@article{WestermaierLinsenmannHomolaetal.2016, author = {Westermaier, Thomas and Linsenmann, Thomas and Homola, Gy{\"o}rgy A. and Loehr, Mario and Stetter, Christian and Willner, Nadine and Ernestus, Ralf-Ingo and Soymosi, Laszlo and Vince, Giles H.}, title = {3D rotational fluoroscopy for intraoperative clip control in patients with intracranial aneurysms - assessment of feasibility and image quality}, series = {BMC Medical Imaging}, volume = {16}, journal = {BMC Medical Imaging}, number = {30}, doi = {10.1186/s12880-016-0133-0}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-146381}, year = {2016}, abstract = {Background Mobile 3D fluoroscopes have become increasingly available in neurosurgical operating rooms. In this series, the image quality and value of intraoperative 3D fluoroscopy with intravenous contrast agent for the evaluation of aneurysm occlusion and vessel patency after clip placement was assessed in patients who underwent surgery for intracranial aneurysms. Materials and methods Twelve patients were included in this retrospective analysis. Prior to surgery, a 360° rotational fluoroscopy scan was performed without contrast agent followed by another scan with 50 ml of intravenous iodine contrast agent. The image files of both scans were transferred to an Apple PowerMac® workstation, subtracted and reconstructed using OsiriX® free software. The procedure was repeated after clip placement. Both image sets were compared for assessment of aneurysm occlusion and vessel patency. Results Image acquisition and contrast administration caused no adverse effects. Image quality was sufficient to follow the patency of the vessels distal to the clip. Metal artifacts reduce the assessability of the immediate vicinity of the clip. Precise image subtraction and post-processing can reduce metal artifacts and make the clip-site assessable and depict larger neck-remnants. Conclusion This technique quickly supplies images at adequate quality to evaluate distal vessel patency after aneurysm clipping. Significant aneurysm remnants may be depicted as well. As it does not require visual control of all vessels that are supposed to be evaluated intraoperatively, this technique may be complementary to other intraoperative tools like indocyanine green videoangiography and micro-Doppler, especially for the assessment of larger aneurysms. At the momentary state of this technology, it cannot replace postoperative conventional angiography. However, 3D fluoroscopy and image post-processing are young technologies. Further technical developments are likely to result in improved image quality.}, language = {en} } @article{Westermaier2013, author = {Westermaier, Thomas}, title = {Neuroprotective Treatment Strategies for Delayed Cerebral Ischemia after Subarachnoid Hemorrhage - Review of Literature and Future Prospects}, doi = {10.4172/2155-9562.1000183}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-112631}, year = {2013}, abstract = {This article reviews experimental and clinical data on the use of various neuroprotective agents and therapeutic measures after aneurysmal subarachnoid hemorrhage (SAH). While calcium antagonists have been used in the past and are still part of the standard treatment regimen in most departments involved in the treatment of SAH, other classes of drugs and various other methods have been tested for their potential to inhibit delayed ischemia after SAH. This article reviews the literature about clinical studies about the efficacy of various neuroprotective agents and methods including statins, steroids and Endothelin-antagonists and other - alternative - methods like cisternal lavage, intrathecal drug delivery and hypercapnia, offering future perspectives for the treatment of this hazardous disease.}, language = {en} } @article{WestermaierKoehlerLinsenmannetal.2015, author = {Westermaier, Thomas and Koehler, Stefan and Linsenmann, Thomas and Kinderlen, Michael and Pakos, Paul and Ernestus, Ralf-Ingo}, title = {Intraoperative Myelography in Cervical Multilevel Stenosis Using 3D Rotational Fluoroscopy: Assessment of Feasibility and Image Quality}, series = {Radiology Research and Practice}, volume = {2015}, journal = {Radiology Research and Practice}, doi = {10.1155/2015/498936}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125779}, pages = {498936}, year = {2015}, abstract = {Background. Intraoperative myelography has been reported for decompression control in multilevel lumbar disease. Cervical myelography is technically more challenging. Modern 3D fluoroscopy may provide a new opportunity supplying multiplanar images. This study was performed to determine the feasibility and image quality of intraoperative cervical myelography using a 3D fluoroscope. Methods. The series included 9 patients with multilevel cervical stenosis. After decompression, 10 mL of water-soluble contrast agent was administered via a lumbar drainage and the operating table was tilted. Thereafter, a 3D fluoroscopy scan (O-Arm) was performed and visually evaluated. Findings. The quality of multiplanar images was sufficient to supply information about the presence of residual stenosis. After instrumentation, metal artifacts lowered image quality. In 3 cases, decompression was continued because myelography depicted residual stenosis. In one case, anterior corpectomy was not completed because myelography showed sufficient decompression after 2-level discectomy. Interpretation. Intraoperative myelography using 3D rotational fluoroscopy is useful for the control of surgical decompression in multilevel spinal stenosis providing images comparable to postmyelographic CT. The long duration of contrast delivery into the cervical spine may be solved by preoperative contrast administration. The method is susceptible to metal artifacts and, therefore, should be applied before metal implants are placed.