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Stigmatisierung tritt bei psychischen, körperlichen sowie chronisch neurologischen Erkrankungen auf. Stigma kann vielfältige Auswirkungen auf Betroffene haben: Es vergrößert Gesundheitsunterschiede, verringert Lebensqualität und schafft Hürden, Gesundheitsleistungen zu nutzen. Internationale Studien zu diesem Thema zeig-ten, dass Stigma bei MS-Patient*innen u.a. die Lebensqualität, das psychische Wohlbefinden, das Offenlegen der Erkrankung und die Einhaltung von Therapien beeinflusst. Hinsichtlich der Stigmatisierung bei chronisch neurologischen Erkran-kungen, wie Multipler Sklerose (MS), gibt es in Deutschland bisher keine Studien. Ziel dieser Arbeit war eine erstmalige Datenerhebung zu Stigmatisierung bei MS. Endpunkte der Erhebung sind, welche Formen von Stigma in dieser Kohorte vorlie-gen und ob es psychische Komponenten, krankheitsspezifische Eigenschaften o-der soziodemographische Daten gibt, die im Zusammenhang mit Stigma stehen. Diese Daten wurden daraufhin in Vergleich zu internationalen Daten gestellt. Auch bisher noch kaum erforschte Assoziationen zu Stigma und Fatigue wurden näher betrachtet.
Die Studie wurde als prospektive Kohortenstudie in Form validierter Fragebögen an der Universität Greifswald (Klinik für Psychiatrie und Klinik für Neurologie) durchge-führt. Zur Auswertung unserer Daten wurden zunächst Basistabellen mit Angaben aus Mittelwert, Standardabweichung, Median und Interquartilenabstand verwendet. Um einen monotonen Zusammenhang zwischen den Variablen zu untersuchen, wurde der Rangkorrelationskoeffizient nach Spearman angewandt; um Assoziatio-nen aufzuzeigen die negative binomiale Regression.
Die Zusammensetzung der Kohorte mit dem Anteil an Männern (26%) und Frauen (74%) ist repräsentativ für MS. Alter und Erkrankungsdauer sind heterogen verteilt. 88 Personen hatten den schubförmig remittierenden MS-Typ, 11 den sekundär pro-gredienten und ein Patient den primär progredienten Verlaufstyp. Der Stigmatisie-rungsgrad in dieser MS-Kohorte ist gering. Der Modalwert für beide Stigma-Skalen liegt jeweils beim Minimum. Stigmatisierung korreliert signifikant auf hohem zweisei-tigen Signifikanzniveau (p>0,05) mit Depression (Korrelationskoeffizient 0,55), Fati-gue (0,51) und Behinderung (0,34). Für Lebensqualität liegt eine negative Korrelati-on vor (-0,54). Bei hohem Signifikanzniveau (p=0,001) erhöhen Behinderung und Depression das Risiko für MS-bezogene Stigmatisierung im Vergleich zu einer ge-sunden Referenzgruppe: Behinderung erhöht es jährlich um 38% und Depression um 5%. Mit jedem weiteren Lebensjahr der Patient*innen sinkt das Stigma-Risiko um 2,7 %. Bei Menschen mit Fatigue steigt das Risiko stigmatisiert zu werden jähr-lich um 2%.
Durch die vorliegende Arbeit konnten Ergebnisse internationaler Studien hinsicht-lich der Zusammenhänge zwischen Depression und Behinderung zu Stigma bestä-tigt werden. Ebenfalls konnte bestätigt werden, dass der Stigmatisierungsgrad bei MS eher gering ist. Der Grad der Behinderung beeinflusst das Stigmatisierungser-leben am stärksten, was sich häufiger in Form von internalisiertem statt öffentlichem Stigma äußert. Dass Jüngere eher betroffen sind, kann mit dem Vorkommen von erwartetem Stigma bei Unvorhersagbarkeit der Diagnose erklärt werden. Das erwar-tete Stigma kann schließlich besonders bei jüngeren Patient*innen zur Verheimli-chung der Erkrankung führen. Dies wurde im Prozess dieser Arbeit herausgearbei-tet und sollte in weiteren Studien noch eingehender untersucht werden. Da im Alter Stigmatisierung vorliegt und Behinderung ebenso wie behinderungsbezogenes Stigma mit dem Alter zunehmen, liegt die Vermutung nahe, dass im Alter andere Formen von Stigma eine Rolle spielen.
