Comparative analyses of immune cells and alpha-smooth muscle actin-positive cells under the immunological microenvironment between with and without dense fibrosis in primary central nervous system lymphoma.

Histopathologic examinations of primary central nervous system lymphoma (PCNSL) reveal concentric accumulation of lymphocytes in the perivascular area with fibrosis. However, the nature of this fibrosis in "stiff" PCNSL remains unclear. We have encountered some PCNSLs with hard masses as surgical findings. This study investigated the dense fibrous status and tumor microenvironment of PCNSLs with or without stiffness. We evaluated by silver-impregnation nine PCNSLs with stiffness and 26 PCNSLs without stiffness. Six of the nine stiff PCNSLs showed pathological features of prominent fibrosis characterized by aggregation of reticulin fibers, and collagen accumulations. Alpha-smooth muscle actin (αSMA)-positive spindle cells as a cancer-associated fibroblast, the populations of T lymphocytes, and macrophages were compared between fibrous and control PCNSLs. Fibrous PCNSLs included abundant αSMA-positive cells in both intra- and extra-tumor environments (5/6, 87% and 3/6, 50%, respectively). Conversely, only one out of the seven control PCNSL contained αSMA-positive cells in the intra-tumoral area. Furthermore, the presence of extra-tumoral αSMA-positive cells was associated with infiltration of T lymphocytes and macrophages. In conclusion, recognizing the presence of dense fibrosis in PCNSL can provide insights into the tumor microenvironment. These results may help stratify patients with PCNSL and improve immunotherapies for these patients.

"TIPS" and Technical Nuances for Digital Illustration in Neurointerventional Surgery.

Medical illustrations represent a precious resource for learning surgical anatomy and surgical techniques, allowing preoperative and postoperative reviews. As traditional hand-drawn illustrations are difficult to use and expressing the area of neurointerventional surgery is time-consuming, we proposed methods for neurointerventional surgeons to create digital illustrations (DIs) for neurointerventional surgery using the iPad-exclusive Procreate application (Savage Interactive, Hobart, Australia). Dedicated "digital pens" were created and used for each endovascular device, creating straightforward representations of neurointerventional procedures and changes over time. DIs in neurointervention easily depict changes to highlighted surgical scenes for various devices with complex configurations and structures. DIs are also versatile, allowing easy intrainstitutional and interinstitutional sharing and discussion of technical tips on the manipulation of medical devices (coils, catheters, stents, etc.) among neurointerventional surgeons worldwide. DIs can be applied as educational tools not only in neurointerventional surgery, but also in craniotomy surgery and for surgical records from other specialties.

The white-collar sign after Neuroform Atlas stent-assisted coil embolization of unruptured intracranial aneurysms.

PURPOSE: Although stent-assisted technique is expected to help provide a scaffold for neointima formation at the orifice of the aneurysm, not all aneurysms treated with stent-assisted technique develop complete neointima formation. The white-collar sign (WCS) indicates neointimal tissue formation at the aneurysm neck that prevents aneurysm recanalization. The aim of this study was to explore factors related to WCS appearance after stent-assisted coil embolization of unruptured intracranial aneurysms (UIAs). METHODS: A total of 59 UIAs treated with a Neuroform Atlas stent were retrospectively analyzed. The WCS was identified on digital subtraction angiography (DSA) 1 year after coil embolization. The cohort was divided into WCS-positive and WCS-negative groups, and possible predictors of the WCS were explored using logistic regression analysis. RESULTS: The WCS appeared in 20 aneurysms (33.9%). In the WCS-positive group, neck size was significantly smaller (4.2 (interquartile range (IQR): 3.8-4.6) versus 5.4 (IQR: 4.2-6.8) mm, p = .006), the VER was significantly higher (31.8% (IQR: 28.6%-38.4%) versus 27.6% (IQR: 23.6%-33.8%), p = .02), and the rate of RROC class 1 immediately after treatment was significantly higher (70% vs 20.5%, p < .001) than in the WCS-negative group. On multivariate analysis, neck size (odds ratio (OR): 0.542, 95% confidence interval (CI): 0.308-0.954; p = .03) and RROC class 1 immediately after treatment (OR: 6.99, 95% CI: 1.769-27.55; p = .006) were independent predictors of WCS appearance. CONCLUSIONS: Smaller neck size and complete occlusion immediately after treatment were significant factors related to WCS appearance in stent-assisted coil embolization for UIAs using the Neuroform Atlas stent.

