A technique for reconstruction of a giant extracranial internal carotid artery aneurysm: A technical note.

Background: Surgery is effective for extracranial internal carotid artery (EICA) aneurysms. However, the risk of cranial nerve injury associated with surgical repair, such as graft-assisted resection and extracranial-intracranial bypass techniques, is relatively high. Here, we report two cases of surgical treatment for EICA aneurysms and describe the surgical techniques and strategies to avoid cranial nerve injury. Methods: Two patients presented to our facility with an increasing cervical pulsatile mass and no neurological symptoms. Angiography showed a large aneurysm in the cervical internal carotid artery. Surgical treatment was performed to prevent rupture of the aneurysm. In both patients, the aneurysm was strongly attached to the vagus nerve. The aneurysm and vagus nerve were carefully dissected using a low-power bipolar (20 Malis; 3 watts), leaving connective tissue on the vagus nerve side. Results: The aneurysm was detached from the vagus nerve without injury. Based on intraoperative findings, one patient underwent clipping, and the other underwent aneurysmectomy and primary closure for aneurysm obliteration and angioplasty. Both patients were discharged without any cranial nerve dysfunction. Conclusion: The selection of a strategy based on intraoperative findings and low-power bipolar cutting is important for the treatment of extracranial carotid artery aneurysms to preserve cranial nerves.

Reversed-Image Mechanical Thrombectomy for Acute Ischemic Stroke in a Situs Inversus Totalis Patient.

An 85-year-old female with situs inversus totalis presented with right hemiplegia, right facial nerve palsy, eye deviation to the left, and aphasia. Magnetic resonance imaging revealed acute ischemic lesions in the left insular cortex and the frontal lobe. Magnetic resonance angiography revealed an occlusion of the left internal carotid artery. Reversed-image mechanical thrombectomy achieved complete reperfusion in three passes within 54 minutes. Six months post-intervention, the patient could walk indoors independently. Our technique, which replicates the normal arterial anatomy by inversion and angulation, was adapted to situs inversus totalis.

Cerebral Infarction Due to Post-traumatic Cerebral Vasospasm in a 12-Year-Old Female.

Cerebral infarction due to post-traumatic cerebral vasospasm is rare. Although some modalities are recommended to detect post-traumatic cerebral vasospasm, its diagnosis remains controversial and challenging. Therefore, in this report, we will use a case report to highlight challenges and to delineate the characteristics of post-traumatic cerebral vasospasm in pediatric patients, including the diagnostic and treatment options. A 12-year-old female was admitted to our hospital following a motor vehicle collision. Her consciousness was severely impaired. Initial computed tomography (CT) revealed an acute subdural hematoma along the tentorium, and a focal subarachnoid hemorrhage was observed in the Sylvian fissure. The patient underwent the insertion of an intracranial pressure sensor and received therapy for increased intracranial pressure (ICP) control under sedation. On the second day, CT angiography (CTA) revealed no signs of arterial abnormality. A patient who is comatose or under sedation has masked neurological symptoms. Thus, new neurological events could only be detected via an intracranial pressure sensor. Her ICP increased on the seventh day, and a CT scan showed a new cerebral infarction in the right middle cerebral artery (MCA) region. We performed decompressive craniectomy to reduce ICP. Postoperative CTA confirmed severe vasospasm in the right MCA. The severe cerebral vasospasm induced the cerebral infarction. Our review suggests that physicians in trauma departments should frequently perform vascular evaluations by CTA, magnetic resonance angiography (MRA), transcranial Doppler ultrasound, or digital subtraction angiography (DSA), especially within two weeks from onset, to detect post-traumatic cerebral vasospasm.

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

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

Frontal Sinus Mucosa Bacteriological Features: Evaluation after Unintentional Opening in Neurosurgery.