}, language = {en} } @article{LillaKesslerWeilandetal.2021, author = {Lilla, Nadine and Kessler, Almuth F. and Weiland, Judith and Ernestus, Ralf-Ingo and Westermaier, Thomas}, title = {Case Report: A Case Series Using Natural Anatomical Gaps — Posterior Cervical Approach to Skull Base and Upper Craniocervical Meningiomas Without Bone Removal}, series = {Frontiers in Surgery}, volume = {8}, journal = {Frontiers in Surgery}, issn = {2296-875X}, doi = {10.3389/fsurg.2021.666699}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-244613}, year = {2021}, abstract = {Background: Removal of anteriorly located tumors of the upper cervical spine and craniovertebral junction (CVJ) is a particular surgical challenge. Extensive approaches are associated with pain, restricted mobility of neck and head and, in case of foramen magnum and clivus tumors, with retraction of brainstem and cerebellum. Methods: Four symptomatic patients underwent resection of anteriorly located upper cervical and lower clivus meningiomas without laminotomy or craniotomy using a minimally invasive posterior approach. Distances of natural gaps between C0/C1, C1/C2, and C2/C3 were measured using preoperative CT scans and intraoperative lateral x-rays. Results: In all patients, safe and complete resection was conducted by the opening of the dura between C0/C1, C1/C2, and C2/C3, respectively. There were no surgical complications. Local pain was reported as very moderate by all patients and postoperative recovery was extremely fast. All tumors had a rather soft consistency, allowing mass reduction prior to removal of the tumor capsule and were well separable from lower cranial nerves and vascular structures. Conclusion: If tumor consistency is appropriate for careful mass reduction before removal of the tumor capsule and if tumor margins are not firmly attached to crucial structures, then upper cervical, foramen magnum, and lower clivus meningiomas can be safely and completely removed through natural gaps in the CVJ region. Both prerequisites usually become clear early during surgery. Thus, this tumor entity may be planned using this minimally invasive approach and may be extended if tumor consistency turns out to be less unfavorable for resection or if crucial structures cannot be easily separated from the tumor.}, language = {en} } @article{LinsenmannMonoranuKessleretal.2013, author = {Linsenmann, Thomas and Monoranu, Camelia M. and Kessler, Almuth F. and Ernestus, Ralf I. and Westermaier, Thomas}, title = {Bone chips, fibrin glue, and osteogeneration following lateral suboccipital craniectomy: a case report}, series = {BMC Research Notes}, journal = {BMC Research Notes}, doi = {10.1186/1756-0500-6-523}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97346}, year = {2013}, abstract = {Background Suboccipital craniectomy is a conventional approach for exploring cerebellopontine angle lesions. A variety of techniques have been successfully employed to reconstruct a craniectomy. This is the first report about the histological findings after performing a cranioplasty by using a mixture of autologous bone chips and human allogenic fibrin glue. Case presentation A 53-year-old German woman underwent left lateral suboccipital retrosigmoidal craniectomy for treatment of trigeminal neuralgia in 2008. Cranioplasty was perfomed by using a mixture of autologous bone chips and human allogenic fibrin glue. Due to recurrent neuralgia, a second left lateral suboccipital craniectomy was performed in 2012. The intraoperative findings revealed a complete ossification of the former craniotomy including widely mature trabecular bone tissue in the histological examination. Conclusion A mixture of autologous bone chips and human allogenic fibrin glue seems to provide sufficient bone-regeneration revealed by histological and neuroradiological examinations.}, language = {en} } @article{WestermaierStetterKunzeetal.2013, author = {Westermaier, Thomas and Stetter, Christian and Kunze, Ekkehard and Willner, Nadine and Raslan, Furat and Vince, Giles H. and Ernestus, Ralf-Ingo}, title = {Magnesium treatment for neuroprotection in ischemic diseases of the brain}, series = {Experimental and Translational Stroke Medicine}, journal = {Experimental and Translational Stroke Medicine}, doi = {10.1186/2040-7378-5-6}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96729}, year = {2013}, abstract = {This article reviews experimental and clinical data on the use of magnesium as a neuroprotective agent in various conditions of cerebral ischemia. Whereas magnesium has shown neuroprotective properties in animal models of global and focal cerebral ischemia, this effect could not be reproduced in a large human stroke trial. These conflicting results may be explained by the timing of treatment. While treatment can be started before or early after ischemia in experimental studies, there is an inevitable delay of treatment in human stroke. Magnesium administration to women