Headache characteristics to screen for cervicocerebral artery dissection in patients with acute onset unusual headache.

OBJECTIVES: The aim of this preplanned primary analysis was to investigate the clinical manifestations of headache to screen for CAD patients with acute onset headache only. BACKGROUND: Spontaneous cervicocerebral artery dissection (CAD) with acute onset headache is not rare in clinical practice; however, it is underdiagnosed. On the other hand, subsequent infarction or subarachnoid hemorrhage mainly occurs within 1 week of headache onset. METHODS: Between April 2017 and January 2022, we conducted a single-center, cross-sectional retrospective study on 197 consecutive referred patients from neurosurgical outpatient clinics with acute onset unusual headache (stronger or longer headache than usual). All patients underwent magnetic resonance imaging to screen for secondary headache and were diagnosed based on the diagnostic protocol. We examined patient background data and the following headache characteristics: distribution, condition at the onset of headache, accompanying vomiting or nausea, worsening headache, and analgesic effects against headache. These factors were analyzed to identify independent diagnostic predictors of CAD. In this study, the rate of missing data was 41% for improvement of headache by analgesia and multiple imputation by chained equations was performed. RESULTS: A total of 93 patients (46 men and 47 women; mean age: 48 years, range: 25-73 years) were diagnosed with CAD. Univariate logistic regression analysis showed CAD was associated with current smoking, systolic blood pressure >140 mmHg, unilateral headache, worsening headache, and no headache improvement by analgesia. Unilateral, worsening headache and no headache improvement by analgesia remained independent diagnostic predictors in multivariable logistic regression after multiple imputation. No headache improvement by analgesia had the highest sensitivity (86%), while worsening headache had the highest specificity (84%). CONCLUSIONS: CAD needs to be considered in patients with unilateral, worsening headache and no headache improvement by analgesia.

Association of circumferential aneurysm wall enhancement with recurrence after coiling of unruptured intracranial aneurysms: a preliminary vessel wall imaging study.

OBJECTIVE: Recent histopathological studies of unruptured intracranial aneurysms (UIAs) have confirmed that aneurysm wall enhancement (AWE) on MR vessel wall imaging (VWI) is related to wall degeneration with in vivo inflammatory cell infiltration. Therefore, pretreatment aneurysm wall status on VWI may be associated with recurrence after endovascular treatment. METHODS: VWI with gadolinium was performed on 67 consecutive saccular UIAs before endovascular treatment between April 2017 and June 2021. The mean (range) follow-up period after treatment was 24.4 (6-54) months. AWE patterns were classified as circumferential AWE (CAWE), focal AWE (FAWE), and negative AWE (NAWE). The authors retrospectively investigated the relationship between aneurysm recurrence and AWE patterns, as well as conventional risk factors. RESULTS: Sixty-seven patients with 67 saccular UIAs were eligible for the present study. AWE patterns were as follows: 10 CAWE (14.9%), 20 FAWE (29.9%), and 37 NAWE (55.2%). Follow-up MRA detected aneurysm recurrence in 18 of 69 cases (26.1%). Univariate analysis identified maximum diameter (mean ± SD 5.8 ± 2.2 mm in patients with stable aneurysms vs 7.7 ± 3.8 mm in those with unstable aneurysms, p = 0.02), aspect ratio (1.4 ± 0.5 vs 1.1 ± 0.4, p < 0.01), aneurysm location in posterior circulation (4.1% vs 27.8%, p < 0.01), volume embolization ratio (29.6% ± 7.8% vs 25.2% ± 6.1%, p = 0.02), and AWE pattern (p = 0.04) as significant predictive factors of recurrence. Among the 3 AWE patterns, CAWE was significantly more frequent in the unstable group, but no significant differences in stability of the treated aneurysms were observed with the FAWE and NAWE patterns. In multivariate logistic regression analysis, CAWE pattern (OR 14.2, 95% CI 1.8-110.8, p = 0.01) and volume embolization ratio ≥ 25% (OR 8.6, 95% CI 2.1-34.3, p < 0.01) remained as significant factors associated with aneurysm stability after coiling. CONCLUSIONS: VWI before coiling provides novel insights into the stability of treated aneurysms. Aneurysms with the CAWE pattern on VWI before coiling may be less stable after treatment.

