Optical Neuronavigation without Rigid Head Fixation During Awake Surgery

OBJECTIVE

Optical neuronavigation without rigid pin fixation of the head may lead to inaccurate results because of the patient's movements during awake surgery. In this study, we report our results using a skull-mounted reference array for optical tracking in patients undergoing awake craniotomy for eloquent gliomas.

METHODS

Between March 2013 and December 2014, 18 consecutive patients (10 men, 8 women) with frontotemporal (n = 16) or frontoparietal (perirolandic; n = 2) lesions underwent awake craniotomy without rigid pin fixation. All patients had a skull-mounted reference array for optical tracking placed on the forehead. Accuracy of navigation was determined with pointer tip deviation measurements on superficial and bony anatomic structures. Good accuracy was defined as a tip deviation <2 mm.

RESULTS

Gross total resection (>98%) was achieved in 7 patients (38%); >90% of tumor was resected in 8 patients (44%). In 3 patients, only subtotal resection or biopsy was performed secondary to stimulation results. In all patients, good accuracy of the optical neuronavigation system could be demonstrated without intraoperative peculiarities or complications. The reference array had to be repositioned because of loosening in 1 patient. Neuronavigation could be reliably applied to support stimulation-based resection.

CONCLUSIONS

A skull-mounted reference array is a simple and safe method for optical neuronavigation tracking without rigid pin fixation of the patient's head.

Decompressive Hemicraniectomy in Malignant Middle Cerebral Artery Infarction: The 'Real World' Beyond Studies

BACKGROUND

Decompressive hemicraniectomy (DHC) is life-saving in patients with malignant middle cerebral artery infarction (MMI), but outcome, perspectives and complications after DHC in daily practice are largely unknown.

METHODS

From 2008 until 2014, we extracted patient's characteristics as well as complications from our database for patients with MMI who underwent DHC. Additionally, we analysed medical records from the different rehabilitation steps.

RESULTS

We identified 48 consecutive patients (mean 57 years, 21 male, 41.7% >60 years) with MMI who underwent DHC. The decision for DHC was made on an individual basis, including patients without impaired consciousness or stroke onset >48 h. In-hospital patients achieved only marginal clinical improvement. Seventy-five percent attended an early-rehabilitation, 44% achieved post-stroke rehabilitation and 6% carried on late-stage rehabilitation. In all, 45.5% returned home after rehabilitation. In-hospital mortality was 14.6%, overall mortality was 16.7%. Surviving patients (78.9%) had a modified Rankin Scale of 4-5. Frequent neurologic complications were symptomatic epilepsy and delirium. Following DHC/bone-flap-reimplantation, wound-healing disorders, epidural hematoma and wound infections were major surgery-related complications. Pulmonary infections were frequent in the acute-phase and urinary tract infections were predominant in the late-phase.

CONCLUSIONS

DHC is a life-saving technique in patients with MMI, but complications are frequent, were underestimated in randomized clinical trials and may worsen the functional outcome.

Dual Anti-angiogenic Chemotherapy with Temozolomide and Celecoxib in Selected Patients with Malignant Glioma Not Eligible for Standard Treatment

AIM

Due to their high rate of neo-angiogenesis, malignant gliomas may qualify for treatment with anti-angiogenic substances. We report on a series of patients with malignant glioma not eligible for standard postoperative combined radiochemotherapy due to decreased health status.

PATIENTS AND METHODS

A total of nine patients with malignant glioma, postoperatively presenting with a Karnofsky performance score (KPS) below 70, were treated with standalone metronomic low-dose chemotherapy with temozolomide and celecoxib (cyclo-oxygenase-2 inhibitor). Overall survival was defined as the primary end-point and the functional status (KPS) and time to progression as secondary end-points of our analysis.

RESULTS

The median KPS after surgery was 60. Treatment achieved a decrease in tumor and edema volume and, more importantly, preserved the functional status defined as the ability to care for self (KPS 70%) until disease progression. No notable side-effects were recorded.

CONCLUSION

In patients with decreased general condition (KPS <70), not eligible for standard treatment, anti-angiogenic therapy offers a reasonable alternative approach. Our results indicate prolonged survival and preserved quality of life in comparison to best supportive care.

A Sandwich Technique for Prevention of Cerebrospinal Fluid Rhinorrhea and Reconstruction of the Sellar Floor after Microsurgical Transsphenoidal Pituitary Surgery

BACKGROUND

Cerebrospinal fluid (CSF) leaks are a well-known complication of transsphenoidal surgery. Several autologous and artificial grafts have been used to close the sellar floor in an attempt to prevent postoperative CSF rhinorrhea.

OBJECTIVE

To evaluate and describe a sandwich technique to close the sellar floor using autologous bone, absorbable gelatin sponge, and coated collagen fleece.

METHODS

We reviewed 50 consecutive patients between April 2010 and August 2011 who underwent transsphenoidal surgery ending with reconstruction of the sellar floor with a particular sandwich technique. Patients with an intraoperative CSF leak received an additional lumbar drain.

RESULTS

There were no cases of CSF rhinorrhea at postoperative follow-up after 6 weeks and no revision surgery.

CONCLUSION

The proposed sandwich technique for closure of the sellar floor to the sphenoid sinus is a suitable alternative to autologous grafts and seems to be effective in preventing CSF rhinorrhea.

An intra-individual comparison of MRI, [18F]-FET and [18F]-FLT PET in patients with high-grade gliomas

Objectives

Intra-individual spatial overlap analysis of tumor volumes assessed by MRI, the amino acid PET tracer [¹⁸F]-FET and the nucleoside PET tracer [¹⁸F]-FLT in high-grade gliomas (HGG).

