302 results on '"Arnd, Dörfler"'
Search Results
52. Extended salvage surgery after high-dose chemoradiation therapy for tumors in the cervico-thoracic junction with invasion of the chest wall and the spine: a case series
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Kurt Wiendieck, Arnd Dörfler, and Björn Sommer
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Surgery ,ddc:610 - Abstract
The treatment of malignant tumors localized in the upper thoracic cavity and involving the spine at the cervico-thoracic junction (CTJ) is challenging. We report on three patients with malignant tumors invading the thoracic inlet and the spine at the CTJ. All three patients underwent radical tumor resection and 360° spine fusion following the posterior pedicle screw instrumentation and anterior vertebrectomy combined with implantation of an expandable titanium cage. Postoperatively, a mild paresis with hypesthesia of the ipsilateral arm occurred in one patient because of brachial plexus involvement. Two patients were still alive at last follow-up after 83 and 143 months, the third patient succumbed to tumor progression 13 months after extended salvage surgery. We display the possibilities of extended ‘salvage’ therapy in well-selected patients that were deemed hopeless regarding neurological function, biomechanical stability and tumor control after multiple courses of combined radio-chemotherapy.
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- 2022
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53. A Deep Learning Approach for Reconstruction Filter Kernel Discretization.
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Christopher Syben, Bernhard Stimpel, Katharina Breininger, Tobias Würfl, Rebecca Fahrig, Arnd Dörfler, and Andreas K. Maier
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- 2017
54. MR to X-Ray Projection Image Synthesis.
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Bernhard Stimpel, Christopher Syben, Tobias Würfl, Katrin Mentl, Arnd Dörfler, and Andreas K. Maier
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- 2017
55. Neurovascular Compression in Arterial Hypertension: Correlation of Clinical Data to 3D-Visualizations of MRI-Findings
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Susanne Jung, Roland E. Schmieder, Peter Hastreiter, Panagiota Manava, Michael Buchfelder, Rudolf Fahlbusch, Ramin Naraghi, Michael Lell, and Arnd Dörfler
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Correlation ,medicine.medical_specialty ,business.industry ,Neurovascular compression ,medicine ,Radiology, Nuclear Medicine and imaging ,Neurology (clinical) ,Radiology ,business ,Mri findings - Abstract
Aims: In this study, we attempted to identify clinical parameters predicting the absence or presence of Neurovascular Compression (NVC) at the Ventrolateral Medulla (VLM) in arterial hypertension (HTN) in MRI findings. Background: Cardiovascular and pulmonary afferences are transmitted through the left vagus and glossopharyngeal nerve to the brain stem and vasoactive centers. Evidence supports the association between HTN and NVC at the left VLM. Several independent studies indicate a reduction of HTN after Microvascular Decompression (MVD) of the left. Several independent studies indicate a reduction of HTN after Microvascular Decompression (MVD) of the left VLM. Image processing of MRI provides comprehensible detection of NVC. HTN affects hemodynamic parameters and organs. Objective: This study analyzes and correlates clinical data and MRI findings in patients with and without NVC at the VLM in treatment resistant HTN to obtain possible selection criteria for neurogenic hypertension. Methods: In 44 patients with treatment resistant HTN, we compared MRI findings of neurovascular imaging to demographic, clinical and lifestyle data, office and 24-hour ambulatory Blood Pressure (BP), and cardiovascular imaging and parameters. Results: Twenty-nine (66%) patients had evidence of NVC at the VLM in MRI. Sixteen patients (36%) had unilateral NVC on the left side, 7 (16%) unilateral right and 6 (14%) bilateral NVC. Fifteen (34%) had no evidence of NVC at the VLM. Patients with left sided NVC were significantly younger, than those without NVC (p=0.034). They showed a statistically significant variance in daytime (p=0.020) and nighttime diastolic BP (p Conclusion: We suggest to examine young adults with treatment resistant HTN for the presence of NVC at VLM, before signs of permanent organ damage appear. Clinical and hemodynamic parameters did not emerge as selection criteria to predict NVC. MVD as a surgical treatment of NVC in HTN is not routine yet as a surgical treatment of NVC in HTN is not routine yet. Detection of NVC by imaging and image processing remains the only criteria to suggest MVD, which should be indicated on an individual decision.
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- 2021
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56. Hybrid ‐shimming and gradient adaptions for improved pseudo‐continuous arterial spin labeling at 7 Tesla
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Christian K. Eisen, Bernhard Hensel, Jürgen Herrler, Max Müller, Michael Uder, Christian R. Meixner, Sebastian Schmitter, Arnd Dörfler, and Armin M. Nagel
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Nuclear magnetic resonance ,Materials science ,Homogeneity (statistics) ,Arterial spin labeling ,Background suppression ,Radiology, Nuclear Medicine and imaging ,Shim (magnetism) ,Continuous arterial spin labeling ,Selective excitation ,Gradient strength - Abstract
PURPOSE To improve pseudo-continuous arterial spin labeling (pcASL) at 7T by exploiting a hybrid homogeneity- and efficiency-optimized B1+ -shim with adapted gradient strength as well as background suppression. METHODS The following three experiments were performed at 7T, each employing five volunteers: (1) A hybrid (ie, homogeneity-efficiency optimized) B1+ -shim was introduced and evaluated for variable-rate selective excitation pcASL labeling. Therefore, B1+ -maps in the V3 segment and time-of-flight images were acquired to identify the feeding arteries. For validation, a gradient-echo sequence was applied in circular polarized (CP) mode and with the hybrid B1+ -shim. Additionally, the gray matter (temporal) signal-to-noise ratio (tSNR) in pcASL perfusion images was evaluated. (2) Bloch simulations for the pcASL labeling were conducted and validated experimentally, with a focus on the slice-selective gradients. (3) Background suppression was added to the B1+ -shimmed, gradient-adapted 7T sequence and this was then compared to a matched sequence at 3T. RESULTS The B1+ -shim improved the signal within the labeling plane (23.6%) and the SNR/tSNR increased (+11%/+11%) compared to its value in CP mode; however, the increase was not significant. In accordance with the simulations, the adapted gradients increased the tSNR (35%) and SNR (45%) significantly. Background suppression further improved the perfusion images at 7T, and this protocol performed as well as a resolution-matched protocol at 3T. CONCLUSION The combination of the proposed hybrid B1+ -phase-shim with the adapted slice-selective gradients and background suppression shows great potential for improved pcASL labeling under suboptimal B1+ conditions at 7T.
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- 2021
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57. DeepCEST 7 T: Fast and homogeneous mapping of 7 T CEST MRI parameters and their uncertainty quantification
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Leonie Hunger, Junaid R. Rajput, Kiril Klein, Angelika Mennecke, Moritz S. Fabian, Manuel Schmidt, Felix Glang, Kai Herz, Patrick Liebig, Armin M. Nagel, Klaus Scheffler, Arnd Dörfler, Andreas Maier, and Moritz Zaiss
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PROVIDES ,SATURATION ,uncertainty quantification ,deep learning ,Radiology, Nuclear Medicine and imaging ,neural networks ,rNOE ,amide ,CEST - Abstract
Purpose: In this work, we investigated the ability of neural networks to rapidly and robustly predict Lorentzian parameters of multi-pool CEST MRI spectra at 7 T with corresponding uncertainty maps to make them quickly and easily available for routine clinical use.Methods: We developed a deepCEST 7 T approach that generates CEST contrasts from just 1 scan with robustness against B1 inhomogeneities. The input data for a neural feed-forward network consisted of 7 T in vivo uncorrected Z-spectra of a single B1 level, and a B1 map. The 7 T raw data were acquired using a 3D snapshot gradient echo multiple interleaved mode saturation CEST sequence. These inputs were mapped voxel-wise to target data consisting of Lorentzian amplitudes generated conventionally by 5-pool Lorentzian fitting of normalized, denoised, B0 - and B1 -corrected Z-spectra. The deepCEST network was trained with Gaussian negative log-likelihood loss, providing an uncertainty quantification in addition to the Lorentzian amplitudes.Results: The deepCEST 7 T network provides fast and accurate prediction of all Lorentzian parameters also when only a single B1 level is used. The prediction was highly accurate with respect to the Lorentzian fit amplitudes, and both healthy tissues and hyperintensities in tumor areas are predicted with a low uncertainty. In corrupted cases, high uncertainty indicated wrong predictions reliably.Conclusion: The proposed deepCEST 7 T approach reduces scan time by 50% to now 6:42 min, but still delivers both B0 - and B1 -corrected homogeneous CEST contrasts along with an uncertainty map, which can increase diagnostic confidence. Multiple accurate 7 T CEST contrasts are delivered within seconds.
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- 2022
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58. Deep learning for brain metastasis detection and segmentation in longitudinal MRI data
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Yixing Huang, Christoph Bert, Philipp Sommer, Benjamin Frey, Udo Gaipl, Luitpold V. Distel, Thomas Weissmann, Michael Uder, Manuel A. Schmidt, Arnd Dörfler, Andreas Maier, Rainer Fietkau, and Florian Putz
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FOS: Computer and information sciences ,Deep Learning ,Brain Neoplasms ,Computer Vision and Pattern Recognition (cs.CV) ,Image and Video Processing (eess.IV) ,FOS: Electrical engineering, electronic engineering, information engineering ,Computer Science - Computer Vision and Pattern Recognition ,Humans ,General Medicine ,ddc:610 ,Electrical Engineering and Systems Science - Image and Video Processing ,Magnetic Resonance Imaging - Abstract
Brain metastases occur frequently in patients with metastatic cancer. Early and accurate detection of brain metastases is very essential for treatment planning and prognosis in radiation therapy. To improve brain metastasis detection performance with deep learning, a custom detection loss called volume-level sensitivity-specificity (VSS) is proposed, which rates individual metastasis detection sensitivity and specificity in (sub-)volume levels. As sensitivity and precision are always a trade-off in a metastasis level, either a high sensitivity or a high precision can be achieved by adjusting the weights in the VSS loss without decline in dice score coefficient for segmented metastases. To reduce metastasis-like structures being detected as false positive metastases, a temporal prior volume is proposed as an additional input of DeepMedic. The modified network is called DeepMedic+ for distinction. Our proposed VSS loss improves the sensitivity of brain metastasis detection for DeepMedic, increasing the sensitivity from 85.3% to 97.5%. Alternatively, it improves the precision from 69.1% to 98.7%. Comparing DeepMedic+ with DeepMedic with the same VSS loss, 44.4% of the false positive metastases are reduced in the high sensitivity model and the precision reaches 99.6% for the high specificity model. The mean dice coefficient for all metastases is about 0.81. With the ensemble of the high sensitivity and high specificity models, on average only 1.5 false positive metastases per patient needs further check, while the majority of true positive metastases are confirmed. The ensemble learning is able to distinguish high confidence true positive metastases from metastases candidates that require special expert review or further follow-up, being particularly well-fit to the requirements of expert support in real clinical practice., Implementation is available to public at https://github.com/YixingHuang/DeepMedicPlus
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- 2022
59. Clinically compatible subject-specific dynamic parallel transmit pulse design for homogeneous fat saturation and water-excitation at 7T: Proof-of-concept for CEST MRI of the brain
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Simon Lévy, Jürgen Herrler, Andrzej Liebert, Katharina Tkotz, Moritz S. Fabian, Christian Eisen, David Grodzki, Michael Uder, Arnd Dörfler, Moritz Zaiss, and Armin M. Nagel
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Humans ,Water ,Brain ,Contrast Media ,Radiology, Nuclear Medicine and imaging ,Magnetic Resonance Imaging ,Lipids ,Algorithms - Abstract
To evaluate the benefits and challenges of dynamic parallel transmit (pTx) pulses for fat saturation (FS) and water-excitation (WE), in the context of CEST MRI."Universal" kWith a 25%-shorter pulse duration, pTx FS largely improved the FA homogeneity (root-mean-square-error (RMSE) = 12.3° vs. 53.4° with circularly-polarized mode, at the fat frequency). However, the spectral selectivity was degraded mainly in the cerebellum and close to the sinuses (RMSE = 5.8° vs. 0.2° at the water frequency). Similarly, pTx WE showed a trade-off between FA homogeneity and spectral selectivity compared to pTx non-selective pulses (RMSE = 0.9° and 1.1° at the fat and water frequencies, vs. 4.6° and 0.5°). In the brain, CEST metrics were reduced by up to 31.9% at -3.3 ppm with pTx FS, suggesting a mitigated lipid-induced bias.This clinically compatible implementation of dynamic pTx pulses improved the fat suppression homogeneity at 7T taking into account the subject-specific B
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- 2022
60. Neurochirurgische Operationsmöglichkeiten bei posteriorer Epilepsie
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Matthias Tomschik, Christian Dorfer, Karl Rössler, Burkhard S. Kasper, Michael Buchfelder, and Arnd Dörfler
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Gynecology ,03 medical and health sciences ,medicine.medical_specialty ,0302 clinical medicine ,business.industry ,030220 oncology & carcinogenesis ,Pediatrics, Perinatology and Child Health ,Medicine ,Neurology (clinical) ,business ,030217 neurology & neurosurgery - Abstract
Zusammenfassung Hintergrund Die chirurgische Therapie der posterioren Epilepsie stellt innerhalb der epilepsiechirurgischen Eingriffe eine besondere Herausforderung dar. Fragestellung Die Arten der Eingriffe zur chirurgischen Therapie der posterioren Epilepsie Material und Methode Darstellung der verschiedenen Eingriffsarten auf Basis der historischen und rezenten technischen Entwicklungen. Ergebnisse Elektrodenimplantation, resektive und diskonnektive Verfahren sowie neue Methoden tragen dazu bei, das Anfallsoutcome der posterioren Epilepsie zu verbessern.