An exploratory prospective phase II study of preoperative neoadjuvant bevacizumab and temozolomide for newly diagnosed glioblastoma.

PURPOSE: This multi-institutional phase I/II study was conducted to confirm the safety and explore the clinical utility of preoperative Bevacizumab (Bev) for newly diagnosed glioblastoma (GB). METHODS: Patients were enrolled based on magnetic resonance imaging (MRI) findings typically suggestive of GB. Preoperative Bev and temozolomide (TMZ) were administered at doses of 10 mg/kg on day 0 and 150 mg/m2 on days 1-5, respectively. Surgical resection was performed between days 21 and 30, inclusive. The safety and efficacy were evaluated in a total of 15 cases by progression-free survival (PFS), changes in tumor volume, Karnofsky Performance Scale (KPS) and Mini-Mental State Examination (MMSE) scores after preoperative therapy. RESULTS: Tumor resection was performed on a mean of day 23.7. Pathological diagnosis was GB, isocitrate dehydrogenase (IDH)-wildtype in 14 cases and GB, IDH-mutant in 1 case. Severe adverse events possibly related to preoperative Bev and TMZ were observed in 2 of the 15 patients, as wound infection and postoperative hematoma and thrombocytopenia. KPS and MMSE scores were significantly improved with preoperative therapy. Tumor volume was decreased in all but one case on T1-weighted imaging with contrast-enhancement (T1CE) and in all cases on fluid-attenuated inversion recovery, with mean volume decrease rates of 36.2% and 54.0%, respectively. Median PFS and overall survival were 9.5 months and 16.5 months, respectively. CONCLUSION: Preoperative Bev and TMZ is safe as long as the instructions are followed. The strategy might be useful for GB in some patients, not only reducing tumor burden, but also improving patient KPS preoperatively. TRIAL REGISTRATION NUMBER: UMIN000025579, jRCT1031180233 https://jrct.niph.go.jp/latest-detail/jRCT1031180233 . Registration Date: Jan. 16, 2017.

Yield of Whole Body Computed Tomography in Hyper-Acute Stroke Patients With Large Vessel Occlusion.

PURPOSE: In the majority of cases, large vessel occlusion (LVO) in ischemic stroke patients has an embolic origin. Systemic embolism can occur simultaneously with brain thrombosis. This retrospective study evaluated the frequency and locations of systemic embolism in LVO stroke patients receiving revascularization therapy. MATERIALS AND METHODS: In our facility, we use contrast-enhanced computed tomography (CE-CT) to assess suspected stroke patients and routinely perform CE-CT from the chest to the abdomen after brain CT angiography to rule out contraindications like aortic dissection and trauma for thrombolysis. Systemic embolism is also assessed using these images, while myocardial infarction is evaluated based on electrocardiograms and laboratory findings. Other relevant clinical features of each patient are also analyzed. RESULTS: In total, 612 consecutively admitted stroke patients and 32 LVO patients who underwent revascularization therapy were included in the present study. Systemic embolism was identified in four patients (13%). The spleen was the most commonly affected organ, followed by the heart, kidneys, limbs, and lungs. All four patients with systemic embolism exhibited LVO resulting from embolism as the underlying mechanism. CONCLUSION: Systemic embolism was observed in 13% of our LVO patients, all of whom had LVO of embolic origin.

Local thrombolytics via balloon-assisted intra-arterial infusion as rescue therapy for thromboembolism during endovascular coil embolisation.

Thromboembolism is the most frequent complication of coil embolisation for intracranial aneurysm. Complications of thromboembolism can lead to stroke and have a serious impact on sequelae and mortality, necessitating appropriate rescue therapy. Here, we succeeded in recanalisation of an occluded stent by balloon-assisted local infusion of a thrombolytic agent following stent-assisted coil embolisation of an unruptured posterior communicating artery aneurysm. This method involves inflating a microballoon just distal to the occluded vessel and then administering a thrombolytic agent through a microcatheter. This technique may increase the rate of vessel reopening by maximising the local drug concentration. This method can be applied to any type of thrombolytic agent and helps reduce the dose of systemic drugs, which might decrease the incidence of haemorrhagic complications. Balloon-assisted intra-arterial thrombolytic infusion for an occluded vessel during endovascular coil embolisation could offer an alternative rescue therapy when conventional thrombolytic agent administration fails to improve thromboembolism.