Objectives The bacteriological features of the frontal sinus mucosa may impose significant complications in neurosurgery, when breached unintentionally. This study aimed to investigate the bacterial flora in patients undergoing frontal craniotomy for cerebrovascular substrate surgery. Design This is a single-center prospective study. Setting When mucosal laceration occurred, the patients underwent frontal sinus reconstruction with mucosa reconstruction, preserving the nasofrontal duct. Participants We enrolled eight consecutive patients who underwent bifrontal craniotomy associated with frontal sinus mucosa laceration. Main Outcome Measures A portion of the mucosa was extracted during the reconstructive procedure and was sent for microbiological analysis. Results None of the patients presented with the bacterial flora in the mucosal cultures. No patient experienced postoperative cerebrospinal fluid leakage or meningitis. One patient with a clinical history of chronic maxillary sinusitis presented with a subcutaneous abscess around the forehead at 9 months postoperatively. The patient rapidly recovered after receiving oral administration of antibiotics. Conclusions Our findings demonstrated that the frontal sinuses were maintained in an aseptic environment in all cases. The results may encourage the development and wider use of transfrontal sinus approaches.

Amyloid ß interferes with wound healing of brain microvascular endothelial cells by disorganizing the actin cytoskeleton.

Cerebral amyloid angiopathy (CAA) is a disease in which amyloid ß (Aß) is deposited in the cerebral blood vessels, reducing compliance, tearing and weakening of vessel walls, leading to cerebral hemorrhage. The mechanisms by which Aß leads to focal wall fragmentation and intimal damage are not well understood. We analyzed the motility of human brain microvascular endothelial cells (hBMECs) in real-time using a wound-healing assay. We observed the suppression of cell migration by visualizing Aß aggregation using quantum dot (QD) nanoprobes. In addition, using QD nanoprobes and a SiR-actin probe, we simultaneously observed Aß aggregation and F-actin organization in real-time for the first time. Aß began to aggregate at the edge of endothelial cells, reducing cell motility. In addition, Aß aggregation disorganized the actin cytoskeleton and induced abnormal actin aggregation. Aß aggregated actively in the anterior group, where cell motility was active. Our findings may be a first step toward explaining the mechanism by which Aß causes vascular wall fragility, bleeding, and rebleeding in CAA.

Another cause of treatable dementia: rapid cognitive improvement after carotid endarterectomy. Illustrative case.

BACKGROUND: Revascularization techniques in cervical internal carotid artery (ICA) stenosis are indicated to prevent the onset or recurrence of ischemic events in the setting of atherosclerotic carotid artery disease. Recent reports, case series, and comparative studies have suggested that revascularization techniques may also improve cognitive outcome in both symptomatic and asymptomatic patients, thus raising the question of whether another surgically treatable dementia has presented itself. OBSERVATIONS: A 70-year-old right-handed female with a history of hypertension, diabetes, and bilateral silent cerebral infarcts was evaluated for progressive cognitive impairment over a 1-year period, which was associated with a severe left cervical ICA stenosis. Carotid endarterectomy (CEA) was indicated as a revascularization technique, and the patient showed significant neurocognitive improvement as early as one month postoperatively, consistent with blood flow restoration to the left hemisphere on control imaging. LESSONS: This case serves as a reminder that CEA may improve the cognitive outcome of patients previously impaired by uncomplicated severe cervical ICA atherosclerotic disease, which can be another cause of treatable dementia. Further prospective studies may help to assess this potential benefit.

C5a-C5AR1 axis as a potential trigger of the rupture of intracranial aneurysms.

