Cervical Spine Prospective Feasibility Study : Dynamic Flexion-Extension Diffusion-Tensor Weighted Magnetic Resonance Imaging.

PURPOSE: Diffusion tensor imaging (DTI) in flexion-extension may serve as a diagnostic tool to improve the sensitivity for detection of myelopathy. In this study, the feasibility and reproducibility of dynamic DTI in the cervical spinal cord was assessed in healthy volunteers and patients. METHODS: All subjects were examined in maximum neck flexion-extension in a 3T magnetic resonance imaging (MRI) scanner. Range of motion, space available for the spinal cord, fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were measured and compared between the neck positions. RESULTS: Volunteers showed no variation in ADC and FA. In patients, extension produced higher ADC in the diseased than in the control segments (p = 0.0045). The ADC of the affected segments was higher in extension than in the neutral position (p = 0.0030) or in flexion (p = 0.0002). The FA was significantly lower in extension in patients at both the control level C2/3 (p = 0.0154) and the affected segment (p = 0.0187). CONCLUSIONS: Dynamic DTI of the cervical spine is feasible and ADC increased in the patient group in extension. This finding may open a previously unexplored avenue to attempt an earlier identification of myelopathy.

Validation and accuracy of intraoperative CT scan using the Philips AlluraXper FD20 angiography suite for assessment of spinal instrumentation.

BACKGROUND: With the concept of the hybrid operating room gaining popularity, the authors adapted a hybrid angiographic suite with intraoperative computed tomography (iCT) to evaluate accuracy of pedicle screw placement in spinal fusion. This retrospective review examines how well iCT detected extrapedicular screw violation, to then allow repositioning and potentially avoid revision surgery. METHODS: A total of 36 consecutive patients underwent pedicle screw placement in posterior cervical, thoracic, and lumbosacral spinal fusions. All patients underwent iCT in the Philips AlluraXper FD20 angiography suite in the lumbar spine XperCT mode and postoperative conventional computed tomography (CT) scanning. Primary endpoints included the sensitivity and specificity of iCT in detecting pedicular violation characterized as minor, moderate, or severe when compared with postoperative CT. Secondary endpoint included the incidence of replaced screws during surgery and number of revision surgeries. RESULTS: Of 241 screws placed in 16 males and 20 females, iCT detected severe pedicle violation in 25 screws (10.4%); 16 screws were then repositioned during surgery. Sensitivity and specificity of iCT to detect severe screw malposition were 92.3% and 99.1%, respectively. No revision surgeries were performed in this series. CONCLUSIONS: In our series, iCT had high sensitivity and specificity in detecting severe screw malposition. As a valuable adjunct for intraoperative assessment of pedicle screw position, immediate intraoperative correction of misplaced screws then eliminated any revision surgery for our patients.

Ipsilateral Dural Thickening and Enhancement: A Sign of Isolated Cortical Vein Thrombosis? A Case Report and Review of the Literature.

BACKGROUND: Isolated cortical vein thrombosis (ICVT) being a rare condition (6% of intracranial vein thromboses), no clinical guidelines and few radiologic clues to it have been established. ICVT mostly appears in conjunction with sinus vein thromboses. ICVTs primarily occur during pregnancy and puerperium (35%). The great variability of cortical veins and difficulty identifying small occluded vessels complicate ICVT diagnosis. We present the first case of isolated ipsilateral dural thickening and enhancement as a potential radiologic sign of ICVT shown on magnetic resonance imaging. CASE DESCRIPTION: A 30-year-old woman presented with sudden position-independent severe headache and neck pain 2 weeks postpartum. Standard magnetic resonance imaging revealed ipsilateral dural thickening and enhancement of the meninges (left hemisphere). The symptoms and findings were interpreted as a post-lumbar puncture syndrome associated with the epidural anesthesia during labor and birth. Deteriorating, the patient was referred to our hospital after a computed tomography scan had revealed atypical left parietal intracranial hemorrhage. Digital cerebral subtraction angiography confirmed a left parietal ICVT as the underlying disease. When systemic anticoagulation was initiated, the patient's condition further deteriorated. Progressive aphasia and right-sided face and arm weakness and numbness developed as a result of increased intracranial hemorrhage volume. We therefore performed craniotomy and hematoma evacuation, after which the patient fully recovered. CONCLUSIONS: We hypothesize that ipsilateral dural thickening and enhancement in patients presenting with severe headache may indicate ICVT and we suggest further diagnostic workup, using venographic study such as computed tomographic venography or magnetic resonance venography. In an inconclusive venographic study with high clinical suspicion for ICVT, catheter cerebral angiography is indicated.