Predicting difficult transradial approach guiding into left internal carotid artery on unruptured intracranial aneurysms.

Background: The transradial approach (TRA) is less invasive than the transfemoral approach (TFA), but the higher conversion rate represents a drawback. Among target vessels, the left internal carotid artery (ICA) is particularly difficult to deliver the guiding catheter to through TRA. The purpose of this study was thus to explore anatomical and clinical features objectively predictive of the difficulty of delivering a guiding catheter into the left ICA via TRA. Methods: Among 78 consecutive patients who underwent coil embolization for unruptured intracranial aneurysms through TRA in a single institution between March 1, 2021, and August 31, 2022, all 29 patients (37%) who underwent delivery of the guiding catheter into the left ICA were retrospectively analyzed. Clinical and anatomical features were analyzed to assess correlations with difficulty in guiding the catheter into the left ICA. Results: Of the 29 aneurysms requiring guidance of a catheter into the left ICA, 9 aneurysms (31%) required conversion from TRA to TFA. More acute innominate-left common carotid artery (CCA) angle (P < 0.001) and older age (P = 0.015) were associated with a higher conversion rate to TFA. Receiver operating characteristic analysis revealed that optimal cutoff values for the innominate-left CCA angle and age to distinguish between nonconversion and conversion to TFA were 16° (area under the curve [AUC], 0.93; 95% confidence interval [CI], 0.83-1.00) and 74 years (AUC, 0.79; 95% CI, 0.61-0.96), respectively. Conclusion: A more acute innominate-left CCA angle and older age appear associated with difficulty delivering the guiding catheter into the left ICA for neurointervention through TRA.

Efficacy and safety of fetal posterior cerebral artery stented coil embolization for fetal posterior cerebral aneurysms.

PURPOSE: Aneurysms at the origin of the fetal posterior cerebral artery (fPCA) often show fPCA bifurcation from the aneurysm dome, impeding complete embolization and dense coil packing. The recanalization rate for fPCA aneurysms is therefore high. This study aimed to evaluate the efficacy and safety of stenting into fPCA for aneurysms with fPCA incorporated into the aneurysm to determine whether stenting can provide effective embolization results and prevent recanalization. METHODS: A total of 19 consecutive coil embolization procedures between February 2012 and June 2022 for unruptured fPCA aneurysms with fPCA branching from the dome of the aneurysm were divided into two groups: non-stenting (NS) group (n = 11) and stenting into fPCA (PS) group (n = 8). Data were obtained retrospectively and compared regarding embolization results, complications, and recanalization. RESULTS: Compared with the NS group, the PS group achieved significantly higher complete occlusion rate and packing density (p < 0.001, p = 0.01, respectively). No symptomatic complications were observed in the PS group. Both immediately after stenting and at the 1-year follow-up, no stent kinking, stenosis, occlusion, or malposition were observed in any patients in the PS group. During 1-year follow-up, the cumulative minor and major recanalization-free rate after coil embolization for fPCA aneurysms were significantly higher in the PS group compared with the NS group (p = 0.022, 0.0024, respectively). CONCLUSION: Stenting into fPCA for aneurysms with fPCA incorporated into the aneurysm achieved high-density complete embolization without increasing complications, and prevented recanalization. The fPCA stent-assisted coil embolization can offer an alternative treatment for fPCA aneurysms.

Risk factors for radial artery occlusion after neurointervention for unruptured intracranial aneurysm via transradial access.