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- 2021
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61. Functional connectivity of the human insular cortex during noxious and innocuous thermal stimulation.
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Elena Peltz, Frank Seifert 0003, Roberto DeCol, Arnd Dörfler, Stefan Schwab, and Christian Maihöfner
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- 2011
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62. Fluid flow simulation on the Cell Broadband Engine using the lattice Boltzmann method.
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Markus Stürmer, Jan Götz, Gregor Richter, Arnd Dörfler, and Ulrich Rüde
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- 2009
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63. Posteriore Epilepsien: Ätiologische Aspekte
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Burkhard S. Kasper, Arnd Dörfler, and Karl Rössler
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0301 basic medicine ,Gynecology ,03 medical and health sciences ,medicine.medical_specialty ,030104 developmental biology ,0302 clinical medicine ,business.industry ,Pediatrics, Perinatology and Child Health ,Medicine ,ddc:610 ,Neurology (clinical) ,business ,030217 neurology & neurosurgery - Abstract
Zusammenfassung Hintergrund Posteriore Epilepsien (PE), also fokale Epilepsien mit Ursprungszonen in den hinteren Anteilen des Neokortex (Parietallappen, Okzipitallappen, dorsaler Temporallappen), sind eine diagnostische und therapeutische Herausforderung mit einem großen Spektrum an möglichen Ätiologien. Fragestellung Das ätiologische Spektrum der PE wird dargestellt. Material und Methode Illustration auf der Basis langjähriger eigener Erfahrung und mit Befundbeispielen eigener Fälle. Ergebnisse Die PE ist vielgestaltig. Die Kenntnis des breiten Spektrums der möglichen Ätiologien ist wichtig, um eine PE mit ihrer Ätiologie verlässlich zu erkennen und ausgewählten Patienten eine gezielte Behandlung anbieten zu können. Erfolgreiche Epilepsiechirurgie ist nicht selten möglich. Background Posterior epilepsies (PE), i.e. focal epilepsies with epileptogenic zones within the posterior parts of the neocortical mantle (parietal, occipital and dorsal temporal lobes), represent a diagnostic and therapeutic challenge encompassing a wide spectrum of possible etiologies. Objective The etiological spectrum of PE is presented. Material and methods Illustration based on the longstanding personal expertise of the authors with examples of findings in personal cases. Results The PE is complex. Knowledge of the broad spectrum of possible etiologies is important in order to be able to reliably identify a PE including its etiology and to offer targeted treatment to selected patients. Successful epilepsy surgery is often possible.
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- 2020
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64. Parenchymatous hematoma in patients with atraumatic subarachnoid hemorrhage: Characteristics, treatment, and clinical outcomes
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Ilker Y. Eyüpoglu, Arnd Dörfler, Jonathan Reichl, Robert Hülsbrink, Hagen B. Huttner, Anne Mrochen, Tobias Engelhorn, Stefan T. Gerner, Joji B. Kuramatsu, Stefan Schwab, and Sebastian Brandner
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Hematoma ,medicine.medical_specialty ,Subarachnoid hemorrhage ,business.industry ,Intracranial Aneurysm ,Subarachnoid Hemorrhage ,medicine.disease ,Surgery ,Stroke ,Treatment Outcome ,Neurology ,Concomitant ,Quality of Life ,medicine ,Humans ,In patient ,business - Abstract
Background Data regarding the influence of concomitant parenchymatous hematoma (PH) on long-term outcomes in patients with atraumatic subarachnoid hemorrhage (SAH) are scarce. Further, it is not established if these patients benefit from surgical intervention. Aim The aim of this study was to determine the influence of concomitant PH in SAH patients on functional long-term outcome, and whether these patients may benefit from surgical hematoma evacuation. Methods Over a 5-year period, all consecutive patients with SAH treated at the Departments of Neurology, Neuroradiology, and Neurosurgery, at the University Hospital Erlangen (Germany) were recorded. In addition to the clinical and imaging characteristics of SAH, we documented the presence, location, and volume of PH as well as treatment parameters. Outcome assessment at 12 months included functional outcome (modified Rankin scale (mRS), favorable = 0–2), health-related quality of life, and long-term complications. For outcome analysis, a propensity score matching (ratio 1:1, caliper 0.1) was performed to compare SAH patients with and without PH. Sub-analyses were performed regarding PH treatment (surgical evacuation vs. conservative). Results A total of 494 patients with atraumatic SAH were available. Eighty-five (17.2%) had PH on initial imaging. SAH patients with PH had a worse clinical condition on admission and had a greater extent of subarachnoid/intraventricular hemorrhage. Median PH volume was 11.0 ml (5.4–31.8) with largest volumes observed in patients with ruptured middle cerebral artery (MCA)-aneurysm (31.7 ml (16.3–43.2)). After propensity-score matching (PSM), patients with PH had worse functional outcomes at 12 months (modified Rankin scale (mRS) 0–2: PH 31.8% vs. ØPH57.7% p 10 ml; OR (95%CI): 1.39 (1.09–1.79)), frontal PH location (OR 1.59 (1.14–2.23)), and early surgery (within 600 min after onset; OR 1.42 (1.03–1.94)). Conclusions Concomitant PH occurs frequently in patients with SAH and is associated with functional impairment after 1 year. Surgical evacuation of PH may improve outcomes in these patients, irrespective of aneurysm-location.
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- 2020
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65. Interdisziplinäre neurovaskuläre Netzwerke: eine Standortbestimmung
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Helmuth Steinmetz, Werner Weber, Jan Regelsberger, D. G. Nabavi, Hartmut Vatter, Daniel Hänggi, Ch. Groden, Arnd Dörfler, Olav Jansen, Ansgar Berlis, J. Meixensberger, O. Müller, Gerhard F. Hamann, Otto Busse, and J. Röther
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Gynecology ,medicine.medical_specialty ,media_common.quotation_subject ,General Medicine ,Art ,030227 psychiatry ,03 medical and health sciences ,Psychiatry and Mental health ,0302 clinical medicine ,Neurology ,medicine ,ddc:610 ,Neurology (clinical) ,Endovascular treatment ,030217 neurology & neurosurgery ,media_common - Abstract
Um das gesamte neurovaskulare Erkrankungsspektrum auf einem hohen Qualitatsniveau abzubilden, das uber die reine akute Schlaganfallversorgung hinausgeht, hat die Deutsche Schlaganfall-Gesellschaft (DSG) gemeinsam mit den Fachgesellschaften fur Neurochirurgie und Neuroradiologie ein Zertifizierungsverfahren fur sog. neurovaskulare Netzwerke (NVN) entwickelt. Strukturell setzt sich ein NVN aus einem koordinierenden Zentrum mit mindestens 3 neurovaskularen Netzwerkpartnern mit einer zertifizierten Stroke-Unit zusammen. Nach diesem neuen Standard wurden von 2018 bis 2020 bisher 15 NVN auditiert und zertifiziert. Wie leistungsfahig sind die NVN? Werden hohe Standards eingehalten? Ausgewertet wurden die Auditberichte. Die Datenlage geht auf die Jahre 2017 bis 2019 zuruck. Die 15 NVN behandelten insgesamt 86.510 Schlaganfallpatienten im Erhebungsjahr und waren mit insgesamt 107 Partnerkliniken vernetzt, die durchschnittlich 25 km entfernt vom koordinierenden Zentrum lagen und insgesamt 2726 Patienten verlegten. In den koordinierenden Zentren wurden 2383 Patienten mit nichttraumatischen intrazerebralen Blutungen behandelt und 2463 Thrombektomien durchgefuhrt. Bei 712 Patienten mit akuten aneurysmatischen Subarachnoidalblutungen wurde eine endovaskulare Therapie und bei 401 ein Clipping vorgenommen. Die Auditierung verlief in der Mehrzahl der NVN erfolgreich. Der Zertifizierungsprozess der NVN ist erfolgreich gestartet und die Audits erwiesen sich als gutes Instrument der Qualitatskontrolle und -verbesserung. Die 15 NVN sind leistungsfahig und behandeln mehr als ein Viertel der Schlaganfallpatienten in deutschen Stroke-Units.