The Extended Subfrontal and Fronto-Orbito-Zygomatic Approach in Skull Base Meningioma Surgery: Clinical, Radiologic, and Cosmetic Outcome.

OBJECTIVE: To review the outcome and cosmetic results of patients undergoing extended subfrontal and fronto-orbito-zygomatic craniotomy for resection of skull base meningiomas. METHODS: All surgeries were performed in cooperation with an oral and maxillofacial surgeon between 2006 and 2012. Clinical presentation, surgical techniques and complications, cosmetic, clinical, and radiologic outcomes are presented. RESULTS: This study included 25 consecutive patients with 26 operations. Total and subtotal tumor removal was obtained in 19 (73.1%) and 7 (26.9%) patients, respectively. Permanent postoperative complications were seen in 5 (19.2%) patients. Eight of 10 patients with preoperative visual impairment showed recovery at 6 months follow-up. Anosmia was improved in 50% and no worsening was seen in any case of hyposmia. All patients showed improved or complete correction of exophthalmos, cognitive deficits, and epilepsy. One patient (3.8%) developed a postoperative ptosis. No mortality was documented. All patients reported a favorable cosmetic satisfactory score over 6 (8.67 ±â€Š1.6). Tumor recurrence rate was 7.7% (n = 2). CONCLUSIONS: The extended subfrontal and fronto-orbito-zygomatic approach, used for resection of meningiomas located in the orbita and the skull base can provide better visibility of the tumor. In addition, these approaches lead to highly satisfying cosmetic and clinical results.

Non-instrumented extradural lumbar spine surgery under low-dose acetylsalicylic acid: a comparative risk analysis study.

PURPOSE: Coronary artery disease (CAD) affects over one-third of adults and is the leading cause of overall mortality and morbidity. Acetylsalicylic acid (ASA) is widely used in the prevention of CAD. As the population continues to mature, the number of patients presenting for spinal surgery that are under ASA treatment is rising. Studies investigating the outcome of lumbar spine surgeries without discontinuation of ASA therapy are lacking. The purpose of this study is to evaluate the peri- and postoperative bleeding and cardiovascular complication rates of patients undergoing non-instrumented, extradural, lumbar spine surgery with or without discontinuation of low-dose ASA. METHODS: We retrospectively compared the intra- and postoperative blood loss, morbidity, mortality, blood transfusion requirements and hematologic findings in the ASA group (40 patients) and the control group (62 patients). The diagnosis in all patients was either lumbar disc herniation or spinal canal stenosis. RESULTS: Intraoperative blood loss was 221 ml in the ASA group and 140.16 ml in the control group, showing no statistical difference (p = 0.08). Postoperative blood loss was 146.58 and 167.97 ml in the ASA and control groups, respectively, also without statistical difference (p = 0.76). In the ASA group one patient developed a postoperative epidural hematoma needing revision surgery, while in the control group no postoperative epidural hematomas were seen (p = 0.40). In addition, blood transfusion requirements, hematologic findings, morbidity and mortality showed no significant difference. CONCLUSION: The continuation of ASA treatment in patients undergoing non-instrumented extradural lumbar spinal surgery seems to be safe and its perioperative continuation might therefore be recommended. Further studies confirming these results are needed.

Parasagittal Dural Arteriovenous Fistula Treated With Embozene Microspheres.

PURPOSE: To describe the use of Embozene microspheres as an alternative treatment for intracranial dural arteriovenous fistulas (DAVF). CASE REPORT: The DAVF was located close to the vertex and mainly fed by the left medial meningeal artery (MMA). Embolization was performed using Embozene microspheres due to stenosis in the posterior branch of the left MMA and a conglomerate of tortuous courses in the anterior branch. Complete occlusion was achieved without complication. Neurological symptoms improved, and the patient remained asymptomatic during 1-year follow-up. Angiography at 1 year did not reveal any revascularization. CONCLUSION: Use of microspheres may be a safe and effective alternative treatment, particularly in patients with impeded access to the DAVF.

Outcomes after combined use of intraoperative MRI and 5-aminolevulinic acid in high-grade glioma surgery.

