A new qualitative interleukin-6 bedside test can predict pneumonia in patients with severe head injury--comparison to the standard Immulite test and a semiquantitative bedside test.

Severe head injury (SHI) leads to systemic immunosuppression, which is processed by central mechanisms and is associated with a high risk of pneumonia. The timely identification of an immunodepressed condition in SHI patients might help prevent infections by changing the intensive care strategy. The aim of this prospective study is to evaluate a new method for identifying immunodepression and predicting pneumonia. We correlated interleukin (IL)-6 levels determined by the standard test (Immulite) and performed by specialized laboratories with those obtained using the new bedside test (PicoScan) with the occurrence of pneumonia in patients with SHI. Thirty-two patients with isolated SHI were investigated. Analyses were performed on serum samples taken 2 to 24 hours after trauma. Pearson correlation coefficient was 0.924 (P<0.001) for IL-6 values determined by PicoScan versus Immulite and Spearman rho was 0.572 for visual interpretation versus Immulite (P=0.01). Immulite and PicoScan have a positive predictive value of 91% and 100%, respectively, and a negative predictive value of 76% and 86%. The present study investigated for the first time the determination of IL-6 concentrations by PicoScan in patients. Our findings show a good correlation with the results of the standard Immulite test and suggest that the PicoScan may be used as a handy tool to predict pneumonia in SHI patients.

Rapidly progressive paraplegia due to an extradural lumbar meningocele mimicking a cyst. Case report.

Unlike arachnoid meningoceles, arachnoid cysts frequently cause local pressure effects probably because there is no free communication between the cyst and the subarachnoid space. Following the first detailed description of cystic lesions of spinal nerve roots by Tarlov in 1938, a simplified classification of spinal meningeal cysts was developed in 1988, containing three major categories. The authors report on a lumbar intraspinal extradural meningocele that caused incomplete paraplegia in an otherwise healthy 31-year-old man in whom magnetic resonance imaging revealed stigmata of Scheuermann disease. Intraoperatively, the lesion was classified as a transitional-type lesion, in accordance with Type IA of the Nabors classification, because a communication with the subarachnoid space was observed. After complete removal of the meningocele, the patient's recovery was prompt and complete.

Real-time tracking of vertebral body movement with implantable reference microsensors.

OBJECTIVE: In the spine, navigation techniques serve mainly to control and accurately target insertion of implants. The main source of error is that the spine is not a rigid organ, but rather a chain of semiflexible movement segments. Any intraoperative manipulation of the patient alters the geometry and volumetry as compared to the 3D volume model created from the image data. Thus, the objective of the study was to implement the theoretical principle of microsensor referencing in a model experiment and to clarify which anatomical structures are suitable for intermittent implantation of positional sensors, as illustrated with cervical vertebral bodies. MATERIALS AND METHODS: Laboratory tests were conducted using 70 models of human cervical vertebral bodies. The first experiment investigated whether arbitrary movements of vertebral bodies can be tracked with the positional information from the implanted microsensors. The accuracy of this movement monitoring was determined quantitatively on the basis of positional error measurement. In the second experiment, different ventral and dorsal surgical operations were simulated on five models of the cervical spine. Quantifiable measurement values such as the spatial extension of the intervertebral space and the relative positions of the planes of the upper plates were determined. RESULTS: With respect to the differing anatomy of the individual vertebral bodies of the cervical spine, the sensors could be placed securely with a 5x2 mm drill. The registration error (RE) was determined as a root mean square error. The mean value was 0.9425 mm (range: 0.57-1.2 mm; median: 0.9400 mm; SD: 0.1903 mm). The precision of the movement monitoring of the vertebral body was investigated along its three main axes. The error tolerance between post-interventional 3D reconstruction and direct measurement on the model did not exceed 1.3 mm in the distance measurements or 2.5 degrees in the angular measurements. The tomograms on the system monitor could be updated in close to real time on the basis of the positional information from the reference sensor. CONCLUSIONS: Motion sensors implanted into the vertebral bodies communicated any change in position to the navigation system in close to real time, thus enabling the preoperative image data set to be updated. The experiments described could ultimately show that continuous real-time visualization of individual vertebral body movements along the movement axes (flexion-extension, tilting and rotation) is possible with high accuracy using implantable microsensors. A future application of such microsensors might be the integration of robot systems into spinal microsurgery.

Evaluation of MR imaging compatibility of a new intracranial pressure monitoring device.