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- 2020
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66. Association of a CAMK2A genetic variant with logical memory performance and hippocampal volume in the elderly
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Michael Hüll, Alfredo Ramirez, Oliver Peters, Johannes Kornhuber, Christian P. Müller, Frank Jessen, Arnd Dörfler, Lutz Frölich, Tanja Richter-Schmidinger, Georgios Kogias, Anbarasu Lourdusamy, Jens Wiltfang, Bernd Lenz, Cosima Rhein, Wolfgang Maier, Fernando Boix, Christiane Mühle, and Stefan J. Teipel
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Male ,0301 basic medicine ,Wechsler Memory Scale ,epidemiology [Cognitive Dysfunction] ,αCaMKII ,diagnostic imaging [Cognitive Dysfunction] ,physiology [Hippocampus] ,methods [Genetic Association Studies] ,Hippocampus ,genetics [Calcium-Calmodulin-Dependent Protein Kinase Type 2] ,Logical address ,Elderly ,methods [Magnetic Resonance Imaging] ,0302 clinical medicine ,ddc:150 ,Germany ,CAMK2A ,diagnostic imaging [Hippocampus] ,Aged, 80 and over ,General Neuroscience ,Cognition ,Organ Size ,Middle Aged ,Magnetic Resonance Imaging ,genetics [Genetic Variation] ,humanities ,genetics [Polymorphism, Single Nucleotide] ,Female ,epidemiology [Germany] ,Single-nucleotide polymorphism ,Biology ,Polymorphism, Single Nucleotide ,03 medical and health sciences ,physiology [Organ Size] ,Memory ,Adults ,Humans ,Cognitive Dysfunction ,Association (psychology) ,physiology [Memory] ,Genetic Association Studies ,Aged ,genetics [Cognitive Dysfunction] ,Genetic Variation ,Minor allele frequency ,030104 developmental biology ,Calcium-Calmodulin-Dependent Protein Kinase Type 2 ,Neuroscience ,030217 neurology & neurosurgery ,Logical memory - Abstract
Calcium/Calmodulin-dependent kinase alpha (αCaMKII) has been shown to play an essential role in synaptic plasticity and in learning and memory in animal models. However, there is little evidence for an involvement in specific memories in humans. Here we tested the potential involvement of the αCaMKII coding gene CAMK2A in verbal logical memory in two Caucasian populations from Germany, in a sample of 209 elderly people with cognitive impairments and a sample of 142 healthy adults. The association of single nucleotide polymorphisms (SNPs) located within the genomic region of CAMK2A with verbal logical memory learning and retrieval from the Wechsler Memory Scale was measured and hippocampal volume was assessed by structural MRI. In the elderly people, we found the minor allele of CAMK2A intronic SNP rs919741 to predict a higher hippocampal volume and better logical memory retrieval. This association was not found in healthy adults. The present study may provide evidence for an association of a genetic variant of the CAMK2A gene specifically with retrieval of logical memory in elderly humans. This effect is possibly mediated by a higher hippocampal volume. published
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- 2020
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67. Early Mortality of Brain Cancer Patients and its Connection to Cytomegalovirus Reactivation During Radiochemotherapy
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Tobias Engelhorn, Florian Putz, Ilker Y. Eyüpoglu, Udo S. Gaipl, Benjamin Frey, Manuel Schmidt, Klaus Überla, Paul F. Rühle, Bernhard Fleckenstein, Arnd Dörfler, Sabine Semrau, Nicole L. Goerig, Rainer Fietkau, and Klaus Korn
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Adult ,Human cytomegalovirus ,Oncology ,Cancer Research ,medicine.medical_specialty ,Lung Neoplasms ,medicine.medical_treatment ,Encephalopathy ,Cytomegalovirus ,Viremia ,03 medical and health sciences ,0302 clinical medicine ,Immunophenotyping ,Immune system ,Carcinoma, Non-Small-Cell Lung ,Internal medicine ,medicine ,Humans ,Retrospective Studies ,Brain Neoplasms ,business.industry ,Chemoradiotherapy ,medicine.disease ,Radiation therapy ,Tumor progression ,030220 oncology & carcinogenesis ,business ,030217 neurology & neurosurgery ,Anaplastic astrocytoma - Abstract
Purpose: If routine diagnostics are inconclusive, neurologic deterioration and death of patients with brain cancer are attributed to tumor or therapy. Therefore, diagnosing symptoms of encephalopathy caused by human cytomegalovirus (HCMV) reactivation remains uncommon. We investigated the role of HCMV reactivation in neurologic decline and clinical outcome after the start of radiochemotherapy. Experimental Design: HCMV analyses and extended MRI studies including additional independent retrospective neuroradiologic evaluation were performed at predetermined intervals and in case of sudden neurologic decline for 118 adult patients: 63 histologically proven high-grade gliomas, 55 with brain metastases. Immunophenotyping from simultaneously taken whole-blood samples was carried out to detect immune cells serving as prognostic marker for HCMV-associated complications. Symptomatic viremia and overall survival (OS) were the endpoints. Results: Twenty-four percent (28/118) of all patients (12/44 glioblastoma, 3/13 anaplastic astrocytoma; 8/31 non–small cell lung cancer (NSCLC), 13/24 other brain metastases) developed HCMV-viremia during or within 4 weeks after radiotherapy; 21 of 28 patients experienced concurrent major neurologic decline, reversible by antiviral treatment. Identified by immunophenotyping, pretherapeutically low basophil counts predicted a high-risk for HCMV-associated encephalopathy (glioblastoma: P = 0.002, NSCLC: P = 0.02). Median OS was substantially reduced after HCMV-associated encephalopathy without MRI signs of tumor progression [glioblastoma: 99 vs. 570 days (calculated 1-year OS: 22% vs. 69%; P = 0.01) and NSCLC: 47 vs. 219 days (calculated 1-year OS: 0% vs. 32%; P = 0.02)]. Conclusions: For patients with brain cancer, HCMV reactivation after the start of radiochemotherapy is a frequent risk for cognitively detrimental but treatable encephalopathy and premature death. Routinely performed HCMV diagnostics, assessing basophil counts and study-based anti-viral regimens, are necessary to combat this hidden threat. See related commentary by Lawler et al., p. 3077
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- 2020
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68. Evaluation After Cochlear Implant Surgery
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Ulrich Hoppe, Stephan P. Kloska, Alessandro Bozzato, Victoria Bozzato, Tobias Struffert, Annika Stock, Arnd Dörfler, and Joachim Hornung
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business.industry ,medicine.medical_treatment ,Significant difference ,Flat detector ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,Cochlear implant surgery ,0302 clinical medicine ,Cochlear implant ,Electrode array ,Postoperative outcome ,Medicine ,Speech audiometry ,Radiology, Nuclear Medicine and imaging ,Neurology (clinical) ,business ,Nuclear medicine ,030217 neurology & neurosurgery ,Neuroradiology - Abstract
Purpose Assessment of the cochlear implant (CI) electrode array position using flat-detector computed tomography (FDCT) to test dependence of postoperative outcome on intracochlear electrode position. Methods A total of 102 patients implanted with 107 CIs underwent FDCT. Electrode position was rated as 1) scala tympani, 2) scala vestibuli, 3) scalar dislocation and 4) no deconvolution. Two independent neuroradiologists rated all image data sets twice and the scalar position was verified by a third neuroradiologist. Presurgical and postsurgical speech audiometry by the Freiburg monosyllabic test was used to evaluate auditory outcome after 6 months of speech rehabilitation. Results Electrode array position was assessed by FDCT in 107 CIs. Of the electrodes 60 were detected in the scala tympani, 21 in the scala vestibuli, 24 electrode arrays showed scalar dislocation and 2 electrodes were not placed in an intracochlear position. There was no significant difference in rehabilitation outcomes between scala tympani and scala vestibuli inserted patients. Rehabilitation was also possible in patients with dislocated electrodes. Conclusion The use of FDCT is a reliable diagnostic method to determine the position of the electrode array. In our study cohort, the electrode position had no significant impact on postoperative outcome except for non-deconvoluted electrode arrays.
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- 2020
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69. Motion-corrected
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Tobias, Wilferth, Max, Müller, Lena V, Gast, Laurent, Ruck, Martin, Meyerspeer, Alfredo L, Lopez Kolkovsky, Michael, Uder, Arnd, Dörfler, and Armin M, Nagel
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Motion ,Imaging, Three-Dimensional ,Sodium ,Image Processing, Computer-Assisted ,Brain ,Humans ,Protons ,Magnetic Resonance Imaging ,Retrospective Studies - Abstract
To evaluate the feasibility of motion correction for sodium (A 3D radial density-adapted sequence for interleavedInterleaved acquisition of two nuclei did not show any relevant influence on image quality (SNR of 13.0 for interleaved versus 13.2 for standardThe feasibility of interleaved acquired
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- 2022
70. Capturing early human memory consolidation utilizing the higher functional specificity of 7T compared to 3T-fMRI
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Silke Kreitz, Angelika Mennecke, Laura Konerth, Julie Rösch, Armin M. Nagel, Frederik B. Laun, Michael Uder, Arnd Dörfler, and Andreas Hess
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Functional magnetic resonance imaging (fMRI) visualizes brain structures at increasingly higher resolution and better signal-to-noise ratio (SNR) as field strength increases. Yet, mapping the BOLD response to distinct neuronal processes continues to be challenging. Here, we performed 3T and 7T-fMRI analysis of motor-task activation and resting-state connectivity with adjusted SNR. We then applied graph theory to analyze resting-state neuronal networks detected by fMRI after a simple motor task. Despite adjusted SNR, 7T achieved a higher functional specificity of the BOLD response than 3T-fMRI. Following the motor task, 7T-fMRI therefore enabled the detection of an ‘offline replay’ that was directly linked to brain regions associated with memory consolidation. These findings reveal how memory processing is initiated even after simple motor tasks and begins earlier than previously shown. Thus, the superior capability of 7T-fMRI to detect subtle functional dynamics promises to improve diagnostics and therapeutic assessment of neurological diseases.
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- 2022
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71. Physiological MRI of microvascular architecture, neovascularization activity, and oxygen metabolism facilitate early recurrence detection in patients with IDH-mutant WHO grade 3 glioma
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Thomas M. Kinfe, Max Zimmermann, Stefan Oberndorfer, Natalia Kremenevski, Arnd Dörfler, Michael Buchfelder, Franz Marhold, Andreas Stadlbauer, and Gertraud Heinz
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Neoplasm recurrence ,medicine.medical_specialty ,Neurology ,World Health Organization ,Neovascularization ,Glioma ,Humans ,Medicine ,Radiology, Nuclear Medicine and imaging ,ddc:610 ,Diagnostic Neuroradiology ,Retrospective Studies ,Neuroradiology ,medicine.diagnostic_test ,Brain Neoplasms ,business.industry ,Standard treatment ,Magnetic resonance imaging ,medicine.disease ,Magnetic Resonance Imaging ,Isocitrate Dehydrogenase ,Oxygen ,Treatment failure ,Mutation ,Biomarker (medicine) ,Neurology (clinical) ,Neurosurgery ,Radiology ,medicine.symptom ,Oxygen metabolism ,Cardiology and Cardiovascular Medicine ,business - Abstract
Purpose This study aimed to determine the diagnostic performance of physiological MRI biomarkers including microvascular perfusion and architecture, neovascularization activity, tissue oxygen metabolism, and tension for recurrence detection of IDH-mutant WHO grade 3 glioma. Methods Sixty patients with IDH-mutant WHO grade 3 glioma who received overall 288 follow-up MRI examinations at 3 Tesla after standard treatment were retrospectively evaluated. A conventional MRI protocol was extended with a physiological MRI approach including vascular architecture mapping and quantitative blood-oxygen-level-dependent imaging which required 7 min extra data acquisition time. Custom-made MATLAB software was used for the calculation of MRI biomarker maps of microvascular perfusion and architecture, neovascularization activity, tissue oxygen metabolism, and tension. Statistical procedures included receiver operating characteristic analysis. Results Overall, 34 patients showed recurrence of the WHO grade 3 glioma; of these, in 15 patients, recurrence was detected one follow-up examination (averaged 160 days) earlier by physiological MRI data than by conventional MRI. During this time period, the tumor volume increased significantly (P = 0.001) on average 7.4-fold from 1.5 to 11.1 cm3. Quantitative analysis of MRI biomarkers demonstrated microvascular but no macrovascular hyperperfusion in early recurrence. Neovascularization activity (AUC = 0.833), microvascular perfusion (0.682), and oxygen metabolism (0.661) showed higher diagnostic performance for early recurrence detection of WHO grade 3 glioma compared to conventional MRI including cerebral blood volume (0.649). Conclusion This study demonstrated that the targeted assessment of microvascular features and tissue oxygen tension as an early sign of neovascularization activity provided valuable information for recurrence diagnostic of WHO grade 3 glioma.