PURPOSE: Neurointervention via transradial access (TRA) is less invasive than via transfemoral access. However, radial artery occlusion (RAO) may occur with TRA. The purpose of this study was to explore risk factors for RAO after coil embolization of unruptured intracranial aneurysms (UIAs) via TRA. METHODS: Forty-two consecutive patients who underwent coil embolization for UIAs via TRA between March 2021 and March 2022 and were available for angiographic evaluation 1 year after treatment were retrospectively reviewed. Multivariate logistic regression analysis was conducted to identify potential risk factors for RAO. RESULTS: Seventeen (40%) of the 42 patients showed RAO. Compared with the non-RAO group, radial artery size was significantly smaller (2.2 mm [interquartile range (IQR): 2.1, 2.4 mm] vs 2.6 mm [IQR: 2.5, 2.7 mm]; p = 0.001) and the incidence of radial artery spasm (RAS) was significantly higher in the RAO group. Multivariate analysis identified radial artery size (odds ratio [OR] 4.9 × 10-3, 95% confidence interval [CI] 6.4 × 10-5-0.38) and incidence of RAS (OR 14.8, 95%CI 2.1-105) as significant independent predictors of subsequent RAO. Based on receiver operating characteristic (ROC) curve analysis, the optimal cutoff for radial artery size was 2.5 mm (sensitivity, 82.4%; specificity, 76.0%; area under the ROC curve, 0.80 [95%CI 0.66-0.95]). CONCLUSION: Radial artery size and RAS represent reliable parameters for predicting RAO 1 year after coil embolization for UIA via TRA. Prophylaxis against RAS and limiting neurointervention via TRA to patients with radial artery larger than 2.5 mm in diameter may reduce the risk of postoperative RAO.

Rupture of the internal carotid artery pseudoaneurysm resulting from fungal sinusitis.

Although vasculitis due to infection with fungi, including Aspergillus, causes aneurysm formation, reports of internal carotid artery aneurysm formation resulting from fungal sinusitis are few. We report on a patient who experienced massive epistaxis from rupture of an internal carotid artery pseudoaneurysm, caused by fungal sinusitis. We treated the aneurysm with endovascular coil embolization, followed by endoscopic sinus surgery to remove the fungal mass. Intraoperative findings included a torn internal carotid artery and exposure of the coil to the sinus. Performing endoscopic sinus surgery before the embolization procedure would have increased the risks of massive intraoperative bleeding and mortality. Even after achieving hemostasis, serious sequelae, such as cerebral infarction, might occur. In this type of case, otorhinolaryngologists and neurosurgeons should collaborate, and an aneurysm should be treated before endoscopic sinus surgery. Although the treatment strategy for fungal internal carotid artery aneurysms is controversial, this case suggested the use of the embolization procedure followed by endoscopic debridement and antifungal therapy to treat a pseudoaneurysm of the internal carotid artery caused by fungal sinusitis.

Thromboelastography 6s for assessment of platelet function during coil embolization of unruptured intracranial aneurysms.

OBJECTIVES: Methods for assessing platelet function in patients with neurovascular disease remain controversial and poorly studied. This study aimed to assess associations between thromboelastography 6s (TEG6s) measurements and postoperative ischemic complications in patients with unruptured intracranial aneurysms (UIAs) treated by coil embolization. METHODS: Eighty-four patients with UIAs taking a combined aspirin and clopidogrel protocol were retrospectively reviewed from January 2021 to May 2022. Blood samples were obtained for TEG6s to assess platelet function on the day of coil embolization. To identify acute ischemic complications, diffusion-weighted imaging (DWI) was performed within 24 h after coil embolization. Multivariate logistic regression analysis was conducted to identify potential risk factors for postoperative positive DWI (DWI (+)) lesions. RESULTS: Forty-three of the 84 patients (51%) with DWI (+) lesions were identified. Compared with patients without DWI (+) lesions, Adenosine diphosphate (ADP)-induced platelet-fibrin clot strength (MAADP) was significantly higher (53.6 mm [Interquartile range (IQR): 48.3-58.3 mm] vs 46.7 mm [IQR: 36.8-52.2 mm]; p=0.001) and ADP inhibition rate (ADP%) was significantly lower (19% [IQR: 11-31%] vs 31% [IQR: 21-44%]; p=0.001) in DWI (+) patients. Multivariate analysis identified MAADP, ADP%, and procedure time as significant independent predictors of subsequent DWI (+) lesions (odds ratios: 1.07, 0.96, and 1.02, respectively). Based on receiver operating characteristic curve analysis, MAADP >50.9 mm and ADP% <28.8% were associated with postoperative DWI (+) lesions in patients undergoing coil embolization for UIAs. CONCLUSIONS: MAADP and ADP% as assessed by TEG6s can offer reliable parameters to predict postoperative ischemic complications after coil embolization of UIAs. Lower MAADP values and higher ADP% may decrease the risk of postoperative ischemic complications.