at risk for preterm birth has been investigated in several randomized controlled trials and was found to reduce the risk of neurological deficits for the premature infant. Postnatal administration of magnesium to babies after perinatal asphyxia has been studied in a number of controlled clinical trials. The results are promising but the trials have, so far, been underpowered. In aneurysmal subarachnoid hemorrhage (SAH), cerebral ischemia arises with the onset of delayed cerebral vasospasm several days after aneurysm rupture. Similar to perinatal asphyxia in impending preterm delivery, treatment can be started prior to ischemia. The results of clinical trials are conflicting. Several clinical trials did not show an additive effect of magnesium with nimodipine, another calcium antagonist which is routinely administered to SAH patients in many centers. Other trials found a protective effect after magnesium therapy. Thus, it may still be a promising substance in the treatment of secondary cerebral ischemia after aneurysmal SAH. Future prospects of magnesium therapy are discussed.}, language = {en} } @article{LinsenmannMonoranuVinceetal.2014, author = {Linsenmann, Thomas and Monoranu, Camelia M. and Vince, Giles H. and Westermaier, Thomas and Hagemann, Carsten and Kessler, Almuth F. and Ernestus, Ralf-Ingo and L{\"o}hr, Mario}, title = {Long-term tumor control of spinal dissemination of cerebellar glioblastoma multiforme by combined adjuvant bevacizumab antibody therapy: a case report}, doi = {10.1186/1756-0500-7-496}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-110536}, year = {2014}, abstract = {Background Glioblastoma multiforme located in the posterior fossa is extremely rare with a frequency up to 3.4\%. Compared with glioblastoma of the hemispheres the prognosis of infratentorial glioblastoma seems to be slightly better. Absence of brainstem invasion and low expression rates of epidermal growth factor receptor are described as factors for long-time survival due to the higher radiosensitivity of these tumors. Case presentation In this case study, we report a German female patient with an exophytic glioblastoma multiforme arising from the cerebellar tonsil and a secondary spinal manifestation. Furthermore, the tumor showed no O (6)-Methylguanine-DNA methyltransferase promotor-hypermethylation and no isocitrate dehydrogenase 1 mutations. All these signs are accompanied by significantly shorter median overall survival. A long-term tumor control of the spinal metastases was achieved by a combined temozolomide/bevacizumab and irradiation therapy, as part of a standard care administered by the treating physician team. Conclusion To our knowledge this is the first published case of a combined cerebellar exophytic glioblastoma with a subsequent solid spinal manifestation. Furthermore this case demonstrates a benefit undergoing this special adjuvant therapy regime in terms of overall survival. Due to the limited overall prognosis of the disease, spinal manifestations of glioma are rarely clinically relevant. The results of our instructive case, however, with a positive effect on both life quality and survival warrant treating future patients in the frame of a prospective clinical study.}, language = {en} } @article{RaslanAlbertWeissenbergerWestermaieretal.2012, author = {Raslan, Furat and Albert-Weißenberger, Christiane and Westermaier, Thomas and Saker, Saker and Kleinschmitz, Christoph and Lee, Jin-Yul}, title = {A modified double injection model of cisterna magna for the study of delayed cerebral vasospasm following subarachnoid hemorrhage in rats}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-76038}, year = {2012}, abstract = {Delayed cerebral vasospasm following subarachnoid hemorrhage (SAH) is a serious medical complication, characterized by constriction of cerebral arteries leading to varying degrees of cerebral ischemia. Numerous clinical and experimental studies have been performed in the last decades; however, the pathophysiologic mechanism of cerebral vasospasm after SAH still remains unclear. Among a variety of experimental SAH models, the double hemorrhage rat model involving direct injection of autologous arterial blood into the cisterna magna has been used most frequently for the study of delayed cerebral vasospasm following SAH in last years. Despite the simplicity of the technique, the second blood injection into the cisterna magna may result in brainstem injury leading to high mortality. Therefore, a modified double hemorrhage model of cisterna magna has been developed in rat recently. We describe here step by step the surgical technique to induce double SAH and compare the degree of vasospasm with other cisterna magna rat models using histological assessment of the diameter and cross-sectional area of the basilar artery}, subject = {Medizin}, language = {en} } @article{KunzePhamRaslanetal.2012, author = {Kunze, Ekkehard and Pham, Mirko and Raslan, Furat and Stetter, Christian and Lee, Jin-Yul and Solymosi, Laszlo and Ernestus, Ralf-Ingo and Hamilton Vince, Giles and Westermaier, Thomas}, title = {Value of Perfusion CT, Transcranial Doppler Sonography and Neurological Examination to detect delayed Vasospasm after aneurysmal Subarachnoid Hemorrhage [Research Article]}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-76241}, year = {2012}, abstract = {Background If detected in time, delayed cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH) may be treated by balloon angioplasty or chemical vasospasmolysis in order to enhance cerebral blood flow (CBF) and protect the brain from ischemic damage. This study was conceived to compare the diagnostic accuracy of detailed neurological examination, Transcranial Doppler Sonography (TCD), and Perfusion-CT (PCT) to detect angiographic vasospasm. Methods The sensitivity, specificity, positive and negative predictive values of delayed ischemic neurological deterioration (DIND), pathological findings on PCT- maps, and accelerations of the mean flow velocity (MVF) were calculated. Results The accuracy of DIND to predict angiographic vasospasm was 0.88. An acceleration of MFV in TCD (>140 cm/s) had an accuracy of 0.64, positive PCT-findings of 0.69 with a higher sensitivity, and negative predictive value than TCD. Interpretation Neurological assessment at close intervals is the most sensitive and specific parameter for cerebral vasospasm. PCT has a higher accuracy, sensitivity and negative predictive value than TCD. If detailed neurological evaluation is possible, it should be the leading parameter in the management and treatment decisions. If patients are not amenable to detailed neurological examination, PCT at regular intervals is a helpful tool to diagnose secondary vasospasm after aneurysmal SAH.}, subject = {Medizin}, language = {en} } @article{WestermaierStetterRaslanetal.2012, author = {Westermaier, Thomas and Stetter, Christian and Raslan, Furat and Vinc, Giles Hamilton and Ernestus, Ralf-Ingo}, title = {Brain edema formation correlates with perfusion deficit during the first six hours after experimental subarachnoid hemorrhage in rats}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75765}, year = {2012}, abstract = {Background: Severe brain edema is observed in a number of patients suffering from subarachnoid hemorrhage (SAH). Little is known about its pathogenesis and time-course in the first hours after SAH. This study was performed to investigate the development of brain edema and its correlation with brain perfusion after experimental SAH. Methods: Male Sprague-Dawley rats, randomly assigned to one of six groups (n = 8), were subjected to SAH using the endovascular filament model or underwent a sham operation. Animals were sacrificed 15, 30, 60, 180 or 360 minutes after SAH. Intracranial pressure (ICP), mean arterial blood pressure (MABP), cerebral perfusion pressure (CPP) and bilateral local cerebral blood flow (LCBF) were continuously measured. Brain water content (BWC) was determined by the wet/dry-weight method. Results: After SAH, CPP and LCBF rapidly decreased. The decline of LCBF markedly exceeded the decline of CPP and persisted until the end of the observation period. BWC continuously increased. A significant correlation was observed between the BWC and the extent of the perfusion deficit in animals sacrificed after 180 and 360 minutes. Conclusions: The significant correlation with the perfusion deficit after SAH suggests that the development of brain edema is related to the extent of ischemia and acute vasoconstriction in the first hours after SAH.}, subject = {Medizin}, language = {en} } @article{LinsenmannCattaneoMaerzetal.2021, author = {Linsenmann, Thomas and Cattaneo, Andrea and M{\"a}rz, Alexander and Weiland, Judith and Stetter, Christian and Nickl, Robert and Westermaier, Thomas}, title = {Combined frameless stereotactical biopsy and intraoperative cerebral angiography by 3D-rotational fluoroscopy with intravenous contrast administration: a feasibility study}, series = {BMC Medical Imaging}, volume = {21}, journal = {BMC Medical Imaging}, doi = {10.1186/s12880-021-00622-3}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-270370}, year = {2021}, abstract = {Background Mobile 3-dimensional fluoroscopes are an integral part of modern neurosurgical operating theatres and can also be used in combination with free available image post processing to depict cerebral vessels. In preparation of stereotactic surgery, preoperative Computed Tomography (CT) may be required for image fusion. Contrast CT may be of further advantage for image fusion as it regards the vessel anatomy in trajectory planning. Time-consuming in-hospital transports are necessary for this purpose. Mobile 3D-fluoroscopes may be used to generate a CT equal preoperative data set without an in-hospital transport. This study was performed to determine the feasibility and image quality of intraoperative 3-dimensional fluoroscopy with intravenous contrast administration in combination with stereotactical procedures. Methods 6 patients were included in this feasibility study. After fixation in a radiolucent Mayfield clamp a rotational fluoroscopy scan was performed with 50 mL iodine contrast agent. The image data sets were merged with the existing MRI images at a planning station and visually evaluated by two observer. The operation times were compared between the frame-based and frameless systems ("skin-to-skin" and "OR entry to exit"). Results The procedure proves to be safe. The entire procedure from fluoroscope positioning to the transfer to the planning station took 5-6 min with an image acquisition time of 24 s. In 5 of 6 cases, the fused imaging was able to reproduce the vascular anatomy accurately and in good quality. Both time end-points were significantly shorter compared to frame-based interventions. Conclusion The images could easily be transferred to the planning and navigation system and were successfully merged with the MRI data set. The procedure can be completely integrated into the surgical workflow. Preoperative CT imaging or transport under anaesthesia may even be replaced by this technique in the future. Furthermore, hemorrhages can be successfully visualized intraoperatively and might prevent time delays in emergencies.