BACKGROUND: Previous studies have shown the individual benefits of 5-aminolevulinic acid (5-ALA) and intraoperative (i)MRI in enhancing survival for patients with high-grade glioma. In this retrospective study, we compare rates of progression-free and overall survival between patients who underwent surgical resection with the combination of 5-ALA and iMRI and a control group without iMRI. METHODS: In 200 consecutive patients with high-grade gliomas, we recorded age, sex, World Health Organization tumor grade, and pre- and postoperative Karnofsky performance status (good ≥80 and poor <80). A 0.15-Tesla magnet was used for iMRI; all patients operated on with iMRI received 5-ALA. Overall and progression-free survival rates were compared using multivariable regression analysis. RESULTS: Median overall survival was 13.8 months in the non-iMRI group and 17.9 months in the iMRI group (P = .043). However, on identifying confounding variables (ie, KPS and resection status) in this univariate analysis, we then adjusted for these confounders in multivariate analysis and eliminated this distinction in overall survival (hazard ratio: 1.23, P = .34, 95% CI: 0.81, 1.86). Although 5-ALA enhanced the achievement of gross total resection (odds ratio: 3.19, P = .01, 95% CI: 1.28, 7.93), it offered no effect on overall or progression-free survival when adjusted for resection status. CONCLUSIONS: Gross total resection is the key surgical variable that influences progression and survival in patients with high-grade glioma and more likely when surgical adjuncts, such as iMRI in combination with 5-ALA, are used to enhance resection.

Estrogen induces nitric oxide production via nitric oxide synthase activation in endothelial cells.

INTRODUCTION: 17ß-estradiol (E2) has been found to induce vasodilation in the cardiovascular system and at physiological levels, resulting in prevention of cerebral vasospasm following subarachnoid hemorrhage (SAH) in animal models. The goal of this study was to analyze the cellular mechanism of nitric oxide (NO) production and its relation to E2, in vitro in brain and peripheral endothelial cells. METHODS: Human umbilical endothelial cells (HUVEC) and brain endothelial cells (bEnd.3) were treated with estradiol (E2, 0.1, 10, 100, and 1,000 nM), and supernatant was collected at 0, 5, 15, 30, 60, and 120 min for nitric oxide metabolome (nitrite, NO2) measurements. Cells were also treated with E2 in the presence of 1400W, a potent eNOS inhibitor, and ICI, an antagonist of estradiol receptors (ERs). Effects of E2 on eNOS protein expression were assessed with Western blot analysis. RESULTS: E2 significantly increased NO2 levels irrespective of its concentration in both cell lines by 35 % and 42 % (p < 0.05). The addition of an E2 antagonist, ICI (10 µM), prevented the E2-induced increases in NO2 levels (11 % p > 0.05). The combination of E2 (10 nM) and a NOS inhibitor (1400W, 5 µM) inhibited NO2 increases in addition (4 %, p > 0.05). E2 induced increases in eNOS protein levels and phosphorylated eNOS (eNOS(p)). CONCLUSIONS: This study indicates that E2 induces NO level increases in cerebral and peripheral endothelial cells in vitro via eNOS activation and through E2 receptor-mediated mechanisms. Further in vivo studies are warranted to evaluate the therapeutic value of estrogen for the treatment of SAH-induced vasospasm.

Proximal arterial diameters on CT angiography and digital subtraction angiography correlate both at admission and in the vasospasm period after aneurysmal subarachnoid hemorrhage.

BACKGROUND: Comparison of artery diameters between CT angiography (CTA) and subtraction arteriography (DSA) has the limitation that measurements on DSA are provided as relative units, making a quantitative comparison difficult. On CTA, artery diameters may depend on windowing settings and may lead to false measurements. This study assesses the correlation between CTA and DSA based on measurements in a basic imaging viewer using normalized DSA values, and assesses whether the validity is time dependent. METHODS: Patients with aneurysmal subarachnoid hemorrhage (aSAH) were included if they underwent both CTA and DSA within 24 h. The analysis was performed using the basic imaging application Centricity Enterprise PACS viewer (GE Healthcare). A total of 15 arterial locations were assessed on CTA and DSA and a specific measurement protocol with normalization of all artery diameters to the cavernous segment of the internal carotid artery was used. Pearson correlation analysis was calculated to access the correlation of normalized arterial diameters measured with both methods at admission and at clinical onset of CVS. RESULTS: A total of 627 arteries in 38 patients were analyzed in both CTA and DSA. There was a significant correlation coefficient (R = 0.706) of artery diameters between CTA and DSA measures (p < 0.0001). This correlation remained high when comparing CTA and DSA at admission (correlation coefficient: 0.641; p < 0.0001) vs. in the vasospasm period (0.835; p < 0.0001). The correlation was good in all proximal artery segments and lost significance only when distal vessel segments were considered. CONCLUSION: Using basic imaging viewers, mostly accessible for clinicians, CTA is a noninvasive and reliable method to assess proximal arterial diameters of the brain in the management of cerebral vasospasm in the acute phase after aSAH. Significance is reached, independent of whether CTA is obtained in the acute phase or during the period of vasospasm, by normalization of basal cerebral artery diameters to a non-variable anatomic landmark, i.e., the petrous or cavernous internal carotid artery diameter.

