@article{NeugebauerSchneiderKollmar2019, author = {Neugebauer, Hermann and Schneider, Hauke and Kollmar, Rainer}, title = {Letter by Neugebauer et al. regarding article "Hypothermia after decompressive hemicraniectomy in treatment of malignant middle cerebral artery stroke: comment on the randomized clinical trial"}, series = {Critical Care}, volume = {23}, journal = {Critical Care}, doi = {10.1186/s13054-019-2600-9}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-232268}, year = {2019}, abstract = {No abstract available.}, language = {en} } @article{PasosSteigerwaldReichetal.2019, author = {Pasos, Uri E. Ramirez and Steigerwald, Frank and Reich, Martin M. and Matthies, Cordula and Volkmann, Jens and Reese, Ren{\´e}}, title = {Levodopa modulates functional connectivity in the upper beta band between bubthalamic nucleus and muscle activity in tonic and phasic motor activity patterns in Parkinson's disease}, series = {Frontiers in Human Neuroscience}, volume = {13}, journal = {Frontiers in Human Neuroscience}, number = {223}, doi = {10.3389/fnhum.2019.00223}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201540}, year = {2019}, abstract = {Introduction: Striatal dopamine depletion disrupts basal ganglia function and causes Parkinson's disease (PD). The pathophysiology of the dopamine-dependent relationship between basal ganglia signaling and motor control, however, is not fully understood. We obtained simultaneous recordings of local field potentials (LFPs) from the subthalamic nucleus (STN) and electromyograms (EMGs) in patients with PD to investigate the impact of dopaminergic state and movement on long-range beta functional connectivity between basal ganglia and lower motor neurons. Methods: Eight PD patients were investigated 3 months after implantation of a deep brain stimulation (DBS)-system capable of recording LFPs via chronically-implanted leads (Medtronic, ACTIVA PC+S®). We analyzed STN spectral power and its coherence with EMG in the context of two different movement paradigms (tonic wrist extension vs. alternating wrist extension and flexion) and the effect of levodopa (L-Dopa) intake using an unbiased data-driven approach to determine regions of interest (ROI). Results: Two ROIs capturing prominent coherence within a grand average coherogram were identified. A trend of a dopamine effect was observed for the first ROI (50-150 ms after movement start) with higher STN-EMG coherence in medicated patients. Concerning the second ROI (300-500 ms after movement start), an interaction effect of L-Dopa medication and movement task was observed with higher coherence in the isometric contraction task compared to alternating movements in the medication ON state, a pattern which was reversed in L-Dopa OFF. Discussion: L-Dopa medication may normalize functional connectivity between remote structures of the motor system with increased upper beta coherence reflecting a physiological restriction of the amount of information conveyed between remote structures. This may be necessary to maintain simple movements like isometric contraction. Our study adds dynamic properties to the complex interplay between STN spectral beta power and the nucleus' functional connectivity to remote structures of the motor system as a function of movement and dopaminergic state. This may help to identify markers of neuronal activity relevant for more individualized programming of DBS therapy.}, language = {en} } @article{SilwedelHaarmannFehrholzetal.2019, author = {Silwedel, Christine and Haarmann, Axel and Fehrholz, Markus and Claus, Heike and Speer, Christian P. and Glaser, Kirsten}, title = {More than just inflammation: Ureaplasma species induce apoptosis in human brain microvascular endothelial cells}, series = {Journal of Neuroinflammation}, volume = {16}, journal = {Journal of Neuroinflammation}, doi = {10.1186/s12974-019-1413-8}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-200711}, pages = {38}, year = {2019}, abstract = {Background Ureaplasma species (spp.) are commonly regarded as low-virulent commensals but may cause invasive diseases in immunocompromised adults and in neonates, including neonatal meningitis. The interactions of Ureaplasma spp. with host defense mechanisms are poorly understood. This study addressed Ureaplasma-driven cell death, concentrating on apoptosis as well as inflammatory cell death. Methods Human brain microvascular endothelial cells (HBMEC) were exposed to Ureaplasma (U.) urealyticum serovar 8 (Uu8) and U. parvum serovar 3 (Up3). Resulting