The combination of carmustine wafers and temozolomide for the treatment of malignant gliomas. A comprehensive review of the rationale and clinical experience.

Current treatment strategies in patients with newly-diagnosed glioblastoma include surgical resection with post-operative radiotherapy and concomitant/adjuvant temozolomide (the "Stupp protocol") or resection with implantation of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) wafers in the surgical cavity followed by radiotherapy. In clinical practice, patients with malignant glioma treated with BCNU wafer often also receive adjuvant temozolomide. However, current treatment guidelines are unclear on whether and how these treatment practices can be combined, and no prospective phase 3 study has assessed the safety and efficacy of combining BCNU wafers with temozolomide and radiation in high-grade malignant glioma. The rationale for multimodal therapy comprising surgical resection with adjunct local BCNU wafers followed by radiotherapy and temozolomide is based on complementary and synergistic mechanisms of action between BCNU and temozolomide in preclinical studies; a shared primary resistance pathway, methylguanine-DNA methyltransferase (MGMT); and the opportunity to overcome resistance through MGMT depletion to boost cytotoxic activity. A comprehensive review of the literature identified 19 retrospective and prospective studies investigating the use of this multimodal strategy. Median overall survival in 14 studies of newly-diagnosed patients suggested a modest improvement versus resection followed by Stupp protocol or resection with BCNU wafers, with an acceptable and manageable safety profile.

Continuous selective intraarterial infusion of nimodipine for therapy of refractory cerebral vasospasm.

BACKGROUND: For endovascular treatment of vasospasm after aneurysmal subarachnoid hemorrhage (aSAH), an intraarterial treatment course with the calcium channel antagonist nimodipine infused for 30 min is proposed. As some patients still show ongoing vasospasm thereafter, we report on our experience with an extended time period of selective intraarterial nimodipine administration. METHODS: In nine patients with aSAH and refractory cerebral vasospasm, we left the catheter in place within the internal carotid artery after angiography. On the neurosurgical ICU, a continuous infusion of intraarterial nimodipine was commenced, combined with intraarterial heparin anticoagulation. Therapy was controlled with extended neuromonitoring techniques. RESULTS: Three patients died from refractory vasospasm and a fourth suffered lethal sepsis. Three patients survived in a good clinical condition, two of them without apparent neurologic deficit. The efficacy of intraarterial nimodipine was best verified with regional CBF monitoring. TCD failed to detect vasospasm in two patients and missed improvement in four. Brain tissue oxygenation increased in all patients, but was not indicative of vasospasm in one. CT perfusion reflected the treatment course adequately in the qualitative scans. CONCLUSION: Selective continuous intraarterial nimodipine treatment for refractory cerebral vasospasm after aSAH seems feasible and may add to the endovascular therapeutic options. Appropriate monitoring technology is essential for further investigation of this novel technique.

11C-Methionine positron emission tomography for preoperative evaluation of suggestive low-grade gliomas.