Therapeutic efficacy and complications of radial versus femoral access in endovascular treatment of unruptured intracranial aneurysms.

PURPOSE: The transradial approach (TRA) in neuroendovascular treatment is known to have a lower risk of complications than the transfemoral approach (TFA). However, little research has focused on assessments of efficacy and risk of complications in the treatment of intracranial aneurysms. This study aimed to compare the efficacy and complications of TRA and TFA in coil embolization of unruptured intracranial aneurysms (UIAs) at our institution. METHODS: Consecutive patients who underwent endovascular surgery via TRA or TFA at a single institution from 1 April 2019, to 28 February 2022, were retrospectively analyzed. Patients were classified into TRA and TFA groups and assessed using propensity-adjusted analysis for outcomes including fluoroscopy time, volume embolization ratio (VER), and complications. RESULTS: A total of 163 consecutive UIAs were treated with coil embolization during the 35-months study period. The incidence of minor access site complications (ASCs) was significantly higher with TFA (20%, 25/126) than with TRA (2.7%, 1/37; p = 0.01). Propensity-adjusted analysis (matched for age, sex, aneurysm volume, embolization technique, and sheath size) revealed that TRA was associated with a lower risk of minor ASCs (odds ratio, 0.085; 95% confidence interval 0.0094-0.78; p = 0.029). However, TRA did not differ significantly from TFA with respect to fluoroscopy time, VER, major ASCs, and non-ASCs. CONCLUSIONS: Coil embolization for UIAs via TRA can reduce risk of minor ASCs without increasing the risk of non-ASCs compared with conventional TFA, and can achieve comparable results in term of efficacy and fluoroscopy time.

A novel 3-Fr guiding sheath for transradial access in aneurysm embolization: Technical note.

Neurointervention via transradial access (TRA) is challenging when the radial artery is narrow. We performed aneurysm embolization via TRA using a novel 3-Fr guiding sheath (GS) (Axcelguide; Medikit, Tokyo, Japan) with an outer diameter of only 1.76 mm for patients with a radial artery of inner diameter less than 2 mm, and described the whole procedure and pitfalls as a technical note. Here, we present two patients with radial arteries less than 2 mm. One patient had a narrow neck intracranial aneurysm at the bifurcation of the left vertebral artery and posterior inferior cerebellar artery, which was embolized with the primary coiling technique. The other was a patient with a wide-necked extracranial aneurysm in the cavernous portion of the right internal carotid artery, which was embolized with the transcell technique with stent. We utilized a 3-Fr GS, distal access catheter, and a 0.0165-inch microcatheter for coil embolization. All aneurysms were completely occluded, without neurological or puncture site-related complications including subcutaneous hematoma, radial artery occlusion, and vasospasm. This report provides the first description of neurointervention using a 3-Fr GS. The 3-Fr GS contributed to successful completion of TRA aneurysm embolization without neurological or puncture site-related complications in patients with radial arteries narrower than 2 mm. The 3-Fr GS may be useful to accomplish aneurysmal embolization via TRA even in patients with a small radial artery.

Horizontal stenting via retrograde route for recurrent ruptured posterior communicating artery aneurysm after clipping: A case report and literature review.

Treatment of recurrent ruptured aneurysms incorporating a branch vessel arising from the dome is challenging. Here, we attempted horizontal stent-assisted coil embolization via a retrograde route from the contralateral internal carotid artery to treat a small ruptured posterior communicating artery aneurysm incorporating a fetal variant posterior cerebral artery after clipping.

Risk factors for recanalization of dense coil packing for unruptured cerebral aneurysms in endovascular coil embolization: Analysis of a single center's experience.