numbers of dead cells as well as mRNA levels and enzyme activity of key agents in programmed cell death were assessed by flow cytometry, RNA sequencing, and qRT-PCR, respectively. xCELLigence data were used for real-time monitoring of changes in cell adhesion properties. Results Both Ureaplasma isolates induced cell death (p < 0.05, vs. broth). Furthermore, Ureaplasma spp. enhanced mRNA levels for genes in apoptosis, including caspase 3 (Up3 p < 0.05, vs. broth), caspase 7 (p < 0.01), and caspase 9 (Up3 p < 0.01). Caspase 3 activity was increased upon Uu8 exposure (p < 0.01). Vice versa, Ureaplasma isolates downregulated mRNA levels for proteins involved in inflammatory cell death, namely caspase 1 (Uu8 p < 0.01, Up3 p < 0.001), caspase 4 (Uu8 p < 0.05, Up3 p < 0.01), NOD-like receptor pyrin domain-containing 3 (Uu8 p < 0.05), and receptor-interacting protein kinase 3 (p < 0.05). Conclusions By inducing apoptosis in HBMEC as main constituents of the blood-brain barrier, Ureaplasma spp. may provoke barrier breakdown. Simultaneous suppression of inflammatory cell death may additionally attenuate host defense strategies. Ultimate consequence could be invasive and long-term CNS infections by Ureaplasma spp.}, language = {en} } @article{HermSchurigMartineketal.2019, author = {Herm, Juliane and Schurig, Johannes and Martinek, Martin R. and H{\"o}ltgen, Reinhard and Schirdewan, Alexander and Kirchhof, Paulus and Wieczorek, Marcus and P{\"u}rerfellner, Helmut and Heuschmann, Peter U. and Fiebach, Jochen B. and Haeusler, Karl Georg}, title = {MRI-detected brain lesions in AF patients without further stroke risk factors undergoing ablation - a retrospective analysis of prospective studies}, series = {BMC Cardiovascular Disorders}, volume = {19}, journal = {BMC Cardiovascular Disorders}, doi = {10.1186/s12872-019-1035-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201226}, pages = {58}, year = {2019}, abstract = {Background Atrial fibrillation (AF) without other stroke risk factors is assumed to have a low annual stroke risk comparable to patients without AF. Therefore, current clinical guidelines do not recommend oral anticoagulation for stroke prevention of AF in patients without stroke risk factors. We analyzed brain magnetic resonance imaging (MRI) imaging to estimate the rate of clinically inapparent ("silent") ischemic brain lesions in these patients. Methods We pooled individual patient-level data from three prospective studies comprising stroke-free patients with symptomatic AF. All study patients underwent brain MRI within 24-48 h before planned left atrial catheter ablation. MRIs were analyzed by a neuroradiologist blinded to clinical data. Results In total, 175 patients (median age 60 (IQR 54-67) years, 32\% female, median CHA\(_2\)DS\(_2\)-VASc = 1 (IQR 0-2), 33\% persistent AF) were included. In AF patients without or with at least one stroke risk factor, at least one silent ischemic brain lesion was observed in 4 (8\%) out of 48 and 10 (8\%) out of 127 patients, respectively (p > 0.99). Presence of silent ischemic brain lesions was related to age (p = 0.03) but not to AF pattern (p = 0.77). At least one cerebral microbleed was detected in 5 (13\%) out of 30 AF patients without stroke risk factors and 25 (25\%) out of 108 AF patients with stroke risk factors (p = 0.2). Presence of cerebral microbleeds was related to male sex (p = 0.04) or peripheral artery occlusive disease (p = 0.03). Conclusion In patients with symptomatic AF scheduled for ablation, brain MRI detected silent ischemic brain lesions in approximately one in 12 patients, and microbleeds in one in 5 patients. The prevalence of silent ischemic brain lesions did not differ in AF patients with or without further stroke risk factors.}, language = {en} } @article{KarlWussmannKressetal.2019, author = {Karl, Franziska and Wußmann, Maximiliane and Kreß, Luisa and Malzacher, Tobias and Fey, Phillip and Groeber-Becker, Florian and {\"U}{\c{c}}eyler, Nurcan}, title = {Patient-derived in vitro skin models for investigation of small fiber pathology}, series = {Annals of Clinical and Translational Neurology}, volume = {6}, journal = {Annals of Clinical and Translational Neurology}, number = {9}, doi = {10.1002/acn3.50871}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201649}, pages = {1797-1806}, year = {2019}, abstract = {Objective To establish individually expandable primary fibroblast and keratinocyte cultures from 3-mm skin punch biopsies for patient-derived in vitro skin models to