Methods

MRI, [¹⁸F]-FET and [¹⁸F]-FLT PET data sets were retrospectively analyzed in 23 HGG patients. Morphologic tumor volumes on MRI (post-contrast T1 (cT1) and T2 images) were calculated using a semi-automatic image segmentation method. Metabolic tumor volumes for [¹⁸F]-FET and [¹⁸F]-FLT PETs were determined by image segmentation using a threshold-based volume of interest analysis. After co-registration with MRI the morphologic and metabolic tumor volumes were compared on an intra-individual basis in order to estimate spatial overlaps using the Spearman's rank correlation coefficient and the Mann-Whitney U test.

Results

[¹⁸F]-FLT uptake was negative in tumors with no or only moderate contrast enhancement on MRI, detecting only 21 of 23 (91%) HGG. In addition, [¹⁸F]-FLT uptake was mainly restricted to cT1 tumor areas on MRI and [¹⁸F]-FLT volumes strongly correlated with cT1 volumes (r = 0.841, p<0.001). In contrast, [¹⁸F]-FET PET detected 22 of 23 (96%) HGG. [¹⁸F]-FET uptake beyond areas of cT1 was found in 61% of cases and [¹⁸F]-FET volumes showed only a moderate correlation with cT1 volumes (r = 0.573, p<0.001). Metabolic tumor volumes beyond cT1 tumor areas were significantly larger for [¹⁸F]-FET compared to [¹⁸F]-FLT tracer uptake (8.3 vs. 2.7 cm³, p<0.001).

Conclusion

In HGG [¹⁸F]-FET but not [¹⁸F]-FLT PET was able to detect metabolic active tumor tissue beyond contrast enhancing tumor on MRI. In contrast to [¹⁸F]-FET, blood-brain barrier breakdown seems to be a prerequisite for [¹⁸F]-FLT tracer uptake.

De novo aneurysm of the anterior communicating artery presenting with subarachnoid hemorrhage 7 years after initial cryptogenic subarachnoid hemorrhage: a case report and review of the literature

Spontaneous subarachnoid hemorrhage (SAH) is usually caused by a ruptured cerebral aneurysm. Despite the use of initial four-vessel cerebral digital subtraction angiography (DSA), 15 % of all cases remain idiopathic. According to the initial computed tomographic scan, the spontaneous SAH can be divided into a perimesencephalic group associated with a benign nature and a nonperimesencephalic group with a similar clinical course as aneurysmal SAH. We present a case of a 49-year-old man with a de novo aneurysm formation of the anterior communicating artery with SAH 7 years after initial cryptogenic nonperimesencephalic SAH. This observation suggests that in some cases, long-term angiographic studies might be justified.

A single-arm phase II Austrian/German multicenter trial on continuous daily sunitinib in primary glioblastoma at first recurrence (SURGE 01-07)

BACKGROUND

Due to the redundancy of molecular pathways simultaneously involved in glioblastoma growth and angiogenesis, therapeutic approaches intervening at multiple levels seem particularly appealing.

METHODS

This prospective, multicenter, single-arm phase II trial was designed to evaluate the antitumor activity of sunitinib, an oral small-molecule inhibitor of several receptor tyrosine kinases, in patients with first recurrence of primary glioblastoma using a continuous once-daily dosing regimen. Patients received a starting dose of sunitinib 37.5 mg, followed by a maintenance dose between 12.5 mg and 50 mg depending on drug tolerability. The primary endpoint was a 6-month progression-free survival (PFS) rate. Secondary endpoints included median PFS, overall survival (OS), safety/toxicity, quality of life, and translational studies on the expression of sunitinib target molecules.

RESULTS

Forty participants were included in this study, and no objective responses were detected. PFS6 was 12.5%, median PFS 2.2 months, and median OS 9.2 months. Five participants (12.5%) showed prolonged stable disease ≥6 months with a median PFS of 16.0 months (range, 6.4-41.4 mo) and a median OS of 46.9 months (range, 21.2-49.2 mo) for this subgroup. c-KIT expression in vascular endothelial cells (n = 14 participants) was associated with improved PFS. The most common toxicities were fatigue/asthenia, mucositis/dermatitis, dysesthesias, gastrointestinal symptoms, cognitive impairment, leukoctopenia, and thrombocytopenia. Two participants (5%) terminated treatment due to toxicity.

CONCLUSION

Continuous daily sunitinib showed minimal antiglioblastoma activity and substantial toxicity when given at higher doses. High endothelial c-KIT expression may define a subgroup of patients who will benefit from sunitinib treatment by achieving prolonged PFS. ClinicalTrials.gov Identifier: NCT00535379.

Distribution of TERT promoter mutations in pediatric and adult tumors of the nervous system

Hot spot mutations in the promoter region of telomerase reverse transcriptase (TERT) have recently been described in several human tumor entities. These mutations result in an upregulation of the telomerase complex activity and thus constitute a relevant mechanism for immortalization of tumor cells. Knowledge of the TERT promoter status in tumors is likely to be of interest for molecular classification and as a potential target for therapy. We, therefore, performed a systematic analysis of TERT promoter mutations in 1,515 tumors of the human nervous system and its coverings including 373 pediatric and 1,142 adult patients. We detected a total of 327 mutations. TERT promoter mutations were exceedingly rare in tumors typically encountered in pediatric patients. In entities typically encountered in adult patients TERT promoter mutations were strongly associated with older age (p < 0.0001). Highest mutation frequencies were detected in gliosarcomas (81 %), oligodendrogliomas (78 %), oligoastrocytomas (58 %), primary glioblastomas (54 %), and solitary fibrous tumors (50 %). Related to other molecular alterations, TERT promoter mutations were strongly associated with 1p/19q loss (p < 0.0001), but inversely associated with loss of ATRX expression (p < 0.0001) and IDH1/IDH2 mutations (p < 0.0001). TERT promoter mutations are typically found in adult patients and occur in a highly tumor type-associated distribution.

