[Presurgical Simulation for Brain Arteriovenous Malformation].

Surgical extirpation of brain arteriovenous malformations(AVMs)requires precise pre-surgical simulation. Utilizing image software, widely used with picture archiving and communication systems(PACS), surgeons can generate simulation images that precisely illustrate the proper feeders, passing arteries, and drainers. The crucial steps for creating informative simulation images include: (1)the free rotation of reconstructed 3D digital subtraction angiography(DSA)images; (2)removal of irrelevant arteries(the most important procedure); and(3)construction of stereo imagery of the "core images." This article presents a detailed description of these procedures.

Posterior cerebral artery involvement in unilateral moyamoya disease is exclusively ipsilateral and influenced by RNF213 mutation gene dose: The SUPRA Japan study: PCA involvement in unilateral moyamoya.

OBJECTIVES: The characteristics and clinical implications of posterior cerebral artery (PCA) involvement in unilateral moyamoya disease (U-MMD), such as laterality, frequency of the RNF213 p.R4810K mutation, and clinical outcomes, have not been well studied. POPULATION AND METHODS: We analyzed a cohort of 93 patients with U-MMD who participated in the SUPRA Japan study. Clinical characteristics and radiological examinations were collected from medical records. The presence of the p.R4810K mutation was determined using a TaqMan assay. The clinical outcome was assessed using the modified Rankin Scale (mRS). Univariate and multivariate logistic regression analyses were performed to assess the associations. RESULTS: Among the patients with U-MMD, PCA involvement was observed in 60.0 % (3/5) of patients with homozygous mutation, 11.3 % (7/62) of those with heterozygous mutation, and 3.8 % (1/26) of those with wild type, showing a significant linear trend (p < 0.001 for trend). PCA involvement was observed exclusively on the same side as the affected anterior circulation. Dyslipidemia and cerebral infarction at initial onset were independently associated with mRS ≥1. Hypertension was associated with mRS ≥1 and it was also linked to infarction at initial onset, suggesting a potential confounding effect. Although PCA involvement showed a trend for higher mRS, it was not statistically significant. CONCLUSIONS: Our findings indicate a gene dose effect of the p.R4810K mutation on PCA involvement, with the homozygous state showing the most significant effect. Both genetic and modifiable factors such as dyslipidemia may influence the progression of U-MMD.

"Transcallosal" periventricular anastomosis in moyamoya disease: the fourth periventricular anastomosis and a potential predictor of hemorrhage.

OBJECTIVES: Choroidal anastomosis is a risk factor for hemorrhage in moyamoya disease. One variant of choroidal anastomosis, "transcallosal anastomosis," originates from the medial posterior choroidal artery, and penetrates the corpus callosum to reconstruct the pericallosal artery. We aimed to investigate the prevalence and the bleeding rate of transcallosal anastomosis using sliding thin-slab maximum intensity projection reformatted from magnetic resonance angiography (MRA). MATERIALS AND METHODS: This study included 222 patients. We defined transcallosal anastomosis grades (0-2) and the stenosis of the anterior (ACA, 0-2), middle (MCA, 1-3), and posterior cerebral artery (PCA, 0-2) by MRA scores, independently by two coauthors. RESULTS: Grade-2 transcallosal anastomosis was detected in 21 patients (9.5 %). There were no correlations of the incidence of transcallosal anastomosis with previous bypass surgery (P = 0.23). Multivariate analysis revealed a significantly higher incidence in hemorrhagic onset and younger age (odds ratio [OR] 3.77, and 0.97). Transcallosal anastomosis had statistically significant correlation with ACA and PCA scores (P = 0.01 and 0.03), but not with MCA scores (P = 0.1). In multivariate analysis, ACA scores 1 and 2 were significantly higher (OR, 15.44 and 11.17), and PCA score 1 was also higher (OR, 3.07), but PCA score 2 was not. Interrater agreement for judgment of transcallosal anastomosis grade was strong (κ = 0.89). Two patients with Grade-2 transcallosal anastomosis had late hemorrhage in the corpus callosum (bleeding rate: 2.5 % per year). CONCLUSIONS: Transcallosal anastomosis may be associated with both advanced ACA and moderate PCA stenosis, and cause hemorrhage at the corpus callosum.