investigate of small fiber pathology. Methods We obtained 6-mm skin punch biopsies from the calf of two patients with small fiber neuropathy (SFN) and two healthy controls. One half (3 mm) was used for diagnostic intraepidermal nerve fiber density (IENFD). From the second half, we isolated and cultured fibroblasts and keratinocytes. Cells were used to generate patient-derived full-thickness three-dimensional (3D) skin models containing a dermal and epidermal component. Cells and skin models were characterized morphologically, immunocyto- and -histochemically (vimentin, cytokeratin (CK)-10, CK 14, ki67, collagen1, and procollagen), and by electrical impedance. Results Distal IENFD was reduced in the SFN patients (2 fibers/mm each), while IENFD was normal in the controls (8 fibers/mm, 7 fibers/mm). Two-dimensional (2D) cultured skin cells showed normal morphology, adequate viability, and proliferation, and expressed cell-specific markers without relevant difference between SFN patient and healthy control. Using 2D cultured fibroblasts and keratinocytes, we obtained subject-derived 3D skin models. Morphology of the 3D model was analogous to the respective skin biopsy specimens. Both, the dermal and the epidermal layer carried cell-specific markers and showed a homogenous expression of extracellular matrix proteins. Interpretation Our protocol allows the generation of disease-specific 2D and 3D skin models, which can be used to investigate the cross-talk between skin cells and sensory neurons in small fiber pathology.}, language = {en} } @article{EvdokimovFrankKlitschetal.2019, author = {Evdokimov, Dimitar and Frank, Johanna and Klitsch, Alexander and Unterecker, Stefan and Warrings, Bodo and Serra, Jordi and Papagianni, Aikaterini and Saffer, Nadine and Meyer zu Altenschildesche, Caren and Kampik, Daniel and Malik, Rayaz A. and Sommer, Claudia and {\"U}ceyler, Nurcan}, title = {Reduction of skin innervation is associated with a severe fibromyalgia phenotype}, series = {Annals of Neurology}, volume = {86}, journal = {Annals of Neurology}, number = {4}, doi = {10.1002/ana.25565}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-206168}, pages = {504-516}, year = {2019}, abstract = {Objective: To assess patterns and impact of small nerve fiber dysfunction and pathology in patients with fibromyalgia syndrome (FMS). Methods: One hundred seventeen women with FMS underwent neurological examination, questionnaire assessment, neurophysiology assessment, and small fiber tests: skin punch biopsy, corneal confocal microscopy, microneurography, quantitative sensory testing including C-tactile afferents, and pain-related evoked potentials. Data were compared with those of women with major depressive disorder and chronic widespread pain (MD-P) and healthy women. Results: Intraepidermal nerve fiber density (IENFD) was reduced at different biopsy sites in 63\% of FMS patients (MDP: 10\%, controls: 18\%; p < 0.001 for each). We found 4 patterns of skin innervation in FMS: normal, distally reduced, proximally reduced, and both distally and proximally reduced (p < 0.01 for each compared to controls). Microneurography revealed initial activity-dependent acceleration of conduction velocity upon low frequencies of stimulation in 1A fibers, besides 1B fiber spontaneous activity and mechanical sensitization in FMS patients. FMS patients had elevated warm detection thresholds (p < 0.01), impaired C-tactile afferents (p < 0.05), and reduced amplitudes (p < 0.001) of pain-related evoked potentials compared to controls. Compared to FMS patients with normal skin innervation, those with generalized IENFD reduction had higher pain intensity and impairment due to pain, higher disease burden, more stabbing pain and paresthesias, and more anxiety (p < 0.05 for each). FMS patients with generalized IENFD reduction also had lower corneal nerve fiber density (p < 0.01) and length (p < 0.05). Interpretation: The extent of small fiber pathology is related to symptom severity in FMS. This knowledge may have implications for the diagnostic classification and treatment of patients with FMS.