In coil embolization of cerebral aneurysms, inadequate packing is known to increase the probability of recanalization. Even tightly embolized aneurysms may be recanalized, but predictive factors for recanalization have not been fully investigated. This retrospective study aimed to identify risk factors for recanalization of treated aneurysms with a volume embolization ratio (VER) ≥ 25%. A total of 301 unruptured aneurysms in 248 patients who underwent coil embolization between March 2012 and January 2021 were analyzed. Cases involving dissecting aneurysm, intraluminal thrombosis, parent artery occlusion, intraoperative rupture, re-treatment, rupture the day after surgery, postoperative coil migration, and postoperative parent artery occlusion were excluded due to the inaccuracy of VER. A total of 105 aneurysms (34.9%) treated with VER ≥ 25% were extracted. Clinical features (age, sex, medical history, family history), anatomical features (shape, location, aneurysm size, inflow angle, and volume), procedural features (stent-assisted, Raymond-Roy occlusion classification [RROC] immediately after treatment, re-treatment rate), and follow-up period were compared between Recanalization and Non-recanalization groups. Predictors of recanalization were determined using logistic regression and receiver operating characteristic (ROC) curve analyses. Eleven aneurysms were recanalized. In multivariate analysis, RROC class 3 (odds ratio [OR] 11.0; 95% confidence interval [CI] 2.03-59.4) and aneurysm volume (OR 1.005; 95%CI 1.001-1.008) were independent predictors of recanalization. ROC curve analysis showed optimal cutoff values for aneurysm volume of 69.5 mm3 (sensitivity, 81.8%; specificity, 72.3%). In coil embolization of unruptured aneurysms that VER ≥ 25%, cases with RROC class 3 or high aneurysm volume may be associated with a higher risk of recanalization, and should be carefully followed-up.

Characteristics of Unruptured Intracranial Aneurysms with Delayed Rupture Following Coil Embolization: Case Series and Review of the Literature.

Objective: Long-term clinical outcomes including delayed rupture of unruptured intracranial aneurysms (UIAs) after coil embolization (CE) remain unclear. The purpose of this study was to evaluate the precise timing of re-treatment for recanalized UIAs before rupture. Methods: From February 2012 to June 2020, a total of 197 patients with 207 UIAs underwent CE in our institution and were followed up for more than 6 months. The follow-up period, as well as morphological changes from treatment to recanalization, regrowth, and rupture, was retrospectively analyzed. Delayed rupture was defined as a rupture that occurred more than 1 month after CE. Results: The average length of follow-up was 48.7 months. Three of 207 UIAs (1.45%) ruptured after CE. The aneurysm locations were the middle cerebral artery (MCA), anterior communicating artery (AcomA), and internal carotid artery-posterior communicating artery (ICA-Pcomm). The annual rupture rate after CE was 0.36%. Immediately after the first CE, treated aneurysms were graded according to the Modified Raymond-Roy Classification with class II for MCA aneurysms and class IIIb for AcomA and ICA-Pcomm aneurysms. The ICA-Pcomm aneurysm was treated with two additional CEs and was finally graded as class I. In all cases, DSA or MRA before aneurysm rupture showed recanalization and regrowth of aneurysms. The average periods from final embolization to regrowth and from regrowth to rupture were 54.3 months (±16.8) and 2.3 months (±0.9), respectively. Conclusion: UIAs with recanalization and regrowth after CE should undergo re-treatment as early as possible.

Delayed Tentorial Subdural Hematoma Caused by Traumatic Posterior Cerebral Artery Aneurysm: A Case Report and Literature Review.

BACKGROUND Subdural hematoma (SDH) caused by traumatic intracranial aneurysm (TICA) is rare. TICAs are known to rupture easily, resulting in a high morbidity and mortality rate. Therefore, accurate diagnosis and treatment are crucial for preserving life. We describe a case of delayed SDH in the setting of posterior cerebral artery (PCA) aneurysm. CASE REPORT A 42-year-old man presented with sustained head injury from a traffic accident, and was being followed-up conservatively for traumatic SDH and subarachnoid hemorrhage. Three weeks after the head trauma, the patient developed a sudden deterioration of mental status and disorientation. Computed tomography revealed de novo SDH at the cerebellar tentorium. Computed tomography angiography and magnetic resonance imaging demonstrated TICA in the PCA. The patient was diagnosed with SDH due to a ruptured PCA aneurysm at the quadrigeminal segment. To avoid SDH growth due to re-rupture of the aneurysm, parent artery occlusion was subsequently performed with no complications. The patient was discharged home 2 months after endovascular treatment, with moderate disability. Follow-up angiography 2 years after the operation showed no recanalization, and the patient had returned to work. CONCLUSIONS TICA in the PCA can cause tentorial SDH with or without the presence of subarachnoid hemorrhage. Routine cerebrovascular assessment is crucial for head trauma with hematoma adjacent to the cerebellar tentorium. Parent artery occlusion via an endovascular procedure is an alternative treatment for TICA in the PCA that is less invasive than other approaches.