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- 2022
72. Surgical planning, histopathology findings and postoperative outcome in MR-negative extra-temporal epilepsy using intracranial EEG, functional imaging, magnetoencephalography, neuronavigation and intraoperative MRI
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Anna Maslarova, Yining Zhao, Julie Rösch, Arnd Dörfler, Roland Coras, Ingmar Blümcke, Johannes Lang, Manuel Schmidt, Hajo M. Hamer, Caroline Reindl, Tamara M. Welte, Stefan Rampp, Karl Rössler, Michael Buchfelder, and Sebastian Brandner
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Surgery ,Neurology (clinical) ,General Medicine - Published
- 2023
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73. Acute right insular ischaemic lesions and poststroke left ventricular dysfunction
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Klemens Winder, Carolina Villegas Millar, Gabriela Siedler, Michael Knott, Arnd Dörfler, Anna Engel, Stephan Achenbach, Max J Hilz, Bernd Kallmünzer, Stefan Schwab, Frank Seifert, and Kilian Fröhlich
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Neurology (clinical) ,Cardiology and Cardiovascular Medicine - Abstract
IntroductionMyocardial injury related to acute ischaemic stroke is common even without primary cardiac disease. We intended to determine associations between values of left ventricular ejection fraction (LVEF) and ischaemic stroke lesion sites.MethodsOf a local database, patients with acute first-ever ischaemic stroke confirmed by brain imaging but without pre-existing heart disease were included. The cardiac morphology and LVEF were obtained from transthoracic or transesophageal echocardiography, and impaired LVEF was categorised as mild (35%–50%), moderate (34%–25%) and severe (0.1 ng/mL), atrial fibrillation and cardiac wall motion abnormalities were assessed and compared between patients with and without impaired LVEF after stroke (significance: pResultsOf 1209 patients who had a stroke, 231 (mean age 66.3±14.0 years) met the inclusion criteria; 40 patients (17.3%) had an impaired LVEF after stroke. Patients with impaired LVEF had higher infarct volumes (53.8 mL vs 30.0 mL, p=0.042), a higher prevalence of troponin increase (17.5% vs 4.2%, p=0.006), cardiac wall motion abnormalities (42.5% vs 5.2%, p50%. The multivariate voxelwise lesion analysis yielded associations between decreased LVEF and damaged voxels in the insula, amygdala and operculum of the right hemisphere.ConclusionOur imaging analysis unveils a prominent role of the right hemispheric central autonomic network, especially of the insular cortex, in the brain–heart axis. Our results support preliminary evidence that acute ischaemic stroke in distinct brain regions of the central autonomic network may directly impair cardiac function and thus further supports the concept of a distinct stroke-heart syndrome.
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- 2023
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74. Linear projection-based chemical exchange saturation transfer parameter estimation
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Felix Glang, Moritz S. Fabian, Alexander German, Katrin M. Khakzar, Angelika Mennecke, Andrzej Liebert, Kai Herz, Patrick Liebig, Burkhard S. Kasper, Manuel Schmidt, Enrique Zuazua, Armin M. Nagel, Frederik B. Laun, Arnd Dörfler, Klaus Scheffler, and Moritz Zaiss
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Molecular Medicine ,Radiology, Nuclear Medicine and imaging ,Spectroscopy - Abstract
Isolated evaluation of multiparametric in vivo chemical exchange saturation transfer (CEST) MRI often requires complex computational processing for both correction of B0 and B1 inhomogeneity and contrast generation. For that, sufficiently densely sampled Z-spectra need to be acquired. The list of acquired frequency offsets largely determines the total CEST acquisition time, while potentially representing redundant information. In this work, a linear projection-based multiparametric CEST evaluation method is introduced that offers fast B0 and B1 inhomogeneity correction, contrast generation and feature selection for CEST data, enabling reduction of the overall measurement time. To that end, CEST data acquired at 7 T in six healthy subjects and in one brain tumor patient were conventionally evaluated by interpolation-based inhomogeneity correction and Lorentzian curve fitting. Linear regression was used to obtain coefficient vectors that directly map uncorrected data to corrected Lorentzian target parameters. L1-regularization was applied to find subsets of the originally acquired CEST measurements that still allow for such a linear projection mapping. The linear projection method allows fast and interpretable mapping from acquired raw data to contrast parameters of interest, generalizing from healthy subject training data to unseen healthy test data and to the tumor patient dataset. The L1-regularization method shows that a fraction of the acquired CEST measurements is sufficient to preserve tissue contrasts, offering up to a 2.8-fold reduction of scan time. Similar observations as for the 7-T data can be made for data from a clinical 3-T scanner. Being a fast and interpretable computation step, the proposed method is complementary to neural networks that have recently been employed for similar purposes. The scan time acceleration offered by the L1-regularization ("CEST-LASSO") constitutes a step towards better applicability of multiparametric CEST protocols in a clinical context.
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- 2021
75. Expression time course and spatial distribution of activated caspase-3 after experimental status epilepticus: Contribution of delayed neuronal cell death to seizure-induced neuronal injury
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Jens Weise, Tobias Engelhorn, Arnd Dörfler, Stefanie Aker, Mathias Bähr, and Andreas Hufnagel
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Status epilepticus ,Pilocarpine ,Caspase-3 ,Apoptosis ,Neuronal cell death ,Rats ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Pilocarpine-induced status epilepticus (PCSE) is a widely used model to study neurodegeneration in limbic structures after prolonged epileptic seizures. However, mechanisms mediating neuronal cell death in this model require further characterization. Examining the expression time course and spatial distribution of activated caspase-3, we sought to determine the role of apoptosis in PCSE-mediated neuronal cell death. Expression of activated caspase-3, predominantly located in neurons, was detected 24 h (amygdala; piriform and temporal cortex) and 7 days (hippocampus; amygdala; piriform, temporal and parietal cortex; thalamus) after PCSE with strongest induction being observed in the amygdala, the piriform cortex, and the hippocampus. Further analysis revealed TUNEL positivity (24 h and 7 days after SE) and a significant, progressive neuronal cell loss in all brain regions displaying caspase-3 activation. Corresponding to high levels of activated caspase-3 expression, neuronal cell loss was most pronounced in the amygdala, piriform cortex, and dorsal CA-1 hippocampus. These results demonstrate that apoptosis contributes significantly to PCSE-induced neuronal cell death.
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- 2005
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76. Direct imaging of white matter ultrashort T
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Max, Müller, Nico, Egger, Stefan, Sommer, Tobias, Wilferth, Christian R, Meixner, Frederik Bernd, Laun, Angelika, Mennecke, Manuel, Schmidt, Konstantin, Huhn, Veit, Rothhammer, Michael, Uder, Arnd, Dörfler, and Armin M, Nagel
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Multiple Sclerosis ,Phantoms, Imaging ,Brain ,Humans ,Magnetic Resonance Imaging ,White Matter ,Myelin Sheath - Abstract
To demonstrate direct imaging of the white matter ultrashort TThe IR UTE technique suppresses long TA frequency shift of -1.2 ppm of the IR pulse (i.e. towards the fat frequency) provided a good suppression of artifacts. With this, an ultrashort compartment of (68 ± 6) % with a TThe quantification results indicate that the observed ultrashort components arise primarily from myelin tissue. Direct IR UTE imaging of the white matter ultrashort T
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- 2021
77. Hybrid
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Christian R, Meixner, Christian K, Eisen, Sebastian, Schmitter, Max, Müller, Jürgen, Herrler, Bernhard, Hensel, Arnd, Dörfler, Michael, Uder, and Armin M, Nagel
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Cerebrovascular Circulation ,Brain ,Spin Labels ,Arteries ,Gray Matter ,Signal-To-Noise Ratio - Abstract
To improve pseudo-continuous arterial spin labeling (pcASL) at 7T by exploiting a hybrid homogeneity- and efficiency-optimizedThe following three experiments were performed at 7T, each employing five volunteers: (1) A hybrid (ie, homogeneity-efficiency optimized)TheThe combination of the proposed hybrid
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- 2021
78. Skin sodium is increased in male patients with multiple sclerosis and related animal models
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Ralf A. Linker, Armin M. Nagel, Franziska Pemsel, Dominik N. Müller, Stefan Seyferth, Stefanie Haase, Mohammad Anwar Chaudri, Arnd Dörfler, Peter Linz, Christoph W. Kopp, Bernhard Michalke, Veit Rothhammer, Konstantin Huhn, Michael Uder, De-Hyung Lee, Tobias Bäuerle, and Anne Waschbisch
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Adult ,Male ,0301 basic medicine ,Pathology ,medicine.medical_specialty ,Multiple Sclerosis ,Experimental Autoimmune Encephalomyelitis ,Skin ,Sodium Magnetic Resonance Imaging ,Sodium ,chemistry.chemical_element ,Proinflammatory cytokine ,03 medical and health sciences ,Multiple Sclerosis, Relapsing-Remitting ,0302 clinical medicine ,Immune system ,Immunopathology ,medicine ,Animals ,Humans ,Inflammation ,Multidisciplinary ,Expanded Disability Status Scale ,business.industry ,Multiple sclerosis ,Experimental autoimmune encephalomyelitis ,Signal Processing, Computer-Assisted ,Biological Sciences ,medicine.disease ,Magnetic Resonance Imaging ,Mice, Inbred C57BL ,Disease Models, Animal ,030104 developmental biology ,chemistry ,Commentary ,Sodium MRI ,business ,030217 neurology & neurosurgery - Abstract
Novel MRI techniques allow a noninvasive quantification of tissue sodium and reveal the skin as a prominent compartment of sodium storage in health and disease. Since multiple sclerosis (MS) immunopathology is initiated in the periphery and increased sodium concentrations induce proinflammatory immune cells, the skin represents a promising compartment linking high sodium concentrations and MS immunopathology. We used a 7-T sodium MRI ((23)Na-MRI) and inductively coupled plasma mass spectrometry to investigate the skin sodium content in two mouse models of MS. We additionally performed 3-T (23)Na-MRI of calf skin and muscles in 29 male relapsing-remitting MS (RRMS) patients and 29 matched healthy controls. Demographic and clinical information was collected from interviews, and disease activity was assessed by expanded disability status scale scoring. (23)Na-MRI and chemical analysis demonstrated a significantly increased sodium content in the skin during experimental autoimmune encephalomyelitis independent of active immunization. In male patients with RRMS, (23)Na-MRI demonstrated a higher sodium signal in the area of the skin compared to age- and biological sex-matched healthy controls with higher sodium, predicting future disease activity in cranial MRI. In both studies, the sodium enrichment was specific to the skin, as we found no alterations of sodium signals in the muscle or other tissues. Our data add to the recently identified importance of the skin as a storage compartment of sodium and may further represent an important organ for future investigations on salt as a proinflammatory agent driving autoimmune neuroinflammation such as that in MS.