Separating EEG correlates of stress: Cognitive effort, time pressure, and social‐evaluative threat
(2022)
Abstract
The prefrontal cortex is a key player in stress response regulation. Electroencephalographic (EEG) responses, such as a decrease in frontal alpha and an increase in frontal beta power, have been proposed to reflect stress‐related brain activity. However, the stress response is likely composed of different parts such as cognitive effort, time pressure, and social‐evaluative threat, which have not been distinguished in previous studies. This distinction, however, is crucial if we aim to establish reliable tools for early detection of stress‐related conditions and monitoring of stress responses throughout treatment. This randomized cross‐over study (N = 38) aimed to disentangle EEG correlates of stress. With linear mixed models accounting for missing values in some conditions, we found a decrease in frontal alpha and increase in beta power when performing the Paced Auditory Serial Addition Test (PASAT; cognitive effort; n = 32) compared to resting state (n = 33). No change in EEG power was found when the PASAT was performed under time pressure (n = 29) or when adding social‐evaluative threat (video camera; n = 29). These findings suggest that frontal EEG power can discriminate stress from resting state but not more fine‐grained differences of the stress response.
Abstract
Objective
This study was undertaken to calculate epilepsy‐related direct, indirect, and total costs in adult patients with active epilepsy (ongoing unprovoked seizures) in Germany and to analyze cost components and dynamics compared to previous studies from 2003, 2008, and 2013. This analysis was part of the Epi2020 study.
Methods
Direct and indirect costs related to epilepsy were calculated with a multicenter survey using an established and validated questionnaire with a bottom‐up design and human capital approach over a 3‐month period in late 2020. Epilepsy‐specific costs in the German health care sector from 2003, 2008, and 2013 were corrected for inflation to allow for a valid comparison.
Results
Data on the disease‐specific costs for 253 patients in 2020 were analyzed. The mean total costs were calculated at €5551 (±€5805, median = €2611, range = €274–€21 667) per 3 months, comprising mean direct costs of €1861 (±€1905, median = €1276, range = €327–€13 158) and mean indirect costs of €3690 (±€5298, median = €0, range = €0–€11 925). The main direct cost components were hospitalization (42.4%), antiseizure medication (42.2%), and outpatient care (6.2%). Productivity losses due to early retirement (53.6%), part‐time work or unemployment (30.8%), and seizure‐related off‐days (15.6%) were the main reasons for indirect costs. However, compared to 2013, there was no significant increase of direct costs (−10.0%), and indirect costs significantly increased (p < .028, +35.1%), resulting in a significant increase in total epilepsy‐related costs (p < .047, +20.2%). Compared to the 2013 study population, a significant increase of cost of illness could be observed (p = .047).
Significance
The present study shows that disease‐related costs in adult patients with active epilepsy increased from 2013 to 2020. As direct costs have remained constant, this increase is attributable to an increase in indirect costs. These findings highlight the impact of productivity loss caused by early retirement, unemployment, working time reduction, and seizure‐related days off.