Recent studies have indicated the involvement of neutrophil-mediated inflammatory responses in the process leading to intracranial aneurysm (IA) rupture. Receptors mediating neutrophil recruitment could thus be therapeutic targets of unruptured IAs. In this study, complement C5a receptor 1 (C5AR1) was picked up as a candidate that may cause neutrophil-dependent inflammation in IA lesions from comprehensive gene expression profile data acquired from rat and human samples. The induction of C5AR1 in IA lesions was confirmed by immunohistochemistry; the up-regulations of C5AR1/C5ar1 stemmed from infiltrated neutrophils, which physiologically express C5AR1/C5ar1, and adventitial fibroblasts that induce C5AR1/C5ar1 in human/rat IA lesions. In in vitro experiments using NIH/3T3, a mouse fibroblast-like cell line, induction of C5ar1 was demonstrated by starvation or pharmacological inhibition of mTOR signaling by Torin1. Immunohistochemistry and an experiment in a cell-free system using recombinant C5 protein and recombinant Plasmin indicated that the ligand of C5AR1, C5a, could be produced through the enzymatic digestion by Plasmin in IA lesions. In conclusion, we have identified a potential contribution of the C5a-C5AR1 axis to neutrophil infiltration as well as inflammatory responses in inflammatory cells and fibroblasts of IA lesions. This cascade may become a therapeutic target to prevent the rupture of IAs.

Initial real-world experience of clazosentan for subarachnoid hemorrhage in Japan.

BACKGROUND: Cerebral vasospasm (CVS) is one of the most critical factors associated with clinical outcomes of patients with subarachnoid hemorrhage (SAH). Clazosentan has been investigated worldwide as a prophylactic agent to prevent CVS. We evaluated a new CVS management protocol which included clazosentan. METHODS: Consecutive 138 patients with SAH, hospitalized in our institution between January 2017 and December 2022, were included in this study. Baseline characteristics, clinical findings, and operative records were analyzed retrospectively. From May 2022, 10 mg/h clazosentan was co-administered with fasudil to all patients according to the indication in the Japanese label. Patients admitted before this date received the conventional combined protocol using the fasudil hydrochloride, nicardipine, and ozagrel. RESULTS: Eighteen (13.0%) patients received the new protocol during the CVS period (defined as day 1 up to day 14 after SAH onset). There were 54 (39.1%) elderly patients aged 75 years or older. Seventy-two (52.2%) patients underwent neurosurgical clipping, whereas 55 (39.9%) patients received endovascular coiling. Among the patients with new protocol, only one patient (5.6%) had symptomatic CVS, compared with 18 patients (15.0%) in those with conventional protocol. More patients who received the new protocol had fluid retention compared with control group (38.9% [7/18] vs. 8.3% [10/120]). Other results did not differ between the two groups. CONCLUSIONS: Clinical outcomes of the new protocol were comparable to those of conventional protocol. Clazosentan may simplify anti-vasospasm treatment. Fluid retention was a specific side-effect of clazosentan, which requires attention especially in the first half of the CVS period.

Superiority of Endovascular Coiling Over Surgical Clipping for Clinical Outcomes at Discharge in Patients With Poor-Grade Subarachnoid Hemorrhage: A Registry Study in Japan.

BACKGROUND AND OBJECTIVES: The differences in clinical outcomes between endovascular coiling (EC) and surgical clipping (SC) in patients with poor-grade aneurysmal subarachnoid hemorrhage (aSAH) are controversial. Therefore, this study aimed to evaluate whether EC is superior to SC and identify risk factors in patients with poor-grade aSAH. METHODS: We used data from the "Predict for Outcome Study of aneurysmal SubArachnoid Hemorrhage." World Federation of Neurological Societies (WFNS) grade III-V aSAH was defined as poor-grade aSAH, and unfavorable clinical outcomes (modified Rankin Scale scores 3-6) were compared between SC and EC after propensity score matching (PSM). In-hospital mortality was similarly evaluated. Predictors of unfavorable clinical outcomes were identified using multivariable analysis. RESULTS: Ultimately, 1326 (SC: 847, EC: 479) and 632 (SC: 316, EC: 316) patients with poor-grade aSAH were included before and after PSM, respectively. Unfavorable clinical outcomes at discharge were significantly different between SC and EC before (72.0% vs 66.2%, P = .026) and after PSM (70.6% vs 63.3%, P = .025). In-hospital mortality was significantly different between groups before PSM (10.5% vs 16.1%, P = .003) but not after PSM (10.4% vs 12.7%, P = .384). Predictors of unfavorable clinical outcomes in both SC and EC were WFNS grade V, older than 70 years, and Fisher computed tomography (CT) grade 4. Predictors of unfavorable clinical outcomes only in SC were WFNS grade IV (odds ratio: 2.46, 95% CI: 1.22-4.97, P = .012) and Fisher CT grade 3 (4.90, 1.42-16.9, P = .012). Predictors of unfavorable clinical outcome only in EC were ages of 50s (3.35, 1.37-8.20, P = .008) and 60s (3.28, 1.43-7.52, P = .005). CONCLUSION: EC resulted in significantly more favorable clinical outcomes than SC in patients with poor-grade aSAH, without clear differences in in-hospital mortality. The benefit of EC over SC might be particularly remarkable in patients with WFNS grade IV and Fisher CT grade 3.

