@article{FriedrichEldebakeyRoothansetal.2022, author = {Friedrich, Maximilian U. and Eldebakey, Hazem and Roothans, Jonas and Capetian, Philipp and Zwergal, Andreas and Volkmann, Jens and Reich, Martin}, title = {Current-dependent ocular tilt reaction in deep brain stimulation of the subthalamic nucleus: Evidence for an incerto-interstitial pathway?}, series = {European Journal of Neurology}, volume = {29}, journal = {European Journal of Neurology}, number = {5}, doi = {10.1111/ene.15257}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-318700}, pages = {1545 -- 1549}, year = {2022}, abstract = {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.}, language = {en} } @article{FriedrichHartigPruessetal.2022, author = {Friedrich, Maximilian and Hartig, Johannes and Pr{\"u}ss, Harald and Ip, Wang Chi and Volkmann, Jens}, title = {Rapidly progressive dementia: Extending the spectrum of GFAP-astrocytopathies?}, series = {Annals of Clinical and Translational Neurology}, volume = {9}, journal = {Annals of Clinical and Translational Neurology}, number = {3}, doi = {10.1002/acn3.51513}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-312957}, pages = {410-415}, year = {2022}, abstract = {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.}, language = {en} } @article{PeixotoBentmannRuessmannetal.2020, author = {Peixoto, Thiago R. F. and Bentmann, Hendrik and R{\"u}ßmann, Philipp and Tcakaev, Abdul-Vakhab and Winnerlein, Martin and Schreyeck, Steffen and Schatz, Sonja and Vidal, Raphael Crespo and Stier, Fabian and Zabolotnyy, Volodymyr and Green, Robert J. and Min, Chul Hee and Fornari, Celso I. and Maaß, Henriette and Vasili, Hari Babu and Gargiani, Pierluigi and Valvidares, Manuel and Barla, Alessandro and Buck, Jens and Hoesch, Moritz and Diekmann, Florian and Rohlf, Sebastian and Kall{\"a}ne, Matthias and Rossnagel, Kai and Gould, Charles and Brunner, Karl and Bl{\"u}gel, Stefan and Hinkov, Vladimir and Molenkamp, Laurens W. and Friedrich, Reinert}, title = {Non-local effect of impurity states on the exchange coupling mechanism in magnetic topological insulators}, series = {NPJ Quantum Materials}, volume = {5}, journal = {NPJ Quantum Materials}, doi = {10.1038/s41535-020-00288-0}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230686}, year = {2020}, abstract = {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.}, language = {en} } @article{SchmittMeybohmNeefetal.2022, author = {Schmitt, Elke and Meybohm, Patrick and Neef, Vanessa and Baumgarten, Peter and Bayer, Alexandra and Choorapoikayil, Suma and Friederich, Patrick and Friedrich, Jens and Geisen, Christof and G{\"u}resir, Erdem and Gr{\"u}newald, Matthias and Gutjahr, Martin and Helmer, Philipp and Herrmann, Eva and M{\"u}ller, Markus and Narita, Diana and Raadts, Ansgar and Schwendner, Klaus and Seifried, Erhard and Stark, Patrick and Steinbicker, Andrea U. and Thoma, Josef and Velten, Markus and Weigt, Henry and Wiesenack, Christoph and Wittmann, Maria and Zacharowski, Kai and Piekarski, Florian}, title = {Preoperative anaemia and red blood cell transfusion in patients with aneurysmal subarachnoid and intracerebral haemorrhage - a multicentre subanalysis of the German PBM Network Registry}, series = {Acta Neurochirurgica}, volume = {164}, journal = {Acta Neurochirurgica}, organization = {German PBM Network Collaborators}, doi = {10.1007/s00701-022-05144-7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-346754}, pages = {985-999}, year = {2022}, abstract = {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.}, language = {en} } @article{KistThomaschewskiKecketal.2022, author = {Kist, Markus and Thomaschewski, Michael and Keck, Yannick and Abdalla, Thaer S. A. and Zeissig, Sylke Ruth and Kleihues-van Tol, Kees and Wellner, Ulrich Friedrich and Keck, Tobias and Hoeppner, Jens and Hummel, Richard}, title = {Specifics of young gastric cancer patients: a population-based analysis of 46,110 patients with gastric cancer from the German Clinical Cancer Registry Group}, series = {Cancers}, volume = {14}, journal = {Cancers}, number = {23}, issn = {2072-6694}, doi = {10.3390/cancers14235927}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-297473}, year = {2022}, abstract = {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.}, language = {en} } @article{FriedrichSchneiderBuerkleinetal.2023, author = {Friedrich, Maximilian U. and Schneider, Erich and Buerklein, Miriam and Taeger, Johannes and Hartig, Johannes and Volkmann, Jens and Peach, Robert and Zeller, Daniel}, title = {Smartphone video nystagmography using convolutional neural networks: ConVNG}, series = {Journal of Neurology}, volume = {270}, journal = {Journal of Neurology}, number = {5}, doi = {10.1007/s00415-022-11493-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-324526}, pages = {2518-2530}, year = {2023}, abstract = {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.}, language = {en} }