IntroductionWith the worldwide increase of life expectancy leading to a higher proportion of older adults experiencing age-associated deterioration of cognitive abilities, the development of effective and widely accessible prevention and therapeutic measures has become a priority and challenge for modern medicine. Combined interventions of cognitive training and transcranial direct current stimulation (tDCS) have shown promising results for counteracting age-associated cognitive decline. However, access to clinical centres for repeated sessions is challenging, particularly in rural areas and for older adults with reduced mobility, and lack of clinical personnel and hospital space prevents extended interventions in larger cohorts. A home-based and remotely supervised application of tDCS would make the treatment more accessible for participants and relieve clinical resources. So far, studies assessing feasibility of combined interventions with a focus on cognition in a home-based setting are rare. With this study, we aim to provide evidence for the feasibility and the effects of a multisession home-based cognitive training in combination with tDCS on cognitive functions of healthy older adults.Methods and analysisThe TrainStim-Home trial is a monocentric, randomised, double-blind, placebo-controlled study. Thirty healthy participants, aged 60–80 years, will receive 2 weeks of combined cognitive training and anodal tDCS over left dorsolateral prefrontal cortex (target intervention), compared with cognitive training plus sham stimulation. The cognitive training will comprise a letter updating task, and the participants will be stimulated for 20 min with 1.5 mA. The intervention sessions will take place at the participants’ home, and primary outcome will be the feasibility, operationalised by two-thirds successfully completed sessions per participant. Additionally, performance in the training task and an untrained task will be analysed.Ethics and disseminationEthical approval was granted by the ethics committee of the University Medicine Greifswald. Results will be available through publications in peer-reviewed journals and presentations at national and international conferences.Trial registration numberNCT04817124.
IntroductionA substantial number of patients diagnosed with COVID-19 experience long-term persistent symptoms. First evidence suggests that long-term symptoms develop largely independently of disease severity and include, among others, cognitive impairment. For these symptoms, there are currently no validated therapeutic approaches available. Cognitive training interventions are a promising approach to counteract cognitive impairment. Combining training with concurrent transcranial direct current stimulation (tDCS) may further increase and sustain behavioural training effects. Here, we aim to examine the effects of cognitive training alone or in combination with tDCS on cognitive performance, quality of life and mental health in patients with post-COVID-19 subjective or objective cognitive impairments.Methods and analysisThis study protocol describes a prospective randomised open endpoint-blinded trial. Patients with post-COVID-19 cognitive impairment will either participate in a 3-week cognitive training or in a defined muscle relaxation training (open-label interventions). Irrespective of their primary intervention, half of the cognitive training group will additionally receive anodal tDCS, all other patients will receive sham tDCS (double-blinded, secondary intervention). The primary outcome will be improvement of working memory performance, operationalised by an n-back task, at the postintervention assessment. Secondary outcomes will include performance on trained and untrained tasks and measures of health-related quality of life at postassessment and follow-up assessments (1 month after the end of the trainings).Ethics and disseminationEthical approval was granted by the Ethics Committee of the University Medicine Greifswald (number: BB 066/21). Results will be available through publications in peer-reviewed journals and presentations at national and international conferences.Trial registration numberNCT04944147.
Background:
Epilepsy development during the course of multiple sclerosis (MS) is considered to be the result of cortical pathology. However, no long-term data exist on whether epilepsy in MS also leads to increasing disability over time.
Objective:
To examine if epilepsy leads to more rapid disease progression.
Methods:
We analyzed the data of 31,052 patients on the German Multiple Sclerosis Register in a case–control study.
Results:
Secondary progressive disease course (odds ratio (OR) = 2.23), age (OR = 1.12 per 10 years), and disability (OR = 1.29 per Expanded Disability Status Scale (EDSS) point) were associated with the 5-year prevalence of epilepsy. Patients who developed epilepsy during the course of the disease had a higher EDSS score at disease onset compared to matched control patients (EDSS 2.0 vs 1.5), progressed faster in each dimension, and consequently showed higher disability (EDSS 4.4 vs 3.4) and lower employment status (40% vs 65%) at final follow-up. After 15 years of MS, 64% of patients without compared to 54% of patients with epilepsy were not severely limited in walking distance.
Conclusion:
This work highlights the association of epilepsy on disability progression in MS, and the need for additional data to further clarify the underlying mechanisms.