Acute angiographic vasospasm and the incidence of delayed cerebral vasospasm: preliminary results.

BACKGROUND: More than half of subarachnoid hemorrhage (SAH) patients develop angiographically detectable delayed cerebral vasospasm (dCVS). It mostly occurs between days 4 and 15 after ictus and can be associated with neurological deficits that contribute to increased morbidity and mortality after SAH. Although dCVS is well studied, there are only a handful of reports on the acute phase of vasospasm (APV) occurring after treatment of intracranial aneurysms, whether ruptured or not. The aim of the current study is to elucidate the association of intraoperative cerebral vasospasm (iCVS) with the incidence of dCVS. METHOD: We retrospectively reviewed consecutive patients who were treated for aneurysmal SAH or incidental aneurysms during the study period. Angiograms of patients undergoing aneurysm treatment were reviewed. Spasm severity was classified with respect to reduction in the transverse diameter. Mild vasospasm was defined as a reduction in vessel diameter of 10-30 %; moderate, 30-50 %; and severe vasospasm, >50 %. Statistical significance was tested using the Χ² test with p < 0.05. Correlations between iCVS and other factors were investigated. RESULTS: Of 109 patients, 77 patients (33 men and 44 women) presented with acute SAH and 32 patients (9 men and 23 women) were treated for incidental aneurysms. Seventeen (22 %) of 77 patients presenting with acute SAH had evidence of acute (within 72 h after SAH ictus) CVS. In 16 of 17 (94.1 %) patients, this vasospasm was observed immediately after treatment and was therefore termed iCVS. Eleven (30 %) of 36 patients undergoing clipping and 5 (14 %) of 36 patients with endovascular aneurysm occlusion had iCVS (p = 0.07). Patients presenting with acute SAH had a higher incidence of iCVS than patients undergoing elective aneurysm treatment (p = 0.02). Only one patient (3 %) had iCVS in the elective treatment group whereas 16 (20 %) had iCVS after SAH. The incidence of dCVS, delayed ischemic neurological deficits (DNDs), and poor outcome in patients presenting with iCVS during surgical treatment of ruptured aneurysms was 56 % (p = 0.001), 63 % (p = 0.02), and 38 % (p = 0.14), respectively. CONCLUSION: APV exists and is a common finding in patients with SAH. Further studies are warranted to correlate the presence of APV with postoperative ischemia, dCVS, and outcome.

Craniotomy without flap replacement for ruptured intracranial aneurysms to reduce ischemic brain injury: a preliminary safety and feasibility analysis.