We report our observations on MR imaging quality and functionality of a recently introduced intracranial pressure monitoring device. The device was tested at two different field strengths in a pig brain specimen to investigate MR imaging artifacts, probe function during and after MR data acquisition, and device-related temperature changes in the brain tissue. Image reading was not impaired, and probe function, although reduced, was not fully interrupted during data acquisition.

Radiologic morphology of low-grade primary central nervous system lymphoma in immunocompetent patients.

BACKGROUND AND PURPOSE: Primary central nervous system lymphomas (PCNSLs) are usually high-grade and are rarely low-grade non-Hodgkin lymphomas (NHLs). On MR imaging, PCNSLs typically present as contrast-enhancing lesions in contact with the subarachnoid space without evidence of necrosis. We evaluated the radiologic morphology and clinical characteristics of low-grade PCNSLs, hypothesizing that they may differ from high-grade PCNSLs. METHODS: Records were reviewed from 332 patients screened for inclusion in 3 multicenter prospective trials. MR imaging scans were obtained from all patients and were centrally reviewed by 2 consultant neuroradiologists. RESULTS: Ten patients (3%) with low-grade PCNSLs (7 men and 3 women; median age, 59 years; age range, 19-61 years) were identified. Four patients had one lesion, 2 patients 2 lesions, and 4 patients had multiple lesions. The following radiologic features infrequently seen in high-grade PCNSLs were found in a substantial proportion of patients: location in deep structures or spine (n = 6); lack of periventricular location (n = 5); hyperintensity on T2-weighted images (n = 10); moderate or absent contrast enhancement (n = 6); and heterogeneous contrast enhancement (n = 5). In 8 patients, >2 of these features were present in at least one lesion, and, thus, the radiologic appearance was assessed atypical of high-grade PCNSLs. The atypical radiologic appearance in combination with atypical or mild symptoms resulted in a false or delayed diagnosis. CONCLUSION: Low-grade PCNSLs may have a variable and atypical radiologic morphology compared with high-grade PCNSLs with the risk of false or delayed diagnosis.

Does preoperative paresis influence intraoperative monitoring of the motor cortex?

Intraoperative monitoring of motor function by means of motor evoked potentials (MEPs) is a new method. The current study examines the influence of preoperative paresis on the feasibility and reliability of this method. Intraoperative monitoring of MEPs was performed in 58 patients during surgery in the central region. The patients were divided into three groups according to their preoperative strength (group I, muscle strength less than or equal to grade 4 according to the British Medical Research Council grading system [n = 17]; group II, normal strength (n = 36); and group III, muscle strength less than grade 5 but not worse than grade 4 [n = 5]). The motor cortex was stimulated directly with a high-frequency monopolar anodal train. In groups II and III, MEPs were elicited in all patients on cortical stimulation, whereas in group I a response was obtained in only 88% of patients. The MEP parameters in all groups had a broad interindividual range of variation. A correlation between individual intraoperative potential changes and surgical maneuvers was observed in seven patients in group II and in four patients in group I. No MEP changes were recorded in group III. Irreversible MEP changes (groups I and II) resulted in postoperative clinical deterioration. No postoperative deterioration of motor function was observed in patients with reversible MEP changes. Preoperative paresis reduces the feasibility of the method; however, it has no influence on the intraoperative pattern and reaction of the MEPs.

Impact of somatosensory evoked potential monitoring on cervical surgery.

Controversy still exists about the necessity of somatosensory evoked potential (SSEP) monitoring during cervical surgery. The purpose of this prospective study is to determine the impact of SSEP monitoring on anterior cervical surgery. Intraoperative SSEP monitoring was performed in 100 patients treated by an anterior cervical approach. The patients were divided into three groups according to their preoperative clinical condition. Somatosensory evoked potential monitoring was performed during five stages of the procedure: M1, after the induction of anesthesia; M2, during positioning; M3, during distraction of the intervertebral space; M4, throughout decompression; and M5, during graft placement. Normal SSEPs were obtained during M1 from all the patients in group 2. Pathologic SSEPs were recorded at M1 in 45 patients from group 1. No SSEPs were recorded at M1 in six patients in group 3. A deterioration of the SSEPs was observed in 35 patients during M2. Deteriorated SSEPs were observed during M3 in 14 patients. No deterioration of the SSEPs was recorded during M4. Intraoperative SSEP monitoring is easy to perform and helps to increase safety during anterior cervical surgery. Critical phases of the surgical procedure were identified and the surgical strategy was modified as a result of this study.