}, language = {en} } @article{ElhfnawyHeuschmannPhametal.2019, author = {Elhfnawy, Ahmed Mohamed and Heuschmann, Peter U. and Pham, Mirko and Volkmann, Jens and Fluri, Felix}, title = {Stenosis length and degree interact with the risk of cerebrovascular events related to internal carotid artery stenosis}, series = {Frontiers in Neurology}, volume = {10}, journal = {Frontiers in Neurology}, number = {317}, issn = {1664-2295}, doi = {10.3389/fneur.2019.00317}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-196225}, year = {2019}, abstract = {Background and Purpose: Internal carotid artery stenosis (ICAS)≥70\% is a leading cause of ischemic cerebrovascular events (ICVEs). However, a considerable percentage of stroke survivors with symptomatic ICAS (sICAS) have <70\% stenosis with a vulnerable plaque. Whether the length of ICAS is associated with high risk of ICVEs is poorly investigated. Our main aim was to investigate the relation between the length of ICAS and the development of ICVEs. Methods: In a retrospective cross-sectional study, we identified 95 arteries with sICAS and another 64 with asymptomatic internal carotid artery stenosis (aICAS) among 121 patients with ICVEs. The degree and length of ICAS as well as plaque echolucency were assessed on ultrasound scans. Results: A statistically significant inverse correlation between the ultrasound-measured length and degree of ICAS was detected for sICAS≥70\% (Spearman correlation coefficient ρ = -0.57, p < 0.001, n = 51) but neither for sICAS<70\% (ρ = 0.15, p = 0.45, n = 27) nor for aICAS (ρ = 0.07, p = 0.64, n = 54). The median (IQR) length for sICAS<70\% and ≥70\% was 17 (15-20) and 15 (12-19) mm (p = 0.06), respectively, while that for sICAS<90\% and sICAS 90\% was 18 (15-21) and 13 (10-16) mm, respectively (p < 0.001). Among patients with ICAS <70\%, a cut-off length of ≥16 mm was found for sICAS rather than aICAS with a sensitivity and specificity of 74.1\% and 51.1\%, respectively. Irrespective of the stenotic degree, plaques of the sICAS compared to aICAS were significantly more often echolucent (43.2 vs. 24.6\%, p = 0.02). Conclusion: We found a statistically insignificant tendency for the ultrasound-measured length of sICAS<70\% to be longer than that of sICAS≥70\%. Moreover, the ultrasound-measured length of sICAS<90\% was significantly longer than that of sICAS 90\%. Among patients with sICAS≥70\%, the degree and length of stenosis were inversely correlated. Larger studies are needed before a clinical implication can be drawn from these results.}, language = {en} } @article{WutzlerKrogiasGrauetal.2019, author = {Wutzler, Alexander and Krogias, Christos and Grau, Anna and Veltkamp, Roland and Heuschmann, Peter U. and Haeusler, Karl Georg}, title = {Stroke prevention in patients with acute ischemic stroke and atrial fibrillation in Germany - a cross sectional survey}, series = {BMC Neurology}, volume = {19}, journal = {BMC Neurology}, doi = {10.1186/s12883-019-1249-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201078}, pages = {25}, year = {2019}, abstract = {Background Atrial fibrillation (AF) is present in 15-20\% of patients with acute ischemic stroke. Oral anticoagulation reduces the risk of AF-related recurrent stroke but clinical guideline recommendations are rather vague regarding its use in the acute phase of stroke. We aimed to assess the current clinical practice of medical stroke prevention in AF patients during the acute phase of ischemic stroke. Methods In April 2017, a standardized anonymous questionnaire was sent to clinical leads of all 298 certified stroke units in Germany. Results Overall, 154 stroke unit leads participated (response rate 52\%). Anticoagulation in the acute phase of stroke is considered feasible in more than 90\% of AF patients with ischemic stroke. Clinicians assume that about two thirds of all AF patients (range 20-100\%) are discharged on oral anticoagulation. According to local preferences, acetylsalicylic acid is given orally in the majority of patients with delayed initiation of oral anticoagulation. A non-vitamin K-dependent oral anticoagulant (NOAC) is more often prescribed than a vitamin K-dependent oral anticoagulant (VKA). VKA is more often chosen in patients with previous VKA intake than in VKA naive patients. In the minority of patients, stroke unit leads discuss the prescription of a specific oral anticoagulant with the treating general practitioner. Adherence to medical stroke prevention after hospital discharge is not assessed on a regular basis in any patient by the majority of participating stroke centers. Conclusions Early secondary stroke prevention in AF patients in German stroke units is based on OAC use but prescription modalities vary in clinical practice.}, language = {en} } @article{ElhfnawyVolkmannSchliesseretal.2019, author = {Elhfnawy, Ahmed Mohamed and Volkmann, Jens and Schliesser, Mira and Fluri, Felix}, title = {Symptomatic vs. asymptomatic 20-40\% internal carotid artery stenosis: Does the plaque size matter?