Clinical features and treatment strategies for vertex epidural hematoma: a systematic review and meta-analysis from individual participant data.

Vertex epidural hematoma (VEDH) is a rare extradural hematoma and often misdiagnosed because of its variety of clinical symptoms and characteristic location. Determining optimal timing and technique for VEDH surgery is difficult because of its midline location and atypical clinical course. This study aims to understand the clinical manifestations and current treatment strategies for VEDH. We searched the published literature regarding VEDH through PubMed and Google Scholar, and individual patient data (IPD) were obtained from the eligible articles. A systematic review and IPD meta-analysis were conducted. In total, 70 patients' individual participant data were gathered. Most patients were male (87%), and traffic-related accidents were the most common injury mechanism (49%). Approximately half the patients (47%) were neurologically intact with nonspecific symptoms such as headache, dizziness, and vomiting at admission. Motor weakness alone (17%) and symptoms related to cranial nerve dysfunction such as anosmia, blurred vision, or diplopia (10%) were also noted. A surgical approach was initially chosen for 20 patients (28%), but eventually chosen for 20 more (total 40, 57%) during the observation period (average delay to surgery, 5 days). Patients who received surgery showed significantly poorer neurological status and larger hematoma size. Totally, two patients (3%) died, but most patients (94%) had a favorable outcome scoring 5 on the Glasgow Outcome Scale. Although VEDH generally showed favorable outcomes, clinicians must be aware of a high rate of delayed neurological deterioration during the observation period, which can be fatal due to central downward herniation.

Efficacy and Safety of Timely Urgent Superficial Temporal Artery-to-Middle Cerebral Artery Bypass Surgery in Patients with Acute Ischemic Stroke: A Single-Institutional Prospective Study and a Pooled Analysis.

BACKGROUND: Clinical outcome in patients with acute ischemic stroke (AIS) caused by large vessel occlusion (LVO) is not satisfactory if reperfusion treatment fails or is not tried. AIMS: We aimed to assess the efficacy and safety of urgent superficial temporal-to-middle cerebral artery (STA-MCA) bypass surgery in selected patients. METHODS: Patients who were diagnosed with LVO-induced AIS in the anterior circulation but had a failed intra-arterial thrombectomy (IAT) or were not tried due to IAT contraindications were prospectively enrolled. Timely urgent STA-MCA bypass surgery was performed if they showed perfusion-diffusion mismatch or symptom-diffusion mismatch in the acute phase of disease. Clinical and radiological data of these patients were assessed to demonstrate the safety and efficacy of urgent bypass procedures. A pooled analysis of published data on urgent bypass surgery in acute stroke patients was conducted and analyzed. RESULTS: In 18 patients who underwent timely bypass, the National Institutes of Health Stroke Scale (NIHSS) score improved from 12.11 ± 4.84 to 9.89 ± 6.52, 1 week after surgery. Three-month and long-term (9.72 ± 5.00 months) favorable outcomes (modified Rankin Scale [mRS] scores 0-2) were achieved in 50 and 75% of the patients, respectively. The pooled analysis (117 patients from 10 articles, including ours) identified favorable mRS scores in 71.79% patients at 3 months. A significant NIHSS score improvement from 11.51 ± 4.89 to 7.59 ± 5.50 was observed after surgery with significance. Major complications occurred in 3 patients (2.6%, 3/117) without mortality. CONCLUSIONS: Urgent STA-MCA bypass surgery can be regarded as a safe optional treatment to prevent cerebral infarct expansion and to improve clinical and radiological outcomes in highly selected patients.

Clinical features and treatment strategy of paraspinal arteriovenous shunt (PAVS): a systematic review with individual participants data meta-analysis.