Effects of Thermal Boundary Resistance on Thermal Management of Gallium-Nitride-Based Semiconductor Devices: A Review.

Wide-bandgap gallium nitride (GaN)-based semiconductors offer significant advantages over traditional Si-based semiconductors in terms of high-power and high-frequency operations. As it has superior properties, such as high operating temperatures, high-frequency operation, high breakdown electric field, and enhanced radiation resistance, GaN is applied in various fields, such as power electronic devices, renewable energy systems, light-emitting diodes, and radio frequency (RF) electronic devices. For example, GaN-based high-electron-mobility transistors (HEMTs) are used widely in various applications, such as 5G cellular networks, satellite communication, and radar systems. When a current flows through the transistor channels during operation, the self-heating effect (SHE) deriving from joule heat generation causes a significant increase in the temperature. Increases in the channel temperature reduce the carrier mobility and cause a shift in the threshold voltage, resulting in significant performance degradation. Moreover, temperature increases cause substantial lifetime reductions. Accordingly, GaN-based HEMTs are operated at a low power, although they have demonstrated high RF output power potential. The SHE is expected to be even more important in future advanced technology designs, such as gate-all-around field-effect transistor (GAAFET) and three-dimensional (3D) IC architectures. Materials with high thermal conductivities, such as silicon carbide (SiC) and diamond, are good candidates as substrates for heat dissipation in GaN-based semiconductors. However, the thermal boundary resistance (TBR) of the GaN/substrate interface is a bottleneck for heat dissipation. This bottleneck should be reduced optimally to enable full employment of the high thermal conductivity of the substrates. Here, we comprehensively review the experimental and simulation studies that report TBRs in GaN-on-SiC and GaN-on-diamond devices. The effects of the growth methods, growth conditions, integration methods, and interlayer structures on the TBR are summarized. This study provides guidelines for decreasing the TBR for thermal management in the design and implementation of GaN-based semiconductor devices.

Asymptomatic subarachnoid hemorrhage following carotid endarterectomy: illustrative case.

BACKGROUND: Carotid endarterectomy (CEA) and carotid artery stenting are common surgical interventions for internal carotid artery stenosis. Cerebral hyperperfusion syndrome (CHS) is a well-known complication of both procedures that can lead to intracranial hemorrhage and worsen clinical outcomes. Here, the authors report a rare case of non-aneurysmal subarachnoid hemorrhage (SAH) following CEA and review the relevant literature. OBSERVATIONS: A 70-year-old woman with hypertension and diabetes presented with progressive visual loss in the right eye and was diagnosed with ocular ischemic syndrome. Imaging revealed severe right cervical carotid artery stenosis. CEA was performed with no complications. Postoperatively, the patient's blood pressure was tightly controlled, with no evidence of CHS. However, an asymptomatic SAH was detected on postoperative day 7. Careful observation and blood pressure control were maintained. Since follow-up magnetic resonance imaging (MRI) showed no enlarging of the SAH and the patient was asymptomatic, she was discharged on postoperative day 15 with a modified Rankin scale score of 0. LESSONS: This case highlights the potential occurrence of non-aneurysmal SAH as a rare complication of CEA, even in asymptomatic patients. Repeated postoperative MRI is necessary to detect such complications. It is crucial to carefully control blood pressure after CEA regardless of symptoms.