OBJECTIVE: The treatment regimen for cerebral gliomas is different, depending on the histological grade of the lesion. The therapeutic strategy for anaplastic gliomas and glioblastomas is more aggressive, including microsurgical removal, radiation and chemotherapy. The management for low-grade gliomas is still under discussion, operation or "wait and see" tactics are possible options. Therefore the diagnostic imaging procedures are crucial for further treatment planning. Although most of the low-grade gliomas appear as hypointense lesions without contrast medium (CM) enhancement on magnetic resonance images, in some cases lesions without CM enhancement can be anaplastic tumours as well. 11C-Methionine positron emission tomography (MET-PET) was performed for preoperative evaluation of non or low CM enhancing intracerebral lesions, so-called suggestive low-grade gliomas. METHOD: 20 patients harbouring suggestive low-grade gliomas were included. Seventeen patients were found to be candidates for open surgery and 3 patients were planned for stereotactic biopsy due to the localisation of the lesions. MET-PET studies were performed a few days prior to surgery. On the day of surgery MRI sequences for neuronavigation planning were carried out (MPRAGE and FLAIR sequences). All image data were fused for operation with neuronavigation-guided microsurgery or stereotactic biopsy (BrainLAB Neuronavigation system, VectorVision 6.1). Biopsies were taken from the MET uptake areas as well as from areas without MET uptake. RESULTS: 2/20 patients showed sparse CM enhancement on MRI T (1) images, 18/20 patients had lesions without CM enhancement. MET uptake was found in 16/20 cases (T/N ratio 1.5 or more) and no MET uptake was documented in 4/20 cases (T/N ratio <1.5). Histologically the 2 patients with sparse CM enhancement and MET uptake were glioblastoma multiforme, 10/14 patients with MET uptake and without CM enhancement had an anaplastic astrocytoma WHO III, 3/14 with MET uptake and no CM enhancement had an anaplastic oligoastrocytoma WHO III, and 1/14 had an oligoastrocytoma grade II. The lesions of the 4 patients without MET uptake and without CM enhancement were classified as astrocytoma grade II in 2 cases, as astrocytoma grade I in 1 case and as astrocytoma III in one case. CONCLUSION: According to the results of this study, we find MET-PET to be a helpful tool for pretreatment evaluation of non-CM enhancing, suggestive low-grade intracerebral lesions. MET-PET adds valuable information for the decision-making for surgery or stereotactic biopsy.

Open lung ventilation in neurosurgery: an update on brain tissue oxygenation.

Recently, we showed the feasibility of ventilating neurosurgical patients with acute intracranial pathology and concomitant acute respiratory distress syndrome (ARDS) according the so-called Open Lung approach. This technique consists of low tidal volume, elevated positive expiratory pressure (PEEP) level and initial recruitment maneuvers to open up collapsed alveoli. In this report, we focus on our experience to guide recruitment with brain tissue oxygenation (pbrO2) probes. We studied recruitment maneuvers in thirteen patients with ARDS and acute brain injury such as subarachnoid hemorrhage and traumatic brain injury. A pbrO2 probe was implanted in brain tissue at risk for hypoxia. Recruitment maneuvers were performed at an inspired oxygen frcation (FiO2) of 1.0 and a PEEP level of 30 40 cmH2O for 40 seconds. The mean FiO2 necessary for normoxemia could be decreased from 0.85 +/- 0.17 before recruitment to 0.55 +/- 0.12 after 24 hours, while mean PbrO2 (24.6 mmHg before recruitment) did not change. At a mean of 17 minutes after the first recruitment maneuver, PbrO2 showed peak a value of 35.6 +/- 16.6 mmHg, reflecting improvement in arterial oxygenation at an FiO2 of 1.0. Brain tissue oxygenation monitoring provides a useful adjunct to estimate the effects of recruitment maneuvers and ventilator settings in neurosurgical patients with acute lung injury.

Lipofundin-induced intracranial pressure rise after severe traumatic brain injury--a case report.

Early nutrition is a recognized component of neurosurgical intensive care treatment. The authors present the case of a patient suffering from severe traumatic brain injury who responded with reproducible intracranial pressure (ICP) crisis to infusion of Lipofundin, a fatty soybean oil-based emulsion for parenteral nutrition. During the described ICP rise, the patient remained hemodynamically stable, therefore an anaphylactic reaction seems to be unlikely. An increase of brain tissue oxygenation parallel to the ICP rise in this case is suggestive for increased cerebral blood flow as a cause of ICP elevation after application of Lipofundin. Without multimodal monitoring and data storage, the described side effect of Lipofundin in our patient would have been difficult to identify.

Neuronavigation combined with electrophysiological monitoring for surgery of lesions in eloquent brain areas in 42 cases: a retrospective comparison of the neurological outcome and the quality of resection with a control group with similar lesions.