BACKGROUND: Because of the rarity of the disease, paraspinal arteriovenous shunt (PAVS) is not well recognized, and therapeutic options remain controversial. To introduce a rare disease of PAVS and demonstrate its etiology, clinical features, treatment options, and outcomes, we presented a case report and conducted a systematic review and individual participants data (IPD) meta-analysis. METHODS: Studies regarding on PAVS were integrated and IPD were obtained including patients' demographics, disease etiology, clinical and radiologic features, clinical courses and outcomes. Clinical manifestation and treatment outcomes were reviewed, and comparison analysis (cervical versus thoracolumbar) were performed. Further, logistic regression analyses were conducted to identify the poor prognostic factors (incomplete obliteration). RESULTS: Fifty-two articles were selected, and 88 patients enrolled. General and location-specific characteristics of PAVSs were identified: '3/4 of the isolated and 1/4 of the associated etiology', 'bruit, thrill, or murmur (cervical) and weakness (thoracolumbar) as common symptoms', '40% multiple feeders', and '22% intradural venous involvement'. Endovascular treatment was usually preferred (75%). Of 88 enrolled patients, 18 patients showed incomplete obliteration (20.5%). In multivariate analysis, 'etiologies of systematic genetic dysplasia (P = 0.031) and trauma (negatively, 0.038)' were significantly associated with incomplete obliteration. The parameters of 'multiple feeders (0.066)' and 'combined approach (negatively, 0.065)' are verified only in univariate analysis. CONCLUSION: General as well as location-specific characteristics of PAVS is successfully demonstrated. Approximately 20% of the incomplete obliteration is noted, and three potential poor prognostic factors are identified, namely, 'etiology of systematic genetic dysplasia (positive) and trauma (negative)', 'combined approach (negative), and 'multiple feeders'.

Color Doppler ultrasonography for predicting the patency of anastomosis after superficial temporal to middle cerebral artery bypass surgery.

BACKGROUND: Color Doppler ultrasonography (CDUS) is used to evaluate the surgical success and postoperative hemodynamic changes of patients who receive superficial temporal to middle cerebral artery (STA-MCA) bypass surgery. Previous studies enrolled small populations, and difficulties interpreting the results have limited their use in clinical settings. OBJECTIVE: We attempted to determine the feasibility of using CDUS to evaluate STA hemodynamics and identify the most reliable parameter as a new clinical implication for determining bypass patency. METHOD: Twenty-six patients who underwent STA-MCA bypass surgery were prospectively enrolled. Four times CDUS and two times digital subtraction angiography (DSA) were performed. The CDUS parameters were compensated using the ratio of the operated to the non-operated sides (R1) and compared before and after surgery (R2). The CDUS parameters are then compared with the patency on DSA by statistical analyses. RESULTS: Increased CDUS parameters of the mean flow rate (MFR) and cross-sectional diameter (CSD) showed significant correlations with good patency on DSA. The R2 at 1 month was identified as the most reliable parameter for predicting the patency in both MFR and CSD. Their cutoff values were 1.475 and 1.15, respectively. CONCLUSION: CDUS can be utilized for predicting the patency after STA-MCA bypass surgery; if the postoperative (compensated and compared) CDUS parameters increased by more than 47.5% in the MFR or 15% in the CSD, the patency of the anastomosis on DSA would be good.

Gender differences in adult traumatic brain injury according to the Glasgow coma scale: A multicenter descriptive study.

PURPOSE: Patients' gender, which can be one of the most important determinants of traumatic brain injury (TBI) outcomes, is also likely to interact with many other outcome variables of TBI. This multicenter descriptive study investigated gender differences in epidemiological, clinical, treatment, mortality, and variable characteristics in adult TBI patients. METHODS: The selection criteria were defined as patients who had been diagnosed with TBI and were admitted to the hospital between January 1, 2016 and December 31, 2018. A total of 4468 adult TBI patients were enrolled at eight University Hospitals. Based on the list of enrolled patients, the medical records of the patients were reviewed and they were registered online at each hospital. The registered patients were classified into three groups according to the Glasgow coma scale (GCS) score: mild (13-15), moderate (9-12), and severe (3-8), and the differences between men and women in each group were investigated. The risk factors of moderated and severe TBI compared to mild TBI were also investigated. RESULTS: The study included 3075 men and 1393 women and the proportion of total males was 68.8%. Among all the TBI patients, there were significant differences between men and women in age, past history, and GCS score. While the mild and severe TBI groups showed significant differences in age, past history, and clinical symptoms, the moderate TBI group showed significant differences in age, past history, cause of justice, and diagnosis. CONCLUSION: To the best of our knowledge, this multicenter study is the first to focus on gender differences of adult patients with TBI in Korea. This study shows significant differences between men and women in many aspects of adult TBI. Therefore, gender differences should be strongly considered in TBI studies.