Rigid but nonmetallic cranioplasty after pterional craniotomy: Technical note.

Background: Given the popularity of pterional craniotomy, numerous modifications have been made to prevent postoperative deformities. With the advent of titanium plates, fixation has become both simple and excellent. However, titanium plates can cause skin problems, infection, or cause skull growth to fail. Methods: To develop a simple, cost-effective, and esthetically satisfactory fixation method, without the use of non-metallic materials, six young and older patients underwent pterional craniotomy. CranioFix Absorbable clamps were used to fix the bone flap in the frontal and temporal regions such that the frontal part was in close contact with the skull. After fixation, the bone chips and bone dust were placed in the bone gap and fixed with fibrin glue. We measured the computed tomography values of the reconstructed area and thickness of the temporal profiles postoperatively over time. Results: Bone fusion was achieved in all patients by 1 year after surgery. Both the thickness of the temporalis muscle and the thickness of the temporal profile had changed within 2 mm as compared with the preoperative state. Conclusion: Our simple craniotomy technique, gentle tissue handling, and osteoplastic cranioplasty yielded satisfactory esthetic results and rigidness in pterional craniotomy.

Neuronal Loss in the Bilateral Medial Frontal Lobe Revealed by 123I-iomazenil Single-photon Emission Computed Tomography in Patients with Moyamoya Disease: The First Report from Cognitive Dysfunction Survey of Japanese Patients with Moyamoya Disease (COSMO-Japan Study).

Cognitive impairment in adult patients with moyamoya disease (MMD) is sometimes overlooked and can occur in patients with no ischemic or hemorrhagic lesions. Better profiling and reliable diagnostic methods that characterize the group and associate the impairments and pathology of MMD are required in order to deliver appropriate treatments and support. The potential of 123I-iomazenil single-photon emission computed tomography (SPECT) for this issue has been reported in some studies, but the universality of this method remains unclear. A multicenter study of adult patients (aged 18-60 years) with MMD who experienced difficulties in social lives despite normal activities of daily living was implemented to delineate the common characteristics of this group of patients. In this study, iomazenil SPECT, besides patient characteristics, cognitive functions, and conventional imaging, was acquired to examine whether this method is suitable as a universal diagnostic tool. A total of 36 patients from 12 institutes in Japan were included in this study. Domain scores of world health organization quality of life 26 indicated low self-rating in physical health and psychological domains. The percentages of patients who had <85 in each index were 27.8%-33.3% in the WAIS-III and 16.7%-47.2% in the Wechsler Memory Scale-Revised. The group analysis of iomazenil SPECT demonstrated a decreased accumulation in the bilateral medial frontal areas in comparison with the normal control, whereas there were no specific characteristics on conventional imaging in the cohort. Iomazenil SPECT is a possible universal diagnostic method for the extraction of patients with cognitive impairment in MMD.

Quantitative regional cerebral blood flow measurement using near-infrared spectroscopy and indocyanine green in patients undergoing superficial temporal to middle cerebral artery bypass for moyamoya disease: a novel method using a frequency filter.

Measuring regional cerebral blood flow (rCBF) after revascularization for moyamoya disease, as a type of ischemic cerebrovascular disease, is crucial. This study aims to validate our novel technology that combines near-infrared spectroscopy (NIRS) with a frequency filter to extract the arterial component. We measured rCBF before and after revascularization for moyamoya disease and at the end of the surgery using NIRO-200NX (Hamamatsu Photonics, Japan) and indocyanine green (ICG). rCBF was calculated using Fick's principle, change in arterial ICG concentrations, and maximum arterial ICG concentration. rCBF measured with NIRS (rCBF_N) was compared with pre- and postoperative rCBF measured with SPECT (rCBF_S). Thirty-four procedures were analyzed. rCBF_N increased from baseline to end of the surgery (mean difference (MD), 2.99 ml/min/100 g; 95% confidence interval (CI), 0.40-5.57 ml/min/100 g on the diseased side; MD, 4.94 ml/min/100 g; 95% CI, 2.35-7.52 ml/min/100 g on the non-diseased side). Similar trends were observed for rCBF_S (MD, 3.98 ml/min/100 g; 95% CI, 2.30-5.67 ml/min/100 g on the diseased side; MD, 2.77 ml/min/100 g; 95% CI, 1.09-4.45 ml/min/100 g on the non-diseased side). Intraclass correlations 3 (ICC3s) between rCBF_N and rCBF_S were weak on the diseased side (ICC3, 0.25; 95% CI, -0.03-0.5; p = 0.07) and the non-diseased side (ICC3, 0.24; 95% CI, -0.05-0.5; p = 0.08). rCBF measurements based on this novel method were weakly correlated with rCBF measurements with SPECT.