BACKGROUND: Cortical and subcortical brain ischemia following aneurysmal subarachnoid hemorrhage (aSAH) remains a central challenge in improving patient outcome. Generally the bone flap is replaced after surgical clipping and no decompression is practiced in endovascularly treated patients. The aim of this preliminary safety and feasibility study is to clarify whether a first-line decompression would improve brain perfusion and salvage more tissue at risk in patients who developed delayed vasospasm. In addition, we assessed whether the risks involved with a second surgery to replace the bone flap would affect patient outcome. METHODS: We retrospectively analyzed patients with aSAH who underwent surgical clipping and developed cerebral vasospasm from 2009 to 2012 at our institution. We selected cases where the bone flap was not replaced at initial surgery and needed a second procedure for bone flap replacement. Primary end points were new delayed ischemic neurological deficits (DINDs), the extent of brain infarctions, and patient functional outcome. Secondary end points were hazards of the second procedure for bone replacement. RESULTS: We identified six patients in whom the surgeon chose not to replace the bone flap. In four patients, this was a pterional bone flap (standard), and in two patients it was a larger frontotemporoparietal flap. Despite the limited extent of the craniotomy, only one patient (16 %) required additional decompression. Two patients (33%) developed DINDs and five patients (83 %) showed delayed cerebral infarctions on computed tomography. Of those, three patients showed good outcome (Glasgow Outcome Scale score >4 and modified Rankin Scale score <3). No complications or new neurological deficits occurred during the second surgery for bone replacement. CONCLUSIONS: To date, no standardized criteria exist to decide whether the bone flap should be removed or replaced at initial surgery. Our single-center experience in a limited number of patients reveals a pattern with respect to initial clinical parameters and imaging findings that might be a first step in developing standardized decision parameters. This may prevent secondary surgery for decompression in deleterious conditions during the vasospasm phase. Based on these findings, we have developed a protocol for a prospective study that will further investigate the benefits of this management.

The rabbit blood shunt subarachnoid haemorrhage model.

The recently introduced rabbit blood shunt subarachnoid haemorrhage model is based on the two standard procedures of subclavian artery cannulation and transcutaneous cisterna magna puncture. An extracorporeal shunt placed in between the arterial system and the subarachnoid space allows examiner-independent SAH in a closed cranium. Despite its straightforwardness, it is worth examining some specific features and characteristics of the model. We outline technical considerations to successfully perform the model with minimal mortality and morbidity. In addition, we discuss outcome measures, advantages and limitations, and the applicability of the model for the study of early brain injury and delayed cerebral vasospasm after SAH.

Blood clot placement model of subarachnoid hemorrhage in non-human primates.

Despite ongoing extensive and promising research to prevent and treat cerebrovascular vasospasm and delayed ischemic neurological deficits (DIND) after aneurysmal subarachnoid hemorrhage (aSAH), clinical outcomes remain unsatisfying. Neuroprotective strategies developed in basic science research laboratories need to be translated from bench-to-bedside using appropriate animal models. While a primate model is widely accepted as the best animal model mimicking development of delayed cerebral vasospasm after aSAH, its worldwide usage has dramatically decreased because of ethical and financial limitations. However, the use of primate models of subarachnoid hemorrhage (SAH) remains a recommended bridge for translation of early preclinical studies in rodents to human clinical trials. This paper discusses the technical aspects as well as advantages and disadvantages of a blood clot placement model of subarachnoid hemorrhage in non-human primates.

Intracranial aneurysm rupture is predicted by measures of solar activity.

OBJECTIVE: The cause precipitating intracranial aneurysm rupture remains unknown in many cases. It has been observed that aneurysm ruptures are clustered in time, but the trigger mechanism remains obscure. Because solar activity has been associated with cardiovascular mortality and morbidity, we decided to study its association to aneurysm rupture in the Swiss population. METHODS: Patient data were extracted from the Swiss SOS database, at time of analysis covering 918 consecutive patients with angiography-proven aneurysmal subarachnoid hemorrhage treated at 7 Swiss neurovascular centers between January 1, 2009, and December 31, 2011. The daily rupture frequency (RF) was correlated to the absolute amount and the change in various parameters of interest representing continuous measurements of solar activity (radioflux [F10.7 index], solar proton flux, solar flare occurrence, planetary K-index/planetary A-index, Space Environment Services Center [SESC] sunspot number and sunspot area) using Poisson regression analysis. RESULTS: During the period of interest, there were 517 days without recorded aneurysm rupture. There were 398, 139, 27, 12, 1, and 1 days with 1, 2, 3, 4, 5, and 6 ruptures per day. Poisson regression analysis demonstrated a significant correlation of F10.7 index and RF (incidence rate ratio [IRR] = 1.006303; standard error (SE) 0.0013201; 95% confidence interval (CI) 1.003719-1.008894; P < 0.001), according to which every 1-unit increase of the F10.7 index increased the count for an aneurysm to rupture by 0.63%. A likewise statistically significant relationship of both the SESC sunspot number (IRR 1.003413; SE 0.0007913; 95% CI 1.001864-1.004965; P < 0.001) and the sunspot area (IRR 1.000419; SE 0.0000866; 95% CI 1.000249-1.000589; P < 0.001) emerged. All other variables analyzed showed no significant correlation with RF. CONCLUSIONS: We found greater radioflux, SESC sunspot number, and sunspot area to be associated with an increased count of aneurysm rupture. The clinical meaningfulness of this statistical association must be interpreted carefully and future studies are warranted to rule out a type-1 error.