Clinical Features of Patients With Spontaneous Intracranial Hypotension Complicated With Bilateral Subdural Fluid Collections.

BACKGROUND: Subdural hygromas are often found bilaterally in spontaneous intracranial hypotension (SIH). They frequently progress to chronic subdural hematomas (CSDHs), and if the hematomas are formed, it is difficult to consider SIH as an underlying cause. Whether SIH is underlying or not among the patients presenting bilateral subdural fluid collections (hygromas or CSDHs) is clinically important because the treatment strategy should be different between them. OBJECTIVES: We designed a retrospective case-control study to figure out differential clinical features of the patients presenting bilateral symptomatic subdural fluid collections owing to SIH. METHODS: Sixty-two patients with bilateral symptomatic subdural fluid collections were enrolled, and their data on general demographics, clinical courses, radiological findings, treatments, and outcomes were collected. The patients were divided into "SIH" and "Non-SIH" groups, and a simple logistic regression analysis was performed to clarify the differences between the groups. The consequent receiver operating characteristics (ROC) curve analyses were performed with the significant predictors. RESULTS: Eight patients (13%) were diagnosed with SIH. Young age (odds ratio [OR] = 0.831, 95% confidence interval [CI]: 0.743-0.929, P = .0012), no underlying disease (OR = 0.062, 95% CI: 0.007-0.544, P = .0121), radiological features of brain sagging (OR = 10.36, 95% CI: 0.912-93.411, P = .0017), pseudo-subarachnoid hemorrhage (OR = 15.6, 95% CI: 2.088-116.52, P = .0074), and small amount of fluid collections (OR = 0.719, 95% CI: 0.579-0.893, P = .0029) were significantly associated with SIH group. ROC curve analyses were performed in parameters of age and amount of fluid collection and the cut-off values for each parameter were ≤55 years old and ≤22.08 mm, respectively. Patients diagnosed with SIH underwent epidural blood patches and showed good results, except 1 patient who underwent burr-hole trephinations. CONCLUSION: Bilateral subdural fluid collections due to underlying SIH is associated with young age (≤55 years old), no underlying diseases, smaller amount of fluid collections (≤22.08 mm of depth), and radiological findings of brain sagging or pseudo-subarachnoid hemorrhages.

Defining "early" cranioplasty to achieve lower complication rates of bone flap failure: resorption and infection.

BACKGROUND: Although cranioplasty (CP) is a frequently performed and simple procedure, complications are common, particularly bone flap resorption and infection. The timing of surgery is as an important contributory factor, but the optimal timing has not been clearly determined. OBJECTIVE: We retrospectively investigated bone flap resorption and surgical site infection after CP to determine the optimal timing of surgery for reduction of complications. METHODS: The study enrolled 126 patients who underwent decompressive craniectomy (DC) and subsequent CP. Patients with bone flap resorption or surgical site infection were analyzed as the "complication" group. Receiver operating characteristic curve analysis was performed and the Youden index was used to dichotomize "early CP" and "late CP" groups. Univariate and multivariate survival analyses were performed. RESULTS: The complication group included 42 patients. The Youden index was used to identify a cutoff value for the DC-CP interval of > 44 days, and this was used to define early (< 45 days) and late (≥ 45 days) CP. Late CP was a significant risk factor in univariate and multivariate Cox regression analyses. CONCLUSION: This study showed that early CP before 45 days after DC is associated with a lower rate of bone flap resorption and surgical site infection than late CP.