Perfusion characteristics of Moyamoya disease: an anatomically and clinically oriented analysis and comparison

BACKGROUND AND PURPOSE

Moyamoya disease (MMD) is characterized by unique angiographic features of collateralization. However, a detailed quantification as well as comparative analysis with cerebrovascular atherosclerotic disease (CAD) and healthy controls have not been performed to date.

METHODS

We reviewed 67 patients with MMD undergoing Xenon-enhanced computed tomography, as well as 108 patients with CAD and 5 controls. In addition to cortical, central, and infratentorial regions of interest, particular emphasis was put on regions that are typically involved in MMD (pericallosal territory, basal ganglia). Cerebral blood flow (CBF), cerebrovascular reserve capacity (CVRC), and hemodynamic stress distribution were calculated.

RESULTS

MMD is characterized by a significant, ubiquitous decrease in CVRC and a cortical but not pericallosal decrease in CBF when compared with controls. Baseline perfusion is maintained within the basal ganglia, and hemodynamic stress distribution confirmed a relative preservation of central regions of interest in MMD, indicative for its characteristic proximal collateralization pattern. In MMD and CAD, cortical and central CBF decreased significantly with age, whereas CVRC and hemodynamic stress distribution are relatively unaffected by age. No difference in CVRC of comparable regions of interest was seen between MMD and CAD, but stress distribution was significantly higher in MMD, illustrating the functionality of the characteristic rete mirabilis.

CONCLUSIONS

Our data provide quantitative support for a territory-specific perfusion pattern that is unique for MMD, including central preservation of CBF compared with controls and patients with CAD. This correlates well with its characteristic feature of proximal collateralization. CVRC and hemodynamic stress distribution seem to be more robust parameters than CBF alone for assessment of disease severity.

[18F]-fluoro-ethyl-L-tyrosine PET: a valuable diagnostic tool in neuro-oncology, but not all that glitters is glioma

BACKGROUND

To assess the sensitivity and specificity of [(18)F]-fluoro-ethyl-l-tyrosine ((18)F-FET) PET in brain tumors and various non-neoplastic neurologic diseases.

METHODS

We retrospectively evaluated (18)F-FET PET scans from 393 patients grouped into 6 disease categories according to histology (n = 299) or distinct MRI findings (n = 94) (low-grade/high-grade glial/nonglial brain tumors, inflammatory lesions, and other lesions). (18)F-FET PET was visually assessed as positive or negative. Maximum lesion-to-brain ratios (LBRs) were calculated and compared with MRI contrast enhancement (CE), which was graded visually on a 3-point scale (no/moderate/intense).

RESULTS

Sensitivity and specificity for the detection of brain tumor were 87% and 68%, respectively. Significant differences in LBRs were detected between high-grade brain tumors (LBR, 2.04 ± 0.72) and low-grade brain tumors (LBR, 1.52 ± 0.70; P < .001), as well as among inflammatory (LBR, 1.66 ± 0.33; P = .056) and other brain lesions (LBR, 1.10 ± 0.37; P < .001). Gliomas (n = 236) showed (18)F-FET uptake in 80% of World Health Organization (WHO) grade I, 79% of grade II, 92% of grade III, and 100% of grade IV tumors. Low-grade oligodendrogliomas, WHO grade II, had significantly higher (18)F-FET uptakes than astrocytomas grades II and III (P = .018 and P = .015, respectively). (18)F-FET uptake showed a strong association with CE on MRI (P < .001) and was also positive in 52% of 157 nonglial brain tumors and nonneoplastic brain lesions.

CONCLUSIONS

(18)F-FET PET has a high sensitivity for the detection of high-grade brain tumors. Its specificity, however, is limited by passive tracer influx through a disrupted blood-brain barrier and (18)F-FET uptake in nonneoplastic brain lesions. Gliomas show specific tracer uptake in the absence of CE on MRI, which most likely reflects biologically active tumor.

Aneurysmal subarachnoid hemorrhage (aSAH) results in low prevalence of neuro-endocrine dysfunction and NOT deficiency

Neuro-endocrine deficiencies have been argued to be common sequelae after aneurysmal subarachnoid hemorrhage (aSAH). As this, however, does not resemble our clinical experience, we studied the incidence of neuro-endocrine and neuropsychological deficits after aSAH. Twenty-six patients (20 females) were prospectively screened for neuro-endocrine and neuropsychological deficits 3, 6 and 12 months after aSAH. GH, IGF-1, prolactin, LH, FSH, estradiol, testosterone, ACTH as well as cortisol during ACTH-stimulation were assessed. Neuropsychological analysis covered verbal comprehension, short term and working memory, visuospatial construction, figural memory, psychomotor speed, attention, and concentration. During the study period 5 individuals demonstrated neuro-endocrine dysfunction. Hypogonadotrophic hypogonadism resolved spontaneously in 2 patients and central hypothyroidism in one of these patients during the study. After 12 months three patients presented low IGF-1 levels. 73.9% of our cohort was affected by neuropsychological deficits during follow-up. At 3, 6 and 12 months the prevalences were 56.5, 52.6 and 42.1%, respectively. Interestingly, all patients with neuro-endocrine dysfunction presented impaired clinical outcome with a GOS 4 at some time point of the study (GOS 4 vs. 5, 45.5% vs. 0, P = 0.007). We found a low prevalence of neuro-endocrine and a high prevalence of neuropsychological deficits in patients 3, 6 and 12 months after aSAH without significant interrelation. Spontaneous recovery of neuro-endocrine alterations most likely presents an adaption to or dysfunction after severe illness. This hypothesis is strengthened by the fact that only patients with inferior clinical outcome after aSAH as assessed by GOS demonstrated neuro-endocrine dysfunction.