Critical cerebellar hemorrhage due to pilocytic astrocytoma in a child: A case report.

BACKGROUND: Cerebellar hemorrhage is rare in children, and its cause is usually vascular disorders such as arteriovenous malformations or hematological disorders. CASE DESCRIPTION: A previously healthy 10-year-old girl presented with a loss of consciousness following sudden headache and vomiting. A non-contrast brain computed tomography (CT) scan revealed a massive cerebellar hemorrhage with obstructive hydrocephalus; however, subsequent CT angiography (CTA) showed no vascular abnormalities. An emergency craniotomy was performed to evacuate the hematoma, and histological analysis of the specimen obtained from the tissue surrounding the hematoma revealed a pilocytic astrocytoma (PA). Six months after the ictus, her recovery was scored at 2 on the modified Rankin Scale. CONCLUSION: PA can be a cause of critical cerebellar hemorrhage. In this case of life-threatening massive hematoma, CTA was useful to exclude a major vascular pathology and to save time.

Avoidance and Improvement in Visual Field Defect After Surgery for Metastatic Brain Tumors in the Parietal and the Occipital Lobe.

OBJECTIVE: Visual field defects occasionally occur secondary to tumors in the parietal and the occipital lobes. The aim of this study was to analyze the efficacy of improvement in hemianopsia after surgery for metastatic brain tumors involving or adjacent to the optic radiation (OR). METHODS: The study included 49 patients with brain metastasis in the parietal and occipital lobes in the present study. Preoperative and postoperative neurological assessments included visual field, Mini-Mental State Examination, and Karnofsky performance scale. RESULTS: Of 49 patients, 33 (67.3%) presented with preoperative homonymous hemianopsia. Of these 33 patients, the visual field was improved postoperatively in 17 patients (51.5%). In all patients regardless of preoperative hemianopsia, postoperative visual fields did not deteriorate. Tractography demonstrated that the OR was split by the tumor (n = 6) and fanning of fibers expanded along the lateral side of the tumor (n = 11). All tumors were removed via surgical access toward the medial side of the tumor. Gross total resection was achieved in most tumors in the group with visual improvement (n = 16/17; 94.1%). Improvement in the visual field was attributed to tumor location in the subcortical white matter, removal rate of the tumor, and higher postoperative Karnofsky performance scale score. CONCLUSIONS: The OR tended to deviate to the lateral side of the tumor in the parieto-occipital junction. The postoperative visual field improved even in cases of an occipital tumor. Based on the present study, total resection via an appropriate surgical route should be considered to preserve the OR, leading to improvement in the postoperative visual field.

MRI characteristics of syringomyelia associated with foramen magnum arachnoiditis: differentiation from Chiari malformation.

BACKGROUND: It is important to distinguish foramen magnum arachnoiditis (FMA) from Chiari malformation (CM) before surgery because the operative strategies for these diseases differ. In the current study, we compared pretreatment magnetic resonance imaging (MRI) of FMA with CM and investigated the MRI findings useful to differentiate between these diseases. METHODS: We retrospectively reviewed patients with FMA or CM aged ≥ 18 years who underwent surgeries at our institution between 2007 and 2019. The morphologies of the syrinx, neural elements, and posterior cranial fossa were preoperatively evaluated with MRI. We used the receiver operating characteristic (ROC) curve for the fourth ventricle-to-syrinx distance (FVSD). RESULTS: Ten patients with FMAs and 179 with CMs were included. FVSD in the FMA group was significantly shorter than that in the CM group (7.5 mm [IQR, 2.8-10 mm] in FMA vs. 29.9 mm [IQR, 16.3-52.9 mm] in CM, p < 0.0001). The other MRI findings that showed the height, size, and length of the syrinx; size of the foramen magnum; degree of cerebellar tonsillar descent; shape of the cerebellar tonsil; and dorsal subarachnoid space at the foramen magnum differed significantly between the two groups. The ROC curve analysis showed that patients whose FVSD was less than 11 mm could be diagnosed with FMA with a specificity of 90% and sensitivity of 96%. CONCLUSIONS: A more cranial syrinx development (FVSD < 11 mm) appears to be the characteristic MRI finding in FMA.