Primary Intracranial Ewing Sarcoma With an Unusual Presentation: A Case Report.

Primary extraosseous intracranial Ewing sarcoma (ES) is an extremely rare disease, limited to the pediatric population, that primarily originates in the skull. Here, we present an unusual case of adult Ewing's sarcoma originating from the brain parenchyma. The 50-year-old male patient visited our hospital with severe headache lasting 3 weeks. MRI presented 6.1×6.2×5.2 cm sized heterogeneously enhanced mass containing peritumoral edema in the right frontal lobe. The patient underwent right frontal craniotomy, at which time the gray and red masses adhered to the surrounding brain parenchyma. The mass was completely resected using neuronavigation and electrophysiological monitoring. Histopathological examination revealed ES-compatible findings of small round cell tumor and CD-99 positive membranous immunostaining. Next generation sequencing revealed translocation and fusion of EWSR1 and FLI1, consistent with a confirmed diagnosis of ES. Consequently, the patient underwent postoperative radiotherapy. The present case revealed adult primary intracranial ES arising from the frontal lobe. Although its etiology remains poorly understood, intraparenchymal ES should be included in the differential diagnosis of parenchymal brain tumors.

Corrigendum: Clinical feasibility of miniaturized Lissajous scanning confocal laser endomicroscopy for indocyanine green-enhanced brain tumor diagnosis.

[This corrects the article DOI: 10.3389/fonc.2022.994054.].

A prospective multicenter assessor blinded pilot study using confocal laser endomicroscopy for intraoperative brain tumor diagnosis.

In this multi-center, assessor-blinded pilot study, the diagnostic efficacy of cCeLL-Ex vivo, a second-generation confocal laser endomicroscopy (CLE), was compared against the gold standard frozen section analysis for intraoperative brain tumor diagnosis. The study was conducted across three tertiary medical institutions in the Republic of Korea. Biopsy samples from newly diagnosed brain tumor patients were categorized based on location and divided for permanent section analysis, frozen section analysis, and cCeLL-Ex vivo imaging. Of the 74 samples from 55 patients, the majority were from the tumor core (74.3%). cCeLL-Ex vivo exhibited a relatively higher diagnostic accuracy (89.2%) than frozen section analysis (86.5%), with both methods showing a sensitivity of 92.2%. cCeLL-Ex vivo also demonstrated higher specificity (70% vs. 50%), positive predictive value (PPV) (95.2% vs. 92.2%), and negative predictive value (NPV) (58.3% vs. 50%). Furthermore, the time from sample preparation to diagnosis was notably shorter with cCeLL-Ex vivo (13 min 17 s) compared to frozen section analysis (28 min 28 s) (p-value < 0.005). These findings underscore cCeLL-Ex vivo's potential as a supplementary tool for intraoperative brain tumor diagnosis, with future studies anticipated to further validate its clinical utility.

The significance of decompressive craniectomy for older patients with traumatic brain injury: a propensity score matching analysis from large multi-center data.

The efficacy of decompressive craniectomy (DC) for traumatic brain injury (TBI) have been investigated in two recent randomized clinical trials (RCTs) and DC is recommended as an optional treatment for improving overall survival compared to medical treatment. However, the two RCTs enrolled extremely young adults, and the efficacy of DC in older adults remains questionable. Therefore, to identify the efficacy of DC in older adults, we compared patients who received medical care with those who underwent DC after propensity score matching (PSM). From the Korea Multi-center Traumatic Brain Injury Database, 443 patients identified as having intracranial hypertension and a necessity of DC were retrospectively enrolled. The patients were classified into the DC (n = 375) and non-DC (n = 68) groups according to operation records. The PSM was conducted to match the patients in the DC group with those receiving medical care (non-DC). After PSM, the newly matched group (DC, n = 126) was compared with patients without DC (non-DC, n = 63). The mean difference in the logit of the propensity scores (LPS) was 0.00391 and the mean age of enrolled patients were 65 years. The results of the comparative analyses after PSM showed that the 6-month mortality rate of the non-DC group was higher than that of the DC group (61.9% vs. 51.6%, p = 0.179). In terms of favorable outcomes (modified Rankin Scale [mRS] score < 4), the DC group showed a lower rate of favorable mRS scores (11.9% vs. 17.5%, p = 0.296) than the non-DC group.