[Complications of Superficial Temporal Artery-Middle Cerebral Artery Anastomosis and Their Prevention: Technical Note].

Complications of the superficial temporal artery-middle cerebral artery(STA-MCA)bypass procedure include skin necrosis, MCA vessel wall injury, and thrombotic occlusion of the anastomotic site. First, deprivation of the STA per se induces ischemia of the skin flap. Skin incisions must be designed carefully to avoid isolating some areas from the blood supply. Secondly, the MCA walls can be extremely thin in moyamoya disease; therefore, the fragile vascular walls must be manipulated gently. The MCA walls should not be grasped directly by forceps. Thirdly, intraluminal thrombi can develop after the completion of the anastomosis. Heparin should be administered intravenously as soon as possible when intraluminal thrombi are detected, followed by aspirin loading via a nasogastric tube. Platelet(white)thrombi are fragile and easily disrupted with mechanical vibration. It is essential to treat them before they develop into a large, firm fibrin thrombus that completely occludes the anastomotic site, which would require suture cutting and surgical thrombus removal.

Aspect Ratio Is Associated with Recanalization after Coiling of Unruptured Intracranial Aneurysms.

The rate of recanalization after coil embolization for unruptured intracranial aneurysms (UIAs) is reported to occur around 11.3%-49%. This study aims to investigate the factors that influence the recanalization after coil embolization for UIAs in our institution. We retrospectively investigated 307 UIAs in 296 patients treated at our institution between April 2004 and December 2016. The stent-used cases were excluded. Cerebral angiography and 3D time-of-flight magnetic resonance angiography (TOF MRA) were used for evaluation of the postoperative occlusion status. Volume embolization ratio (VER), aneurysmal size, neck width, and aspect ratio (AR) were compared between the recanalized and non-recanalized groups. The mean follow-up period ranged from 6 to 172 months (mean: 79.0 ± 39.8 months). Recanalization was noted in 78 (25.4%) aneurysms, and 19 (6.2%) aneurysms required retreatment. There was no aneurysmal rupture during the follow-up period. Univariate analysis showed that the aneurysm size (p < 0.001), neck width (p < 0.001), AR (p = 0.003), and VER (p = 0.012) were associated with recanalization. Multivariate logistic regression analysis showed that the AR (p =0.004) and VER (p =0.015) were significant predictors of recanalization. To summarize, a higher AR and a lower VER could lead to recanalization after coil embolization of UIAs. Careful follow-up is required for coiled aneurysms with these features.

Experience With Tirabrutinib in the Treatment of Primary Central Nervous System Lymphoma that Is Difficult to Treat With Standard Treatment.

