering the presence of impaired cognitive function with dysexecutive syndrome as well as hemodynamic compromise shown by single photon emission computed tomography (SPECT), we proceeded with A3-A3 anastomosis in conjunction with STA-RA-A3 bypass. Various neuropsychiatric tests were performed before and after the surgery. Results: We confirmed good bypass patency without periprocedural complications. One patient recovered from apallic and bedridden status and regained ambulatory condition and ability to take in an oral diet. Another patient demonstrated improved scores in several cognitive tests with some persistent executive dysfunction. Conclusions: Bilateral ACA revascularization was technically feasible in two patients. This bypass surgery could have some positive effects in some basic cognitive function, such as memory, attention, and concentration by bilateral ACA hemodynamic improvement, although executive function, which is specific to prefrontal function, might not be reversible. [ABSTRACT FROM AUTHOR]

Background: The white-collar sign (WCS) is represented by the formation of neointimal tissue at the level of the aneurysm neck as the successful outcome on follow-up angiography after coil embolization. WCS has been reported only in aneurysms treated with Matrix® coils. This is the first study to report WCS emergence in aneurysms treated with bare platinum coils, and potential factors associated with WCS emergence were evaluated. Method: Total 130 unruptured (female: male ratio, 100: 30; mean age, 60 years) cerebral aneurysms were treated with coil embolization. Embolization status was assessed immediately and 1 year after treatment, and emergence of WCS in follow-up angiography was assessed. We evaluated the association between WCS emergence and aneurysm location, dome diameter, neck diameter, dome-neck ratio, and type of coil used (bare platinum or bioactive). Results: WCS appeared in nine aneurysms (6.9 %), of which six were treated only with bare platinum coils. Neck diameter was significantly smaller in the WCS-positive group than in the WCS-negative group. The proportion of aneurysms treated with bioactive coils was not significantly different between the groups. Immediate embolization status in the WCS-positive group tended to be slightly better than that in the WCS-negative group. No aneurysmal morphological characteristics other than small neck diameter were associated with WCS emergence. Conclusions: WCS is not specific to bioactive coil usage. Small neck diameter was significantly associated with WCS emergence in our series. Further investigations to clarify the predictors of WCS will contribute to progress of aneurysmal embolization. [ABSTRACT FROM AUTHOR]

Three-dimensional vessel model reconstruction from patient-specific magnetic resonance angiography (MRA) images often requires some manual maneuvers. This study aimed to establish the deep learning (DL)-based method for vessel model reconstruction. Time of flight MRA of 40 patients with internal carotid artery aneurysms was prepared, and three-dimensional vessel models were constructed using the threshold and region-growing method. Using those datasets, supervised deep learning using 2D U-net was performed to reconstruct 3D vessel models. The accuracy of the DL-based vessel segmentations was assessed using 20 MRA images outside the training dataset. The dice coefficient was used as the indicator of the model accuracy, and the blood flow simulation was performed using the DL-based vessel model. The created DL model could successfully reconstruct a three-dimensional model in all 60 cases. The dice coefficient in the test dataset was 0.859. Of note, the DL-generated model proved its efficacy even for large aneurysms (> 10 mm in their diameter). The reconstructed model was feasible in performing blood flow simulation to assist clinical decision-making. Our DL-based method could successfully reconstruct a three-dimensional vessel model with moderate accuracy. Future studies are warranted to exhibit that DL-based technology can promote medical image processing.Graphical Abstract: Three-dimensional vessel model reconstruction from patient-specific magnetic resonance angiography (MRA) images often requires some manual maneuvers. This study aimed to establish the deep learning (DL)-based method for vessel model reconstruction. Time of flight MRA of 40 patients with internal carotid artery aneurysms was prepared, and three-dimensional vessel models were constructed using the threshold and region-growing method. Using those datasets, supervised deep learning using 2D U-net was performed to reconstruct 3D vessel models. The accuracy of the DL-based vessel segmentations was assessed using 20 MRA images outside the training dataset. The dice coefficient was used as the indicator of the model accuracy, and the blood flow simulation was performed using the DL-based vessel model. The created DL model could successfully reconstruct a three-dimensional model in all 60 cases. The dice coefficient in the test dataset was 0.859. Of note, the DL-generated model proved its efficacy even for large aneurysms (> 10 mm in their diameter). The reconstructed model was feasible in performing blood flow simulation to assist clinical decision-making. Our DL-based method could successfully reconstruct a three-dimensional vessel model with moderate accuracy. Future studies are warranted to exhibit that DL-based technology can promote medical image processing. [ABSTRACT FROM AUTHOR]