Enhancement of Fas-ligand-mediated programmed cell death by taurolidine.

BACKGROUND: Taurolidine was recently found to have a direct and selective antineoplastic effect on brain tumor cells. The ability of taurolidine to exert antineoplastic action by enhancement of Fas-mediated apoptosis in different malignant glioma cell lines was investigated. MATERIALS AND METHODS: Human derived U373 cells were cultured and incubated with taurolidine and the median inhibitory concentration (IC50) was calculated. Flow cytometric analysis was performed to assess changes in DNA content. The cells were qualitatively and quantitatively examined using light microscopy and electron microscopy. LN-18 and LN-229 cells were incubated in the absence or presence of either Fas-ligand, taurolidine or respective combinations thereof. The cell viability was determined by adding a double concentrated WST-1 reagent. The activity of the mitochondrial succinate reductase was measured in an ELISA reader. RESULTS: The exposure of U373 cells to taurolidine led to a concentration-dependent (IC50 35.8 +/- 2.2 micrograms/ml) loss of cell viability. Flow cytometric analysis demonstrated a concentration-dependent appearance of DNA debris in the sub-Go/G1 region. In the presence of 6.25 vol.% Fas-ligand, LN-18 cells displayed more than 90% loss of cell viability, whereas the viability of LN-229 cells was reduced only at higher concentrations of Fas-ligand. Taurolidine by itself did not appreciably affect the viability of LN-18 cells in the investigated concentration range, but was able to enhance the effect of Fasligand on LN-18 cells. The exposure of LN-229 cells to taurolidine alone caused an appreciable loss of cell viability by about 70% at the highest concentration tested. Cell destruction by Fas-ligand (10 vol.%) was enhanced in the presence of taurolidine. CONCLUSION: The antineoplastic activity of taurolidine seems to be partially based on the enhancement of Fas-ligand-induced apoptosis. In addition, taurolidine was demonstrated to have an antieoplastic effect independent of Fas-ligand. Perhaps taurolidine exerts antineoplastic activity based on different mechanisms.

The effect of taurolidine on brain tumor cells.

BACKGROUND: Although an inhibiting effect of the antibacterial substance taurolidine on several tumor cell lines was suggested in 1990, no specific research has been performed concerning its effect on brain tumor cells. MATERIALS AND METHODS: Monolayers of rat-derived C6 glioma, mouse-derived HT22 neuronal tumor, and human-derived U373 astrocytoma/glioblastoma cell lines were cultured and incubated with 1 microg/ml to 4 mg/ml of taurolidine. Neuronal and glial brain cells were obtained from rat fetuses at day 15 of gestation and incubated with taurolidine to investigate its effect on normal brain cells. RESULTS: Following incubation with taurolidine, the tumor cells started to shrink and to become denser. Ultrastructurally, shrinkage of cytoplasm and condensation and marginalization of chromatin could be observed. Exposure to taurolidine at concentrations of 2.8 microg/ml to 2 mg/ml led to cell death of the evaluated tumor cell types. Results of flow cytometry suggested a fragmentation of DNA. Phosphatidylserine expression increased from 6% to 25% following exposure to taurolidine at a concentration of 25 microg/ml. Normal brain cells did not show any significant changes following incubation with taurolidine. CONCLUSION: The characteristics identified by light and electron microscopy and the data obtained by flow cytometry indicate an apoptotic mechanism of cell death via currently unknown pathways. Taurolidine was found to have a direct and selective antineoplastic effect on glial and neuronal brain tumor cells in vitro.

Treatment of glioblastoma with intravenous taurolidine. First clinical experience.

BACKGROUND: Despite progress in diagnosis and therapy, the prognosis of patients with glioblastoma remains poor. Recently it has been found that the antibacterial agent taurolidine has a direct and selective antineoplastic effect on brain tumor cells by the induction of programmed cell death. This paper reports on intravenous taurolidine treatment in two patients with a progressive glioblastoma despite conventional therapy. PATIENTS AND METHODS: Two male patients with histopathologically diagnosed glioblastoma were included. The tumors were progressive despite conventional therapy. Intravenous taurolidine treatment was initiated. RESULTS: The neurological condition and quality of life improved in both patients such that they could be discharged for further outpatient treatment. Follow-up demonstrated partial remission of the tumor in both patients. However, both patients died about 4 months following the start of taurolidine treatment, from pneumonia and acute thrombembolism, respectively. CONCLUSION: Both patients achieved a transient, marked improvement in quality of life and partial tumor remission. There was a clear response to the taurolidine treatment.