}, language = {en} } @article{StetterWeidnerLillaetal.2021, author = {Stetter, Christian and Weidner, Franziska and Lilla, Nadine and Weiland, Judith and Kunze, Ekkehard and Ernestus, Ralf-Ingo and Muellenbach, Ralf Michael and Westermaier, Thomas}, title = {Therapeutic hypercapnia for prevention of secondary ischemia after severe subarachnoid hemorrhage: physiological responses to continuous hypercapnia}, series = {Scientific Reports}, volume = {11}, journal = {Scientific Reports}, number = {1}, doi = {10.1038/s41598-021-91007-7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-260779}, pages = {11715}, year = {2021}, abstract = {Temporary hypercapnia has been shown to increase cerebral blood flow (CBF) and might be used as a therapeutical tool in patients with severe subarachnoid hemorrhage (SAH). It was the aim of this study was to investigate the optimum duration of hypercapnia. This point is assumed to be the time at which buffer systems become active, cause an adaptation to changes of the arterial partial pressure of carbon dioxide (PaCO2) and annihilate a possible therapeutic effect. In this prospective interventional study in a neurosurgical ICU the arterial partial pressure of carbon dioxide (PaCO\(_2\)) was increased to a target range of 55 mmHg for 120 min by modification of the respiratory minute volume (RMV) one time a day between day 4 and 14 in 12 mechanically ventilated poor-grade SAH-patients. Arterial blood gases were measured every 15 min. CBF and brain tissue oxygen saturation (StiO\(_2\)) were the primary and secondary end points. Intracranial pressure (ICP) was controlled by an external ventricular drainage. Under continuous hypercapnia (PaCO\(_2\) of 53.17 ± 5.07), CBF was significantly elevated between 15 and 120 min after the start of hypercapnia. During the course of the trial intervention, cardiac output also increased significantly. To assess the direct effect of hypercapnia on brain perfusion, the increase of CBF was corrected by the parallel increase of cardiac output. The maximum direct CBF enhancing effect of hypercapnia of 32\% was noted at 45 min after the start of hypercapnia. Thereafter, the CBF enhancing slowly declined. No relevant adverse effects were observed. CBF and StiO\(_2\) reproducibly increased by controlled hypercapnia in all patients. After 45 min, the curve of CBF enhancement showed an inflection point when corrected by cardiac output. It is concluded that 45 min might be the optimum duration for a therapeutic use and may provide an optimal balance between the benefits of hypercapnia and risks of a negative rebound effect after return to normal ventilation parameters.}, language = {en} } @article{SchadtIsraelBeezetal.2023, author = {Schadt, Fabian and Israel, Ina and Beez, Alexandra and Alushi, Kastriot and Weiland, Judith and Ernestus, Ralf-Ingo and Westermaier, Thomas and Samnick, Samuel and Lilla, Nadine}, title = {Analysis of cerebral glucose metabolism following experimental subarachnoid hemorrhage over 7 days}, series = {Scientific Reports}, volume = {13}, journal = {Scientific Reports}, number = {1}, doi = {10.1038/s41598-022-26183-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300725}, year = {2023}, abstract = {Little is known about changes in brain metabolism following SAH, possibly leading towards secondary brain damage. Despite sustained progress in the last decade, analysis of in vivo acquired data still remains challenging. The present interdisciplinary study uses a semi-automated data analysis tool analyzing imaging data independently from the administrated radiotracer. The uptake of 2-[18F]Fluoro-2-deoxy-glucose ([\(^{18}\)F]FDG) was evaluated in different brain regions in 14 male Sprague-Dawley rats, randomized into two groups: (1) SAH induced by the endovascular filament model and (2) sham operated controls. Serial [\(^{18}\)F]FDG-PET measurements were carried out. Quantitative image analysis was performed by uptake ratio using a self-developed MRI-template based data analysis tool. SAH animals showed significantly higher [\(^{18}\)F]FDG accumulation in gray matter, neocortex and olfactory system as compared to animals of the sham group, while white matter and basal forebrain region showed significant reduced tracer accumulation in SAH animals. All significant metabolic changes were visualized from 3 h, over 24 h (day 1), day 4 and day 7 following SAH/sham operation. This [\(^{18}\)F]FDG-PET study provides important insights into glucose metabolism alterations following SAH—for the first time in different brain regions and up to day 7 during course of disease.