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- 2021
79. Disability-Adjusted Life-Years Associated With Intracerebral Hemorrhage and Secondary Injury
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Stefanie Balk, Hannes Lücking, Hagen B. Huttner, Bastian Volbers, Arnd Dörfler, Maximilian I. Sprügel, Joji B. Kuramatsu, Jochen A. Sembill, Philip Hoelter, David Haupenthal, Stefan Schwab, Anne Mrochen, and Tobias Engelhorn
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Male ,medicine.medical_specialty ,Global Burden of Disease ,Cohort Studies ,Internal medicine ,medicine ,Disability-adjusted life year ,Humans ,cardiovascular diseases ,Disease burden ,Original Investigation ,Aged ,Cerebral Hemorrhage ,Intracerebral hemorrhage ,Aged, 80 and over ,business.industry ,Research ,Disability-Adjusted Life Years ,General Medicine ,Middle Aged ,medicine.disease ,Cerebral Intraventricular Hemorrhage ,nervous system diseases ,Hospitalization ,Online Only ,Intraventricular hemorrhage ,Years of potential life lost ,Neurology ,Cohort ,Female ,business ,Cohort study - Abstract
This cohort study examines the association of intracerebral hemorrhage and secondary injury with disability-adjusted life years., Key Points Question What is the burden of intracerebral hemorrhage and secondary injury? Findings In this cohort study of 1322 patients with intracerebral hemorrhage, the condition was associated with 9.46 disability-adjusted life-years, while perihemorrhagic edema and intraventricular hemorrhage were associated with increased disability compared with hematoma expansion in the overall cohort. Meaning These findings suggest that intracerebral hemorrhage is associated with a high burden of disability, and these findings may guide public health strategies., Importance Intracerebral hemorrhage (ICH) contributes significantly to the global burden of disease. Objective To examine the association of ICH and secondary injury with disability-adjusted life-years (DALYs) for the individual patient. Design, Setting, and Participants This cohort study was conducted using data from the Universitätsklinikum Erlangen Cohort of Patients With Spontaneous Intracerebral Hemorrhage study. Consecutive patients admitted to a single tertiary care center from January 1, 2006, to December 31, 2015, were included. The sample comprised patients with oral anticoagulation–associated ICH (OAC-ICH) or primary spontaneous ICH (non-OAC-ICH). Statistical analysis was conducted from October 1 to December 31, 2020. Exposures ICH occurrence and secondary injury. Main Outcomes and Measures DALYs, years of life lost (YLL), and years lived with disability (YLD) were analyzed by hematoma location, ICH volume, and secondary injury (ie, hematoma expansion [HE], intraventricular hemorrhage [IVH], and perihemorrhagic edema [PHE]). Results Among 1322 patients with ICH, 615 (46.5%) were women and the mean (SD) age at hospital admission was 71 (13) years; ICH was associated with a mean (SD) of 9.46 (8.08) DALYs, 5.72 (8.29) YLL, and 3.74 (5.95) YLD. There were statistically significant differences in mean (SD) DALYs by extent of hematoma volume (< 10 mL ICH: 7.05 [6.79] DALYs; 10-30 mL ICH: 9.91 [8.35] DALYs; >30 mL ICH: 12.42 [8.47] DALYs; P
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- 2021
80. Siponimod (BAF-312) Attenuates Perihemorrhagic Edema And Improves Survival in Experimental Intracerebral Hemorrhage
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Ralf A. Linker, Arnd Dörfler, Maximilian I. Sprügel, Stefan Schwab, Lisa Seyler, Tobias Bobinger, Tobias Bäuerle, Armin M. Nagel, Sebastian S. Roeder, Anatol Manaenko, Stephan von Hörsten, Petra Burkardt, Hagen B. Huttner, Vanessa D. Beuscher, and Tobias Engelhorn
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Male ,Dose ,medicine.medical_treatment ,Brain Edema ,Pharmacology ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Edema ,Benzyl Compounds ,medicine ,Animals ,Receptor ,Sphingosine-1-Phosphate Receptors ,Cerebral Hemorrhage ,030304 developmental biology ,Advanced and Specialized Nursing ,Intracerebral hemorrhage ,0303 health sciences ,medicine.diagnostic_test ,business.industry ,Multiple sclerosis ,Magnetic resonance imaging ,Immunosuppression ,medicine.disease ,Disease Models, Animal ,Siponimod ,chemistry ,Azetidines ,Neurology (clinical) ,medicine.symptom ,Cardiology and Cardiovascular Medicine ,business ,030217 neurology & neurosurgery ,Signal Transduction - Abstract
Background and Purpose— Perihemorrhagic edema (PHE) is associated with poor outcome after intracerebral hemorrhage (ICH). Infiltration of immune cells is considered a major contributor of PHE. Recent studies suggest that immunomodulation via S1PR (sphingosine-1-phosphate receptor) modulators improve outcome in ICH. Siponimod, a selective modulator of sphingosine 1-phosphate receptors type 1 and type 5, demonstrated an excellent safety profile in a large study of patients with multiple sclerosis. Here, we investigated the impact of siponimod treatment on perihemorrhagic edema, neurological deficits, and survival in a mouse model of ICH. Methods— ICH was induced by intracranial injection of 0.075 U of bacterial collagenase in 123 mice. Mice were randomly assigned to different treatment groups: vehicle, siponimod given as a single dosage 30 minutes after the operation or given 3× for 3 consecutive days starting 30 minutes after operation. The primary outcome of our study was evolution of PHE measured by magnetic resonance-imaging on T2-maps 72 hours after ICH, secondary outcomes included evolution of PHE 24 hours after ICH, survival and neurological deficits, as well as effects on circulating blood cells and body weight. Results— Siponimod significantly reduced PHE measured by magnetic resonance imaging ( P =0.021) as well as wet-dry method ( P =0.04) 72 hours after ICH. Evaluation of PHE 24 hours after ICH showed a tendency toward attenuated brain edema in the low-dosage group ( P =0.08). Multiple treatments with siponimod significantly improved neurological deficits measured by Garcia Score ( P =0.03). Survival at day 10 was improved in mice treated with multiple dosages of siponimod ( P =0.037). Mice treated with siponimod showed a reduced weight loss after ICH ( P =0.036). Conclusions— Siponimod (BAF-312) attenuated PHE after ICH, increased survival, and reduced ICH-induced sensorimotor deficits in our experimental ICH-model. Findings encourage further investigation of inflammatory modulators as well as the translation of BAF-312 to a human study of ICH patients.
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- 2019
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81. Voxel‐wise lesion mapping of self‐reported urinary incontinence in multiple sclerosis
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Kilian Fröhlich, Klemens Winder, Manuel Schmidt, De-Hyung Lee, Arnd Dörfler, Ruihao Wang, Max J. Hilz, Tobias Bobinger, Florian T. Nickel, Ralf A. Linker, and Frank Seifert
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Adult ,Male ,medicine.medical_specialty ,Multiple Sclerosis ,Urology ,Urinary system ,030232 urology & nephrology ,Urinary incontinence ,Lesion ,03 medical and health sciences ,Imaging, Three-Dimensional ,0302 clinical medicine ,Neuroimaging ,medicine ,Humans ,Retrospective Studies ,030219 obstetrics & reproductive medicine ,medicine.diagnostic_test ,business.industry ,Multiple sclerosis ,Magnetic resonance imaging ,Retrospective cohort study ,Middle Aged ,medicine.disease ,Magnetic Resonance Imaging ,Pathophysiology ,Frontal Lobe ,Urinary Incontinence ,Parahippocampal Gyrus ,Female ,Neurology (clinical) ,medicine.symptom ,business - Abstract
Aims Besides spinal lesions, urinary incontinence may be attributed to particular cerebral lesion sites in multiple sclerosis (MS) patients. We intended to determine the contribution of suprapontine lesions to urinary incontinence in MS using a voxel-wise lesion analysis. Methods In this retrospective study, we sought MS patients with documented urinary incontinence in a local database. We established a control group of MS-patients without documented urinary incontinence matched for gender, age, and disease severity. Patients with urinary incontinence due to local diseases of the urinary tract were excluded. The MS lesions were analyzed on T2-weighted magnetic resonance imaging scans (1.5 or 3T). After manual delineation and transformation into stereotaxic space, we determined the lesion overlap and compared the presence or absence of urinary incontinence voxel-wise between patients with and without lesions in a given voxel performing the Liebermeister test with 4000 permutations. Results A total of 56 patients with urinary incontinence and MS fulfilled the criteria and were included. The analysis yielded associations between urinary incontinence and MS in the frontal white matter, temporo-occipital, and parahippocampal regions. Conclusions Our voxel-wise analysis indicated associations between self-reported urinary incontinence and lesions in the left frontal white matter and right parahippocampal region. Thus, our data suggest that dysfunction of supraspinal bladder control due to cerebral lesions may contribute to the pathophysiology of urinary incontinence in MS.
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- 2019
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82. Perihemorrhagic edema
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Stefan T. Gerner, Jochen A. Sembill, Joji B. Kuramatsu, Kathrin Kölbl, Tobias Bobinger, Hagen B. Huttner, Hannes Lücking, Bastian Volbers, Arnd Dörfler, Maximilian I. Sprügel, Stefan Schwab, Dominik Madžar, and Philip Hoelter
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Male ,medicine.medical_specialty ,Brain Edema ,Cohort Studies ,Hematoma ,Edema ,medicine ,Humans ,Prospective Studies ,cardiovascular diseases ,Spontaneous intracerebral hemorrhage ,Prospective cohort study ,Aged ,Cerebral Hemorrhage ,Retrospective Studies ,Aged, 80 and over ,Intracerebral hemorrhage ,business.industry ,Retrospective cohort study ,Middle Aged ,medicine.disease ,Time course ,Female ,Neurology (clinical) ,Radiology ,medicine.symptom ,business ,Hospital stay - Abstract
ObjectiveTo determine the influence of intracerebral hemorrhage (ICH) location and volume and hematoma surface on perihemorrhagic edema evolution.MethodsPatients with ICH of the prospective Universitätsklinikum Erlangen Cohort of Patients With Spontaneous Intracerebral Hemorrhage (UKER-ICH) cohort study (NCT03183167) between 2010 and 2013 were analyzed. Hematoma and edema volume during hospital stay were volumetrically assessed, and time course of edema evolution and peak edema correlated to hematoma volume, location, and surface to verify the strength of the parameters on edema evolution.ResultsOverall, 300 patients with supratentorial ICH were analyzed. Peak edema showed a high correlation with hematoma surface (R2 = 0.864, p < 0.001) rather than with hematoma volumes, regardless of hematoma location. Smaller hematomas with a higher ratio of hematoma surface to volume showed exponentially higher relative edema (R2 = 0.755, p < 0.001). Multivariable logistic regression analysis revealed a cutoff ICH volume of 30 mL, beyond which an increase of total mass lesion volume (combined volume of hematoma and edema) was not associated with worse functional outcome. Specifically, peak edema was associated with worse functional outcome in ICH p < 0.001), contrary to ICH ≥30 mL (OR 1.20, 95% CI 0.88–1.63, p = 0.247). There were no significant differences between patients with lobar and those with deep ICH after adjustment for hematoma volumes.ConclusionsPeak perihemorrhagic edema, although influencing mortality, is not associated with worse functional outcomes in ICH volumes >30 mL. Although hematoma volume correlates with peak edema extent, hematoma surface is the major parameter for edema evolution. The effect of edema on functional outcome is therefore more pronounced in smaller and irregularly shaped hematomas, and these patients may particularly benefit from edema-modifying therapies.
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- 2019
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83. Angioedema in Stroke Patients With Thrombolysis
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Manuel Schmidt, Arnd Dörfler, Tobias Bobinger, Frank Seifert, Kilian Fröhlich, Stefan Schwab, Klemens Winder, Stefan T. Gerner, Max J. Hilz, Bernd Kallmünzer, and Kosmas Macha
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Advanced and Specialized Nursing ,medicine.medical_specialty ,medicine.diagnostic_test ,Angioedema ,business.industry ,medicine.medical_treatment ,Magnetic resonance imaging ,Thrombolysis ,030204 cardiovascular system & hematology ,medicine.disease ,Lesion ,Brain ischemia ,03 medical and health sciences ,0302 clinical medicine ,Blood pressure ,Internal medicine ,Heart rate ,Cardiology ,Medicine ,Neurology (clinical) ,medicine.symptom ,Cardiology and Cardiovascular Medicine ,business ,Complication ,030217 neurology & neurosurgery - Abstract
Background and Purpose— Oral angioedema (OA) is a rare but life-threatening complication in patients with ischemic stroke receiving intravenous thrombolysis with r-tPA (recombinant tissue-type plasminogen activator). This study intended to determine associations between thrombolysis-related OA and ischemic stroke lesion sites using a voxel-wise lesion analysis. Methods— Prospective registry data were used to identify ischemic stroke patients with thrombolysis-related OA between 2002 and 2018. For the study registry, ethics approval was obtained by the Ethics Committee of the Friedrich-Alexander Universität (FAU) Erlangen-Nürnberg (clinical registry registration: 377_17Bc). Ischemic stroke patients with thrombolysis treatment but without OA admitted in the years 2011 and 2012 comprised the control group. Ischemic lesions were manually outlined on magnetic resonance imaging (1.5T or 3T) or computed tomographic scans and transformed into stereotaxic space. We determined the lesion overlap and compared the absence or presence of OA voxel-wise between patients with and without lesions in a given voxel using the Liebermeister test. Stroke severity was rated using the National Institutes of Health Stroke Scale score, and blood pressure, heart rate, blood glucose levels, and body temperature were determined on admission. Results— Fifteen ischemic stroke patients with thrombolysis-related OA were identified. The voxel-wise analysis yielded associations between OA and ischemic lesions in the insulo-opercular region with a right hemispheric dominance. Mean blood pressure was significantly lower in patients with OA than in controls. Age, National Institutes of Health Stroke Scale scores, infarct volumes, heart rate, and blood glucose levels did not differ between patients with and without OA. Conclusions— The voxel-wise analysis linked thrombolysis-related OA to right insulo-opercular lesions. The lower blood pressure in patients with thrombolysis-related OA may reflect bradykinin effects causing vasodilatation and increasing vascular permeability.