}, series = {Frontiers in Neurology}, volume = {10}, journal = {Frontiers in Neurology}, number = {960}, doi = {10.3389/fneur.2019.00960}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201262}, year = {2019}, abstract = {Background: Around 9-15\% of ischemic strokes are related to internal carotid artery (ICA)-stenosis ≥50\%. However, the extent to which ICA-stenosis <50\% causes ischemic cerebrovascular events is uncertain. We examined the relation between plaque cross-sectional area and length and the risk of ischemic stroke or TIA among patients with ICA-stenosis of 20-40\%. Methods: We retrospectively identified patients admitted to the Department of Neurology, University Hospital of W{\"u}rzburg, from January 2011 until September 2016 with ischemic stroke or TIA and concomitant ICA-stenosis of 20-40\%, either symptomatic or asymptomatic. Plaque length and cross-sectional area were assessed on ultrasound scans. Results: We identified 41 patients with ischemic stroke or TIA and ICA-stenosis of 20-40\%; 14 symptomatic and 27 asymptomatic. The plaque cross-sectional area was significantly larger among symptomatic than asymptomatic ICA-stenosis; median values (IQR) were 0.45 (0.21-0.69) cm2 and 0.27 (0.21-0.38) cm2, p = 0.03, respectively. A plaque cross-sectional area ≥0.36 cm2 had a sensitivity of 71\% and a specificity of 76\% for symptomatic compared with asymptomatic ICA-stenosis. In a sex-adjusted multivariate logistic regression, a plaque cross-sectional area ≥0.36 cm2 and a plaque length ≥1.65 cm were associated with an OR (95\% CI) of 5.54 (1.2-25.6), p = 0.028 and 1.78 (0.36-8.73), p = 0.48, respectively, for symptomatic ICA-stenosis. Conclusion: Large plaques might increase the risk of ischemic stroke or TIA among patients with low-grade ICA-stenosis of 20-40\%. Sufficiently powered prospective longitudinal cohort studies are needed to definitively test the stroke risk stratification value of carotid plaque length and cross-sectional area in the setting of current optimal medical treatment.}, language = {en} } @article{SchuhmannKraftBieberetal.2019, author = {Schuhmann, Michael K. and Kraft, Peter and Bieber, Michael and Kollikowski, Alexander M. and Schulze, Harald and Nieswandt, Bernhard and Pham, Mirko and Stegner, David and Stoll, Guido}, title = {Targeting platelet GPVI plus rt-PA administration but not α2β1-mediated collagen binding protects against ischemic brain damage in mice}, series = {International Journal of Molecular Science}, volume = {20}, journal = {International Journal of Molecular Science}, number = {8}, issn = {1422-0067}, doi = {10.3390/ijms20082019}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201700}, year = {2019}, abstract = {Platelet collagen interactions at sites of vascular injuries predominantly involve glycoprotein VI (GPVI) and the integrin α2β1. Both proteins are primarily expressed on platelets and megakaryocytes whereas GPVI expression is also shown on endothelial and integrin α2β1 expression on epithelial cells. We recently showed that depletion of GPVI improves stroke outcome without increasing the risk of cerebral hemorrhage. Genetic variants associated with higher platelet surface integrin α2 (ITGA2) receptor levels have frequently been found to correlate with an increased risk of ischemic stroke in patients. However until now, no preclinical stroke study has addressed whether platelet integrin α2β1 contributes to the pathophysiology of ischemia/reperfusion (I/R) injury. Focal cerebral ischemia was induced in C57BL/6 and Itga2\(^{-/-}\) mice by a 60 min transient middle cerebral artery occlusion (tMCAO). Additionally, wild-type animals were pretreated with anti-GPVI antibody (JAQ1) or Fab fragments of a function blocking antibody against integrin α2β1 (LEN/B). In anti-GPVI treated animals, intravenous (IV) recombinant tissue plasminogen activator (rt-PA) treatment was applied immediately prior to reperfusion. Stroke outcome, including infarct size and neurological scoring was determined on day 1 after tMCAO. We demonstrate that targeting the integrin α2β1 (pharmacologic; genetic) did neither reduce stroke size nor improve functional outcome on day 1 after tMCAO. In contrast, depletion of platelet GPVI prior to stroke was safe and effective, even when combined with rt-PA treatment. Our results underscore that GPVI, but not ITGA2, is a promising and safe target in the setting of ischemic stroke.}, language = {en} }