}, language = {en} } @article{LinsenmannMaerzDufneretal.2021, author = {Linsenmann, Thomas and M{\"a}rz, Alexander and Dufner, Vera and Stetter, Christian and Weiland, Judith and Westermaier, Thomas}, title = {Optimization of radiation settings for angiography using 3D fluoroscopy for imaging of intracranial aneurysms}, series = {Computer Assisted Surgery}, volume = {26}, journal = {Computer Assisted Surgery}, number = {1}, doi = {10.1080/24699322.2021.1894240}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-259251}, pages = {22-30}, year = {2021}, abstract = {Mobile 3D fluoroscopes have become increasingly available in neurosurgical operating rooms. We recently reported its use for imaging cerebral vascular malformations and aneurysms. This study was conducted to evaluate various radiation settings for the imaging of cerebral aneurysms before and after surgical occlusion. Eighteen patients with cerebral aneurysms with the indication for surgical clipping were included in this prospective analysis. Before surgery the patients were randomized into one of three different scan protocols according (default settings of the 3D fluoroscope): Group 1: 110 kV, 80 mA (enhanced cranial mode), group 2: 120 kV, 64 mA (lumbar spine mode), group 3: 120 kV, 25 mA (head/neck settings). Prior to surgery, a rotational fluoroscopy scan (duration 24 s) was performed without contrast agent followed by another scan with 50 ml of intravenous iodine contrast agent. The image files of both scans were transferred to an Apple PowerMac(R) workstation, subtracted and reconstructed using OsiriX(R) MD 10.0 software. The procedure was repeated after clip placement. The image quality regarding preoperative aneurysm configuration and postoperative assessment of aneurysm occlusion and vessel patency was analyzed by 2 independent reviewers using a 6-grade scale. This technique quickly supplies images of adequate quality to depict intracranial aneurysms and distal vessel patency after aneurysm clipping. Regarding these features, a further optimization to our previous protocol seems possible lowering the voltage and increasing tube current. For quick intraoperative assessment, image subtraction seems not necessary. Thus, a native scan without a contrast agent is not necessary. Further optimization may be possible using a different contrast injection protocol.}, language = {en} } @article{VadokasKoehlerWeilandetal.2019, author = {Vadokas, Georg and Koehler, Stefan and Weiland, Judith and Lilla, Nadine and Stetter, Christian and Westermaier, Thomas}, title = {Early antiinflammatory therapy attenuates brain damage after SAH in rats}, series = {Translational Neuroscience}, volume = {10}, journal = {Translational Neuroscience}, number = {1}, doi = {10.1515/tnsci-2019-0018}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201440}, pages = {104-111}, year = {2019}, abstract = {Background Early inflammatory processes may play an important role in the development of early brain injury (EBI) after subarachnoid hemorrhage (SAH). Experimental studies suggest that anti-inflammatory and membrane-stabilizing drugs might have beneficial effects, although the underlying mechanisms are not fully understood. The aim of this study was to investigate the effect of early treatment with methylprednisolone and minocycline on cerebral perfusion and EBI after experimental SAH. Methods Male Sprague-Dawley rats were subjected to SAH using the endovascular filament model. 30 minutes after SAH, they were randomly assigned to receive an intravenous injection of methylprednisolone (16mg/kg body weight, n=10), minocycline (45mg/kg body weight, n=10) or saline (n=11). Mean arterial blood pressure (MABP), intracranial pressure (ICP) and local cerebral blood flow (LCBF) over both hemispheres were recorded continuously for three hours following SAH. Neurological assessment was performed after 24 hours. Hippocampal damage was analyzed by immunohistochemical staining (caspase 3). Results Treatment with methylprednisolone or minocycline did not result in a significant improvement of MABP, ICP or LCBF. Animals of both treatment groups showed a non-significant trend to better neurological recovery compared to animals of the control group. Mortality was reduced and hippocampal damage significantly attenuated in both methylprednisolone and minocycline treated animals. Conclusion The results of this study suggest that inflammatory processes may play an important role in the pathophysiology of EBI after SAH. Early treatment with the anti-inflammatory drugs methylprednisolone or minocycline in the acute phase of SAH has the potential to reduce brain damage and exert a neuroprotective effect.}, language = {en} } @article{LillaFuellgrafStetteretal.2017, author = {Lilla, Nadine and F{\"u}llgraf, Hannah and Stetter, Christian and K{\"o}hler, Stefan and Ernestus, Ralf-Ingo and Westermaier, Thomas}, title = {First Description of Reduced Pyruvate Dehydrogenase Enzyme Activity Following Subarachnoid Hemorrhage (SAH)}, series = {Frontiers in Neuroscience}, volume = {11}, journal = {Frontiers in Neuroscience}, number = {37}, doi = {10.3389/fnins.2017.00037}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-157636}, year = {2017}, abstract = {Object: Several previous studies reported metabolic derangements and an accumulation of metabolic products in the early phase of experimental subarachnoid hemorrhage (SAH), which may contribute to secondary brain damage. This may be a result of deranged oxygen utilization due to enzymatic dysfunction in aerobic glucose metabolism. This study was performed to investigate, if pyruvate dehydrogenase enzyme (PDH) is affected in its activity giving further hints for a derangement of oxidative metabolism. Methods: Eighteen male Sprague-Dawley rats were randomly assigned to one of two experimental groups (n = 9): (1) SAH induced by the endovascular filament model and (2) sham-operated controls. Mean arterial blood pressure (MABP), intracranial pressure (ICP), and local cerebral blood flow (LCBF; laser-Doppler flowmetry) were continuously monitored from 30 min before until 3 h after SAH. Thereafter, the animals were sacrificed and PDH activity was measured by ELISA. Results: PDH activity was significantly reduced in animals subjected to SAH compared to controls. Conclusion: The results of this study demonstrate for the first time a reduction of PDH activity following SAH, independent of supply of substrates and may be an independent factor contributing to a derangement of oxidative metabolism, failure of oxygen utilization, and secondary brain damage.