Distance to the neurooncological center: a negative prognostic factor in patients with glioblastoma multiforme. An epidemiological study

BACKGROUND

Regardless of current multimodal treatment strategies, the prognosis of patients harboring glioblastoma multiforme (GBM) is still dismal. The introduction of concomitant radiochemotherapy and adjuvant cyclic temozolomide has significantly improved the overall survival, compared to postoperative radiotherapy-alone. Furthermore this regimen shows a lower toxicity profile compared to previous nitrosourea-based chemotherapy and can easily be applied on an outpatient basis, thus potentially facilitating chemotherapy in rural and more remote areas. The distance to the oncological center has been shown to be a negative prognostic parameter in other types of cancer. Therefore, we aimed to investigate whether the introduction of temozolomide as the standard regimen in the treatment of GBM has influenced the administration of chemotherapy and the prognosis of patients depending on the distance to our neurooncological center.

PATIENTS AND METHODS

A total of 208 patients diagnosed with GBM (M:F=1.4:1), surgically resected between 1990 and 2009, thus covering the pre-temozolomide and the temozolomide-era, were included retrospectively in this analysis. The distance from the patients' residences to the neurooncological center was determined and statistical analysis was performed to assess its influence on overall survival and administration of adjuvant treatment (radiotherapy-only, nitrosourea-based chemotherapy and adjuvant temozolomide).

RESULTS

Overall, 41.3% of the cohort underwent subtotal surgical resection, whereas a gross total resection was accomplished in 57.2%. The median distance to the neurooncological center was 75 km (range=1-870 km). Postoperatively, 68 patients (32.7%) received concomitant and adjuvant radiochemotherapy with temozolomide, 31 (14.9%) were treated with nitrosourea other than the Procarbazin, Lomustin, Vincristin (PCV), 34 (16.3%) with PCV, and 71 patients (34.1%) had radiotherapy-alone. The distance to the neurooncological center had a significant influence on overall survival for the whole cohort (p=0.027) and patients with increasing distances, were significantly less often treated with chemotherapy (p=0.05). With the introduction of temozolomide this relation was lost (overall survival, temozolomide and other agents: p=0.685/p=0.007; administration of adjuvant chemotherapy in the temozolomide-era/whole cohort: p=0.612/p=0.05).

CONCLUSION

The distance to the neurooncological center negatively-influenced the prognosis of patients with GBM. Patients were less often treated with adjuvant chemotherapy in the pre-temozolomide era with increasing distance to the neurooncological center. Although the introduction of temozolomide as the standard chemotherapeutic agent in GBM treatment changed this fact, the influence of the distance to the specialized center should be kept in mind as a prognostic factor for this disease.

Pharmacokinetics, pharmacodynamics, safety and tolerability of APG101, a CD95-Fc fusion protein, in healthy volunteers and two glioma patients

APG101 is a glycosylated fusion protein consisting of the extracellular domain of human CD95 (APO-1/Fas) and the Fc domain of human IgG1. Administration of APG101 blocks the interaction between CD95 and its cognate ligand CD95L, thereby inhibiting various pathways involved in e.g. proliferation, migration, differentiation and apoptosis induction. The safety and tolerability of ascending single doses of intravenously applied APG101 was examined in a randomized, double-blind, placebo-controlled, mono-centre "first in man" dose escalation study in 34 healthy male volunteers. Pharmacokinetics and pharmacodynamics were also assessed. The maximum serum concentration of 460 μg/ml was achieved following 1h infusion of the highest dose of 20 mg/kg. The systemic clearance was low (0.4 to 0.5 ml/hkg). Mean terminal elimination half-life was 12 to 15 days. Two patients suffering from malignant glioma received APG101 intravenously under compassionate use conditions. They received doses ranging from 5mg to 600 mg APG101. No adverse events and no clinical significant changes in laboratory parameters related to APG101 were reported. The presence of anti-drug-antibodies (ADA) was investigated and revealed no detectable levels of ADA. Overall, single ascending doses of APG101 up to 20 mg/kgbody weight (bw) administered as infusion over 1h were considered as safe and well tolerated in healthy volunteers. After the application of multiple doses of 400 mg in two glioma patients, steady state for APG101 seemed to be reached. These results support further clinical evaluation of APG101 at a dose of 400 mg per week in glioblastoma patients.

Prolonged administration of temozolomide in adult patients with anaplastic glioma

PURPOSE

Prolonged administration of temozolomide is widely used in patients with glioblastoma; whereas the treatment of anaplastic glioma differs between neurooncological centres. The safety, feasibility and efficacy of prolonged temozolomide administration in patients with anaplastic gliomas was evaluated.