The purpose of this study was to achieve a more radical resection of tumors in the area of the motor cortex via minimal craniotomy using a combination of neuronavigation and neurophysiological monitoring with direct electrical cortical stimulation and to compare retrospectively the clinical outcome and postoperative magnetic resonance imaging with a control group that was operated on in our service when the combination of these monitoring techniques was not available. A total of 42 patients with tumors in or near the central region underwent surgery with neuronavigation guidance and neurophysiological monitoring. The primary motor cortex was identified intraoperatively by the somatosensory evoked phase reversal method and direct cortical stimulation. The functional areas were transferred into the neuronavigation system. By stimulating the identified primary motor cortex and displaying the motor area in the operating microscope a permanent control of the motor function was possible during the whole operation. Using these techniques a more radical tumor resection - evaluated by postoperative MRI - was achieved in the study group (p = 0.04) and also a trend toward a better neurological outcome.

Intraoperative imaging using a mobile computed tomography scanner.

OBJECTIVE: The radicality of tumour removal in patients suffering from glioma is discussed to be an important factor for longer survival times. Therefore intraoperative imaging modalities like magnetic resonance imaging (MRI), computed tomography (CT) and ultrasound (US) are tested in many neurosurgical facilities for clinical use. In our department a mobile CT for intraoperative applications is used for this purpose since 1999. The handling and useful application of the mobile CT scanner as well as results without intraoperative imaging are discussed. MATERIAL AND METHODS: 470 CT scans with the mobile CT were accomplished, including 270 cases of neuronavigation planning, 76 cases of intraoperative scans, 48 cases of postoperative scans, 69 CT scans for stereotactic biopsy planning and control as well as 3 cases of emergency scanning in trauma patients and 4 spine applications. The results of the intraoperative CT scans are compared with those of the postoperative MRI scans. Additionally 87 patients with glioma were evaluated. These patients underwent surgery without intraoperative imaging. RESULTS: In 27 out of 43 patients with glioma residual tumour was detected with intraoperative CT. In 13 cases the surgery was resumed to complete resection, in 14 cases the operation was not continued due to close vicinity to eloquent areas or difficulties in image interpretation. In 44 cases the results of intraoperative CT and postoperative MRI were compared. In 6 cases the MRI demonstrated residual tumour in contrast to the results of the CT scans. In 3 cases the tumour removal could have been more complete (6.8 %). In 87 cases glioma surgery was performed without intraoperative CT. In 6 cases a more complete tumour removal could have been performed (6.9 %) according to the results of postoperative MRI. CONCLUSION: Intraoperative imaging with a mobile CT scanner is a good method for detection of residual tumour. The CT scanner can be integrated in an operative setting without problems. Although intraoperative imaging can be helpful in some selected cases, most of the neurosurgical procedures can be well performed with proper neuronavigation planning.

Stereotactic guided laser-induced interstitial thermotherapy (SLITT) in gliomas with intraoperative morphologic monitoring in an open MR: clinical expierence.

Stereotactic guided laser-induced interstitial thermotherapy (SLITT) is a minimal invasive method to produce thermonecrosis in cerebral tumour tissue. Clinical data are sparse due to its limited application until now and the value of this approach for tumour control and survival time remain to be defined. Twenty-four patients (7 low-grade gliomas, 11 anaplastic gliomas, 6 glioblastomas) with brain tumours, most recurrences, were treated with SLITT, in total 30 laser procedures were performed. Under local anaesthesia a 600 micro m laser-fiber was inserted by the stereotactic-guided technique. In open low-field MR the denaturation of the tumour by a Nd-YAG-laser (1064 nm) was monitored using T 1 -weighted 3-D turbo FLASH sequences. The ablation procedure had to be stopped twice because of neurological deficit, one major infection occurred. In two cases neurological improvement was observed. Mean survival times for low grade astrocytomas, anaplastic gliomas and glioblastomas were 144 months, 39 months, 17 months, respectively. Mean survival times after SLITT were 34 months, 30 months and 9 months, respectively. Mean times to progression after SLITT for the 3 histological subgroups were 16 months, 10 months and 4 months, respectively. Five patients with low grade astrocytoma and a KI greater or equal 70 maintained a high quality functional status for 11, 20, 21, 33 and 43 months. In anaplastic tumours patients maintained a KI of 70 for a median time of 15 months and for those with glioblastoma the respective high quality duration was 7.5 months after SLITT. SLITT for selected patients with glioma could have a clinical value in a multimodality treatment schedule maintaining quality of live. Due to the minimal invasive technique, the method is a therapy of choice and may be favoured to reoperation. Major indications of this treatment are small tumours, in eloquent regions and deep seated, as well as in older patients or patients in poor functional status.