}, language = {en} } @article{WeilandBeezWestermaieretal.2021, author = {Weiland, Judith and Beez, Alexandra and Westermaier, Thomas and Kunze, Ekkehard and Sir{\´e}n, Anna-Leena and Lilla, Nadine}, title = {Neuroprotective strategies in aneurysmal subarachnoid hemorrhage (aSAH)}, series = {International Journal of Molecular Sciences}, volume = {22}, journal = {International Journal of Molecular Sciences}, number = {11}, issn = {1422-0067}, doi = {10.3390/ijms22115442}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-260755}, year = {2021}, abstract = {Aneurysmal subarachnoid hemorrhage (aSAH) remains a disease with high mortality and morbidity. Since treating vasospasm has not inevitably led to an improvement in outcome, the actual emphasis is on finding neuroprotective therapies in the early phase following aSAH to prevent secondary brain injury in the later phase of disease. Within the early phase, neuroinflammation, thromboinflammation, disturbances in brain metabolism and early neuroprotective therapies directed against delayed cerebral ischemia (DCI) came into focus. Herein, the role of neuroinflammation, thromboinflammation and metabolism in aSAH is depicted. Potential neuroprotective strategies regarding neuroinflammation target microglia activation, metalloproteases, autophagy and the pathway via Toll-like receptor 4 (TLR4), high mobility group box 1 (HMGB1), NF-κB and finally the release of cytokines like TNFα or IL-1. Following the link to thromboinflammation, potential neuroprotective therapies try to target microthrombus formation, platelets and platelet receptors as well as clot clearance and immune cell infiltration. Potential neuroprotective strategies regarding metabolism try to re-balance the mismatch of energy need and supply following aSAH, for example, in restoring fuel to the TCA cycle or bypassing distinct energy pathways. Overall, this review addresses current neuroprotective strategies in aSAH, hopefully leading to future translational therapy options to prevent secondary brain injury.}, language = {en} } @article{KunzeLillaStetteretal.2018, author = {Kunze, Ekkehard and Lilla, Nadine and Stetter, Christian and Ernestus, Ralf-Ingo and Westermaier, Thomas}, title = {Magnesium protects in episodes of critical perfusion after aneurysmal SAH}, series = {Translational Neuroscience}, volume = {9}, journal = {Translational Neuroscience}, number = {1}, doi = {10.1515/tnsci-2018-0016}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-177078}, pages = {99-105}, year = {2018}, abstract = {Background: To analyze whether magnesium has a neuroprotective effect during episodes that indicate a critical brain perfusion after aneurysmal subarachnoid hemorrhage (SAH). Methods: 107 patients with aSAH were randomized to continuously receive intravenous magnesium sulfate with target serum levels of 2.0 - 2.5 mmol/l (n = 54) or isotonic saline (n = 53). Neurological examination and transcranial Doppler sonography (TCD) were performed daily, Perfusion-CT (PCT) was acquired in 3-day intervals, angiography in case of suspected vasospasm. The primary endpoint was the development of secondary infarction following episodes of delayed ischemic neurological deficit (DIND), elevated mean flow velocity (MFV) in TCD or pathological findings in PCT. Results: In the magnesium group, 9 episodes of DIND were registered, none was followed by secondary infarction. In the control group, 23 episodes of DIND were registered, 9 were followed by secondary infarction (p < 0.05). In the magnesium group, 114 TCD-measurements showed an elevated MFV(> 140 cm/s). 7 were followed by new infarction. In control patients, 135 measurements showed elevated MFV, 32 were followed by new infarction (p < 0.05). 10 of 117 abnormal PCT-findings were followed by new infarction, compared to 30 of 122 in the control-group (p < 0.05). Conclusion: DIND, elevated MFV in TCD and abnormal PCT are findings which are associated with an increased risk to develop delayed secondary infarction. The results of this analysis suggest that magnesium-treatment may reduce the risk to develop infarction in a state of critical brain perfusion.