Hydration-induced rapid growth and regression after indirect revascularization of an anterior choroidal artery aneurysm associated with Moyamoya disease: A case report.

The prevalence of aneurysm formation in adults with Moyamoya disease (MMD) is higher than that in the general population. The treatment strategy is often individualized based on the patient's disease characteristics. A 22-year-old man was diagnosed with MMD after presenting a small thalamic intracerebral and subarachnoid hemorrhage in the quadrigeminal cistern. Cerebral angiography revealed a small aneurysm (2.42 mm) in the left anterior choroidal artery. Since the hemodynamics in the left hemisphere was compromised, an indirect bypass surgery was performed. The patient's condition deteriorated postoperatively because of poor perfusion of the internal carotid artery, and massive hydration was required. During neurocritical care, the aneurysm increased in size (5.33 mm). An observation strategy was adopted because of the distal aneurysmal location and the high risk involved. Subsequently, the patient recovered, and newly developed collateral flow appeared from the external carotid artery. Additionally, a dramatic size reduction of the aneurysm (1.51 mm) was noticed. Our case suggests that MMD-related dissecting aneurysms on a distal cerebral artery, which present a high risk of embolization, could be managed by indirectly reducing the hemodynamic burden. Massive hydration in such cases should be avoided or balanced to avoid the risk of rapid growth and aneurysm rupture.

Recurrence of Rathke's Cleft Cyst Following Surgery and Histopathological Considerations for Recurrence: A Case Presentation.

Recurrence of Rathke's cleft cysts (RCC) following surgery is not uncommon. We present a 33-year-old male patient with chronic headache and visual disturbances whose MRI showed mostly cystic, suprasellar mass with peripheral enhancement. Endoscopic extended transsphenoidal approach and tumor resection was performed and RCC was pathologically confirmed postoperatively. Early recurrence was first suspected at 3 months following surgery, and his serial MRIs showed a recurred mass without associated clinical symptoms. Upon further histopathological study, extensive squamous metaplasia and high Ki-67 were seen. Also, in this study, we discuss important factors associated with cyst recurrence following surgery.

Role of human dural fibroblasts in the angiogenic responses of human endothelial cells: An in vitro dural model and the application of lab-on-a-chip for EDAS.

Encephaloduroarteriosynangiosis (EDAS), an indirect anastomosis procedure, is widely accepted as a primary treatment for moyamoya disease (MMD) to improve collateral blood flow. During surgical intervention, dural fibroblasts (DuF) are thought to produce various proteins that create an angiogenic microenvironment. However, the biophysiological evidence supporting the angiogenic properties of this surgical technique has not been thoroughly elucidated. The purpose of these studies was to determine whether DuF releases pro-angiogenic factors and chemokines and promotes angiogenic properties in human endothelial cells (ECs) under IL-1ß-mediated wound conditions, which are expected to occur during the process of neo-vascularization within the dura mater. Furthermore, a microfluidic chemotaxis platform was implemented to investigate the angiogenic activity of ECs in response to a reconstituted dura model. Transcriptome sequencing revealed that IL-1ß stimulation on DuF induced a significant upregulation of various pro-angiogenic genes, including IL-6, IL-8, CCL-2, CCL-5, SMOC-1, and SCG-2 (p < 0.05). Moreover, compared to ECs cultured in naïve media or naïve DuF media, those exposed to IL-1ß-DuF conditioned media expressed higher mRNA and protein levels of these pro-angiogenic factors (p < 0.001). ECs co-cultured with IL-1ß-DuF also exhibited considerable migration on the microfluidic chemotaxis platform. Furthermore, the chemotactic effects on the ECs were reduced upon neutralization of IL-8 or inhibition of NF-κB signaling. Our findings demonstrate that IL-1ß-DuFs release factors that activate and enhance the angiogenic properties of ECs. These results suggest a potential interaction between DuF and ECs following EDAS for MMD, and these components could be targeted for the development of therapeutic biomarkers.