BACKGROUND/AIM: Standard treatment options for primary central nervous system lymphoma (PCNSL) include high-dose methotrexate (HD-MTX)-based drug therapy and whole-brain radiation therapy. However, there are many cases in which these standard treatment options are not tolerated for various reasons. In the present study, five cases of refractory/relapsed PCNSL that are difficult to treat with standard treatment were successfully treated by tirabrutinib. PATIENTS AND METHODS: A total of 5 patients (4 women, 1 man) with refractory (n=3) and relapsed (n=2) PCNSL were included. The patients had a median age of 76 years and a median Karnofsky performance status (KPS) of 40. The reasons why standard treatment cannot be given to these patients are the low KPS, renal dysfunction, and resistance to HD-MTX. Administration of a drug via the oral route was challenging in three patients; thus, these patients were administered tirabrutinib in suspension through a nasogastric tube. RESULTS: Imaging findings showed that the patients achieved a 100% response rate to tirabrutinib, with a median survival of 8 months. As symptoms improved, 2 of the 3 patients who were initially administered tirabrutinib via a nasogastric tube were able to receive the drug via the oral route. Three patients developed adverse reactions; however, treatment was not interrupted because they were manageable. CONCLUSION: Tirabrutinib was effective in the treatment of patients who were unable to receive standard treatment options. Tirabrutinib may be considered one of the novel treatment strategies that could improve the prognosis of PCNSL patients in the future.

Task-specific dystonia in hairdressers: a questionnaire survey and review of the literature.

Hairdresser dystonia is one of the occupational dystonias and task-specific movement disorders occurring as a result of long-term repetitive cutting with scissors. The task-specific dystonia manifests itself as a loss of voluntary motor control during extensive practice of cutting requiring a high level of technical proficiency. The prevalence rate of hairdresser dystonia is not well-known worldwide. A questionnaire regarding dystonia was prepared for hairdressers. After sending the questionnaires to 800 hairdressers by direct mail, 134 answers were received by mail. Five of the 134 were suspected to have hairdresser-associated focal dystonia. Thus, 3.7% of hairdressers might have task-specific dystonia. This report was limited because of the small number of participants. However, this research is valuable because it was difficult to find a patient with suspected dystonia due to concerns related to job security.

Japan Stroke Society Guideline 2021 for the Treatment of Stroke.

The revised Japan Stroke Society Guidelines for the Treatment of Stroke were published in Japanese in July 2021. In this article, the extracted recommendation statements are published. The revision keeps pace with the great progress in stroke control based on the recently enacted Basic Act on Stroke and Cardiovascular Disease in Japan. The guideline covers the following areas: primary prevention, general acute management of stroke, ischemic stroke and transient ischemic attack, intracerebral hemorrhage, subarachnoid hemorrhage, asymptomatic cerebrovascular disease, other cerebrovascular disease, and rehabilitation.

A Case of Direct Carotid-Cavernous Fistulae Successfully Treated by Bidirectional Double Catheter Technique: A Technical Note.

Objective: Ruptured carotid-cavernous aneurysms (CCAs) are known to result in direct carotid-cavernous fistula (CCF). Although endovascular treatment is recognized as the first-line treatment for direct CCF, obliteration is sometimes difficult because of the high-flow shunt. In this report, we present a case of a direct CCF treated by the combination of transarterial and transvenous approaches. Case Presentation: A 57-year-old woman presented with conjunctival chemosis, exophthalmos, and tinnitus. Ophthalmological examination revealed increased intraocular pressure. DSA demonstrated a direct CCF due to a right ruptured CCA with retrograde shunted flow through the superior ophthalmic vein (SOV), superficial middle cerebral vein, basal vein of Rosenthal, and middle temporal vein. Two microcatheters were guided into the shunt segment from the internal carotid artery and SOV. In addition, a balloon catheter was placed at the neck of the aneurysm to assist coiling. Coil embolization for the CCF was performed using two microcatheters in the opposite direction, which enabled compact and tight packing of the shunt segment with only six coils. The CCF was eliminated. Two-year-follow-up MRA revealed no recurrence. Conclusion: The bidirectional double catheter technique is a useful approach to obliterate a shunt in a short segment with minimal coils.

Coiling for Ruptured Aneurysms in the Vasospasm Period: Safety and Efficacy Based on a Propensity Score Analysis.