The impact of high-resolution cone-beam CT findings on decision-making for the treatment of unruptured middle cerebral artery aneurysms.

Even with the advent of endovascular treatment for intracranial aneurysms, microsurgical clipping continues to play a significant role in the treatment of middle cerebral artery (MCA) aneurysms. Securing perforators around unruptured intracranial aneurysms (UIAs) is essential for minimizing procedural risks in each treatment option. Therefore, we herein investigated whether the findings of high-resolution cone-beam computed tomography (HR-CBCT) have an impact on decision-making for the treatment of MCA UIAs. Patients with MCA UIAs between October 2017 and September 2021 were consecutively recruited for this study. All patients underwent HR-CBCT and 3D-DSA before treatment. The imaging quality of both modalities to visualize the microvasculature around aneurysms was evaluated. Specific findings on the microvasculature surrounding aneurysms on HR-CBCT were investigated to facilitate microsurgical clipping. Fifty-two MCA UIAs were treated, including 43 by microsurgical clipping and 9 by endovascular approaches. The overall imaging quality of HR-CBCT was superior to that of 3D-DSA. Regarding microsurgical insights, sensitivity and specificity for the visualization of small vessels around aneurysms were 79 and 100%, respectively, using HR-CBCT, and 57 and 93%, respectively, using 3D-DSA. The presence of a low-density band between adhesive vessels and aneurysm sacs was indicative of successful and safe microsurgical dissection between these structures. HR-CBCT enabled visualization of the intracranial microvasculature around MCA UIAs at the submillimeter level in vivo. In cases in which the tight adhesion of the microvasculature to the aneurysm sac is indicated by HR-CBCT, an endovascular approach may be considered in order to avoid the risks associated with securing perforators.

Diagnostic accuracy of MR vessel wall imaging at 2 weeks to predict morphological healing of vertebral artery dissection.

OBJECTIVES: The spontaneous healing of non-hemorrhagic intracranial vertebral artery dissection (VAD) may be associated with the stabilization of intramural hematoma (IMH). We previously suggested that the signal intensity of IMH increases until approximately 2 weeks in VAD with spontaneous healing. We herein investigated the diagnostic accuracy of the signal intensity of IMH at 2 weeks to predict the spontaneous healing of VAD. METHODS: From April 2017 to April 2021, we prospectively investigated patients with non-hemorrhagic VAD who underwent vessel wall imaging (VWI). Morphological healing of VAD was evaluated by MR angiography three months after its onset. The relative signal intensity (RSI) of IMH against the posterior cervical muscle on VWI was calculated. Univariate and multivariate analyses were performed on factors associated with the spontaneous healing of VAD among patient baseline data, vascular morphology at the diagnosis, and RSI parameters. RESULTS: Forty-eight patients (23 men and 25 women; mean age: 51 years, range: 34-73 years) with 50 non-hemorrhagic VAD were included in the present study. Spontaneous healing was observed in 28 VAD (56%). RSI two weeks after the onset of VAD (RSI2w) and morphological feature such as the string sign were associated with spontaneous healing, respectively. The multivariate logistic regression analysis identified RSI2w as an independent predictive factor of spontaneous healing (OR: 7.3; 95% CI, 1.9-28, p = 0.004). The cut-off value for RSI2w to predict spontaneous healing was 1.22 (AUC = 0.90, sensitivity: 91%, specificity: 82%). CONCLUSION: RSI2w predicted the spontaneous healing of non-hemorrhagic VAD 3 months after its onset.

Association of Neutrophil Extracellular Traps with Plaque Instability in Patient with Carotid Artery Stenosis.