ObjectiveTo evaluate individual and group long-term efficacy and safety of erenumab in individuals with episodic migraine (EM) for whom 2–4 prior preventatives had failed.MethodsParticipants completing the 12-week double-blind treatment phase (DBTP) of the LIBERTY study could continue into an open-label extension phase (OLEP) receiving erenumab 140 mg monthly for up to 3 years. Main outcomes assessed at week 112 were: ≥50%, ≥75% and 100% reduction in monthly migraine days (MMD) as group responder rate and individual responder rates, MMD change from baseline, safety and tolerability.ResultsOverall 240/246 (97.6%) entered the OLEP (118 continuing erenumab, 122 switching from placebo). In total 181/240 (75.4%) reached 112 weeks, 24.6% discontinued, mainly due to lack of efficacy (44.0%), participant decision (37.0%) and adverse events (AEs; 12.0%). The ≥50% responder rate was 57.2% (99/173) at 112 weeks. Of ≥50% responders at the end of the DBTP, 36/52 (69.2%) remained responders at ≥50% and 22/52 (42.3%) at >80% of visits. Of the non-responders at the end of the DBTP, 60/185 (32.4%) converted to ≥50% responders in at least half the visits and 24/185 (13.0%) converted to ≥50% responders in >80% of visits. Change from baseline at 112 weeks in mean (SD) MMD was −4.2 (5.0) days. Common AEs (≥10%) were nasopharyngitis, influenza and back pain.ConclusionsEfficacy was sustained over 112 weeks in individuals with difficult-to-treat EM for whom 2–4 prior migraine preventives had failed. Erenumab treatment was safe and well tolerated, in-line with previous studies.Trial registration number
NCT03096834
BackgroundWhile meta-analyses confirm treatment for chronic post-stroke aphasia is effective, a lack of comparative evidence for different interventions limits prescription accuracy. We investigated whether Constraint-Induced Aphasia Therapy Plus (CIAT-plus) and/or Multimodality Aphasia Therapy (M-MAT) provided greater therapeutic benefit compared with usual community care and were differentially effective according to baseline aphasia severity.MethodsWe conducted a three-arm, multicentre, parallel group, open-label, blinded endpoint, phase III, randomised-controlled trial. We stratified eligible participants by baseline aphasia on the Western Aphasia Battery-Revised Aphasia Quotient (WAB-R-AQ). Groups of three participants were randomly assigned (1:1:1) to 30 hours of CIAT-Plus or M-MAT or to usual care (UC). Primary outcome was change in aphasia severity (WAB-R-AQ) from baseline to therapy completion analysed in the intention-to-treat population. Secondary outcomes included word retrieval, connected speech, functional communication, multimodal communication, quality of life and costs.ResultsWe analysed 201 participants (70 in CIAT-Plus, 70 in M-MAT and 61 in UC). Aphasia severity was not significantly different between groups at postintervention: 1.05 points (95% CI −0.78 to 2.88; p=0.36) UC group vs CIAT-Plus; 1.06 points (95% CI −0.78 to 2.89; p=0.36) UC group vs M-MAT; 0.004 points (95% CI −1.76 to 1.77; p=1.00) CIAT-Plus vs M-MAT. Word retrieval, functional communication and communication-related quality of life were significantly improved following CIAT-Plus and M-MAT. Word retrieval benefits were maintained at 12-week follow-up.ConclusionsCIAT-Plus and M-MAT were effective for word retrieval, functional communication, and quality of life, while UC was not. Future studies should explore predictive characteristics of responders and impacts of maintenance doses.Trial registration numberACTRN 2615000618550.
Background
The Symbol Digit Modalities Test (SDMT) is most frequently used to test processing speed in patients with multiple sclerosis (MS). Functional imaging studies emphasize the importance of frontal and parietal areas for task performance, but the influence of frontoparietal tracts has not been thoroughly studied. We were interested in tract-specific characteristics and their association with processing speed in MS patients.
Methods
Diffusion tensor imaging was obtained in 100 MS patients and 24 healthy matched controls to compare seed-based tract characteristics descending from the superior parietal lobule [Brodman area 7A (BA7A)], atlas-based tract characteristics from the superior longitudinal fasciculus (SLF), and control tract characteristics from the corticospinal tract (CST) and their respective association with ability on the SDMT.
Results
Patients had decreased performance on the SDMT and decreased white matter volume (each p < 0.05). The mean fractional anisotropy (FA) for the BA7A tract and CST (p < 0.05), but not the SLF, differed between MS patients and controls. Furthermore, only the FA of the SLF was positively associated with SDMT performance even after exclusion of the lesions within the tract (r = 0.25, p < 0.05). However, only disease disability and total white matter volume were associated with information processing speed in a linear regression model.