Intraoperative visualization of bilateral thrombosis in the posterior inferior cerebellar artery apparent in the telovelomedullary segment.

Unilateral posterior inferior cerebellar artery (PICA) thrombosis is frequent. However, bilateral PICA thrombosis is rare. Herein we report about an intraoperative visualization of a bilateral thrombosis of the telovelomedullary segment of the PICA. A 74-year-old woman was admitted to our department on day two of a bilateral PICA thrombosis with developing cerebellar infarction. Her Glasgow Coma Scale score dropped from 15 to 13, and cranial computed tomography revealed compression of the fourth ventricle with consecutive occlusive hydrocephalus. After the insertion of an external ventricular drainage, the patient underwent urgent suboccipital decompressive craniectomy with removal of infarcted cerebellar tonsils, which allowed the bilateral visualization of the thrombosed telovelomedullary segments. The surgical access may offer surgical therapeutic options in a hyperacute occlusion, such as thromb-/embolectomy or bypass procedures.

Management of aneurysmal subarachnoid haemorrhage.

Aneurysmal subarachnoid haemorrhage (aSAH) occurs as a result of rupture of an intracranial aneurysm and affects a younger population compared with ischaemic stroke or intracerebral haemorrhage. Although it makes up only about 5% of all cerebrovascular events, it accounts for over a quarter of the productive life-years lost to stroke. Its surgical and medical treatment represents a multidisciplinary effort. We herein provide an overview of current management options for aSAH.

Use of fluorescence to guide resection or biopsy of primary brain tumors and brain metastases.

OBJECT: The accurate discrimination between tumor and normal tissue is crucial for determining how much to resect and therefore for the clinical outcome of patients with brain tumors. In recent years, guidance with 5-aminolevulinic acid (5-ALA)-induced intraoperative fluorescence has proven to be a useful surgical adjunct for gross-total resection of high-grade gliomas. The clinical utility of 5-ALA in resection of brain tumors other than glioblastomas has not yet been established. The authors assessed the frequency of positive 5-ALA fluorescence in a cohort of patients with primary brain tumors and metastases. METHODS: The authors conducted a single-center retrospective analysis of 531 patients with intracranial tumors treated by 5-ALA-guided resection or biopsy. They analyzed patient characteristics, preoperative and postoperative liver function test results, intraoperative tumor fluorescence, and histological data. They also screened discharge summaries for clinical adverse effects resulting from the administration of 5-ALA. Intraoperative qualitative 5-ALA fluorescence (none, mild, moderate, and strong) was documented by the surgeon and dichotomized into negative and positive fluorescence. RESULTS: A total of 458 cases qualified for final analysis. The highest percentage of 5-ALA-positive fluorescence in open resection was found in glioblastomas (96%, n = 99/103). Among other tumors, 5-ALA-positive fluorescence was detected in 88% (n = 21/32) of anaplastic gliomas (WHO Grade III), 40% (n = 8/19) of low-grade gliomas (WHO Grade II), no (n = 0/3) WHO Grade I gliomas, and 77% (n = 85/110) of meningiomas. Among metastases, the highest percentage of 5-ALA-positive fluorescence was detected in adenocarcinomas (48%, n = 13/27). Low rates or absence of positive fluorescence was found among pituitary adenomas (8%, n = 1/12) and schwannomas (0%, n = 0/7). Biopsies of high-grade primary brain tumors showed positive rates of fluorescence similar to those recorded for open resection. No clinical adverse effects associated with use of 5-ALA were observed. Only 1 patient had clinically silent transient elevation of liver enzymes. CONCLUSIONS: Study findings suggest that the administration of 5-ALA as a surgical adjunct for resection and biopsy of primary brain tumors and brain metastases is safe. In light of the high rate of positive fluorescence in high-grade gliomas other than glioblastomas, meningiomas, and a variety of metastatic cancers, 5-ALA seems to be a promising tool for enhancing intraoperative identification of neoplastic tissue and optimizing the extent of resection.

Cortical hemosiderin is associated with seizures in patients with newly diagnosed malignant brain tumors.