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- 2019
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84. Heparin for prophylaxis of venous thromboembolism in intracerebral haemorrhage
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Miriam Bauer, Gereon R. Fink, Sebastian Stösser, Gerhard F. Hamann, Albrecht Guenther, Georg Hagemann, Armin J. Grau, Hansjörg Bäzner, Florian Rakers, Frederick Palm, Anna Lena Fisse, Joji B. Kuramatsu, Joachim Röther, Timolaos Rizos, Martin Nueckel, Markus Horn, Manuel Hagen, Arnd Dörfler, Maximilian I. Sprügel, Hauke Schneider, Matthias Endres, Johannes C. Wöhrle, Peter Michels, Hagen B. Huttner, Christian Urbanek, Peter D. Schellinger, Fahid Alshammari, Frank Erbguth, Dirk Bahner, Jan C. Purrucker, Stefan T. Gerner, Michael P. Schwarz, Otto W. Witte, Jochen A. Sembill, Jörg Glahn, Hermann Neugebauer, Karl Georg Haeusler, Stefan Schwab, Johannes Schurig, Joseph Classen, Sebastian S. Roeder, Henning Schwert, Hannes Lücking, Peter A. Ringleb, Dominik Michalski, Albert C. Ludolph, Sigrid Wöpking, Jens Volkmann, Sarah Zweynert, Jan Sobesky, Wolfgang Muellges, Heinz Reichmann, Ulrich J. Knappe, Gernot Reimann, Peter Kraft, Peter Vajkoczy, Christian Dohmen, Jens Minnerup, Anna-Lena Schubert, and Henning Stetefeld
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Male ,medicine.medical_specialty ,medicine.drug_class ,030204 cardiovascular system & hematology ,Rate ratio ,Gastroenterology ,03 medical and health sciences ,0302 clinical medicine ,Modified Rankin Scale ,Internal medicine ,medicine ,Humans ,Prospective Studies ,cardiovascular diseases ,Stroke ,Aged ,Cerebral Hemorrhage ,Retrospective Studies ,Aged, 80 and over ,Heparin ,business.industry ,Retrospective cohort study ,Venous Thromboembolism ,Vitamin K antagonist ,medicine.disease ,nervous system diseases ,Psychiatry and Mental health ,Immunohistochemistry ,Female ,Surgery ,Neurology (clinical) ,business ,030217 neurology & neurosurgery ,Cohort study ,medicine.drug - Abstract
ObjectiveTo determine the occurrence of intracranial haemorrhagic complications (IHC) on heparin prophylaxis (low-dose subcutaneous heparin, LDSH) in primary spontaneous intracerebral haemorrhage (ICH) (not oral anticoagulation-associated ICH, non-OAC-ICH), vitamin K antagonist (VKA)-associated ICH and non-vitamin K antagonist oral anticoagulant (NOAC)-associated ICH.MethodsRetrospective cohort study (RETRACE) of 22 participating centres and prospective single-centre study with 1702 patients with VKA-associated or NOAC-associated ICH and 1022 patients with non-OAC-ICH with heparin prophylaxis between 2006 and 2015. Outcomes were defined as rates of IHC during hospital stay among patients with non-OAC-ICH, VKA-ICH and NOAC-ICH, mortality and functional outcome at 3 months between patients with ICH with and without IHC.ResultsIHC occurred in 1.7% (42/2416) of patients with ICH. There were no differences in crude incidence rates among patients with VKA-ICH, NOAC-ICH and non-OAC-ICH (log-rank p=0.645; VKA-ICH: 27/1406 (1.9%), NOAC-ICH 1/130 (0.8%), non-OAC-ICH 14/880 (1.6%); p=0.577). Detailed analysis according to treatment exposure (days with and without LDSH) revealed no differences in incidence rates of IHC per 1000 patient-days (LDSH: 1.43 (1.04–1.93) vs non-LDSH: 1.32 (0.33–3.58), conditional maximum likelihood incidence rate ratio: 1.09 (0.38–4.43); p=0.953). Secondary outcomes showed differences in functional outcome (modified Rankin Scale=4–6: IHC: 29/37 (78.4%) vs non-IHC: 1213/2048 (59.2%); p=0.019) and mortality (IHC: 14/37 (37.8%) vs non-IHC: 485/2048 (23.7%); p=0.045) in disfavour of patients with IHC. Small ICH volume (OR: volume ConclusionsHeparin administration for venous thromboembolism (VTE) prophylaxis in patients with ICH appears to be safe regarding IHC among non-OAC-ICH, VKA-ICH and NOAC-ICH in this observational cohort analysis. Randomised controlled trials are needed to verify the safety and efficacy of heparin compared with other methods for VTE prevention.
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- 2019
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85. Evaluation of Functional Recovery Following Thrombectomy in Patients With Large Vessel Occlusion and Prestroke Disability
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Maximilian I, Sprügel, Jochen A, Sembill, Svenja, Kremer, Stefan T, Gerner, Michael, Knott, Stefan, Hock, Tobias, Engelhorn, Arnd, Dörfler, Hagen B, Huttner, and Stefan, Schwab
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Aged, 80 and over ,Cohort Studies ,Stroke ,Infarction ,Humans ,Female ,General Medicine ,Brain Ischemia ,Thrombectomy - Abstract
It is uncertain whether thrombectomy is associated with benefits in patients with prestroke disability.To evaluate the use of thrombectomy for patients with large vessel occlusion and prestroke disability.This cohort study included patients with large vessel occlusion stroke and prestroke disability (modified Rankin Scale score, 3 or 4) admitted to a single tertiary care center between January 1, 2006, and June 30, 2019 (controls: 2006-2015; thrombectomy: 2015-2019). Follow-up was conducted at 90 days. Data analysis was performed from November 1 to December 31, 2021.Use of thrombectomy vs no thrombectomy.The primary outcome was functional recovery at 90 days defined as clinical recovery to the functional status before stroke onset. Secondary outcomes included functional dependency, mortality, early neurologic improvement, and recanalization.Among 205 patients (149 women [72.7%]; median age, 82 years [IQR, 75-87 years]), 102 individuals (49.8%) received thrombectomy and 103 (50.2%) were controls. Thrombectomy was significantly associated with functional recovery (thrombectomy, 20 [19.6%]; controls, 8 [7.8%]; adjusted difference, 9.4%; 95% CI, 2.2% to 16.7%; P = .005). Secondary outcomes showed differences in mortality, early neurologic improvement, and recanalization in favor of thrombectomy treatment. The rate of functional dependency did not differ significantly between the 2 groups (adjusted difference, 8.9%; 95% CI, -2.5% to 20.2%; P = .13). The rate of functional recovery after thrombectomy was 44.0% for patients with early neurologic improvement, 29.4% for patients with small infarct volume (50 mL), and 7.0% for patients with neither of these parameters.Findings of this study suggest that selected patients with prestroke disability may benefit from thrombectomy. However, the thrombectomy-associated increase in functional recovery was small. Therefore, routine use of thrombectomy may not be beneficial among patients with a large ischemic core and infarct volumes less than 50 mL may be necessary to obtain functional recovery. Patients with higher chances of functional recovery are also at an increased risk of survival with substantial disability, indicating potential harms from the intervention; further studies are needed.
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- 2022
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86. How art changes your brain: differential effects of visual art production and cognitive art evaluation on functional brain connectivity.
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Anne Bolwerk, Jessica Mack-Andrick, Frieder R Lang, Arnd Dörfler, and Christian Maihöfner
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Medicine ,Science - Abstract
Visual art represents a powerful resource for mental and physical well-being. However, little is known about the underlying effects at a neural level. A critical question is whether visual art production and cognitive art evaluation may have different effects on the functional interplay of the brain's default mode network (DMN). We used fMRI to investigate the DMN of a non-clinical sample of 28 post-retirement adults (63.71 years ±3.52 SD) before (T0) and after (T1) weekly participation in two different 10-week-long art interventions. Participants were randomly assigned to groups stratified by gender and age. In the visual art production group 14 participants actively produced art in an art class. In the cognitive art evaluation group 14 participants cognitively evaluated artwork at a museum. The DMN of both groups was identified by using a seed voxel correlation analysis (SCA) in the posterior cingulated cortex (PCC/preCUN). An analysis of covariance (ANCOVA) was employed to relate fMRI data to psychological resilience which was measured with the brief German counterpart of the Resilience Scale (RS-11). We observed that the visual art production group showed greater spatial improvement in functional connectivity of PCC/preCUN to the frontal and parietal cortices from T0 to T1 than the cognitive art evaluation group. Moreover, the functional connectivity in the visual art production group was related to psychological resilience (i.e., stress resistance) at T1. Our findings are the first to demonstrate the neural effects of visual art production on psychological resilience in adulthood.
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- 2014
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87. Pulseq‐CEST: Towards multi‐site multi‐vendor compatibility and reproducibility of CEST experiments using an open‐source sequence standard
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Jinyuan Zhou, Peter C.M. van Zijl, Kerstin Heinecke, Or Perlman, Moritz Zaiss, Linda Knutsson, Sebastian Mueller, Klaus Scheffler, Maxim Zaitsev, Manuel Schmidt, Phillip Zhe Sun, Arnd Dörfler, Patrick Schuenke, Christian T. Farrar, and Kai Herz
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Protocol (science) ,Reproducibility ,Sequence ,Standardization ,SIMPLE (military communications protocol) ,Computer science ,Vendor ,Reproducibility of Results ,Amides ,Magnetic Resonance Imaging ,Field (computer science) ,Article ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Computer engineering ,Compatibility (mechanics) ,Humans ,Radiology, Nuclear Medicine and imaging ,Computer Simulation ,Protons ,030217 neurology & neurosurgery - Abstract
PURPOSE: As the field of CEST grows, various novel preparation periods using different parameters are being introduced. At the same time, large, multisite clinical studies require clearly defined protocols, especially across different vendors. Here, we propose a CEST definition standard using the open Pulseq format for a shareable, simple, and exact definition of CEST protocols.METHODS: We present the benefits of such a standard in three ways: (1) an open database on GitHub, where fully defined, human-readable CEST protocols can be shared; (2) an open-source Bloch-McConnell simulation to test and optimize CEST preparation periods in silico; and (3) a hybrid MR sequence that plays out the CEST preparation period and can be combined with any existing readout module.RESULTS: The exact definition of the CEST preparation period, in combination with the flexible simulation, leads to a good match between simulations and measurements. The standard allowed finding consensus on three amide proton transfer-weighted protocols that could be compared in healthy subjects and a tumor patient. In addition, we could show coherent multisite results for a sophisticated CEST method, highlighting the benefits regarding protocol sharing and reproducibility.CONCLUSION: With Pulseq-CEST, we provide a straightforward approach to standardize, share, simulate, and measure different CEST preparation schemes, which are inherently completely defined. (Less)
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- 2021
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88. In Reply
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Nima Etminan, Arnd Dörfler, and Helmuth Steinmetz
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General Medicine - Published
- 2020
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89. Association between tissue hypoxia, perfusion restrictions, and microvascular architecture alterations with lesion-induced impairment of neurovascular coupling
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Max Zimmermann, Michael Buchfelder, Andreas Stadlbauer, Arnd Dörfler, Thomas M. Kinfe, Moritz Zaiss, Sebastian Brandner, Nadja Brandner, and Ilker Y. Eyüpoglu
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Adult ,Male ,Pathology ,medicine.medical_specialty ,Neuroimaging ,behavioral disciplines and activities ,Multimodal Imaging ,030218 nuclear medicine & medical imaging ,Lesion ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Humans ,Hypoxia ,Aged ,medicine.diagnostic_test ,business.industry ,Brain Neoplasms ,Microvascular architecture ,Magnetoencephalography ,Original Articles ,Hypoxia (medical) ,Middle Aged ,Neurology ,nervous system ,Microvessels ,Tissue hypoxia ,Neurovascular Coupling ,Female ,Neurology (clinical) ,medicine.symptom ,Cardiology and Cardiovascular Medicine ,Neurovascular coupling ,Functional magnetic resonance imaging ,business ,Perfusion ,030217 neurology & neurosurgery ,psychological phenomena and processes - Abstract
Functional magnetic resonance imaging (fMRI) has been mainly utilized for the preoperative localization of eloquent cortical areas. However, lesion-induced impairment of neurovascular coupling (NVC) in the lesion border zone may lead to false-negative fMRI results. The purpose of this study was to determine physiological factors impacting the NVC. Twenty patients suffering from brain lesions were preoperatively examined using multimodal neuroimaging including fMRI, magnetoencephalography (MEG) during language or sensorimotor tasks (depending on lesion location), and a novel physiologic MRI approach for the combined quantification of oxygen metabolism, perfusion state, and microvascular architecture. Congruence of brain activity patterns between fMRI and MEG were found in 13 patients. In contrast, we observed missing fMRI activity in perilesional cortex that demonstrated MEG activity in seven patients, which was interpreted as lesion-induced impairment of NVC. In these brain regions with impaired NVC, physiologic MRI revealed significant brain tissue hypoxia, as well as significantly decreased macro- and microvascular perfusion and microvascular architecture. We demonstrated that perilesional hypoxia with reduced vascular perfusion and architecture is associated with lesion-induced impairment of NVC. Our physiologic MRI approach is a clinically applicable method for preoperative risk assessment for the presence of false-negative fMRI results and may prevent severe postoperative functional deficits.