PATIENTS AND METHODS

Forty-two patients with primary, recurrent or secondary anaplastic glioma were retrospectively analysed for the course of their disease. Treatment mostly consisted of surgery, followed by radiotherapy with concomitant and adjuvant temozolomide. In five patients with recurrence of primary anaplastic glioma, chemotherapy was initiated without previous surgery. Temozolomide was administered until evidence of tumour recurrence, appearance of serious side-effects or patients' wish to finish chemotherapy.

RESULTS

The median overall survival (OS) was 39 months with a median cycle number of 7.5 (1-42). Treatment with temozolomide was stopped in 12 patients due to side-effects in general, whereas in only three patients (7.1%) treatment had to be discontinued due to haematological side-effects. There was no evidence of treatment related infections or grade IV toxicity. Extent of surgery had a significant influence on OS in anaplastic gliomas, the number of adjuvant temozolomide cycles showed a positive influence as well on time to progression (TTP) and OS.

CONCLUSION

Prolonged administration of adjuvant temozolomide is safe and can be favorable for patients with anaplastic gliomas.

Perfusion Characteristics in Chronic Cerebrovascular Insufficiency : An Anatomically and Clinically Oriented XeCT Analysis of Cerebrovascular Atherosclerotic Disease

Xenon-enhanced computed tomography (XeCT) allows quantification of hemodynamic insufficiency in the setting of cerebrovascular atherosclerotic disease (CAD). However, data regarding the relationship between hemodynamic indices [cerebral blood flow (CBF) and cerebrovascular reserve capacity (CVRC)] and normal subjects (with aging) and pathology (progression of CAD or development of stroke symptoms) are limited. In this study, we analyzed 103 consecutive patients undergoing XeCT according to age, anatomical location and disease severity. We stratified anatomically defined ROIs according to a classification system that observes the presence of proximal stenosis (class I vs. class II/III) as well as the presence of neurological symptoms (class II vs. III); CBF, CVRC and hemodynamic stress distribution were calculated. Supratentorial CBF decreases significantly with age, but not infratentorially. Cortical CVRC remains stable over time. Our classification of disease severity correlated highly significantly with a decrease in supratentorial CBF and CVRC, though CVRC is less sensitive to age-related changes. Regression analysis delineated a CVRC of 34% to discriminate between ROI classes. Age-dependent perfusion characteristics in normal vascular territories were characterized. In CAD, CVRC remains the most sensitive parameter. A simplified classification of ROIs according to disease severity correlates well with established markers for hemodynamic insufficiency. It may facilitate comparison of different pathologies such as CAD and Moyamoya disease and will be the focus of further studies.

Microembolic signal monitoring after coiling of unruptured cerebral aneurysms: an observational analysis of 123 cases

BACKGROUND AND PURPOSE

Thromboembolic events after aneurysm coiling are common, but the optimal algorithm for emboli prevention remains unclear. MESs correlate with the occurrence of impending ischemic events and may be used for management guidance. This study reports the use of MES monitoring with regard to aneurysm characteristics and coiling technique after a specific anticoagulation protocol.

MATERIALS AND METHODS

We analyzed 123 consecutive, elective endovascular procedures. Patients received intraprocedural and continuous heparin if feasible. Demographic data, aneurysm size, type of intervention/complication, medication, imaging, and clinical outcome were analyzed. MES monitoring was performed in all patients both immediately after as well as >12 hours after the procedure.

RESULTS

Heparinization within the first 12 hours was associated with lower numbers of MESs early after coiling (3.4 versus 18.8 MESs/hr). When on heparin, larger aneurysm size, stent-assisted procedures, or incomplete occlusion did not lead to a significant increase in MESs. If the initial MES count on heparin was >10 MESs/hr, it was always safe to discontinue heparin. Inability to initiate early, continuous heparinization was associated with new neurologic deficits. Additional administration of antiplatelet agents showed lower MES counts initially, but the difference was not significant.

CONCLUSIONS

MES monitoring is a powerful adjunct to monitor efficacy of treatment algorithms for emboli prevention after coiling. In our series, early heparinization was associated with a lower incidence of MESs. This is of particular importance in larger aneurysms, stent-assisted procedures, and incomplete occlusions, in which the thromboembolic risk is greatest early on and antiplatelet treatment alone may not suffice.

Management of patients with low-grade gliomas - a survey among German neurosurgical departments

BACKGROUND AND AIMS OF THE STUDY

The diagnosis and treatment of low-grade gliomas (LGG) are multimodal. Today, there is no defined standard in diagnosis and treatment. Controversies are, in general, about a "wait-and-see" strategy, diagnostic workup, surgical intervention, postoperative imaging, adjuvant treatment, and follow-up. The aim of this study is to gain an overview about management strategies of high-volume German neurosurgical departments treating these patients.

MATERIAL AND METHODS

A questionnaire including diagnostic, preoperative, perioperative, and postoperative parameters and 5 cases with magnetic resonance imaging data with questions to various treatment options in these patients was sent to all 34 German neurosurgical departments at university hospitals.

RESULTS

In total, 24 questionnaires were returned and analysed. Centres were divided into those who generally practice a "wait-and-see" strategy vs. those who do not or only in highly selected cases. Statistical analyses were performed with Fisher test and Chi (2)-test. Interestingly, 50% of all centres routinely follow a "wait-and-see" strategy.

CONCLUSION

Although the management of patients with LGG is complex and a simple questionnaire will not be able to define a standard in diagnosis and treatment, this study offers an overview on strategies at high-volume academic centres dealing with these patients. There is consensus to resect superficially located lobar and circumscribed low-grade lesions. However, the differences between centres become apparent with increasing complexity of the lesions.