Feasibility of a combined swirl and blending sign on non-contrast computed tomography for predicting early hematoma expansion after spontaneous intracerebral hemorrhage.

BACKGROUND: For predicting the hematoma expansion of spontaneous intracerebral hemorrhage, spot and swirl signs have been investigated. However, the clinical effectiveness of these signs remains debatable. These signs do not consider the peripheral hypodense lesions, which may imply a greater chance of ongoing bleedings. We proposed a new combined swirl and blending sign and evaluated its clinical usefulness in predicting hematoma expansion in non-contrast computed tomography settings. METHODS: A total of 201 patients who were diagnosed with spontaneous intracerebral hemorrhage were enrolled. Their clinical and radiologic data were retrospectively reviewed. Patients were classified into hematoma expansion (N.=51) and nonexpansion groups (N.=150), and multivariable logistic regression analyses were performed to identify the factors associated with hematoma expansion. RESULTS: In the hematoma expansion group, an average of 20 mL of volume increase was noted. In multivariate analyses, several factors, including higher systolic blood pressure (P=0.026), larger initial hematoma volume (0.002), spot sign (0.019) and combined swirl and blending sign (<0.001), were identified as reliable predictors of hematoma expansion. A swirl (P=0.396) or blending sign (P=0.124) alone was not identified as a significant predictor of hematoma growth. The sensitivity, specificity, and positive and negative predictive values of the combined swirl and blending sign were 31%, 97%, 80%, and 81%, respectively. CONCLUSIONS: A newly defined "combined swirl and blending sign" on non-contrast computed tomography was positively associated with an increased risk of hematoma expansion of spontaneous intracerebral hemorrhage and could be regarded as a reliable predictor in non-contrast computed tomography settings.

Feasibility of rescue stenting technique in patients with acute ischemic stroke due to middle cerebral artery occlusion after failed thrombectomy: A single-center retrospective experience.

BACKGROUND: Despite remarkable advancements in intra-arterial mechanical thrombectomy (IAT), recanalization failure rates up to 24% have been reported. Recently, permanent stent placement (rescue stent, RS) during IAT has been suggested as an optional modality for better reperfusion and outcomes in these patients. However, previous studies were limited owing to non-standardized procedure protocols and small sample sizes. Here, we aimed to determine the efficacy and safety of RS in patients with acute ischemic stroke (AIS) with middle cerebral artery (MCA) occlusion. METHODS: Of the 243 patients in our IAT database (2015-2021), 183 were identified as having MCA occlusion alone. Among them, we extracted 53 patients in whom the IAT failed to show thrombolysis in cerebral ischemia (TICI) scores of 2A or worse. Intraoperatively, RS was deployed in 22 patients (RS group), whereas 31 patients (no-stent group) received IAT without stenting. The baseline characteristics and radiologic and clinical outcomes were reviewed. Comparisons between the groups and multivariate logistic analyses for recanalization and good functional outcomes (modified Rankin Scale 0-2) were performed. RESULTS: No baseline differences were noted (RS vs. no-stent); however, the recanalization outcomes (59.1% vs. 25.8%, p = 0.15) and proportion of good modified Rankin Scale scores (45.5% vs. 19.4%, p = 0.041) were better in the RS group. The parameters of symptomatic ICH (9.7% vs. 9.4%) and mortality (6.5% vs. 5.7%) showed no significant difference. In the multivariate analyses, 'hypertension' and 'RS deployment' were identified as significantly associated factors with recanalization and good prognosis. CONCLUSION: In select patients with MCA occlusion AIS after failed IAT, the RS technique can be an optional rescue treatment modality for acquiring better functional outcomes and delayed recanalization.