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- 2020
90. Known Operator Learning Enables Constrained Projection Geometry Conversion: Parallel to Cone-Beam for Hybrid MR/X-Ray Imaging
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Philipp Roser, Bernhard Stimpel, Christopher Syben, Andreas Maier, and Arnd Dörfler
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Computer science ,Parallel projection ,Geometry ,Iterative reconstruction ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Operator (computer programming) ,Sampling (signal processing) ,medicine ,Image Processing, Computer-Assisted ,Electrical and Electronic Engineering ,Projection (set theory) ,Radiological and Ultrasound Technology ,medicine.diagnostic_test ,Phantoms, Imaging ,X-Rays ,Perspective (graphical) ,X-ray ,Magnetic resonance imaging ,Magnetic Resonance Imaging ,Computer Science Applications ,Radiographic Image Interpretation, Computer-Assisted ,Tomography ,Software ,Algorithms - Abstract
X-ray imaging is a wide-spread real-time imaging technique. Magnetic Resonance Imaging (MRI) offers a multitude of contrasts that offer improved guidance to interventionalists. As such simultaneous real-time acquisition and overlay would be highly favorable for image-guided interventions, e.g., in stroke therapy. One major obstacle in this setting is the fundamentally different acquisition geometry. MRI ${k}$ -space sampling is associated with parallel projection geometry, while the X-ray acquisition results in perspective distorted projections. The classical rebinning methods to overcome this limitation inherently suffers from a loss of resolution. To counter this problem, we present a novel rebinning algorithm for parallel to cone-beam conversion. We derive a rebinning formula that is then used to find an appropriate deep neural network architecture. Following the known operator learning paradigm, the novel algorithm is mapped to a neural network with differentiable projection operators enabling data-driven learning of the remaining unknown operators. The evaluation aims in two directions: First, we give a profound analysis of the different hypotheses to the unknown operator and investigate the influence of numerical training data. Second, we evaluate the performance of the proposed method against the classical rebinning approach. We demonstrate that the derived network achieves better results than the baseline method and that such operators can be trained with simulated data without losing their generality making them applicable to real data without the need for retraining or transfer learning.
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- 2020
91. Unruptured Intracranial Aneurysms
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Helmuth Steinmetz, Arnd Dörfler, and Nima Etminan
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medicine.medical_specialty ,Subarachnoid hemorrhage ,business.industry ,MEDLINE ,General Medicine ,030204 cardiovascular system & hematology ,medicine.disease ,Surgery ,Clinical trial ,Pathogenesis ,03 medical and health sciences ,0302 clinical medicine ,Blood pressure ,Aneurysm ,Hospital discharge ,Medicine ,Rupture risk ,business ,030217 neurology & neurosurgery - Abstract
Background About 2 million adults in Germany harbor an unruptured intracranial aneurysm (IA). Rupture can lead to a life-threatening subarachnoid hemorrhage. If an IA is detected incidentally in cranial imaging, it must be decided how to proceed. Methods This review includes key publications that were identified by a selective search in the PubMed database using the search term "unruptured intracranial aneurysms," which was performed in July 2019, and based on information obtained from the German Federal Statistical Office on the frequency of the hospital discharge diagnosis "cerebral aneurysm," excluding the diagnosis "subarachnoid hemorrhage," in Germany from 2005 to 2017. Results The number of patients in Germany who were admitted or treated for an unruptured IA increased by a factor of 2.3 from 2005 to 2017. The average 5-year rupture risk of approximately 3% must be weighed against the approximately 4% risk associated with an endovascular or microneurosurgical treatment. This emphasizes the need for more precise data on the risk of rupture and for algorithms enabling individualized decision-making for patients with unruptured IA. Risk factors such as IA morphology, arterial hypertension, active smoking, and alcohol consumption (>150 g/week) can markedly increase the risk of rupture, which is generally relatively low. Growing aneurysms are 12 times more likely to rupture than stable ones. Follow-up imaging is thus essential whenever observation rather than intervention is chosen as the initial management. Conclusion Patients with unruptured IA should be massessed and managed individually. It is also important that risk factors should be treated, if present. Eligible patients are currently being recruited for a phase III clinical trial on the efficacy of blood pressure reduction combined with acetylsalicylic acid intake to counteract inflammatory processes in the arterial wall.
- Published
- 2020
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92. Interventionelle Neuroradiologie
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Arnd Dörfler and Michael Forsting
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- 2020
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93. On PTV definition for glioblastoma based on fiber tracking of diffusion tensor imaging data
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Tobias Engelhorn, Michael Uder, Barbara Witulla, Florian Putz, Frederik Bernd Laun, Rainer Fietkau, Benjamin Frey, Christoph Bert, Arnd Dörfler, and Nicole L. Goerig
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medicine.medical_treatment ,Cancer Treatment ,Pathology and Laboratory Medicine ,Tracking (particle physics) ,Diagnostic Radiology ,030218 nuclear medicine & medical imaging ,0302 clinical medicine ,Medizinische Fakultät ,Medicine and Health Sciences ,Blastomas ,Neurological Tumors ,Brain Mapping ,Multidisciplinary ,medicine.diagnostic_test ,Brain Neoplasms ,Radiology and Imaging ,Prognosis ,Tumor Resection ,Magnetic Resonance Imaging ,Primary tumor ,Tumor Burden ,Diffusion Tensor Imaging ,Surgical Oncology ,Oncology ,Neurology ,Medicine ,Radiology ,Algorithms ,Research Article ,Clinical Oncology ,medicine.medical_specialty ,Imaging Techniques ,Brain Morphometry ,Science ,Radiation Therapy ,Neuroimaging ,Surgical and Invasive Medical Procedures ,Research and Analysis Methods ,03 medical and health sciences ,Signs and Symptoms ,Text mining ,Diagnostic Medicine ,medicine ,Humans ,ddc:610 ,Surgical Resection ,business.industry ,Fiber (mathematics) ,Radiotherapy Planning, Computer-Assisted ,Biology and Life Sciences ,Cancers and Neoplasms ,Magnetic resonance imaging ,medicine.disease ,Radiation therapy ,Lesions ,Neoplasm Recurrence, Local ,Clinical Medicine ,Glioblastoma ,business ,Glioblastoma Multiforme ,030217 neurology & neurosurgery ,Follow-Up Studies ,Neuroscience ,Diffusion MRI - Abstract
Radiotherapy (RT) is commonly applied for the treatment of glioblastoma multiforme (GBM). Following the planning target volume (PTV) definition procedure standardized in guidelines, a 20% risk of missing non-local recurrences is present. Purpose of this study was to evaluate whether diffusion tensor imaging (DTI)-based fiber tracking may be beneficial for PTV definition taking into account the prediction of distant recurrences. 56 GBM patients were examined with magnetic resonance imaging (MRI) including DTI performed before RT after resection of the primary tumor. Follow-up MRIs were acquired in three month intervals. For the seven patients with a distant recurrence, fiber tracking was performed with three algorithms and it was evaluated whether connections existed from the primary tumor region to the distant recurrence. It depended strongly on the used tracking algorithm and the used tracking parameters whether a connection was observed. Most of the connections were weak and thus not usable for PTV definition. Only in one of the seven patients with a recurring tumor, a clear connection was present. It seems unlikely that DTI-based fiber tracking can be beneficial for predicting distant recurrences in the planning of PTVs for glioblastoma multiforme.
- Published
- 2020
94. Symmetric tract-based spatial statistics of patients with left versus right mesial temporal lobe epilepsy with hippocampal sclerosis
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Roland Coras, Angelika Mennecke, Julie Rösch, Frederik Bernd Laun, Hajo M. Hamer, Burkhard S. Kasper, Manuel Schmidt, Karl Rössler, and Arnd Dörfler
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Adult ,Male ,Tract based spatial statistics ,Right temporal lobe ,Hippocampus ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,Epilepsy ,0302 clinical medicine ,Text mining ,Neural Pathways ,Humans ,Medicine ,Retrospective Studies ,Hippocampal sclerosis ,Sclerosis ,business.industry ,General Neuroscience ,medicine.disease ,nervous system diseases ,Diffusion Tensor Imaging ,Epilepsy, Temporal Lobe ,Female ,business ,Neuroscience ,030217 neurology & neurosurgery ,Mesial temporal lobe epilepsy - Abstract
This study aims to investigate the diffusion metrics of left versus right temporal lobe epilepsy in a well-defined subgroup of patients with mesial temporal lobe epilepsy (mTLE) because of unilateral hippocampal sclerosis while taking into account interhemispheric differences. Eighteen patients with TLE [nine left temporal lobe epilepsy (LTLE) and nine right temporal lobe epilepsy (RTLE)] and a norm group of 36 nonepileptic individuals were scanned with a multiband accelerated diffusion tensor imaging protocol at 3T. The scalar diffusion tensor parameters fractional anisotropy (FA), mean diffusivity (MD), and radial diffusivity (RD) and, after projection on a symmetric skeleton, their hemispheric difference (dFA, dMD, and dRD) were analyzed using tract-based spatial statistics. In the cluster with significantly (P0.008) different dFA, dMD, and dRD between right TLE and left TLE, the hemispheric difference in the mean scalar indices (dmFA, dmMD, and dmRD) was assessed and tested for differences using a one-way analysis of variance and for correlation with patient age, seizure onset, or duration of epilepsy using Pearson's correlation. Patients with LTLE showed lower dFA, higher dMD, and higher dRD (P0.008) compared with patients with RTLE in a cluster including parts of the uncinated and inferior longitudinal fasciculus and the inferior fronto-occipital fasciculus. dmFA, dmMD, and dmRD differed significantly between groups (P10, corrected) and showed no correlation with patient age, seizure onset, or duration of epilepsy. The exclusion of bilateral interindividual variance through the calculation of the hemispheric difference of the diffusion metrics by the symmetric variant of tract-based spatial statistics allows for a sensitive differentiation of LTLE and RTLE with unilateral hippocampal sclerosis.