Response to temozolomide in supratentorial multifocal recurrence of malignant ependymoma

Intracranial anaplastic ependymomas are a very rare entity within the group of adult CNS neoplasms. Thus, no standard adjuvant therapy after surgical resection has been defined so far. External radiotherapy is commonly administered, but the role of chemotherapy is still unclear in malignant ependymomas. The case of a 25-year-old female patient with multifocal recurrence of a supratentorial malignant ependymoma administered temozolomide as second-line therapy is reported. Currently, 5 months after initiation of temozolomide treatment, there is no evidence of radiographic progression. Temozolomide could constitute a promising approach to supratentorial recurrent and multifocal anaplastic ependymoma of adults.

Hypoperfusion in the acute phase of subarachnoid hemorrhage

PURPOSE

Acute disruption of cerebral perfusion and metabolism is a well-established hallmark of the immediate phase after subarachnoid hemorrhage (SAH). It is thought to contribute significantly to acute brain injury, but despite its prognostic importance, the exact mechanism and time course is largely unknown and remains to be characterized.

METHODS

We investigated changes in cerebral perfusion after SAH in both an experimental and clinical setting. Using an animal model of massive, experimental SAH (n=91), we employed Laser-Doppler flowmetry (LDF), parenchymal microdialysis (MD; n=61), Diffusion-weighted imaging (DWI) and MR spectroscopy (MRS; n=30) to characterize the first hours after SAH in greater detail. The effect of prophylactic treatment with hypothermia (HT; 32°C) and an endothelin-A (ET-A) receptor antagonist (Clazosentan) was also studied. In a group of patients presenting with acute SAH (n=17) we were able to determine cerebral blood flow (CBF) via Xenon-enhanced computed tomography (XeCT) within 12 h after the ictus.

RESULTS

The acute phase after SAH is characterized both experimentally and clinically by profound and prolonged hypoperfusion independent from current intracranial pressure (ICP), indicating acute vasospasm. Experimentally, when treated with hypothermia or a ET-A receptor antagonist prophylactically, acute hypoperfusion improved rapidly. DWI showed a generalized, significant decline of the apparent diffusion coefficient (ADC) after SAH, indicating cytotoxic edema which was not present under hypothermia. SAH causes a highly significant reduction in glucose, as well as accumulation of lactate, glutmate and aspartate (MD and MRS). HT significantly ameliorated these metabolic disturbances.

CONCLUSION

Acute vasospasm, cytotoxic edema and a general metabolic stress response occur immediately after experimental SAH. Prophylactic treatment with hypothermia or ET-A antagonists can correct these disturbances in the experimental setting. Clinically, prolonged and ICP-independent hypoperfusion was also confirmed. As the initial phase is of particular importance regarding the neurological outcome and is amenable to beneficial intervention, the acute stage after SAH demands further investigation and warrants the exploration of measures to improve the immediate management of SAH patients.

Nicardipine pellets for the prevention of cerebral vasospasm

Regardless of numerous efforts there is no prophylactic treatment proven to be effective in the prevention of cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH). As systemic administration of vasoactive drugs has been associated with significant side effects and insufficient efficacy, intrathecal administration of nicardipine prolonged-release implants (NPRI) has been developed. At the time of surgical clipping of the ruptured aneurysm, NPRIs are positioned next to the large cerebral arteries. Several clinical protocols revealed that NPRIs dramatically reduce the incidence and severity of angiographic vasospasm, which was paralled by a reduction in cerebral infarction and delayed ischemic neurologic deficit. On average, the incidence of angiographic vasospasm decreased from approximately 70% to less than 10%. Efficacy seemed to be dose-dependent and reduced for peripheral vasospasm. Nevertheless, a significant improvement of functional outcome was demonstrated. A separate patient series demonstrated the efficacy of fewer NPRIs in the perichiasmatic cistern. Further investigations were performed in comparison to coiled patients and with intraventricular implantation of NPRIs, which had a less pronounced effect. Overall, NPRIs are a most promising option for the prevention of cerebral vasospasm after SAH and large controlled trials are needed to further confirm these results.

Dual-energy CT after peri-interventional subarachnoid haemorrhage: a feasibility study

PURPOSE

The aim was to assess the feasibility of dual-energy computed tomography (DE-CT) for detection of peri-interventional re-bleeding in patients with aneurysmal subarachnoid hemorrhage (re-SAH).

METHODS

For in vitro-analyses DE-CT of partially clotted blood intermixed with fresh blood containing contrast agent was performed. In a clinical setting, 4 patients routinely underwent DE-CT after suspected peri-interventional re-SAH. DE-CT source data images, iodine maps and virtual non-contrast images (VNC) were analyzed and regions-of-interest (ROI) measurements of density values were performed.

RESULTS

In vitro experiments demonstrated the feasibility of DE-CT to discriminate between blood with and without contrast agent. In all patients peri-interventional re-SAH was confirmed by detection of extravasated iodine within the subarachnoid spaces in post-interventional DE-CT. Dual-energy CT allowed the discrimination of old blood clots of the initial SAH and blood originating from peri-interventional re-SAH. After subtraction of the iodine-related high density signal, VNC images optimized the estimation of the true amount of subarachnoid blood.

CONCLUSION

Dual-energy CT allows the discrimination and subtraction of blood and iodine mixed within the subarachnoid spaces in patients with peri-interventional re-SAH. It helps to avoid overestimation of SAH after peri-interventional re-bleeding and therefore is a potentially valuable tool in the assessment of peri-interventional re-SAH.