Facet joint thickness and lumbar instability documented on myelo-computed tomography studies in patients with lumbar degenerative disease.

Background: Various indicators of vertebral instability in patients with lumbar degenerative disease can be identified in myelo-computed tomography (CT) studies. Methods: Of 120 patients, 45 with lumbar degenerative spondylolisthesis (LDS; 53 lumbar lesions) and 75 with lumbar spinal stenosis alone (LSS; 105 lesions) (2015-2019) myelo-CT studies and surgery confirmed the presence of lumbar instability. Myelo-CT findings indicative of instability included facet joint thickness (FJT), fluid in the facet joint, facet tropism, and air in the facet and/or disc. Results: For the 120 study patients, FJT was significantly elevated in both the LDS and LSS groups. Conclusion: FJT on myelo-CT is more specific for lumbar instability than other imaging parameters when evaluating LDS. An increase in FJT suggests vertebral instability likely warranting fusion.

Simplified Transradial Access for Aneurysms Treatment: A Guiding System Using Solo Distal Access Catheter and Anatomical Considerations.

OBJECTIVE: The recent shift from transfemoral access to transradial access in neurointervention has led to gaps in guiding systems. We propose a useful guiding system, the solo distal access catheter system without a conventional guiding catheter or a sheath in transradial access for aneurysms treatment. We also assessed the anatomical features required for suitable patient selection. METHODS: We retrospectively collected data from consecutive patients with aneurysms treated with the solo distal access catheter system at our institution between April 2022 and April 2023, and evaluated the anatomical factors that appeared to affect the procedure. RESULTS: Of the 20 patients who underwent transradial access, 11 were treated using the solo distal access catheter system, and 10 (90.9%) completed the procedure. No radial artery occlusion was detected. The entry angle of the target vessel ranged from 37° to 139°, and the mean proximal parent artery diameter was 9.34 ± 1.48 mm. A double subclavian innominate curve was observed in 3 of 5 patients whose target vessels were the right common carotid artery. CONCLUSIONS: Using a solo distal access catheter as a guiding system for treating aneurysm proved effective and feasible with appropriate patient selection. Anatomical assessment of the entry angle of the target vessel, proximal parent artery diameter, and tortuosity may be important factors for the success of this method.

Ischemic stroke in a young adult with a known epileptogenic arteriovenous malformation: illustrative case.

BACKGROUND: Brain arteriovenous malformations (AVMs) usually manifest as hemorrhages or seizures. They rarely present with ischemic symptoms, especially in young patients. We present a case of an epileptogenic AVM that led to cerebral infarction due to paradoxical embolic occlusion of the middle cerebral artery (MCA) involving the main feeder of the lesion. OBSERVATIONS: A 35-year-old male had been suffering from AVM-associated epilepsy for 10 years and was scheduled for surgery. He suddenly developed right-sided hemiconvulsions followed by hemiparalysis and impaired consciousness. Computed tomography revealed no intracerebral hemorrhage, and symptoms were initially thought to indicate epilepsy and Todd's palsy. Because of his prolonged symptoms, he underwent magnetic resonance imaging, which revealed a large cerebral infarction due to occlusion of the MCA involving the main feeder of the AVM. The patient underwent AVM resection, and the partially thrombosed nidus was completely removed. Histopathological investigation revealed a fresh thrombus in totally occluded nonarteriosclerotic feeders. He had no atrial fibrillation; however, subsequent transesophageal echocardiography revealed a patent foramen ovale, suggesting a paradoxical embolism. LESSONS: This case serves as a reminder that AVMs can present with considerable variability. Acute cerebral infarction should be considered a possible mechanism of seizures, even in patients with epileptogenic AVM.