- Published
- 2018
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95. Lesion correlates of secondary paroxysmal dyskinesia in multiple sclerosis
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De-Hyung Lee, Klemens Winder, Ralf A. Linker, Konstantin Huhn, Arnd Dörfler, Tobias Engelhorn, Stefan Schwab, Frank Seifert, and Kilian Fröhlich
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Male ,0301 basic medicine ,Pathology ,medicine.medical_specialty ,Multiple Sclerosis ,Internal capsule ,Neurology ,Lesion ,03 medical and health sciences ,0302 clinical medicine ,Chorea ,Basal ganglia ,otorhinolaryngologic diseases ,medicine ,Humans ,Retrospective Studies ,Neuroradiology ,medicine.diagnostic_test ,business.industry ,Multiple sclerosis ,Brain ,Magnetic resonance imaging ,Paroxysmal dyskinesia ,medicine.disease ,Magnetic Resonance Imaging ,030104 developmental biology ,Female ,Neurology (clinical) ,medicine.symptom ,business ,030217 neurology & neurosurgery - Abstract
Secondary paroxysmal dyskinesia is a rare but life-quality-compromising symptom in multiple sclerosis (MS) and might be associated with particular MS lesions. The present study intended to determine associations between paroxysmal dyskinesia and the MS-associated lesion site using a voxelwise lesion analysis. We conducted a retrospective study and sought MS patients with documented paroxysmal dyskinesia and controls without paroxysmal dyskinesia matched for age, disease severity, and disease duration in a local database. The MS lesions were analysed on T2-weighted magnetic resonance imaging scans (1.5 or 3 T), manually outlined, and transformed into stereotaxic space. We determined the lesion overlap and compared the absence or presence of paroxysmal dyskinesia voxelwise between patients with and without lesions in a given voxel using the Liebermeister test with 4000 permutations. From 15,869 MS patient records screened, we identified 25 patients with paroxysmal dyskinesia. The voxelwise analysis in 22 subjects yielded associations between paroxysmal dyskinesia and MS lesions in the internal capsule, the basal ganglia, and another prominent lesion cluster in the posterior periventricular white matter. Our voxelwise analysis shows associations between paroxysmal dyskinesia and MS lesions in the internal capsule and basal ganglia, areas contributing to motor sequence programming. This association in another lesion site located in the posterior thalamic radiation suggests that lesions in subcortical sensory pathways may also contribute to paroxysmal dyskinesia in MS.
- Published
- 2018
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96. Snack food as a modulator of human resting-state functional connectivity
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Silke Kreitz, Andrea Mendez-Torrijos, Monika Pischetsrieder, L. Konerth, Arnd Dörfler, Claudiu Ivan, Oliver Kratz, Gunther H. Moll, Andreas Hess, Stefanie Horndasch, and Julie Rösch
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Adult ,Male ,0301 basic medicine ,Middle temporal gyrus ,Thalamus ,Biology ,Nucleus accumbens ,Somatosensory system ,Body Mass Index ,Food Preferences ,03 medical and health sciences ,0302 clinical medicine ,Basal ganglia ,Connectome ,Humans ,Resting state fMRI ,Brain ,Caloric theory ,Middle Aged ,Magnetic Resonance Imaging ,Psychiatry and Mental health ,030104 developmental biology ,Female ,Neurology (clinical) ,Snacks ,Neuroscience ,Insula ,030217 neurology & neurosurgery - Abstract
ObjectiveTo elucidate the mechanisms of how snack foods may induce non-homeostatic food intake, we used resting state functional magnetic resonance imaging (fMRI), as resting state networks can individually adapt to experience after short time exposures. In addition, we used graph theoretical analysis together with machine learning techniques (support vector machine) to identifying biomarkers that can categorize between high-caloric (potato chips) vs. low-caloric (zucchini) food stimulation.MethodsSeventeen healthy human subjects with body mass index (BMI) 19 to 27 underwent 2 different fMRI sessions where an initial resting state scan was acquired, followed by visual presentation of different images of potato chips and zucchini. There was then a 5-minute pause to ingest food (day 1=potato chips, day 3=zucchini), followed by a second resting state scan. fMRI data were further analyzed using graph theory analysis and support vector machine techniques.ResultsPotato chips vs. zucchini stimulation led to significant connectivity changes. The support vector machine was able to accurately categorize the 2 types of food stimuli with 100% accuracy. Visual, auditory, and somatosensory structures, as well as thalamus, insula, and basal ganglia were found to be important for food classification. After potato chips consumption, the BMI was associated with the path length and degree in nucleus accumbens, middle temporal gyrus, and thalamus.ConclusionThe results suggest that high vs. low caloric food stimulation in healthy individuals can induce significant changes in resting state networks. These changes can be detected using graph theory measures in conjunction with support vector machine. Additionally, we found that the BMI affects the response of the nucleus accumbens when high caloric food is consumed.
- Published
- 2018
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97. Regional Differences in Thrombectomy Rates
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Hans-Ulrich Prokosch, Joachim Berkefeld, Waltraud Pfeilschifter, Thomas Ganslandt, Petar Horki, Eva Neumaier-Probst, Horst Urbach, Christoph Best, Siegfried Bien, Christian Haverkamp, Kristina Szabo, Karl Egger, Marc A. Brockmann, Martin Skalej, Martin Boeker, Manfred Kaps, Wolf-Dirk Niesen, Arnd Dörfler, and Stefan Schwab
- Subjects
Male ,medicine.medical_specialty ,medicine.medical_treatment ,Health informatics ,Brain Ischemia ,03 medical and health sciences ,0302 clinical medicine ,Fibrinolytic Agents ,Mechanical Thrombolysis ,Germany ,Humans ,Medicine ,Thrombolytic Therapy ,Radiology, Nuclear Medicine and imaging ,030212 general & internal medicine ,Practice Patterns, Physicians' ,Stroke ,Aged ,Thrombectomy ,Neuroradiology ,Aged, 80 and over ,business.industry ,Health services research ,Guideline ,Thrombolysis ,Middle Aged ,medicine.disease ,Treatment Outcome ,Tissue Plasminogen Activator ,Emergency medicine ,Female ,Neurology (clinical) ,Neurosurgery ,business ,Medical Informatics ,030217 neurology & neurosurgery - Abstract
Mechanical thrombectomy, in addition to intravenous (i.v.) thrombolysis is recommended for treatment of acute stroke in patients with large vessel occlusions (LVO) in the anterior circulation up to 6 h after symptom onset. We compared thrombectomy rates of eight university hospitals of the MIRACUM consortium to analyze the implementation of this guideline in clinical routine. Anonymized billing data in a standardized format were loaded into a local i2b2 data warehouse by applying already existing extract, transform and load (ETL) routines. A locally executed uniform SQL (structured query language) query delivered aggregated site data for all inpatients with a discharge diagnosis of ischemic stroke (ICD-10 I63) containing counts for type of acute treatment, type of admission and age groups, which were centrally analyzed with R. From 2014 to 2016, the thrombectomy rate almost doubled from a mean of 4.7% to 9.6%, although significant differences between centers exist (range in 2016: 5.8–17%). The number of drip-and-ship procedures increased in 3 out of 8 centers. There was no evidence for a decrease in thrombectomy rates during weekends/holiday or among patients older than 80 years, but this age group is more likely to receive i.v. recombinant tissue plasminogen activator (rtPA). The observed increase of thrombectomy rates and drip-and-ship procedures without a significant difference between weekdays and weekends or patients of different ages is substantiating a rapid implementation of stroke guidelines within the analyzed neurovascular centers. The prototype of the MIRACUM Data Integration Center already contributes to health services research in Germany.
- Published
- 2018
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98. Association of prothrombin complex concentrate administration and hematoma enlargement in non-vitamin K antagonist oral anticoagulant-related intracerebral hemorrhage
- Author
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Joachim Röther, Hagen B. Huttner, Timolaos Rizos, Jochen A. Sembill, Frank Erbguth, Dominik Michalski, Matthias Endres, Hauke Schneider, Peter Vajkoczy, Hermann Neugebauer, Henning Stetefeld, Stefan Schwab, Karl Georg Haeusler, Retrace Investigators, Joji B. Kuramatsu, J Claßen, Gereon R. Fink, Arnd Dörfler, Maximilian I. Sprügel, Jan C. Purrucker, Peter D. Schellinger, Stefan T. Gerner, and Peter A. Ringleb
- Subjects
Intracerebral hemorrhage ,medicine.drug_mechanism_of_action ,business.industry ,medicine.drug_class ,Factor Xa Inhibitor ,Retrospective cohort study ,030204 cardiovascular system & hematology ,Vitamin K antagonist ,medicine.disease ,Prothrombin complex concentrate ,03 medical and health sciences ,0302 clinical medicine ,Hematoma ,Blood pressure ,Neurology ,Modified Rankin Scale ,Anesthesia ,Medicine ,cardiovascular diseases ,Neurology (clinical) ,business ,030217 neurology & neurosurgery ,medicine.drug - Abstract
OBJECTIVE To investigate parameters associated with hematoma enlargement in non-vitamin K antagonist oral anticoagulant (NOAC)-related intracerebral hemorrhage (ICH). METHODS This retrospective cohort study includes individual patient data for 190 patients with NOAC-associated ICH over a 5-year period (2011-2015) at 19 departments of neurology across Germany. Primary outcome was the association of prothrombin complex concentrate (PCC) administration with hematoma enlargement. Subanalyses were calculated for blood pressure management and its association with the primary outcome. Secondary outcomes include associations with in-hospital mortality and functional outcome at 3 months assessed using the modified Rankin Scale. RESULTS The study population for analysis of primary and secondary outcomes consisted of 146 NOAC-ICH patients with available follow-up imaging. Hematoma enlargement occurred in 49/146 (33.6%) patients with NOAC-related ICH. Parameters associated with hematoma enlargement were blood pressure ≥ 160mmHg within 4 hours and-in the case of factor Xa inhibitor ICH-anti-Xa levels on admission. PCC administration prior to follow-up imaging was not significantly associated with a reduced rate of hematoma enlargement either in overall NOAC-related ICH or in patients with factor Xa inhibitor intake (NOAC: risk ratio [RR] = 1.150, 95% confidence interval [CI] = 0.632-2.090; factor Xa inhibitor: RR = 1.057, 95% CI = 0.565-1.977), regardless of PCC dosage given or time interval until imaging or treatment. Systolic blood pressure levels
- Published
- 2018
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99. Towards real-time guidewire detection and tracking in the field of neuroradiology.
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Martin Spiegel, Marcus Pfister, Dieter A. Hahn, Volker Daum, Joachim Hornegger, Tobias Struffert, and Arnd Dörfler
- Published
- 2009
- Full Text
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100. Correction to: Evaluation After Cochlear Implant Surgery
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Ulrich Hoppe, Stephan P. Kloska, Joachim Hornung, Victoria Bozzato, Arnd Dörfler, Alessandro Bozzato, Annika Stock, and Tobias Struffert
- Subjects
medicine.medical_specialty ,Neurology ,business.industry ,Correction ,Scala Vestibuli ,Scala Tympani ,Cochlear Implantation ,Surgery ,Cochlear implant surgery ,Cochlear Implants ,Medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Neurology (clinical) ,Neurosurgery ,business ,Tomography, X-Ray Computed ,Neuroradiology - Abstract
Assessment of the cochlear implant (CI) electrode array position using flat-detector computed tomography (FDCT) to test dependence of postoperative outcome on intracochlear electrode position.A total of 102 patients implanted with 107 CIs underwent FDCT. Electrode position was rated as 1) scala tympani, 2) scala vestibuli, 3) scalar dislocation and 4) no deconvolution. Two independent neuroradiologists rated all image data sets twice and the scalar position was verified by a third neuroradiologist. Presurgical and postsurgical speech audiometry by the Freiburg monosyllabic test was used to evaluate auditory outcome after 6 months of speech rehabilitation.Electrode array position was assessed by FDCT in 107 CIs. Of the electrodes 60 were detected in the scala tympani, 21 in the scala vestibuli, 24 electrode arrays showed scalar dislocation and 2 electrodes were not placed in an intracochlear position. There was no significant difference in rehabilitation outcomes between scala tympani and scala vestibuli inserted patients. Rehabilitation was also possible in patients with dislocated electrodes.The use of FDCT is a reliable diagnostic method to determine the position of the electrode array. In our study cohort, the electrode position had no significant impact on postoperative outcome except for non-deconvoluted electrode arrays.
- Published
- 2021
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