Objective: To evaluate the efficacy and safety of interventional radiology (IVR) for aneurysmal subarachnoid hemorrhage (SAH) later than 3 days after onset. Methods: A total of 71 patients between 2012 and 2017 who underwent endovascular coiling were divided into two groups according to the timing of treatment: Group E (treated within 3 days after onset) and group D (treated between 4 and 14 days after onset), and the outcomes between two groups were compared. A case-matched study was conducted to minimize the selection bias lying in this cohort. Results: There were 56 (78.9%) and 15 (21.1%) patients in groups E and D, respectively. In group D, all patients arrived at the hospital later than 3 days after onset. The rates of patients with WFNS grade 1, 2, 3 and the presence of vasospasm upon the access route to the targeted aneurysm at the time of IVR were significantly higher in group D than in group E (93.3% vs 60.7%; p = 0.027, 33.3% vs 3.6%; p = 0.0037, respectively). There were no significant differences in the rate of intraprocedural complications, symptomatic vasospasm, delayed cerebral infarction due to vasospasm, retreatment, or modified Rankin Scale (mRS) at discharge. After propensity score matching, there were no significant differences in the outcomes between two groups. Conclusion: Prompt coiling for patients with ruptured aneurysms who arrived later than 3 days after onset can be safely performed, even if they had vasospasm upon the access route.

Transarterial and Transvenous Coil Embolization of Direct Carotid-Cavernous Fistulas.

Objective: Transvenous embolization (TVE) is typically used in combination with the residual shunt of transarterial embolization (TAE) for the treatment of direct carotid-cavernous fistulas (direct CCFs). This report is about our additional embolization method using combination therapy. Case Presentation: Five consecutive cases of direct CCF were presented; two were caused by aneurysms and three by head injuries. The treatment for each was started with TAE, with the addition of TVE if a shunt remained. At the time of TVE, a microcatheter positioned in the internal carotid artery passing from the cavernous sinus through the aneurysm neck or fistula was pulled back (pull-back method). It was then placed in the coil mass with TAE, and additional coils were filled. In two cases, the shunt disappeared by using only TAE, whereas it disappeared after being additionally embolized by the pull-back method in the remaining cases. All patients recovered with no postoperative complications. Conclusion: The TAE and TVE combination therapy with the pull-back method could efficiently embolize the residual shunt after TAE.

Genetic and nongenetic factors for contralateral progression of unilateral moyamoya disease: the first report from the SUPRA Japan Study Group.

OBJECTIVE: Although many studies have analyzed risk factors for contralateral progression in unilateral moyamoya disease, they have not been fully elucidated. The aim of this study was to examine whether genetic factors as well as nongenetic factors are involved in the contralateral progression. METHODS: The authors performed a multicenter cohort study in which 93 cases with unilateral moyamoya disease were retrospectively reviewed. The demographic features, RNF213 R4810K mutation, lifestyle factors such as smoking and drinking, past medical history, and angiographic findings were analyzed. A Cox proportional hazards model was used to find risk factors for contralateral progression. RESULTS: Contralateral progression was observed in 24.7% of cases during a mean follow-up period of 72.2 months. Clinical characteristics were not significantly different between 67 patients with the R4810K mutation and those without it. Cox regression analysis showed that the R4810K mutation (hazard ratio [HR] 4.64, p = 0.044), childhood onset (HR 7.21, p < 0.001), male sex (HR 2.85, p = 0.023), and daily alcohol drinking (HR 4.25, p = 0.034) were independent risk factors for contralateral progression. CONCLUSIONS: These results indicate that both genetic and nongenetic factors are associated with contralateral progression of unilateral moyamoya disease. The findings would serve to help us better understand the pathophysiology of moyamoya disease and to manage patients more appropriately.

A multicenter prospective registry of Borden type I dural arteriovenous fistula: results of a 3-year follow-up study.