Surgery and outcome for aneurysmal subarachnoid hemorrhage in elderly patients.

OBJECTIVE: The goal was to report treatment results of elderly patients (over 70 years) who underwent clipping of aneurysms after subarachnoid hemorrhage (SAH). MATERIAL AND METHODS: From 1994 to 2000 41/284 (14%) patients older than 70 years were operated on aneurysmal SAH in our department. Localization of ruptured aneurysm was anterior communicating artery (n = 14), middle cerebral artery (n = 14), internal carotid artery (n = 6), anterior cerebral artery (n = 2), pericallosal artery (n = 1) and multiple in 4 patients. We used the Hunt and Hess classification for initial grading and the Glasgow Outcome Score at day 30 after surgery. RESULTS: Patients with HH 1-3 had a low mortality (1/18, 6%), whereas 9 of 23 patients (39%) with HH 4-5 decreased within 30 days after surgery. Overall mortality was 24.5% (10/41) at 30 days after surgery. Most patients (n = 32) underwent early surgery (within 72 hours). Shunt dependent hydrocephalus developed in 15 patients (37%). The outcome was better in patients graded HH 1-3, in those without serious atherosclerotic changes in angiography, and in AcoA and ICA localization compared to MCA. CONCLUSION: Advanced age does not preclude successful surgery for ruptured aneurysm. Most important factor for outcome was a good initial clinical status, though the majority of our patients presented with poor grades. Early surgical clipping and postoperative intensive care can attain a favorable outcome in a significant percentage of elderly patients.

Neuronavigation and functional MRI for surgery in patients with lesion in eloquent brain areas.

OBJECTIVE: Surgery in patients with lesions in eloquent areas is still a challenge for the neurosurgeon. The aim of surgical interventions should be the radical removal of the lesions with functional preservation. Functional brain imaging methods provide the preoperative demonstration of those brain areas and their relationship to pathologic structures. MATERIAL: Twenty-seven patients with pathologic lesions in or near eloquent regions were investigated with functional magnetic resonance imaging (fMRI). Nineteen patients were neurologically intact preoperatively, and presented only with headache and/or seizure. Eight patients had a minor neurological deficit. Twenty-five patients underwent surgery. Preoperatively a computed tomography (CT) scan or a magnetic resonance imaging procedure with five skin fiducials was performed. The data were transferred to the neuronavigation workstation. The tumour was lined out in colours, and reconstruction in a triplanar format as well as three-dimensionally was implemented. The information from the fMRI concerning the functional areas was transferred into the images manually to account for EPI distortions. Fifteen patients were operated on using the combination fMRI/neuronavigation. Diagnoses included eleven gliomas, two meningeomas, one metastasis and one cavernoma. RESULTS: In seven patients the tumour was removed completely, eight patients had residual tumour, demonstrated by early postoperative MRI. All patients with residual tumour had gliomas that involved functional areas. Postoperatively no patient had an additional neurological deficit. CONCLUSION: Functional MRI provides important additional information in patients with lesions in eloquent brain areas. In combination with neuronavigation this is a very helpful technique for surgical interventions on these patients to reduce morbidity. Nonetheless, there are still open questions concerning accuracy of display of the functional areas and integration into a neuronavigation system.

The safety of the open lung approach in neurosurgical patients.

