TY - JOUR A1 - Friedrich, Maximilian U. A1 - Eldebakey, Hazem A1 - Roothans, Jonas A1 - Capetian, Philipp A1 - Zwergal, Andreas A1 - Volkmann, Jens A1 - Reich, Martin T1 - Current-dependent ocular tilt reaction in deep brain stimulation of the subthalamic nucleus: Evidence for an incerto-interstitial pathway? JF - European Journal of Neurology N2 - Background and purpose The aim was to characterize a combined vestibular, ocular motor and postural syndrome induced by deep brain stimulation (DBS) of the subthalamic nucleus in a patient with Parkinson's disease. Methods In a systematic DBS programming session, eye, head and trunk position in roll and pitch plane were documented as a function of stimulation amplitude and field direction. Repeat ocular coherence tomography was used to estimate ocular torsion. The interstitial nucleus of Cajal (INC), zona incerta (ZI) and ascending vestibular fibre tracts were segmented on magnetic resonance imaging using both individual and normative structural connectomic data. Thresholded symptom-associated volumes of tissue activated (VTA) were calculated based on documented stimulation parameters. Results Ipsilateral ocular tilt reaction and body lateropulsion as well as contralateral torsional nystagmus were elicited by the right electrode in a current-dependent manner and subsided after DBS deactivation. With increasing currents, binocular tonic upgaze and body retropulsion were observed. Symptoms were consistent with an irritative effect on the INC. Symptom-associated VTA was found to overlap with the dorsal ZI and the ipsilateral vestibulothalamic tract, while lying rather distant to the INC proper. A ZI-to-INC ‘incerto-interstitial’ tract with contact to the medial-uppermost portion of the VTA could be traced. Conclusion Unilateral stimulation of INC-related circuitry induces an ipsilateral vestibular, ocular motor and postural roll-plane syndrome, which converts into a pitch-plane syndrome when functional activation expands bilaterally. In this case, tractography points to an incerto-interstitial pathway, a tract previously only characterized in non-human primates. Directional current steering proved useful in managing this rare side effect. KW - deep brain stimulation KW - vestibular KW - movement disorders Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-318700 VL - 29 IS - 5 SP - 1545 EP - 1549 ER - TY - JOUR A1 - Friedrich, Maximilian A1 - Hartig, Johannes A1 - Prüss, Harald A1 - Ip, Wang Chi A1 - Volkmann, Jens T1 - Rapidly progressive dementia: Extending the spectrum of GFAP-astrocytopathies? JF - Annals of Clinical and Translational Neurology N2 - Autoimmune glial fibrillary acidic protein astrocytopathy (GFAP-A) is a steroid-responsive meningoencephalomyelitis, sometimes presenting with atypical clinical signs such as movement disorders or psychiatric and autonomic features. Beyond clinical presentation and imaging, diagnosis relies on detection of GFAP-antibodies (AB) in CSF. Using quantitative behavioral, serologic, and immunohistochemical analyses, we characterize two patients longitudinally over 18–24 months who presented with rapidly progressive neurocognitive deterioration in the context of GFAP-AB in CSF and unremarkable cranial MRI studies. Intensified immunotherapy was associated with clinical stabilization. The value of GFAP-AB screening in selected cases of rapidly progressive dementias is discussed. KW - GFAP-astrocytopathies KW - dementia Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-312957 VL - 9 IS - 3 ER - TY - JOUR A1 - Peixoto, Thiago R. F. A1 - Bentmann, Hendrik A1 - Rüßmann, Philipp A1 - Tcakaev, Abdul-Vakhab A1 - Winnerlein, Martin A1 - Schreyeck, Steffen A1 - Schatz, Sonja A1 - Vidal, Raphael Crespo A1 - Stier, Fabian A1 - Zabolotnyy, Volodymyr A1 - Green, Robert J. A1 - Min, Chul Hee A1 - Fornari, Celso I. A1 - Maaß, Henriette A1 - Vasili, Hari Babu A1 - Gargiani, Pierluigi A1 - Valvidares, Manuel A1 - Barla, Alessandro A1 - Buck, Jens A1 - Hoesch, Moritz A1 - Diekmann, Florian A1 - Rohlf, Sebastian A1 - Kalläne, Matthias A1 - Rossnagel, Kai A1 - Gould, Charles A1 - Brunner, Karl A1 - Blügel, Stefan A1 - Hinkov, Vladimir A1 - Molenkamp, Laurens W. A1 - Friedrich, Reinert T1 - Non-local effect of impurity states on the exchange coupling mechanism in magnetic topological insulators JF - NPJ Quantum Materials N2 - Since the discovery of the quantum