Efficacy, safety, and predictors for functional outcomes of mechanical thrombectomy in patients aged over 90 years with acute ischemic stroke and literature review.

BACKGROUND: No evidence supports the efficacy and safety of mechanical thrombectomy (MT) in patients aged ≥ 90 years with acute ischemic stroke (AIS). This study clarifies the efficacy, safety, and predictors of MTs in patients aged ≥ 90 years by investigating our results and reviewing previous studies. METHODS: We retrospectively investigated data from 80 consecutive patients who underwent MT at our hospital between 2018 and 2021. We analyzed outcomes using the modified Thrombolysis in the Cerebral Infarction (mTICI) scale and modified Rankin Scale (mRS). Functional outcomes were investigated at 90 days or discharge. RESULTS: We obtained functional outcomes mRS ≤ 3 patients in 41.6%. The mortality rate was 16.6%. The rate of successful recanalization was 75%. Comparison mRS ≤ 3 and mRS ≥ 4 at 90 days or discharge showed statistical significance in the National Institute of Health Stroke Scale, the location of occluded vessels, and mTICI ≥ 2b at the first pass. Univariable logistic regression analysis indicated that the Alberta Stroke Program Early Computed Tomography Score was a predictor of mRS ≤ 3. CONCLUSIONS: The efficacy is lower than that of patients aged < 90; however, MT is effective even in patients aged ≥ 90 years. The safety of MT in patients aged ≥ 90 years was similar to that in those aged < 90 years. Neuro-interventionalists should consider predictors and take the best strategies to achieve successful recanalization in patients aged ≥ 90 years with AIS.

Giant saccular aneurysm of the cervical internal carotid artery treated with aneurysmectomy and side-to-end anastomosis.

Background: Cervical aneurysms are rare, accounting for <1% of all arterial aneurysms, including dissecting, traumatic, mycotic, atherosclerotic, and dysplastic aneurysms. Symptoms are usually caused by cerebrovascular insufficiency; local compression or rupture is rare. We present the case of a 77-year-old man with a giant saccular aneurysm of the cervical internal carotid artery (ICA), which was treated with aneurysmectomy and side-to-end anastomosis of the ICA. Case Description: The patient had experienced cervical pulsation and shoulder stiffness for 3 months. The patient had no significant medical history. An otolaryngologist performed the vascular imaging and referred the patient to our hospital for definitive management. Neurological deficits were not observed. Digital subtraction angiography showed a giant cervical aneurysm with a diameter of 25 mm within the ICA, and there was no evidence of thrombosis within the aneurysm. Aneurysmectomy and side-to-end anastomosis of the cervical ICA were performed under general anesthesia. After the procedure, the patient experienced partial hypoglossal nerve palsy but fully recovered with speech therapy. Postoperative computed tomography angiography revealed the complete aneurysm removal and patency of the ICA. The patient was discharged on postoperative day 7. Conclusion: Despite several limitations, surgical aneurysmectomy and reconstruction are recommended to eliminate the mass effect and to avoid postoperative ischemic complications, even in the endovascular era.

Association between population changes and the number of endovascular thrombectomies.

Background: Randomized controlled trials have demonstrated the efficacy of mechanical thrombectomy (MT) for acute ischemic stroke. However, few studies indicate an association between the number of mechanical thrombectomies and population changes. We aimed to clarify the association between population changes and the number of mechanical thrombectomies for proper allocation of limited medical resources. Methods: We retrospectively analyzed data from 162 patients who underwent MT for large vessel occlusion at our hospitals and compared the number of mechanical thrombectomies per 100,000 person/year to population changes in five regions covered by our hospitals within 2015-2016 and 2017-2019. We performed a simple linear regression analysis to determine the association between population changes and the number of mechanical thrombectomies. Results: Overall, the number of mechanical thrombectomies increased from 15.1 to 19. However, a significant decrease was noted in Toya Lake and Sobetsu/Toyoura. Furthermore, there was a significant negative linear correlation between the overall population reduction rate and the number of mechanical thrombectomies and a positive linear correlation between the increased proportion of the population aged >65 years and the number of mechanical thrombectomies. Conclusion: The number of mechanical thrombectomies may decrease in areas where the overall population reduction rate exceeds 8% or the increased rate of the population aged >65 years is <4%. However, it is necessary to continue establishing a system for MT in areas that have yet to reach these levels.