BACKGROUND: Vulnerable carotid plaques are related to cerebral thromboembolic and ischemic events. Neutrophil extracellular traps (NETs) can induce endothelial dysfunction and induce inflammation and coagulation. The aim of the present study was to investigate NETs in patients with carotid artery plaques. METHODS: Carotid plaques were collected by carotid endarterectomy (CEA) from 26 symptomatic and 8 asymptomatic patients between August 2017 and January 2021. The specimens were stained with hematoxylin-eosin and Elastica-van Gieson. Immunohistochemistry was performed staining by CD31 for identifying endothelial cells. NETs were detected by digoxigenin-labeled antihistone H3 (HH3) (citrulline R2+R8+R17). The relationships between the presence of NETs and patient profile and histopathological findings were assessed. RESULTS: HH3-positive cells were detected in 17 (asymptomatic = 2 symptomatic = 15) of 34 carotid plaques (median = 9.7/mm). The number of NETs was correlated with the number of diffusion-weighted imaging high-intensity lesions [P = 0.01], plaque rupture [P = 0.001], intraplaque hemorrhage [P = 0.02], intra luminal thrombus [P = 0.001], and thin fibrous cap [P = 0.001]. CONCLUSIONS: The presence of NETs was associated with the instability of carotid plaques, intraluminal thrombus, which may lead to subsequent cerebral infarction. Clarifying the roles of NETs in carotid plaques may improve the treatment of carotid artery disease.

Hypertension and Advanced Age Increase the Risk of Cognitive Impairment after Mild Traumatic Brain Injury: A Registry-Based Study.

BACKGROUND: As the global population ages, the incidence of traumatic brain injury (TBI) is increasing. Whereas mild TBI can impair the cognitive function of older adults, the cause and background of mild TBI-induced cognitive impairment remain unclear, and the evaluation of risk factors for cognitive impairment after mild TBI remains open for consideration, especially in the aging population. This study aimed to evaluate the risks associated with cognitive impairment following mild TBI. METHODS: Between January 2006 and December 2018, a total of 2209 patients with TBI required hospitalization in Shimane Prefectural Central Hospital. Mild TBI was defined as a Japan Coma Scale ≤10 at admission. Patients' cognitive function was measured with the Hasegawa Dementia Rating Scale-Revised or Mini-Mental State Examination at least twice during the patients' hospital stays. The odds ratio (OR) and 95% confidence interval (CI) of each considered risk factor was calculated with multivariable logistic regression analysis after univariate analysis. RESULTS: Among 1674 patients with mild TBI, 172 patients underwent cognitive function examinations, of whom 145 (84.3%) were found to have cognitive impairment at discharge. Significant risk factors for cognitive impairment included age (P = 0.008) and hypertension (P = 0.013) in univariate analysis; and age (OR, 1.04: 95% CI, 1.01-1.07) and hypertension (OR, 5.81: 95% CI, 1.22-27.68) by multivariable analysis. CONCLUSIONS: Older patients with hypertension displayed a significantly higher risk for cognitive impairment after even mild TBI. These patients warrant careful management after even mild TBI.

Segmentation of aneurysm wall enhancement in evolving unruptured intracranial aneurysms.

OBJECTIVE: Morphological changes in unruptured intracranial aneurysms (UIAs) are an imaging marker of aneurysm instability. Recent studies have indicated the ability of MR vessel wall imaging (VWI) to stratify unstable UIAs based on a correlation with histopathological aneurysm wall inflammation. In the present study the authors investigated the relationships between aneurysm growth patterns and the segmentation of aneurysm wall enhancement (AWE) in VWI. METHODS: A total of 120 aneurysms with serial angiography from a follow-up period of at least 2 years (mean 65 months, range 24-215 months) were assessed by VWI. Two readers independently evaluated the patterns of morphological changes (stable, whole sac expansion, and secondary aneurysm formation) and the segmentation of AWE (no, focal, and circumferential AWE). The contrast enhancement ratio of the aneurysm wall versus the pituitary stalk (CRstalk) was calculated for the quantitative assessment of AWE. Statistical analyses were performed to investigate the relationships between AWE patterns and patient baseline profiles, aneurysm characteristics, and morphological modifications. RESULTS: Forty-one of 120 UIAs (34%) exhibited aneurysm growth (whole sac expansion in 19 and secondary aneurysm formation in 22). AWE was detected in 35 of 120 UIAs (focal AWE in 25 and circumferential AWE in 10). The maximum diameter of, irregularities in, and morphological modifications in aneurysms were associated with the segmentation of AWE. Focal AWE correlated with secondary aneurysm formation, and circumferential AWE correlated with whole sac expansion. In focal AWE, CRstalk was significantly higher in secondary aneurysm formation than in stable UIAs. UIAs without AWE (categorized as no AWE) correlated with aneurysm stability. CONCLUSIONS: The segmentation of AWE was associated with aneurysm growth scenarios and may provide a novel insight into the evaluation of unstable UIAs.