SOM230 (pasireotide) and temozolomide achieve sustained control of tumour progression and ACTH secretion in pituitary carcinoma with widespread metastases

Pituitary carcinomas are rare and neurosurgically challenging lesions, as they commonly relapse after surgical removal. Their prognosis is dismal due to their limited response to radiotherapy and chemotherapy. In recent studies, temozolomide was administered in very few patients with partial effects. We report a patient with an ACTH-secreting pituitary carcinoma and widespread intracranial, spinal and systemic metastases despite repeated surgical treatment, bilateral adrenalectomy, medical treatment and radiotherapy. Additionally to chemotherapy with temozolomide, the patient received SOM230 as salvage therapy with an improvement of the patient's clinical status, and a reduction of ACTH levels. After 12 months of combination therapy a sustained tumor control was achieved and persisted upon monotherapy with SOM230 for more than 9 months thereafter. Thus, temozolomide in combination with SOM230 seems to be promising in patients with ACTH-secreting metastasized pituitary carcinoma.

A healthy man with intractable hiccups

We present a patient with intractable hiccups. Medical treatment decreased the frequency of the hiccups to only 5-10 per minute. After exclusion of gastrointestinal reasons for the hiccups, cranial MRI revealed a small lesion in the right rhomboid fossa, close to the vagal trigone. Microsurgical resection of the lesion was performed via a suboccipital median craniotomy. The histopathological diagnosis was a cavernoma. Promptly after surgery the patient was free of symptoms. Intractable hiccups can be associated with intracranial pathologies, including lesions in the brain stem, which we highlight with the presentation of this patient.

Far-distant metastases along the CSF pathway of glioblastoma multiforme during continuous low-dose chemotherapy with temozolomide and celecoxib

Glioblastoma multiforme is the most common and most malignant primary brain tumour. Prognosis after diagnosis remains poor despite recent advances in adjuvant therapy. Treatment of choice is gross surgical resection and combined radio-chemotherapy with temozolomide as chemotherapeutic agent. Experimental continuous low-dose chemotherapy with temozolomide in combination with a cyclooxygenase-2 inhibitor has shown encouraging effects on progression-free survival and overall survival in patients, but leads to a high proportion of distant recurrences. Here, we describe extreme far-distant metastases along the neural axis of glioblastoma multiforme in four patients receiving metronomic antiangiogenic chemotherapy and review the literature to discuss possible mechanisms.

First experiences with low-dose anti-angiogenic treatment in gliomatosis cerebri with signs of angiogenic activity

BACKGROUND

Gliomatosis cerebri is a rare primary cerebral tumour entity characterized by diffuse infiltrative growth patterns representing a WHO grade III malignancy. The prognosis is dismal and therapeutical options are still controversial. In contrast to other high-grade gliomas, angiogenesis is thought to be absent in gliomatosis cerebri.

PATIENTS AND METHODS

Despite this assumption, histopathological analyses of samples of six patients with gliomatosis cerebri were performed and surprisingly there was angiogenic activity with expression of vascular endothelial growth factor and cyclooxygenase 2. It was therefore decided to administer continuous low-dose chemotherapy with temozolomide and celecoxib for antiangiogenic treatment in the four patients that were in good clinical condition following external radiotherapy.

RESULTS

In all patients, treatment was well tolerated and MRI follow-up showed no tumour progression for at least six months. One patient died due to pulmonary embolism 9 months after diagnosis; another patient survived 15 months after diagnosis with progressive disease in the last follow-up MRI before death. Two other patients at the present time are still in a stable clinical condition without signs of tumour progression in MRI (12 and 18 months).

CONCLUSION

From our initial experience in a small number of patients with gliomatosis cerebri with signs of angiogenic activity, we conclude that low-dose chemotherapy might provide a promising approach for treatment of these patients and that overexpression of angiogenic factors such as VEGF or COX-2 seems to be more frequent than hitherto reported.

Recurrence pattern in glioblastoma multiforme patients treated with anti-angiogenic chemotherapy

PURPOSE

Glioblastoma multiforme is the prototype of an angiogenic tumour. Under experimental conditions, anti-angiogenic therapy strategies lead to an increased invasion. Here we report on the pattern of tumour recurrence in glioblastoma patients treated with an anti-angiogenic chemotherapy.

PATIENTS AND METHODS

A total of 32 patients with glioblastoma multiforme and a residual tumour mass after operation were treated with a continuous low-dose chemotherapy with temozolomide and a COX-II inhibitor, a presumably anti-angiogenic therapy.

RESULTS

While anti-tumour activity of this therapy regimen was excellent with a mean overall time to progression of 10.4 (+/-0.9) months and a mean overall survival of 17.8 (+/-1.5) months, an unusually high rate of distant recurrences was observed (62.5%).

CONCLUSION

Patients treated with an anti-angiogenic chemotherapy experience distant recurrences at a higher rate than reported for conventional therapies. This may reflect an anti-angiogenic therapy-induced activation of glioma invasion confirming similar recently published experimental results.

Thoracic intramedullary arachnoid cyst in an infant

Symptomatic intramedullary arachnoid cysts are rare, especially in children; these lesions are rarely described as a cause of spinal cord compression in this age group. The authors report on an 18-month-old boy who experienced a sudden loss of his ability to stand and walk due to a paraparesis. Magnetic resonance imaging of the spine exhibited a cystic intramedullary lesion at the level of T5-6. A hemilaminectomy was performed, and after myelotomy the cystic lesion was decompressed by fenestration to the subarachnoid space. The histopathological examination verified the diagnosis of an arachnoid cyst. In the postoperative course the boy experienced complete resolution of the initial paraparesis.