Disappearance of hemichorea as the initial presentation of moyamoya disease after revascularization surgery regardless of residual hypoperfusion evaluated by quantitative N-isopropyl-p-123I-iodoamphetamine SPECT.

BACKGROUND AND IMPORTANCE: Although hypoperfusion of the basal ganglia or the frontal subcortical matter is suspected, the pathology of chorea in moyamoya disease remains unclarified. Herein, we report a case of moyamoya disease presenting with hemichorea and evaluate pre- and postoperative perfusion using single photon emission computed tomography with N-isopropyl-p-123I-iodoamphetamine (123I-IMP SPECT). CLINICAL PRESENTATION: An 18-year-old woman presented with choreic movement of her left limbs. Magnetic resonance imaging revealed an ivy sign, and 123I-IMP SPECT demonstrated decreased cerebral blood flow (CBF) and cerebral vascular reserve (CVR) values in the right hemisphere. The patient underwent direct and indirect revascularization surgery to improve cerebral hemodynamic impairment. The choreic movements entirely resolved immediately after surgery. Although CBF and CVR values in the ipsilateral hemisphere demonstrated by quantitative SPECT increased, these did not reach the normal values threshold. CONCLUSION: Choreic movement in moyamoya disease may be related to cerebral hemodynamic impairment. Further studies are required to elucidate its pathophysiological mechanisms.

Association of antithrombotic therapy with postoperative rebleeding in patients with cerebral amyloid angiopathy.

BACKGROUND: Cerebral amyloid angiopathy is a common cause of subcortical hemorrhage in older adults. Although open hematoma removal may be performed for severe subcortical hemorrhage, its safety in patients with cerebral amyloid angiopathy has not been established, and postoperative rebleeding may occur. Therefore, this study aimed to investigate factors associated with postoperative rebleeding. METHODS: Out of 145 consecutive patients who had undergone craniotomy for surgical removal of subcortical intracerebral hemorrhage between April 2010 and August 2019 at a single institution in Japan, we examined 109 patients with subcortical hemorrhage who met the inclusion criteria. After excluding 30 patients whose tissue samples were unsuitable for the study, the final study cohort comprised 79 patients. RESULTS: Of the 79 patients, 50 (63%) were diagnosed with cerebral amyloid angiopathy (cerebral amyloid angiopathy group) and 29 (37%) were not diagnosed with noncerebral amyloid angiopathy (noncerebral amyloid angiopathy group). Postoperative rebleeding occurred in 12 patients (24%) in the cerebral amyloid angiopathy group and in 2 patients (7%) in the noncerebral amyloid angiopathy group. Preoperative prothrombin time-international normalized ratio and intraoperative bleeding volume were significantly associated with postoperative rebleeding in the cerebral amyloid angiopathy group (odds ratio = 42.4, 95% confidence interval = 1.14-1578; p = 0.042 and odds ratio = 1.005, 95% confidence interval = 1.001-1.008; p = 0.007, respectively). CONCLUSIONS: Patients with cerebral amyloid angiopathy-related cerebral hemorrhage who are receiving antithrombotic therapy, particularly warfarin therapy, are at a high risk of postoperative rebleeding. TRIAL REGISTRATION: Registry and Registration Number of the study: 19-220, 2019/12/23, retrospectively registered.