Monitoring Intramural Hematoma on Vessel Wall Imaging to Evaluate the Healing of Intracranial Vertebral Artery Dissection.

OBJECTIVE: Unruptured intracranial vertebral artery dissection (VAD) generally heals spontaneously. A chronological evaluation of intramural hematoma (IMH) using T1-weighted vessel wall imaging (VWI) may provide a more detailed understanding of the pathophysiology of VAD. We herein investigated the relationship between chronological signal changes in IMH on VWI and the spontaneous healing of VAD. MATERIALS AND METHODS: We retrospectively investigated 26 patients with 27 unruptured VADs who underwent magnetic resonance (MR) imaging more than three times during the follow-up period. Morphological changes were evaluated using MR angiography (MRA). The relative signal intensity (RSI) of IMH against the posterior cervical muscle on T1-weighted VWI was calculated. The ratio of chronological RSI changes was defined as follows: maximum RSI/minimum RSI (RSI max/min). Based on the median value of RSI max/min, 27 VADs were divided into VADs with and without chronological RSI changes. Statistical analyses were performed to compare clinical and radiological findings between the two groups. RESULTS: Spontaneous healing occurred in 17 out of 27 VADs (63%). The median value of RSI max/min was 1.48. The RSI of VADs with chronological RSI changes (RSI max/min ≥ 1.48) increased until three weeks after their onset and decreased over time, while that of VADs without chronological RSI changes (RSI max/min < 1.48) showed no change. The frequency of healing was significantly higher in VADs with than without chronological RSI changes (100% vs 23%, p < 0.0001). CONCLUSIONS: Chronological signal changes in IMH on T1-weighted VWI have potential as a diagnostic imaging marker of the spontaneous healing of VAD.

Peptidylarginine Deiminase 4 as a Possible Biomarker of Plaque Instability in Carotid Artery Stenosis.

BACKGROUND AND PURPOSE: Neutrophil extracellular traps (NETs) exhibit pro-inflammatory and pro-thrombotic properties. However, they have only been reported as important regulators in atherosclerosis, especially in atherothrombosis. We investigated the presence of NETs and plaque instability in patients with carotid artery stenosis. MATERIAL AND METHODS: A total of 39 consecutive patients with carotid artery stenosis were evaluated. All patients underwent carotid artery stenting (CAS) with dual protection (simultaneous flow reversal + distal filter) and blood aspiration as a method of distal embolism prevention. Local arterial blood was aspirated at the stent site and peptidylarginine deiminase 4 (PAD4), which is essential for the formation of NETs, was measured. The relationships between PAD4 and the patient profile, blood examination and plaque data were investigated. RESULTS: The mean value of PAD4 in local arterial blood in CAS was 0.5 ng/ml. Bivariate analysis demonstrated that PAD4 was associated with the neutrophil to lymphocyte ratio (p = 0.007), high-density lipoprotein (p = 0.02), triglycerides to high-density lipoprotein ratio (p = 0.007), ulceration (p = 0.02) and plaque contrast enhancement on T1 black blood imaging (p = 0.03). In multiple linear regression analyses, PAD4 was correlated with the neutrophil to lymphocyte ratio (p = 0.01) and ulceration (p = 0.01, cut-off value: 0.49 odds ratio: 19.3). CONCLUSIONS: PAD4, representative of the presence of NETs, was high in carotid plaques with unstable features. The neutrophil to lymphocyte ratio in peripheral blood was suggested to be a biomarker of vulnerable plaques. Elucidating the role of NETs may aid in clarifying factors that promote the instability of carotid plaques.