}, language = {en} } @article{LinsenmannMonoranuAlkonyietal.2019, author = {Linsenmann, Thomas and Monoranu, Camelia M. and Alkonyi, Balint and Westermaier, Thomas and Hagemann, Carsten and Kessler, Almuth F. and Ernestus, Ralf-Ingo and L{\"o}hr, Mario}, title = {Cerebellar liponeurocytoma - molecular signature of a rare entity and the importance of an accurate diagnosis}, series = {Interdisciplinary Neurosurgery}, volume = {16}, journal = {Interdisciplinary Neurosurgery}, doi = {10.1016/j.inat.2018.10.017}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-177652}, pages = {7-11}, year = {2019}, abstract = {Background: Cerebellar liponeurocytoma is an extremely rare tumour entity of the central nervous system. It is histologically characterised by prominent neuronal/neurocytic differentiation with focal lipidisation and corresponding histologically to WHO grade II. It typically develops in adults, and usually shows a low proliferative potential. Recurrences have been reported in almost 50\% of cases, and in some cases the recurrent tumour may display increased mitotic activity and proliferation index, vascular proliferations and necrosis. Thus pathological diagnosis of liponeurocytoma is challenging. This case presentation highlights the main clinical, radiographic and pathological features of a cerebellar liponeurocytoma. Case presentation: A 59-year-old, right-handed woman presented at our department with a short history of persistent headache, vertigo and gait disturbances. Examination at presentation revealed that the patient was awake, alert and fully oriented. The cranial nerve status was normal. Uncertainties were noted in the bilateral finger-to-nose testing with bradydiadochokinesis on both sides. Strength was full and no pronator drift was observed. Sensation was intact. No signs of pyramidal tract dysfunction were detected. Her gait appeared insecure. The patient underwent surgical resection. Afterward no further disturbances could be detected. Conclusions: To date >40 cases of liponeurocytoma have been reported, including cases with supratentorial location. A review of the 5 published cases of recurrent cerebellar. Liponeurocytoma revealed that the median interval between the first and second relapse was rather short, indicating uncertain malignant potential. The most recent WHO classification of brain tumours (2016) classifies the cerebellar liponeurocytoma as a separate entity and assigns the tumour to WHO grade II. Medulloblastoma is the most important differential diagnosis commonly seen in children and young adults. In contrast, cerebellar liponeurocytoma is typically diagnosed in adults. The importance of accurate diagnosis should not be underestimated especially in the view of possible further therapeutic interventions and for the determination of the patient's prognosis.}, language = {en} } @article{NotzLotzHerrmannetal.2021, author = {Notz, Quirin and Lotz, Christopher and Herrmann, Johannes and Vogt, Marius and Schlesinger, Tobias and Kredel, Markus and Muellges, Wolfgang and Weismann, Dirk and Westermaier, Thomas and Meybohm, Patrick and Kranke, Peter}, title = {Severe neurological complications in critically ill COVID‑19 patients}, series = {Journal of Neurology}, journal = {Journal of Neurology}, issn = {0340-5354}, doi = {10.1007/s00415-020-10152-7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-232429}, pages = {1576-1579}, year = {2021}, abstract = {No abstract available.}, language = {en} } @article{ConradsGrunzHuflageetal.2023, author = {Conrads, Nora and Grunz, Jan-Peter and Huflage, Henner and Luetkens, Karsten Sebastian and Feldle, Philipp and Grunz, Katharina and K{\"o}hler, Stefan and Westermaier, Thomas}, title = {Accuracy of pedicle screw placement using neuronavigation based on intraoperative 3D rotational fluoroscopy in the thoracic and lumbar spine}, series = {Archives of Orthopaedic and Trauma Surgery}, volume = {143}, journal = {Archives of Orthopaedic and Trauma Surgery}, number = {6}, doi = {10.1007/s00402-022-04514-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-324966}, pages = {3007-3013}, year = {2023}, abstract = {Introduction In spinal surgery, precise instrumentation is essential. This study aims to evaluate the accuracy of navigated, O-arm-controlled screw positioning in thoracic and lumbar spine instabilities. Materials and methods Posterior instrumentation procedures between 2010 and 2015 were retrospectively analyzed. Pedicle screws were placed using 3D rotational fluoroscopy and neuronavigation. Accuracy of screw placement was assessed using a 6-grade scoring system. In addition, screw length was analyzed in relation to the vertebral body diameter. Intra- and postoperative revision rates were recorded. Results Thoracic and lumbar spine surgery was performed in 285 patients. Of 1704 pedicle screws, 1621 (95.1\%) showed excellent positioning in 3D rotational fluoroscopy imaging. The lateral rim of either pedicle or vertebral body was protruded in 25 (1.5\%) and 28 screws (1.6\%), while the midline of the vertebral body was crossed in 8 screws (0.5\%). Furthermore, 11 screws each (0.6\%) fulfilled the criteria of full lateral and medial displacement. The median relative screw length was 92.6\%. Intraoperative revision resulted in excellent positioning in 58 of 71 screws. Follow-up surgery due to missed primary malposition had to be performed for two screws in the same patient. Postsurgical symptom relief was reported in 82.1\% of patients, whereas neurological deterioration occurred in 8.9\% of cases with neurological follow-up. Conclusions Combination of neuronavigation and 3D rotational fluoroscopy control ensures excellent accuracy in pedicle screw positioning. As misplaced screws can be detected reliably and revised intraoperatively, repeated surgery for screw malposition is rarely required.}, language = {en} }