A recent randomized controlled trial in patients with ARDS showed the beneficial effect of mechanical ventilation according to the so called Open Lung Approach, consisting of low tidal volumes and elevated PEEP settings after performing recruiting maneuvers. However, neurosurgical patients were excluded from this and other ARDS trials due to concerns of intracranial deterioration. In this report, we present the clinical data of eleven patients with known intracranial pathology and concomitant ARDS which was treated according to the Open Lung concept. The mean oxygenation index (paO2/FiO2) increased from 132 +/- 88 to 325 +/- 64 measured 24 hours after initiation of Open Lung ventilation (p < 0.001). Mean PEEP level after the first recruiting maneuver was 14.9 +/- 3.2 mmHg. Comparison of mean and peak ICP values over 24 hours of time before and after the first recruitment maneuver revealed a non-significant decline in ICP despite a moderate increase in mean paCO2. Although two patients needed additional ICP treatment, no patient had to be withdrawn from Open Lung ventilation. In our series, Open Lung ventilation in neurosurgical patients with ARDS was a safe method to improve oxygenation. Careful ICP monitoring provided, there is no reason to withhold this modern ARDS treatment in the neurosurgical intensive care unit.

[Dislocation tendency, stabilizing effect and sintering tendency of different lumbar vertebrae cages in an in vitro experiment]. / Dislokationstendenz, stabilisierende Wirkung und Einbruchtendenz unterschiedlicher LWS-Cages im In-vitro-Experiment.

For biomechanical purposes, interbody fusion cages should not dislocate, should provide high stability, and should have a low subsidence risk. Zientek (Marquardt Medzintechnik), Stryker (Stryker Implants), and Ray lumbar interbody fusion cages (Surgical Dynamics) were tested in this study. They were implanted by pairs from a posterior approach without further stabilization. In a first step, each cage design was implanted into four human L3-4 segments and extracted posteriorly under an axial preload of 200 N. In a second step, standard flexibility tests were carried out with 24 human L2-3 and L4-5 specimens in an intact condition, directly after cage implantation, and after cyclic axial compression loading (200-1000 N, 40,000 cycles, 5 Hz). In a third step, a destructive axial compression test was carried out. Maximum pullout force was highest with Ray cages (median 945 N), followed by Zientek (605 N) and Stryker cages (130 N). With all three cage designs, primary stability was higher in lateral bending and flexion than in extension and axial rotation. Implantation of Ray cages caused a decreased range of motion in all three loading directions ranging between 49% and 99%. Zientek cages only stabilized in lateral bending, flexion, and extension (45-78%) and Stryker cages in none of the three loading directions. Cyclic loading caused an increased range of motion in all cases up to 190%. Axial compression force at failure was 8413 N with Ray cages, 8359 N with Stryker cages, and 5486 N with Zientek cages. The cage design seems to influence the dislocation tendency. In this regard, threaded cages or cages with anchorage systems seem to provide more security. The stabilizing effect seems to be mainly influenced by factors such as the degree of distraction or destruction of the facet joints rather than by the cage design.

Xanthogranuloma of the Erdheim-Chester type within the sellar region: case report.

Manifestations of Erdheim-Chester disease in the central nervous system are very rare. Cases with localization in the retroorbital space, hypothalamic area and posterior pituitary as well as intracerebral lesions are known. In our neurosurgical unit, a 51-year-old male patient with a history of hypophyseal insufficiency and visual deficits underwent surgery for a pituitary lesion. Histological and immunohistochemical examination revealed a xanthogranulomatous lesion composed of very large CD68-positive foam cells with small nuclei and some Touton-like giant cells, histiocytes, as well as loci with small lymphocytes and isolated eosinophilic granuolcytes, embedded in fibrotic tissue. Based on these findings, the histological diagnosis was a xanthogranuloma of the Erdheim-Chester type.

Correlation between postoperative 3-[(123)I]iodo-L-alpha-methyltyrosine uptake and survival in patients with gliomas.