Development and Validation of Scoring Indication of Surgical Clipping and Endovascular Coiling for Aneurysmal Subarachnoid Hemorrhage from the Post Hoc Analysis of Japan Stroke Data Bank.

There are no scoring methods for optimal treatment of patients with aneurysmal subarachnoid hemorrhage (aSAH). We developed a scoring model to predict clinical outcomes according to aSAH risk factors using data from the Japan Stroke Data Bank (JSDB). Of 5344 patients initially registered in the JSDB, 3547 met the inclusion criteria. Patients had been diagnosed with aSAH and treated with surgical clipping or endovascular coiling between 1998 and 2013. We performed multivariate logistic regression for poor outcomes at discharge, indicated by a modified Rankin Scale (mRS) score >2, and in-hospital mortality for both treatment methods. Based on each risk factor, we developed a scoring model assessing its validity using another dataset of our institution. In the surgical clipping group, scoring criteria for aSAH were age >72 years, history of more than once stroke, World Federation of Neurological Societies (WFNS) grades II-V, aneurysmal size >15 mm, and vertebrobasilar artery (VBA) aneurysm location. In the endovascular coiling group, scoring criteria were age >80 years, history of stroke, WFNS grades III-V, computed tomography (CT) Fisher group 4, and aneurysmal location in the middle cerebral artery (MCA) and anterior cerebral artery (ACA). The rates of poor outcome of mRS score >2 in an isolated dataset using these scoring criteria were significantly correlated with our model's scores, so this scoring model was validated. This scoring model can help in the more objective treatment selection in patients with aSAH.

Aging Changes of Aneurysmal Subarachnoid Hemorrhage: A 35-year, Hospital-Based Study.

BACKGROUND: The etiology and background factors which cause decreases in the size of ruptured intracranial aneurysms remain unclear. OBJECTIVE: To clarify the age- and sex-related differences in aneurysmal subarachnoid hemorrhage (SAH) based on a 35-year-old hospital database and demographic data. METHODS: A database of patients admitted to our hospital with aneurysmal SAH from 1983 to 2017 was split into 5-year intervals and analyzed. Demographic data of the general population were also analyzed for reference. RESULTS: Altogether, 1,523 aneurysmal SAH events were enrolled in the analysis. Age (p<0.001), proportion of elderly patients ≥ 65 years old (p<0.001), female sex (p=0.005), very small aneurysms less than 5 mm (p<0.001), and the yearly-averaged number of fatal events showed increasing trends. The proportion of aneurysm size of 10 mm or more (p = 0.011) and the yearly-averaged population of Shimane prefecture (p < 0.001) showed declining trends. In the subgroup analyses, the proportion of very small aneurysms was found to increase significantly in the non-elderly male and elderly female subgroups. The proportion of large aneurysms (10 mm or more) decreased in the non-elderly subgroup (p<0.05). As for the elderly subgroups, the yearly-averaged number of events did not show a significant tendency, although the yearly-averaged population of Shimane prefecture showed an increasing trend. CONCLUSION: We found an increasing trend in the prevalence of very small aneurysms in elderly females. Recent aging may contribute to this trend. The number of aneurysmal SAH events was confirmed to not increase, despite the increased aging population of Shimane prefecture.

Impact of Cone-Beam Computed Tomography Angiography on Visualization of Sylvian Veins.