anomalous Hall (QAH) effect in the magnetically doped topological insulators (MTI) Cr:(Bi,Sb)\(_2\)Te\(_3\) and V:(Bi,Sb)\(_2\)Te\(_3\), the search for the magnetic coupling mechanisms underlying the onset of ferromagnetism has been a central issue, and a variety of different scenarios have been put forward. By combining resonant photoemission, X-ray magnetic circular dichroism and density functional theory, we determine the local electronic and magnetic configurations of V and Cr impurities in (Bi,Sb)\(_2\)Te\(_3\). State-of-the-art first-principles calculations find pronounced differences in their 3d densities of states, and show how these impurity states mediate characteristic short-range pd exchange interactions, whose strength sensitively varies with the position of the 3d states relative to the Fermi level. Measurements on films with varying host stoichiometry support this trend. Our results explain, in an unified picture, the origins of the observed magnetic properties, and establish the essential role of impurity-state-mediated exchange interactions in the magnetism of MTI. KW - shape-truncation functions KW - semiconductors Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230686 VL - 5 ER - TY - JOUR A1 - Schmitt, Elke A1 - Meybohm, Patrick A1 - Neef, Vanessa A1 - Baumgarten, Peter A1 - Bayer, Alexandra A1 - Choorapoikayil, Suma A1 - Friederich, Patrick A1 - Friedrich, Jens A1 - Geisen, Christof A1 - Güresir, Erdem A1 - Grünewald, Matthias A1 - Gutjahr, Martin A1 - Helmer, Philipp A1 - Herrmann, Eva A1 - Müller, Markus A1 - Narita, Diana A1 - Raadts, Ansgar A1 - Schwendner, Klaus A1 - Seifried, Erhard A1 - Stark, Patrick A1 - Steinbicker, Andrea U. A1 - Thoma, Josef A1 - Velten, Markus A1 - Weigt, Henry A1 - Wiesenack, Christoph A1 - Wittmann, Maria A1 - Zacharowski, Kai A1 - Piekarski, Florian T1 - Preoperative anaemia and red blood cell transfusion in patients with aneurysmal subarachnoid and intracerebral haemorrhage - a multicentre subanalysis of the German PBM Network Registry JF - Acta Neurochirurgica N2 - Purpose Anaemia is common in patients presenting with aneurysmal subarachnoid (aSAH) and intracerebral haemorrhage (ICH). In surgical patients, anaemia was identified as an idenpendent risk factor for postoperative mortality, prolonged hospital length of stay (LOS) and increased risk of red blood cell (RBC) transfusion. This multicentre cohort observation study describes the incidence and effects of preoperative anaemia in this critical patient collective for a 10-year period. Methods This multicentre observational study included adult in-hospital surgical patients diagnosed with aSAH or ICH of 21 German hospitals (discharged from 1 January 2010 to 30 September 2020). Descriptive, univariate and multivariate analyses were performed to investigate the incidence and association of preoperative anaemia with RBC transfusion, in-hospital mortality and postoperative complications in patients with aSAH and ICH. Results A total of n = 9081 patients were analysed (aSAH n = 5008; ICH n = 4073). Preoperative anaemia was present at 28.3% in aSAH and 40.9% in ICH. RBC transfusion rates were 29.9% in aSAH and 29.3% in ICH. Multivariate analysis revealed that preoperative anaemia is associated with a higher risk for RBC transfusion (OR = 3.25 in aSAH, OR = 4.16 in ICH, p < 0.001), for in-hospital mortality (OR = 1.48 in aSAH, OR = 1.53 in ICH, p < 0.001) and for several postoperative complications. Conclusions Preoperative anaemia is associated with increased RBC transfusion rates, in-hospital mortality and postoperative complications in patients with aSAH and ICH. KW - aneurysmal subarachnoid haemorrhage KW - intracerebral haemorrhage KW - anaemia KW - red blood cell transfusion KW - patient blood management Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-346754 VL - 164 ER - TY - JOUR A1 - Kist, Markus A1 - Thomaschewski, Michael A1 - Keck, Yannick A1 - Abdalla, Thaer S. A. A1 - Zeissig, Sylke Ruth A1 - Kleihues-van Tol, Kees A1 - Wellner, Ulrich Friedrich A1 - Keck, Tobias A1 - Hoeppner, Jens A1 - Hummel, Richard T1 - Specifics of young gastric cancer patients: a population-based analysis of 46,110 patients with gastric cancer from the German Clinical Cancer Registry Group JF - Cancers N2 - Introduction: 2–8% of all gastric cancer occurs at a younger age, also known as early-onset gastric cancer (EOGC). The aim of the