Conclusions
Processing speed in MS is associated with the structural integrity of frontoparietal white matter tracts.
Background
Fatigue is a common symptom in patients with multiple sclerosis. Several studies suggest that outdoor temperature can impact fatigue severity, but a systematic study of seasonal variations is lacking.
Methods
Fatigue was assessed with the Fatigue Scale for Motor and Cognitive Functions (FSMC) in a temperate climatic zone with an average outdoor temperature of 8.8°C. This study included 258 patients with multiple sclerosis from 572 visits temporally distributed over the year. The data were adjusted for age, sex, cognition, depression, disease severity, and follow-up time. Linear regression models were performed to determine whether the temporal course of fatigue was time-independent, linearly time dependent, or non-linearly time dependent.
Results
Fatigue was lowest during January (mean FSMC: 49.84) and highest during August (mean FSMC: 53.88). The regression analysis showed the best fit with a model that included months + months2, which was a non-linear time dependency. Mean FSMC per month correlated significantly with the average monthly temperature (ρ = 0.972; p < 0.001).
Conclusion
In multiple sclerosis, fatigue showed a natural temporal fluctuation. Fatigue was higher during summer compared to winter, with a significant relationship of fatigue with outdoor temperature. This finding should be carefully taken into account when clinically monitoring patients over time to not interpret higher or lower scores independent of seasonal aspects.
Metrological methods for word learning list tests can be developed with an information theoretical approach extending earlier simple syntax studies. A classic Brillouin entropy expression is applied to the analysis of the Rey’s Auditory Verbal Learning Test RAVLT (immediate recall), where more ordered tasks—with less entropy—are easier to perform. The findings from three case studies are described, including 225 assessments of the NeuroMET2 cohort of persons spanning a cognitive spectrum from healthy older adults to patients with dementia. In the first study, ordinality in the raw scores is compensated for, and item and person attributes are separated with the Rasch model. In the second, the RAVLT IR task difficulty, including serial position effects (SPE), particularly Primacy and Recency, is adequately explained (Pearson’s correlation R=0.80) with construct specification equations (CSE). The third study suggests multidimensionality is introduced by SPE, as revealed through goodness-of-fit statistics of the Rasch analyses. Loading factors common to two kinds of principal component analyses (PCA) for CSE formulation and goodness-of-fit logistic regressions are identified. More consistent ways of defining and analysing memory task difficulties, including SPE, can maintain the unique metrological properties of the Rasch model and improve the estimates and understanding of a person’s memory abilities on the path towards better-targeted and more fit-for-purpose diagnostics.
Most children use their fingers when learning to count and calculate. These sensorimotor experiences were argued to underlie reported behavioral associations of finger gnosis and counting with mathematical skills. On the neural level, associations were assumed to originate from overlapping neural representations of fingers and numbers. This study explored whether finger-based training in children would lead to specific neural activation in the sensorimotor cortex, associated with finger movements, as well as the parietal cortex, associated with number processing, during mental arithmetic. Following finger-based training during the first year of school, trained children showed finger-related arithmetic effects accompanied by activation in the sensorimotor cortex potentially associated with implicit finger movements. This indicates embodied finger-based numerical representations after training. Results for differences in neural activation between trained children and a control group in the IPS were less conclusive. This study provides the first evidence for training-induced sensorimotor plasticity in brain development potentially driven by the explicit use of fingers for initial arithmetic, supporting an embodied perspective on the representation of numbers.