BACKGROUND: A detailed understanding of the anatomy of Sylvian veins preoperatively is needed for venous-preserving Sylvian dissection. Better visualization of the venous architecture will facilitate surgical strategies for Sylvian dissection. This study evaluated and compared the image quality of the Sylvian veins and their tributaries using high-resolution cone-beam computed tomography angiography (CBCT-A) and three-dimensional computed tomography angiography (3D-CTA). METHODS: Twenty-four patients who underwent 3D-CTA and CBCT-A as a preoperative simulation for clipping of unruptured intracranial aneurysms were retrospectively reviewed. In comparisons with intraoperative inspections, 3 raters evaluated the image quality of the Sylvian veins by 3D-CTA and CBCT-A with a 5-point scale. Visualization of the Sylvian veins and their tributaries by the 2 imaging modalities was compared using Wilcoxon signed rank test. RESULTS: CBCT-A showed superior image quality to 3D-CTA in evaluations of the discrimination of adjacent superficial Sylvian veins (2.8 ± 0.80 vs. 4.6 ± 0.37, P < 0.0001), adjacent Sylvian veins at the sphenoid wing (3.1 ± 0.71 vs. 4.1 ± 0.56, P = 0.0001), and visualization of the tributaries of the Sylvian veins (2.5 ± 0.70 vs. 4.4 ± 0.37, P < 0.0001). CONCLUSIONS: CBCT-A was superior to 3D-CTA for visualizing the Sylvian veins and their tributaries. CBCT-A will provide important information on the anatomy of the Sylvian veins preoperatively.

Risk Factor for Poor Outcome in Elderly Patients with Aneurysmal Subarachnoid Hemorrhage Based on Post Hoc Analysis of the Modified WFNS Scale Study.

OBJECTIVE: There is currently no precise guide for the treatment and management of elderly patients with aneurysmal subarachnoid hemorrhage (aSAH). Thus, the aim of this study was to clarify the factors of poor outcome and mortality in elderly patients with aSAH. METHODS: In the modified World Federation of Neurosurgical Societies (mWFNS) scale study, 1124 patients were divided into 2 groups, elderly (age ≥65 years) and non-elderly (age <65 years), with aSAH investigated between October 2010 and March 2013 in Japan. The odds ratio (OR) and 95% confidence interval (CI) of each risk factor was calculated through multivariate logistic regression analysis for poor outcomes, as indicated by the modified Rankin Scale (mRS) score ≥3 and mortality at 3 months after onset in each group. RESULTS: Both groups demonstrated that the mWFNS scale was significant as a grade order risk factor for poor outcomes and mortality associated with disease. In the elderly group, risk factors for poor outcomes at 3 months after onset were older age (OR 1.10, 95% CI 1.06-1.14), male sex (OR 2.03, 95% CI 1.10-3.73), and severe cerebral vasospasm category (OR 10.13, 95% CI 4.30-23.87). Risk factors for mortality at 3 months after onset were older age (OR 1.06, 95% CI 1.01-1.11) and severe vasospasm category (OR 2.17, 95% CI 1.00-4.72). CONCLUSIONS: The mWFNS scale is a useful prognostic predictor for both non-elderly and elderly patients with aSAH. Elderly male patients with aSAH presenting with severe vasospasm should be managed more carefully.

Characteristics of Cerebral Aneurysms in Japan.

The characteristics of cerebral aneurysms in Japan differ from other countries in the higher incidence of unruptured cerebral aneurysm detected by brain check-up screening, higher rupture rate of unruptured cerebral aneurysm, higher incidence of subarachnoid hemorrhage, and superior outcome after subarachnoid hemorrhage based on meta-analysis. Head shape, genetic features, environmental factors, demographics, and medical system in Japan are also different from other countries. Unruptured cerebral aneurysms are 2.8 times more likely to rupture in Japanese than western aneurysms, resulting in the highest incidence of subarachnoid hemorrhage in the world. The exact and specific mechanisms of de novo, growth, and rupture of cerebral aneurysms have not been elucidated. Investigations will contribute to the understanding of cerebral aneurysms and subarachnoid hemorrhage worldwide. Some features of cerebral aneurysm in Japan are discussed for possible research guidance in the elucidation of the predominance of subarachnoid hemorrhage in Japan.

Questionnaire Survey Regarding Prevention of Surgical Site Infection after Neurosurgery in Japan: Focus on Perioperative Management and Administration of Surgical Antibiotic Prophylaxis.