Ruptured intracranial dermoid cysts.

BACKGROUND: Intracranial dermoid cysts are rare congenital neoplasms that are believed to arise from ectopic cell rests incorporated in the closing neural tube. The rupture of an intracranial dermoid cyst is a relatively rare event that typically occurs spontaneously. In the past it was believed that rupture is always fatal, a hypothesis that is not supported by more recently reported cases. The symptoms associated with rupture vary from no symptoms to sudden death. METHODS: The present paper analyzes published cases of ruptured intracranial dermoid cysts in terms of their age profile and their clinical presentation and describes an additional case. RESULTS: Analysis of published cases revealed headache (14 out of 44 patients; 31.8%) and seizures (13 out of 44 patients; 29.5%), to be the most common signs of rupture followed by, often temporary, sensory or motor hemisyndrome (7 out of 44 patients; 15.9%), and chemical meningitis (3 out of 44 patients; 6.9%). CONCLUSION: Headache occurred primarily in younger patients (mean age 23.5 +/- 9.3 years), whereas seizures primarily occurred in older patients (mean age 42.8 +/- 11.3 years). The patients with sensory or motor hemisyndrome associated with rupture of an intracranial dermoid cyst showed a more homogeneous age distribution (mean age 38.4 +/- 23.5 years).

Novalis frameless image-guided noninvasive radiosurgery: initial experience.

OBJECTIVE: To evaluate our initial experience with Novalis (BrainLAB, Heimstetten, Germany) frameless image-guided noninvasive radiosurgery. METHODS: The system combines the dedicated Novalis linear accelerator with ExacTrac X-Ray 6D, an infrared camera and a kilovolt stereoscopic x-ray imaging system, a noninvasive mask system, and ExacTrac robotics for patient positioning in six degrees of freedom. Reference cranial skeletal structures are radiographically imaged and automatically fused to digital reconstructed radiographs calculated from the treatment planning computed tomographic scan to find the target position and accomplish automatic real-time tracking before and during radiosurgery. We present the acceptance testing and initial experience in 15 patients with 19 intracranial lesions treated between December 2005 and June 2006 at the Charité by frameless image-guided radiosurgery with doses between 12 and 20 Gy prescribed to the target-encompassing isodose. RESULTS: Phantom tests showed an overall system accuracy of 1.04 +/- 0.47 mm, with an average in-plane deviation of 0.02 +/- 0.96 mm for the x-axis and 0.02 +/- 0.70 mm for the y-axis. After infrared-guided patient setup of all patients, the overall average translational deviation determined by stereoscopic x-ray verification was 1.5 +/- 1.3 mm, and the overall average rotational deviation was 1.0 +/- 0.8 degree. The data used for radiosurgery, after stereoscopic x-ray verification and correction, demonstrated an overall average setup error of 0.31 +/- 0.26 mm for translation and 0.26 +/- 0.23 degree for rotation. CONCLUSION: This initial evaluation demonstrates the system accuracy and feasibility of Novalis image-guided noninvasive radiosurgery for intracranial benign and malignant lesions.

Neuronavigation without rigid pin fixation of the head in left frontotemporal tumor surgery with intraoperative speech mapping.

OBJECTIVE: Intraoperative speech mapping has evolved into the "gold standard" for neurosurgical removal of lesions near the language cortex. The integration of neuronavigation into a multimodal protocol can improve the reliability of this type of operation, but most systems require rigid fixation of the patient's head throughout the operation. This article describes and evaluates a new noninvasively attached sensor-based reference tool, which can replace rigid pin fixation of the patient's head during awake craniotomies. METHODS: The attachment technique and the resulting application accuracy were investigated under clinical conditions in 13 patients undergoing awake craniotomy with intraoperative mapping of cortical language sites. RESULTS: Spatial information was used for updating the image guidance by continuously adjusting the image planes relative to the position of the patient's head. The mean registration error achieved with this technique was 1.53 +/- 0.51 mm (fiducial registration error +/- standard deviation). The system's median application accuracy between dura opening and closure ranged from 0.83 to 1.85 mm (position error). CONCLUSION: The use of a reference sensor can replace uncomfortable pin fixation of the patient's head during navigation-supported awake craniotomies. Application accuracy is not affected by repositioning of the patient or by unavoidable head movements. Thus, this technique enables full exploitation of the benefits of navigation in a multimodal operative protocol without the need to rigidly fix the patient's head.