UNLABELLED: The aim of this study was to evaluate the prognostic value of SPECT imaging using the amino acid analog 3-[(123)I]iodo-L-alpha-methyltyrosine (IMT) in patients with gliomas. METHODS: One hundred fourteen consecutive patients with newly diagnosed gliomas were examined by IMT SPECT (low-grade glioma, n = 12; anaplastic astrocytoma or oligodendroglioma, n = 46; glioblastoma, n = 56). Seventy-one of these patients had undergone tumor resection 4-6 wk before SPECT imaging (group A). Forty-three patients with unresectable tumors were examined after stereotactic biopsy (group B). IMT uptake at the site of the tumor was assessed visually and quantified relative to a contralateral reference region (IMT uptake ratio). After IMT SPECT, all patients were treated with conformal radiotherapy. The median follow-up time was 27 mo. RESULTS: In group A, focal IMT uptake at the resection site was visible in 52 of 71 patients (73%). Median survival was only 13 mo in these patients, whereas median survival was reached in patients without focal IMT uptake (P = 0.02). Furthermore, the intensity of IMT uptake significantly correlated with survival: patients with an IMT uptake ratio > 1.7 were at a 4.6 times higher risk of death than were patients with a lower IMT uptake (P < 0.001). The IMT uptake ratio remained a significant prognostic factor when age and grading were included in a multivariate model. In contrast, IMT uptake did not correlate with survival in group B (P = 0.95). CONCLUSION: In patients with unresectable high-grade gliomas, IMT uptake appears not to correlate with the biologic aggressiveness of tumor cells. Nevertheless, the clear association between focal IMT uptake after tumor resection and poor survival suggests that IMT is a specific marker for residual tumor tissue. Therefore, IMT SPECT is expected to become a valuable tool for the planning and monitoring of local therapeutic modalities.

Lhermitte-Duclos disease (Dysplastic gangliocytoma of the cerebellum).

OBJECTIVE: Dysplastic gangliocytoma of the cerebellum (Lhermitte-Duclos disease) is a rare hamartomatous lesion of the cerebellar cortex. The pathogenesis of the disease is still poorly understood. Lhermitte-Duclos disease was recently considered to be part of a multiple hamartoma-neoplasia syndrome (Cowden disease). We add two further cases to this rare entity. PATIENTS: A 24-year old woman presented with occipital headaches, blurred vision, diplopia and ataxia of gait. Physical examination revealed turricephaly. The second patient was a 37-year old woman, who presented with progressive occipital headache with nausea and vomiting. Physical examination revealed congenital facial asymmetry. Computed tomography and NMR-imaging, respectively demonstrated a space occupying mass of a cerebellar hemisphere in both cases. RESULTS: Suboccipital craniotomy and complete removal of the infratentorial tumour were performed in both patients. Histopathological findings clinched the diagnosis of Lhermitte-Duclos disease. Postoperative course was uneventful in the first and complicated by progressive occlusive hydrocephalus in the second patient, necessitating permanent surgical shunt drainage. Both patients were discharged free of complaints. CONCLUSIONS: Dysplastic cerebellar gangliocytoma is commonly associated with progressive mass effects in the posterior fossa and typically presents with headaches, cerebellar dysfunction, occlusive hydrocephalus and cranial nerve palsies. The disease usually manifests in young adults, but the age at presentation ranges from birth to the sixth decade. There is no sex predilection. NMR-imaging became a useful clue to the diagnosis within the last decade. Therapy consists of decompression of the posterior fossa by total surgical removal of the tumour mass.

Stereotactic guided laser-induced interstitial thermotherapy (SLITT) in gliomas with intraoperative morphologic monitoring in an open MR-unit.

Stereotactic guided laser-induced interstitial thermotherapy (SLITT) represents a minimal invasive method to produce necrosis in cerebral tumor tissue by local heating. The dose/response relationship relies on experimental studies and few clinical data performed in high field MR systems. A better understanding of the energy-dose/tissue response in human brain tumors is important to optimize this treatment modality. Twenty-four patients with gliomas were treated with SLITT, with a total of 30 laser procedures performed. Under local anesthesia 600 microns laser-fibers were inserted by stereotactic-guided technique into the center of the tumor. In a low field open MR system (0.2 T) the denaturation of the tumor using a neodymium YAG laser (1064 nm) was monitored by 3D-turbo FLASH T1-weighted sequences. Laser energy was applied in steps of 400 to 1200 Joules. Development of necrosis at a mean total energy dose of 2979 Joules could be monitored in all procedures. Two different thermal lesion architectures were observed. First signal changes were monitored after a mean of 1108 Joules and 1393 Joules, respectively. Mean max. total lesion size was 21.2 mm. The higher the total energy the larger was the thermolesion, but no linear relationship could be seen. Tumor tissue response showed no dependency on tumor grading. Monitoring of stereotactic guided laser-induced thermolesions in the low-power MR OPEN is feasible and safe. Although lesion size basically is energy dependent, it should be applied individually, since the thermal response in brain tumors varies due to different optical properties, even in the same tumor gradings.