Various guidelines regarding surgical site infection (SSI) have recently been established. However, perioperative management of the wound and use of antibiotics have never been standardized completely in departments of neurosurgery in Japan. This survey investigated current perioperative management and administration of surgical antibiotic prophylaxis (SAP) and compared with guidelines intended to reduce SSI associated with neurosurgery in Japan. Questionnaires were distributed to members of the conference on Neurosurgical Techniques and Tools and the Japan Society of Aesthetic Neurosurgery via internet. The questionnaires asked about methods of perioperative management. A total of 255 members returned answers to the questionnaires. The questionnaires revealed that partial or no removal of the hair and hair shampooing at the day before surgery were performed in 96.1% and 88.1% of each institute following the World Health Organization (WHO) guidelines. Use of SAP at just before, during, and after surgery were 65.0%, 86.2%, and 63.0%, respectively. The postoperative period of use of intravenous SAP prolonged beyond 24 h in 80.0% against the recommendation of WHO. Perioperative management of wounds and use of SAP varies in institutes in Japan and some procedures were far different from the WHO guidelines. Japanese neurosurgeons should notice the prolonged SAP and comply with the WHO guidelines.

Newly developed electromagnetic tracked flexible neuroendoscope.

Flexible endoscopes can be used in areas that are difficult to approach using rigid endoscopes. No current real-time navigation systems identify the tip of the flexible neuroendoscope. We have developed a flexible neuroendoscope mounted with a magnetic field sensor tip position-tracking system and evaluated the accuracy of this magnetic field neuronavigation system. Based on an existing flexible neuroendoscope, we created a prototype with a built-in magnetic field sensor in the tip. A magnetic field measurement device provides a magnetic field with a working volume of 500 × 500 × 500 mm in front of the device. The device consists of a flat field generator that creates a pulsed magnetic field, connected to a system control unit that interfaces with a computer. The magnetic field sensor (1.8 × 9 mm) was sealed in a site 0.9 mm from the endoscope tip. Accuracy of neuroendoscope tracking was measured using a three-dimensional coordinate-measuring machine that measures the position of objects along 3 axes, with an error of about 3 µm. The accuracy for this neuroendoscope with built-in magnetic field sensor was root mean square error of 1.2 mm and standard deviation of 0.5 mm. This magnetic field neuronavigation system enables real-time tracking of the tip of the flexible neuroendoscope. Application of this flexible neuroendoscope to intraoperative navigation appears promising, and may provide new advantages for minimally invasive endoscopic surgery.

Impact of the combination of 5-aminolevulinic acid-induced fluorescence with intraoperative magnetic resonance imaging-guided surgery for glioma.

OBJECTIVE: To compare intraoperative magnetic resonance imaging (MRI)-guided resection with resection guided by 5-aminolevulinic acid (5-ALA)-induced fluorescence in patients with gliomas and to evaluate the impact of intraoperative MRI in glioma surgery. METHODS: From January 2005 to February 2009, 33 patients with gliomas (6 with World Health Organization [WHO] grade II, 7 with WHO grade III, 20 with WHO grade IV) who underwent craniotomy with neuronavigation and received 5-ALA by the same neurosurgeon were investigated retrospectively. In 19 patients, operations were performed using a combination of 5-ALA with intraoperative 1.5-T MRI. All patients were subjected to postoperative 1.5-T MRI to confirm the extent of resection. RESULTS: Of 33 patients with gliomas, 21 (4 with WHO grade III and 17 with WHO grade IV) were 5-ALA-induced fluorescence-positive (5-ALA (+)). Surgery with intraoperative MRI was performed in 10 of the 21 patients, and the average resection rate was 92.6%. The average resection rate of patients who underwent surgery without intraoperative MRI was 91.8%. 5-ALA-induced fluorescence was not detected in 12 patients (6 with WHO grade II, 3 with WHO grade III, and 3 with WHO grade IV) with gliomas. Surgery with intraoperative MRI was performed in 9 of 12 patients, and the average resection rate was 89.2%. The average resection rate of patients who underwent surgery without intraoperative MRI was 68.7%. Intraoperative MRI-guided tumor resection resulted in a better resection rate in patients with 5-ALA-induced fluorescence-negative (5-ALA (-)) gliomas than in patients with 5-ALA (+) gliomas (20.5% vs 0.8%). CONCLUSIONS: Intraoperative MRI-guided resection is a powerful tool to treat 5-ALA (-) gliomas (mostly low grade), and 5-ALA is useful for high-grade gliomas. The combination of intraoperative MRI and 5-ALA has a synergistic effect in glioma surgery. Additionally, precise tumor grading in preoperative imaging studies can be difficult. Surgery for gliomas should be performed using both 5-ALA-induced fluorescence and intraoperative MRI-guided resection.