Background: Oligoclonal bands represent intrathecal immunoglobulin G (IgG) synthesis and play an important role in the diagnosis of multiple sclerosis (MS). Kappa free light chains (KFLC) are increasingly recognized as an additional biomarker for intrathecal Ig synthesis. However, there are limited data on KFLC in neurological diseases other than MS. Methods: This study, conducted at two centers, retrospectively enrolled 346 non-MS patients. A total of 182 patients were diagnosed with non-inflammatory and 84 with inflammatory neurological diseases other than MS. A further 80 patients were classified as symptomatic controls. Intrathecal KFLC production was determined using different approaches: KFLC index, Reiber’s diagram, Presslauer’s exponential curve, and Senel’s linear curve. Results: Matching results of oligoclonal bands and KFLC (Reiber’s diagram) were frequently observed (93%). The Reiber’s diagram for KFLC detected intrathecal KFLC synthesis in an additional 7% of the patient samples investigated (4% non-inflammatory; 3% inflammatory), which was not found by oligoclonal band detection. Conclusions: The determination of both biomarkers (KFLC and oligoclonal bands) is recommended for routine diagnosis and differentiation of non-inflammatory and inflammatory neurological diseases. Due to the high sensitivity and physiological considerations, the assessment of KFLC in the Reiber’s diagram should be preferred to other evaluation methods.
Neuronal cells are specialists for rapid transfer and translation of information. Their electrical properties relay on a precise regulation of ion levels while their communication via neurotransmitters and neuropeptides depends on a high protein and lipid turnover. The endoplasmic Reticulum (ER) is fundamental to provide these necessary requirements for optimal neuronal function. Accumulation of misfolded proteins in the ER lumen, reactive oxygen species and exogenous stimulants like infections, chemical irritants and mechanical harm can induce ER stress, often followed by an ER stress response to reinstate cellular homeostasis. Imbedded between glial-, endothelial-, stromal-, and immune cells neurons are constantly in communication and influenced by their local environment. In this review, we discuss concepts of tissue homeostasis and innate immunity in the central and peripheral nervous system with a focus on its influence on ER stress, the unfolded protein response, and implications for health and disease.
The Role of Vascular Risk Factors in Post-Stroke Delirium: A Systematic Review and Meta-Analysis
(2022)
Vascular risk factors may predispose to post-stroke delirium (PSD). A systematic review and meta-analysis were performed by searching PubMed, Web of Science, and Scopus. The primary outcome was the prevalence of vascular risk factors in PSD vs. non-PSD patients. Odds ratios (ORs) with 95% confidence intervals (CIs) and mean differences (MDs) with 95% CIs were calculated for categorical and continuous variables, respectively. Fixed effects or random effects models were used in case of low- or high-statistical heterogeneity, respectively. We found an increased prevalence of atrial fibrillation (OR = 1.74, p = 0.0004), prior stroke (OR = 1.48, p < 0.00001), coronary artery disease (OR = 1.48, p < 0.00001), heart failure (OR = 2.01, p < 0.0001), and peripheral vascular disease (OR = 2.03, p < 0.00001) in patients with vs. without PSD. PSD patients were older (MD = 5.27 y, p < 0.00001) compared with their non-PSD counterparts. Advanced age, atrial fibrillation, prior stroke, coronary artery disease, heart failure, and peripheral vascular disease appeared to be significantly associated with PSD.
Background and aim
To report the six-month safety analyses among patients enrolled in the “Physical Fitness Training in Subacute Stroke—PHYS-STROKE” trial and identify underlying risk factors associated with serious adverse events.
Methods
We performed a pre-specified safety analysis of a multicenter, randomized controlled, endpoint-blinded trial comprising 200 patients with moderate to severe subacute stroke (days 5–45 after stroke) that were randomly assigned (1:1) to receive either aerobic, bodyweight supported, treadmill-based training (n = 105), or relaxation sessions (n = 95, control group). Each intervention session lasted for 25 min, five times weekly for four weeks, in addition to standard rehabilitation therapy. Serious adverse events defined as cerebro- and cardiovascular events, readmission to hospital, and death were assessed during six months of follow-up. Incident rate ratios (IRR) were calculated, and Poisson regression analyses were conducted to identify risk factors for serious adverse events and to test the association with aerobic training.
Results
Six months after stroke, 50 serious adverse events occurred in the trial with a higher incidence rate (per 100 patient-months) in the training group compared to the relaxation group (6.31 vs. 3.22; IRR 1.70, 95% CI 0.96 to 3.12). The association of aerobic training with serious adverse events incidence rates were modified by diabetes mellitus (IRR for interaction: 7.10, 95% CI 1.56 to 51.24) and by atrial fibrillation (IRR for interaction: 4.37, 95% CI 0.97 to 31.81).