PURPOSE: Although intracranial dural arteriovenous fistula (DAVF) without retrograde leptomeningeal venous drainage (Borden type I) is reported to have a benign nature, no study has prospectively determined its clinical course. Here, we report a 3-year prospective observational study of Borden type I DAVF. METHODS: From April 2013 to March 2016, consecutive patients with DAVF were screened at 13 study institutions. We collected data on baseline characteristics, clinical symptoms, angiography, and neuroimaging. Patients with Borden type I DAVF received conservative care while palliative intervention was considered when the neurological symptoms were intolerable, and were followed at 6, 12, 24, and 36 months after inclusion. RESULTS: During the study period, 110 patients with intracranial DAVF were screened and 28 patients with Borden type I DAVF were prospectively followed. None of the patients had conversion to higher type of Borden classification or intracranial hemorrhage during follow-up. Five patients showed spontaneous improvement or disappearance of neurological symptoms (5/28, 17.9%), and 5 patients showed a spontaneous decrease or disappearance of shunt flow on imaging during follow-up (5/28, 17.9%). Stenosis or occlusion of the draining sinuses on initial angiography was significantly associated with shunt flow reduction during follow-up (80.0% vs 21.7%, p = 0.02). CONCLUSION: In this 3-year prospective study, patients with Borden type I DAVF showed benign clinical course; none of these patients experienced conversion to higher type of Borden classification or intracranial hemorrhage. The restrictive changes of the draining sinuses at initial diagnosis might be an imaging biomarker for future shunt flow reduction.

Histopathological analysis of retrieved thrombi from patients with acute ischemic stroke with malignant tumors.

BACKGROUND: The procoagulant state in cancer increases the thrombotic risk, and underlying cancer could affect treatment strategies and outcomes in patients with ischemic stroke. However, the histopathological characteristics of retrieved thrombi in patients with cancer have not been well studied. This study aimed to assess the histopathological difference between thrombi in patients with and without cancer. METHODS: We studied consecutive patients with acute major cerebral artery occlusion who were treated with endovascular therapy between October 2010 and December 2016 in our single-center registry. The retrieved thrombi were histopathologically investigated with hematoxylin and eosin and Masson's trichrome staining. The organization and proportions of erythrocyte and fibrin/platelet components were studied using a lattice composed of 10×10 squares. RESULTS: Of the 180 patients studied, 17 (8 women, age 76.5±11.5 years) had cancer and 163 (69 women, age 74.1±11.2 years) did not. Those with cancer had a higher proportion of fibrin/platelets (56.6±27.4% vs 40.1±23.9%, p=0.008), a smaller proportion of erythrocytes (42.1±28.3% vs 57.5±25.1%, p=0.019), and higher serum D-dimer levels (5.9±8.2 vs 2.4±4.3 mg/dL, p=0.005) compared with the non-cancer cases. Receiver operating characteristic curve analysis showed the cut-off ratio of fibrin/platelet components related to cancer was 55.7% with a sensitivity of 74.8%, specificity 58.8% and area under the curve (AUC) value of 0.67 (95% CI 0.53 to 0.81), and the cut-off ratio of erythrocyte components was 44.7% with a sensitivity of 71.2%, specificity 58.9% and AUC value of 0.66 (95% CI 0.51 to 0.80). CONCLUSIONS: Thromboemboli of major cerebral arteries in patients with cancer were mainly composed of fibrin/platelet-rich components.

Usefulness of Craniograms in Discriminating Coiled Intracranial Aneurysms Requiring Retreatment.

While endovascular coil embolization has become one of the major therapeutic modalities for intracranial aneurysms, long-term imaging follow-up is required because of the higher rate of retreatment compared with surgical clipping. The purpose of this study was to show the usefulness of craniograms to discriminate coiled intracranial aneurysms that required retreatment. Under the study protocol approved by institutional review board, a retrospective review of the medical record was done regarding coil embolization for intracranial aneurysms performed between January 2014 and December 2018. Coil embolization performed as the initial treatment and followed up for more than 1 year without additional treatment, and those performed as retreatment after the initial coil embolization performed at our institution were recruited. Craniograms obtained just after the initial treatment were compared with those obtained just before the additional treatment in the retreated cases and compared with the latest ones in the non-recurrence cases. Correlation between the morphological changes in the coil mass on the craniograms and retreatments was evaluated. During the study period, 288 coil embolization procedures for intracranial aneurysms were performed. From these, 191 treatments that were followed up for more than 1 year without any additional treatments and 30 retreatments were included. Morphological change of the coil mass was observed in 4 of the 191 non-recurrence treatments and 26 of the 30 retreatments, which was significantly correlated with retreatments (p <0.001). Craniogram was a useful modality in following up the coiled intracranial aneurysms to detect those required retreatments.