Hemorrhage is common in brain tumors. Due to characteristic magnetic field changes induced by hemosiderin it can be detected using susceptibility weighted MRI (SWI). Its relevance to clinical syndromes is unclear. Here we investigated the patterns of intra-tumoral SWI positivity (SWI(pos)) as a surrogate for hemosiderin with regard to the prevalence of epilepsy. We report on 105 patients with newly diagnosed supra-tentorial gliomas and brain metastasis. The following parameters were recorded from pre-operative MRI: (1) SWI(pos) defined as dot-like or fine linear signal changes; (2) allocation of SWI(pos) to tumor compartments (contrast enhancement, central hypointensity, non-enhancing area outside contrast-enhancement); (3) allocation of SWI(pos) to include the cortex, or SWI(pos) in subcortical tumor parts only; (4) tumor size on T2 weighted and gadolinium-enhanced T1 images. 80 tumors (76 %) showed SWI(pos) (4/14 diffuse astrocytoma WHO II, 5/9 anaplastic astrocytoma WHO III, 41/46 glioblastoma WHO IV, 30/36 metastasis). The presence of SWI(pos) depended on tumor size but not on patient's age, medication with antiplatelet drugs or anticoagulation. Seizures occurred in 60 % of patients. Cortical SWI(pos) significantly correlated with seizures in brain metastasis (p = 0.044), and as a trend in glioblastoma (p = 0.062). Cortical SWI(pos) may confer a risk for seizures in patients with newly diagnosed brain metastasis and glioblastoma. Whether development of cortical SWI(pos) induced by treatment or by the natural course of tumors also leads to the new onset of seizures has to be addressed in longitudinal studies in larger patient cohorts.

The role of intraoperative magnetic resonance imaging in complex meningioma surgery.

Intraoperative magnetic resonance imaging (iMRI) has gained importance in the treatment of gliomas and sellar tumors. In intracranial meningiomas, the extent of surgical tumor removal is one of the most important factors in the prevention of tumor recurrence and patient survival. Complex meningiomas located at the skull base or near eloquent brain regions show higher recurrence rates, morbidity and mortality. The aim of this study was to evaluate whether iMRI contributes to more extensive surgical resection in these tumors. Patients undergoing complex meningioma resection using iMRI from January 2007 to January 2011 were included in this study. The indication for iMRI-guided tumor resection included patients presenting with meningiomas located in the skull base or compressing eloquent brain areas in whom a radical resection was considered to be difficult. Intraoperative 0.15-T MRI scan (PoleStar; Medtronic Navigation, Louisville, CO, USA) was performed before and after maximal possible resection using standard microsurgical and neuronavigation techniques. All patients underwent fluorescence-guided resection. The following data were analyzed: tumor localization, histological grade, Simpson resection grade, duration of the procedure, iMRI scan time, iMRI findings, resection extent based on postresection iMRI, hospitalization time, surgical complications and outcome, and MRI follow-up 2-27months postoperation. Twenty-seven consecutive patients undergoing complex meningioma resection using iMRI were included. In this series, only one patient (3.4%) underwent resection of tumor remnant after iMRI, although without improvement of the Simpson resection grade. Temporary neurologic deficits were found in 8 patients (27.6%) postoperatively, whereas 11 patients (37.9%) had permanent postoperative neurologic deficits. In one case (3.4%), fatal postoperative bleeding occurred which was not detected by iMRI. Our results show that iMRI has no influence on intraoperative strategy in terms of resection grade or detection of early postoperative complications. The benefits of iMRI in complex meningioma surgery are therefore doubtful; however, it may still prove to be effective in certain subsets of complex meningiomas.

Meningioma.

Meningiomas represent the most common primary brain tumor and comprise 3 World Health Organization (WHO) grades, the most frequent being WHO grade I (90%). Surgery is mandatory to establish the diagnosis and to remove the tumor; however, complete resection can be achieved in only <50% of patients. Depending on the extent of resection, tumor location and the WHO grade radiation therapy can be applied. The issue of systemic treatment such as chemotherapy or targeted therapy (eg, somatostatin receptors, antiangiogenic agents) is yet not solved, particularly as current data are derived from small uncontrolled series in patients with long-standing disease and after several pretreatments. A more thorough understanding of molecular genetics, signaling pathways and prognostic factors in meningiomas should lead to the design of studies which stratify according to these factors. These studies have to be conducted in newly diagnosed patients after incomplete resection and in tumors of WHO grade II and III.