Conclusions
Safety analysis of the PHYS-STROKE trial found a higher rate of serious adverse events in patients randomized to aerobic training compared to control within six months after stroke. Exploratory analyses found an association between serious adverse events occurrence in the aerobic training group with pre-existing diabetes mellitus and atrial fibrillation which should be further investigated in future trials.
Data access statement
The raw data and analyses scripts are provided by the authors on a secure online repository for reproduction of reported findings.
In der Vergangenheit ergaben sich aus zahlreichen Untersuchungen vermehrt Hinweise für eine wichtige Rolle von Insulin-like Growth Factor-1 (IGF-1) für das Überleben, den Erhalt, sowie das Differenzierungsverhalten von verschiedenen Zelltypen. Hierbei wurden Effekte von IGF-1 auf Zellen unterschiedlicher Gewebearten, u. a. auch des Zentralen Nervensystems, festgestellt. Für viele der beobachteten IGF-1-Wirkungen konnte eine Vermittlung über den PI3-Kinase/Akt/NF-κB-Signalweg bestätigt werden. Aber auch der ERK-Signal- weg scheint an der IGF-1-vermittelten Signaltransduktion beteiligt zu sein.
Aus früheren Untersuchungen der eigenen Arbeitsgruppe mit dem auch in der vorliegenden Arbeit verwendeten Zellsystem ist bekannt, dass der PI3-Kinase/Akt/NF-κB-Signalweg die astrogliale Differenzierung der fetalen mesenzephalen neuralen Precursorzellen („fetal mesencephalic precursor cells“ [fmNPCs]) maßgeblich beeinflusst.
Hingegen wird die durch Interleukin-1β (IL-1β) induzierte dopaminerge Differenzierung von fmNPCs über den ERK/MAP-Kinase-Signalweg vermittelt und durch die Hemmung des PI3-Kinase/Akt/NF-κB-Signalweges erleichtert.
Die vorliegende Arbeit beschäftigte sich vor diesem Hintergrund mit dem Einfluss von IGF-1 auf langzeitexpandierte fmNPCs der Ratte. Dazu wurde das in vitro-Modell der primären Dissoziationskultur aus mesenzephalem Gewebe 14 Tage alter embryonaler Ratten herangezogen. Es wurde der Frage nachgegangen, inwieweit IGF-1 die Überlebensfähigkeit, das Proliferationspotenzial, die Expression des IGF-1-Rezeptors, sowie das neuronale, astrogliale und oligodendrogliale Differenzierungsverhalten dieser fmNPCs der Ratte beeinflussen kann. Weiterhin sollten an der Differenzierung beteiligte intrazelluläre Signaltransduktionsmechanismen näher charakterisiert werden.
Bei der Untersuchung der Überlebensfähigkeit der Zellen zeigte sich, dass die Behandlung mit IGF-1 (50 ng/ml) sowohl während der Expansion als auch während der Differenzierung über 24 h und 72 h im Vergleich zur unbehandelten Kontrollreihe zu einer signifikanten Steigerung der Überlebensrate führte. Dieser überlebenssteigernde Effekt von IGF-1 auf die fmNPCs konnte durch die gleichzeitige Behandlung mit AG 1024 – einem Inhibitor des IGF-1-Rezeptors – während der Differenzierung, nicht jedoch während der Expansion, aufgehoben werden. Dies spricht für eine besondere Rolle von IGF-1 für den Differenzierungsprozess der fmNPCs, welche folglich während ihrer Differenzierung in höherem Maße auf die Expression des IGF-1-Rezeptors angewiesen sind als während der Expansion. Übereinstimmend mit diesem Ergebnis zeigte sich bei den Untersuchungen zur Expression des IGF-1-Rezeptors eine signifikante Hochregulierung der IGF-1-Rezeptor-Expression während der Differenzierung im Vergleich zur Expansion der Zellen. Weiterhin konnte unter IGF-1-Behandlung und Differenzierung der Zellen wiederum eine signifikante Hochregulierung der IGF-1-Rezeptor-Expression im Vergleich zur Differenzierung unter Kontrollbedingungen beobachtet werden.