Cerebrovascular insufficiency as the criterion for revascularization procedures in selected patients: a correlation study of xenon contrast-enhanced CT and PWI

In order to identify patients who suffer from hemodynamic cerebral insufficiency and can benefit from cerebral revascularization procedures, xenon-CT scanning has been established to reliably measure the critical cerebrovascular reserve capacity. As a need for alternative quantification methods arises, this study aims to characterize the significance of both time-to-peak (TTP) and mean transit time (MTT) in perfusion-weighted imaging (PWI) in this particular subset of patients. Ten patients in routine preoperative work-up for cerebral revascularization were prospectively enrolled and underwent both XeCT scanning and PWI. Cerebrovascular reserve capacity (CVRC) was calculated for each region of interest (ROI, n = 504) after administration of a vasoactive stimulus. ROIs were anatomically matched with those of PWI after TTP and MTT were calculated. Highly significant negative correlation was found for TTP and CVRC for all ROIs (r = -0.3954, p < 0.0001; symptomatic ROIs: r = -0.4867, p < 0.0001). Correlation was weak for MTT and CVCR (r = -0.1287; p < 0.01). The optimum threshold for TTP to detect impaired cerebrovascular reactivity in our patient group was 4 s (specificity 90.8%, sensitivity 44.4%) for all ROIs (TTP > 4.4 s for symptomatic ROIs, specificity 88.4%, sensitivity 62.7%). An approximative equation to calculate the probability of pathological findings could be derived from the data. The positive predictive value (PPV) was 0.76 (symptomatic 0.78) with a negative predictive value (NPV) of 0.71 (symptomatic 0.78). While PWI currently is not able to replace XeCT in the direct quantification of CVRC, it may serve as a readily available follow-up tool. A TTP threshold of greater than 4 s allows to confirm a cerebrovascular compromise in a selected high-risk subgroup of patients.

Differentiation between malignant transformation and tumour recurrence by (68)Ga-bombesin and (18)F-FDG-PET, in patients with low grade gliomas

Treatment of gliomas is multimodal. Magnetic resonance imaging (MRI) in the posttreatment course is of limited value due to therapy-induced changes. In low-grade gliomas (LGG) malignant transformation is of special interest. Our patients and methods were as follows: In nine consecutive patients with LGG we examined the role of bombesin labelled with gallium-68 ((68)Ga-bombesin) studied with positron emission tomography (PET), in addition to fluoro-18-fluorodeoxyglucose ((18)F-FDG) in the differential diagnosis of tumour recurrence versus malignant transformation. We used (68)Ga-bombesin combined with (18)F-FDG-PET in these patients with suspicious new contrast enhancement at the original tumour site or resection cavity in MRI. Eight patients were operated. In one patient, tumour recurrence was most likely as shown by the PET findings and chemotherapy was administered. Our results have shown that in this last mentioned patient after the follow-up period, MRI contrast enhancement was definitively regressive. In the operated patients the tumour was graded as glioblastoma multiforme, gliosarcoma and WHO grade III tumour. In two patients histological grading confirmed the PET findings without malignant transformation. In all of the 9 patients the combination of (68)Ga-bombesin and (18)F-FDG-PET predicted correctly malignant transformation or recurrence of the initial tumour grade which shows that (68)Ga-bombesin-PET can provide additional important information to detect a malignant transformation. In conclusion it is crucial for the patient to differentiate the nature of the new lesion in order to endorse an aggressive or non-aggressive treatment.

Endovascular treatment of traumatic high flow dural arterio-venous fistula involving the middle meningeal artery and facial veins

Dural arterio-venous fistulas are rare lesions. Traumatic dural AV-fistulas in particular, are very rare complications of head and neck trauma. We report on a 59-year old man with a severe facial and head trauma. Initial computed tomography demonstrated a left frontal subdural hematoma, leading to progressive midline shift. Additionally, a complex skull base fracture was present, involving the frontal, temporal and sphenoid bone. A few days after the accident the patient reported a left pulsatile tinnitus. Subsequent selective carotid angiography revealed a high flow dural arterio-venous fistula involving the middle meningeal artery and facial veins. Complete endovascular embolization was performed by a transarterial approach using microparticles and an electrolytically detachable coil resulting in an immediate disappearance of the tinnitus. Remarkably, this case nicely illustrates possible "dangerous" collateral circulation to the ophthalmic artery-a feature that should be kept in mind during endovascular treatment of this entity.

Alveolar rhabdomyosarcoma of the clivus with intrasellar expansion: Case report

Rhabdomyosarcomas are common tumors of the head and neck region in children. However, a primarily intracranial localization of this tumor entity is rare. We report on a 3-year-old boy presenting with double vision due to left VI (th) nerve palsy. No other neurological deficits were recognized by clinical inspection. MRI scans visualized an enhancing mass lesion in the upper clivus compressing the cavernous sinus and the pituitary gland. Transsphenoidal biopsy was performed and histopathological examination as well as molecular diagnostics confirmed the diagnosis of an alveolar rhabdomyosarcoma (ARMS). Staging identified a metastatic lesion in the fourth thoracic vertebra resulting in the diagnosis of stage IV disease. Treatment modality included stereotactic radio- and chemotherapy.