Intraoperative electrocortical stimulation of Brodman area 4: a 10-year analysis of 255 cases.

BACKGROUND: Brain tumor surgery is limited by the risk of postoperative neurological deficits. Intraoperative neurophysiological examination techniques, which are based on the electrical excitability of the human brain cortex, are thus still indispensable for surgery in eloquent areas such as the primary motor cortex (Brodman Area 4). METHODS: This study analyzed the data obtained from a total of 255 cerebral interventions for lesions with direct contact to (121) or immediately adjacent to (134) Brodman Area 4 in order to optimize stimulation parameters and to search for direct correlation between intraoperative potential changes and specific surgical maneuvers when using monopolar cortex stimulation (MCS) for electrocortical mapping and continuous intraoperative neurophysiological monitoring. RESULTS: Compound muscle action potentials (CMAPs) were recorded from the thenar muscles and forearm flexors in accordance with the large representational area of the hand and forearm in Brodman Area 4. By optimizing the stimulation parameters in two steps (step 1: stimulation frequency and step 2: train sequence) MCS was successful in 91% (232/255) of the cases. Statistical analysis of the parameters latency, potential width and amplitude showed spontaneous latency prolongations and abrupt amplitude reductions as a reliable warning signal for direct involvement of the motor cortex or motor pathways. CONCLUSION: MCS must be considered a stimulation technique that enables reliable qualitative analysis of the recorded potentials, which may thus be regarded as directly predictive. Nevertheless, like other intraoperative neurophysiological examination techniques, MCS has technical, anatomical and neurophysiological limitations. A variety of surgical and non-surgical influences can be reason for false positive or false negative measurements.

Study on the clinical application of pulsed DC magnetic technology for tracking of intraoperative head motion during frameless stereotaxy.

BACKGROUND: Tracking of post-registration head motion is one of the major problems in frameless stereotaxy. Various attempts in detecting and compensating for this phenomenon rely on a fixed reference device rigidly attached to the patient's head. However, most of such reference tools are either based on an invasive fixation technique or have physical limitations which allow mobility of the head only in a restricted range of motion after completion of the registration procedure. METHODS: A new sensor-based reference tool, the so-called Dynamic Reference Frame (DRF) which is designed to allow an unrestricted, 360 degrees range of motion for the intraoperative use in pulsed DC magnetic navigation was tested in 40 patients. Different methods of non-invasive attachment dependent on the clinical need and type of procedure, as well as the resulting accuracies in the clinical application have been analyzed. RESULTS: Apart from conventional, completely rigid immobilization of the head (type A), four additional modes of head fixation and attachment of the DRF were distinguished on clinical grounds: type B1 = pin fixation plus oral DRF attachment; type B2 = pin fixation plus retroauricular DRF attachment; type C1 = free head positioning with oral DRF; and type C2 = free head positioning with retroauricular DRF. Mean fiducial registration errors (FRE) were as follows: type A interventions = 1.51 mm, B1 = 1.56 mm, B2 = 1.54 mm, C1 = 1.73 mm, and C2 = 1.75 mm. The mean position errors determined at the end of the intervention as a measure of application accuracy were: 1.45 mm in type A interventions, 1.26 mm in type B1, 1.44 mm in type B2, 1.86 mm in type C1, and 1.68 mm in type C2. CONCLUSION: Rigid head immobilization guarantees most reliable accuracy in various types of frameless stereotaxy. The use of an additional DRF, however, increases the application scope of frameless stereotaxy to include e.g. procedures in which rigid pin fixation of the cranium is not required or desired. Thus, continuous tracking of head motion allows highly flexible variation of the surgical strategy including intraoperative repositioning of the patient without impairment of navigational accuracy as it ensures automatic correction of spatial distortion. With a dental cast for oral attachment and the alternative option of non-invasive retroauricular attachment, flexibility in the clinical use of the DRF is ensured.

Arteriovenous malformation in the cerebellopontine angle presenting as trigeminal neuralgia

Registro de caso de malformaçäo arteriovenosa no ângulo cerebelopontino esqueräo que determinava sintomatologia ipsilateral de nevralgia do trigêmeo. A remoçäo microcirúrgica de malformaçäo foi seguida de remissäo da dor. Os autores revêem a literatura acerca do assunto