Oligodendrogliomas in the CT/MR-era.

BACKGROUND: The aim of this study was to investigate survival times and 4 prognostic factors of oligodendrogliomas in the CT/MR-era, since most previous studies result from the pre-CT-era, where modern histopathological classification, diagnostic and therapeutic tools were not used. Thus, in the past mixed gliomas were included, and survival times and prognostic factors were not corrected for grades. METHOD: We present a retrospective study of 19 pure low grade (LO) and 21 pure anaplastic (AO) oligodendrogliomas (according to WHO) treated in the CT/MR-era 1987 to 1999. Survival times and rates were calculated in each grade according to the Kaplan-Meier-method. Following factors were analyzed for influence on survival in each grade using uni- and multivariate analysis: KI (karnofski index) equal or greater than 80 at time of diagnosis, contrast medium enhancement and calcification in preoperative CT or MRI, radiation therapy. FINDINGS: In LO median survival time was 114 months and 5 and 10-year survival rates were 78.9 and 44.1%, respectively. For AO median survival time was 21 months and 5- and 10-year survival rates were 23.8% and 0.05%, respectively. This difference reached statistical difference (p=0.0002). In LO none of the factors were statistically associated with better survival. Patients with AO had a significantly better outcome, when presenting with a KI of 80 or higher (uni- and multivariate analysis), than had tumours without contrast medium uptake (univariate) and for those with radiation therapy (univariate and multivariate). INTERPRETATION: In the CT/MR-era we did not observe a longer survival time or rate for patients with pure oligodendrogliomas compared to historical data. Prognostic factors should be evaluated separately in each grade, since grading according to WHO is strongly associated with survival. Patients with AO had a statistically longer survival when presenting with higher KI, without contrast enhancement and after postoperative radiation therapy.

Resistance of the lumbar spine against axial compression forces after implantation of three different posterior lumbar interbody cages.

BACKGROUND: The aim of using interbody fusion cages is to distract the degeneratively decreased disc height to decompress the neural structures in the intervertebral foramina and allow bony fusion. Prerequisite for a successful fusion therapy is a high resistance against subsidence and breakage. METHOD: Three types of implants, a cylindrical threaded titanium cage (Ray) (1c), a bullet shaped PEEK cage (Stryker) (1a) and a rectangular titanium cage with an endplate anchorage device (Marquardt) (1b) were implanted in eight monosegmental lumbar spine specimens (L 2/3 and L 4/5). Each specimen underwent a cyclic loading test with 40000 cycles at a rate of 5 Hz. A cyclic axial compression force ranging from 200 Newton [N] to 1000 N was applied and the axial translation recorded simultaneously to determine the subsidence tendency. After this procedure the specimens were tested with a progressive axial force until breakage. FINDINGS: There were only small differences in the subsidence tendency for the three cage designs. The height reduction due to cyclic loading ranged between 0.9 mm (Marquardt), 1.2 mm (Stryker) and 1.4 mm (Ray). The median break force ranged from 5486 N (Marquardt), 8359 N (Stryker) to 8413 N (Ray). No correlation between bone mineral density and failure load could be detected. INTERPRETATION: Endplate preparation and cage design of the tested implants do not seem to influence the resistance of the segment against cyclic axial compression. The compression with a continuously increasing load revealed that an implant-bone failure is not to be expected in physiological limits for all three cage types.

Intracerebral paraganglioma.

Paragangliomas of the CNS are relatively rare. Cases of location in the pineal and pituitary glands, cerebellopontine angle, cauda equina and filum terminale are known. In our neurosurgical unit a 42-year-old male patient with a history of vertigo and a generalized seizure underwent an operation for a fronto-temporal tumour. The histological diagnosis was paraganglioma.