Radiologic assessment of rupture risk in small (<5 mm) posterior communicating artery aneurysms.

ABSTRACT: Although previous studies have investigated the predictors of posterior communicating artery (PCoA) aneurysm rupture with clinical and radiologic parameters, the accessibility of "small PCoA aneurysms (<5 mm)" has rarely been reported. Here, we designed a study to identify the factors which are thought to be risky and prone to rupture in small PCoA aneurysms (<5 mm).A total of 114 patients diagnosed with PCoA aneurysm under 5 mm in size on digital subtraction angiography were retrospectively enrolled and divided into ruptured (n = 51) and unruptured (n = 63) groups. Clinical variables were reviewed, and 10 radiologic parameters were obtained, including maximum diameter, height, width, neck width, aspect ratio, dome-to-neck ratio, bleb formation, size ratio, presence of fetal-type PCoA, and inflow angle. Statistical analyses were conducted to compare the groups (ruptured vs unruptured) and identify the risk factors for rupture.High rupture rate of small PCoA aneurysm is noted (51/114, 44.7%). In the comparison analysis, parameters of size ratio (P = .045), aspect ratio (P = .001), and bleb formation (P = .015) were significantly different between the 2 groups. In the regression model, the aspect ratio (P = .045) and bleb formation (P = .004) were significantly associated with the rupture of aneurysm.In respect of small (<5 mm) PCoA aneurysms of our cohort, morphologic parameters of "bleb formation" and "a high aspect ratio" are present more often in ruptured aneurysms as compared to unruptured aneurysms.

Arterial Wall Imaging in Angiographically Occult Spontaneous Subarachnoid Hemorrhage : New Insight into the Usual Suspect.

OBJECTIVE: The etiology of angiographically occult spontaneous subarachnoid hemorrhage (AOsSAH) is unclear. Threedimensional (3D) high-resolution vessel wall magnetic resonance imaging (HVM) might be useful in detecting the hidden arterial wall angiopathy in patients with AOsSAH. We aimed to demonstrate the feasibility of HVM for detecting the arterial cause of AOsSAH. METHODS: Patients, who were diagnosed with AOsSAH in the first evaluations and underwent HVM, were enrolled. Their clinical and radiologic data were retrospectively reviewed. Especially, focal enhancement of arterial wall on HVM and repetitive catheterized angiograms were precisely compared. RESULTS: Among 251 patients with spontaneous SAH, 22 patients were diagnosed with AOsSAH in the first evaluations (8.76%). After excluding three patients who did not undergo 3D-HVM, 19 patients were enrolled and classified as convexal (n=2) or perimesencephalic (n=4), and diffuse (n=13) groups. In convexal and perimesencephalic groups, no focal enhancement on HVM and no positive findings on repetitive angiography were noted. In diffuse group, 10 patients showed focal enhancement of arterial wall on HVM (10/13, 76.9%). Repeated angiography with 3D reconstruction revealed four patients of angiographically positive causative arteriopathy and possible lesion in one case in the concordant location of intramural enhancement on 3D-HVM (5/10, 50%). Three of them were treated with endovascular stent insertion. All patients, except one, recovered with good clinical outcome (3-month modified Rankin score, 0 and 1). CONCLUSION: 3D-HVM was useful in detecting hidden true arteriopathy in AOsSAH. It may provide new insights into the etiologic investigation of AOsSAH by proving information about the arterial wall status.

The relationship between air pollutant levels and aneurysmal subarachnoid hemorrhage.