present work was to use clinical registry data to classify and characterize the young cohort of patients with gastric cancer more precisely. Methods: German Cancer Registry Group of the Society of German Tumor Centers—Network for Care, Quality and Research in Oncology (ADT)was queried for patients with gastric cancer from 2000–2016. An approach that stratified relative distributions of histological subtypes of gastric adenocarcinoma according to age percentiles was used to define and characterize EOGC. Demographics, tumor characteristics, treatment and survival were analyzed. Results: A total of 46,110 patients were included. Comparison of different groups of age with incidences of histological subtypes showed that incidence of signet ring cell carcinoma (SRCC) increased with decreasing age and exceeded pooled incidences of diffuse and intestinal type tumors in the youngest 20% of patients. We selected this group with median age of 53 as EOGC. The proportion of female patients was lower in EOGC than that of elderly patients (43% versus 45%; p < 0.001). EOGC presented more advanced and undifferentiated tumors with G3/4 stages in 77% versus 62%, T3/4 stages in 51% versus 48%, nodal positive tumors in 57% versus 53% and metastasis in 35% versus 30% (p < 0.001) and received less curative treatment (42% versus 52%; p < 0.001). Survival of EOGC was significantly better (five-years survival: 44% versus 31% (p < 0.0001), with age as independent predictor of better survival (HR 0.61; p < 0.0001). Conclusion: With this population-based registry study we were able to objectively define a cohort of patients referred to as EOGC. Despite more aggressive/advanced tumors and less curative treatment, survival was significantly better compared to elderly patients, and age was identified as an independent predictor for better survival. KW - gastric cancer in young patients KW - german clinical cancer registry group KW - early-onset gastric cancer patients Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-297473 SN - 2072-6694 VL - 14 IS - 23 ER - TY - JOUR A1 - Friedrich, Maximilian U. A1 - Schneider, Erich A1 - Buerklein, Miriam A1 - Taeger, Johannes A1 - Hartig, Johannes A1 - Volkmann, Jens A1 - Peach, Robert A1 - Zeller, Daniel T1 - Smartphone video nystagmography using convolutional neural networks: ConVNG JF - Journal of Neurology N2 - Background Eye movement abnormalities are commonplace in neurological disorders. However, unaided eye movement assessments lack granularity. Although videooculography (VOG) improves diagnostic accuracy, resource intensiveness precludes its broad use. To bridge this care gap, we here validate a framework for smartphone video-based nystagmography capitalizing on recent computer vision advances. Methods A convolutional neural network was fine-tuned for pupil tracking using > 550 annotated frames: ConVNG. In a cross-sectional approach, slow-phase velocity of optokinetic nystagmus was calculated in 10 subjects using ConVNG and VOG. Equivalence of accuracy and precision was assessed using the “two one-sample t-test” (TOST) and Bayesian interval-null approaches. ConVNG was systematically compared to OpenFace and MediaPipe as computer vision (CV) benchmarks for gaze estimation. Results ConVNG tracking accuracy reached 9–15% of an average pupil diameter. In a fully independent clinical video dataset, ConVNG robustly detected pupil keypoints (median prediction confidence 0.85). SPV measurement accuracy was equivalent to VOG (TOST p < 0.017; Bayes factors (BF) > 24). ConVNG, but not MediaPipe, achieved equivalence to VOG in all SPV calculations. Median precision was 0.30°/s for ConVNG, 0.7°/s for MediaPipe and 0.12°/s for VOG. ConVNG precision was significantly higher than MediaPipe in vertical planes, but both algorithms’ precision was inferior to VOG. Conclusions ConVNG enables offline smartphone video nystagmography with an accuracy comparable to VOG and significantly higher precision than MediaPipe, a benchmark computer vision application for gaze estimation. This serves as a blueprint for highly accessible tools with potential to accelerate progress toward precise and personalized Medicine. KW - digital medicine KW - nystagmus KW - eye movement disorders KW - videooculography KW - computer vision KW - telemedicine KW - precision medicine Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-324526 VL - 270 IS - 5 ER -