Brain metastasis from large cell neuroendocrine carcinoma of the urinary bladder.

BACKGROUND: In patients with urinary bladder cancer, brain metastases are quite rare and occur in only 1-7% of these patients. Of the urinary bladder cancers, large cell neuroendocrine carcinoma (LCNEC) is extremely rare; only 16 cases have been reported to date. In this report, a case of brain metastasis from LCNEC of the urinary bladder is described. CASE DESCRIPTION: A 74-year-old man was admitted with confusion and left-sided hemiparesis. Head magnetic resonance imaging demonstrated a ring-enhancing lesion in the right frontal lobe. Whole body computed tomography revealed a suspicious lesion in the urinary bladder. These findings were considered consistent with metastatic brain tumor. Craniotomy and tumor removal were performed. After craniotomy, the patient underwent cystoscopy and the bladder mass was biopsied. Histological and immunohistochemical examination of both the brain tumor and bladder mass revealed LCNEC. According to these findings, the patient was diagnosed with a brain metastasis from LCNEC of the urinary bladder. CONCLUSION: To our knowledge, this is the first report of a patient with a brain metastasis from LCNEC of the urinary bladder.

Cortical subarachnoid hemorrhage caused by cerebral venous thrombosis.

Patients with non-traumatic, non-aneurysmal, and non-perimesencephalic subarachnoid hemorrhage (SAH) tend to have clots circumscribed along the cortical convexity, a condition referred to as acute cortical SAH. Cerebral venous thrombosis (CVT) is a potential cause of cortical SAH. The study tried to establish the diagnosis and management of cortical SAH caused by CVT. Retrospective review of 145 patients with non-traumatic SAH identified 15 patients with no ruptured aneurysm. Clinical features were investigated with a specific focus on patients with SAH caused by CVT. Eight of the 15 patients had perimesencephalic SAH, and 7 had cortical SAH. SAH caused by CVT was diagnosed in 4 of the 7 patients with cortical SAH. The cortical SAH involved the unilateral convexity or sylvian cistern and spared the basal cistern on computed tomography in all 4 patients. CVT occurred in the transverse sinus and cortical vein (1 patient), insular vein (1 patient), and cortical vein (2 patients). Identification of thrombosed veins or sinuses was established directly by T(2)*-weighted and diffusion-weighted magnetic resonance (MR) imaging in the acute stage and diffusion-weighted and T(1)-weighted MR imaging in the subacute stage. All patients had cortical swelling without findings of venous hemorrhagic infarction on T(2)*-weighted MR imaging. None of the 4 patients received active treatment, and all had favorable outcomes. CVT in patients with non-traumatic cortical SAH should be first excluded as a potential hemorrhagic cause by MR imaging for thrombosed veins or sinuses before initiating antifibrinolytic therapy.

Multimodality imaging suite: neo-futuristic diagnostic imaging operating suite marks a significant milestone for innovation in medical technology.

In February 2006, Tokai University Hospital officially opened the imaging operation suite, which is the first hybrid neurosurgical procedure suite to combine magnetic resonance imaging, computed tomography and angiography with a neurosurgical operating room. Here, we describe the concept of the imaging operation suite and the first 4 years' experience using this suite.