BACKGROUND: The relationship between air pollutants, including fine particles (particulate matter [PM] < 10 µm and < 2.5 µm), and aneurysmal subarachnoid hemorrhage (SAH) has been inadequately studied, and the results remain inconclusive. In this study, we attempted to investigate the relationship between air pollutant levels and aneurysmal SAH. METHODS: Ninety-two patients diagnosed with aneurysmal SAH were retrospectively included in the study. Medical records were reviewed, and levels of pollutants, including those of sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), carbon monoxide (CO), and PM with an aerodynamic diameter < 10 and 2.5 µm (PM10 and PM2.5), were collected from the open-source Air Korea website for a period of 4 days. Independent t-tests were conducted to identify the difference in the pollutant levels between the data obtained on the day of aneurysm rupture (D-0) and the other 3 days (D-7, D-2, and D-1). RESULTS: A majority (40.2%) of the patients experienced aneurysm rupture during the fall season when the mean daily pollutant levels were 0.004 ± 0.001 (ppm, SO2), 0.517 ± 0.218 (ppm, CO), 0.02056 ± 0.012 (ppm, O3), 0.02628 ± 0.015 (ppm, NO2), 36.36957 ± 24.538 (µg/m3, PM10), and 19.75581 ± 13.494 (µg/m3, PM2.5), respectively. The level of NO2 was significantly higher on the day of aneurysm rupture (P = .035) than on the other days, while the levels of CO and O3 were nonsignificantly higher (P = .081, P = .055, respectively) on the day of aneurysm rupture than on the other days. There was no significant differences in the PM levels between the 4 days. CONCLUSION: A relationship between PM levels and aneurysm rupture was not identified. Only the levels of classic air pollutant (CO, O3, and NO2) were higher on the aneurysm rupture day than on the other days.

Clinical feasibility of miniaturized Lissajous scanning confocal laser endomicroscopy for indocyanine green-enhanced brain tumor diagnosis.

Background: Intraoperative real-time confocal laser endomicroscopy (CLE) is an alternative modality for frozen tissue histology that enables visualization of the cytoarchitecture of living tissues with spatial resolution at the cellular level. We developed a new CLE with a "Lissajous scanning pattern" and conducted a study to identify its feasibility for fluorescence-guided brain tumor diagnosis. Materials and methods: Conventional hematoxylin and eosin (H&E) histological images were compared with indocyanine green (ICG)-enhanced CLE images in two settings (1): experimental study with in vitro tumor cells and ex vivo glial tumors of mice, and (2) clinical evaluation with surgically resected human brain tumors. First, CLE images were obtained from cultured U87 and GL261 glioma cells. Then, U87 and GL261 tumor cells were implanted into the mouse brain, and H&E staining was compared with CLE images of normal and tumor tissues ex vivo. To determine the invasion of the normal brain, two types of patient-derived glioma cells (CSC2 and X01) were used for orthotopic intracranial tumor formation and compared using two methods (CLE vs. H&E staining). Second, in human brain tumors, tissue specimens from 69 patients were prospectively obtained after elective surgical resection and were also compared using two methods, namely, CLE and H&E staining. The comparison was performed by an experienced neuropathologist. Results: When ICG was incubated in vitro, U87 and GL261 cell morphologies were well-defined in the CLE images and depended on dimethyl sulfoxide. Ex vivo examination of xenograft glioma tissues revealed dense and heterogeneous glioma cell cores and peritumoral necrosis using both methods. CLE images also detected invasive tumor cell clusters in the normal brain of the patient-derived glioma xenograft model, which corresponded to H&E staining. In human tissue specimens, CLE images effectively visualized the cytoarchitecture of the normal brain and tumors. In addition, pathognomonic microstructures according to tumor subtype were also clearly observed. Interestingly, in gliomas, the cellularity of the tumor and the density of streak-like patterns were significantly associated with tumor grade in the CLE images. Finally, panoramic view reconstruction was successfully conducted for visualizing a gross tissue morphology. Conclusion: In conclusion, the newly developed CLE with Lissajous laser scanning can be a helpful intraoperative device for the diagnosis, detection of tumor-free margins, and maximal safe resection of brain tumors.