Bei den Untersuchungen zum Einfluss von IGF-1 auf den Erhalt des Proliferationspotentials der fmNPCs konnte bezüglich der Ki-67-markierten Zellen nach der Expansion über 72 h ein signifikanter Effekt von IGF-1 beobachtet werden, mit einer höheren Anzahl Ki-67-positiver Zellen im Vergleich zur Kontrollreihe. Allerdings konnte dieser, das Proliferationspotential steigernde, Effekt nach der Expansion über 24 h und anschließender Markierung der Zellen mit BrdU nicht beobachtet werden. Trotzdem zeigten sich im Vergleich zur Kontrolle mehr Zellen mit Proliferationspotential (BrdU-positiv) und somit eine Tendenz in Richtung des Ergebnisses nach der Expansion über 72 h.
Ein weiterer Fokus der vorliegenden Arbeit lag auf der Untersuchung des Einflusses von IGF-1 auf das neuronale und gliale Differenzierungsverhalten von fmNPCs. Hierbei zeigte sich, dass die Behandlung der Zellen mit IGF-1 über einen Differenzierungszeitraum von 7 d zu signifikant mehr Zellen mit neuronalem Phänotyp (MAP2-positiv) im Vergleich zur Kontrollreihe führte. Bezüglich der astroglialen und oligodendroglialen Differenzierung der fmNPCs konnte eine Behandlung mit IGF-1 keine signifikanten Ergebnisse zeigen.
Schließlich beschäftigte sich die vorliegende Arbeit auch damit, die an der Differenzierung beteiligten intrazellulären Signaltransduktionsmechanismen näher zu charakterisieren. Dazu wurden ELISA-Experimente durchgeführt, um die Aktivierung ausgewählter Kinasen und Transkriptionsfaktoren in der Frühphase der Differenzierung der fmNPCs zu bestimmen. Hierbei zeigte sich unter IGF-1-Behandlung, im Vergleich zur unbehandelten Kontrollreihe, ein Abfall der Aktivität der PI3-Kinase, Akt und von NF-κB mit signifikanten Werten nach 0 h, 3 h und 6 h für die PI3-Kinase, nach 1 h und 6 h für Akt und nach 0,5 h für NF-κB. Im Gegensatz dazu konnte die Aktivität der ERK unter IGF-1-Behandlung nach 1 h, 3 h und 6 h signifikant gesteigert werden. Für die p38 MAP-Kinase zeigte sich nach 3 h Behandlung mit IGF-1 eine signifikante Reduktion der Aktivität im Vergleich zur Kontrollreihe. Auf die JNK-Aktivität zeigte die Behandlung mit IGF-1 hingegen keinen signifikanten Effekt.
Die Ergebnisse der vorliegenden Arbeit lassen folgende Schlussfolgerungen zu:
• IGF-1 erhöht die Überlebensrate von fmNPCs während deren Expansion und Differenzierung in vitro über 24 h und 72 h.
• AG 1024 inhibiert diesen überlebenssteigernden Effekt während der Differenzierung von fmNPCs, nicht aber während deren Expansion.
• IGF-1 steigert das Proliferationspotenzial von fmNPCs in vitro.
• IGF-1 induziert die Neurogenese von fmNPCs in vitro.
• Effekte von IGF-1 auf die fmNPCs werden vermittelt über den IGF-1-Rezeptor, welcher während der Differenzierung durch die Behandlung mit IGF-1 hochreguliert wird.
• IGF-1 führt in der weiteren zellulären Signaltransduktion während der Differenzierung von fmNPCs zu einer Herunterregulierung des PI3-Kinase/Akt/NF-κB-Signalwegs und zu einer Hochregulierung von ERK1/2 des MAP-Kinase-Signalwegs.
MRI-based vessel size imaging (VSI) allows for in-vivo assessment of cerebral microvasculature and perfusion. This exploratory analysis of vessel size (VS) and density (Q; both assessed via VSI) in the subacute phase of ischemic stroke involved sixty-two patients from the BAPTISe cohort (‘Biomarkers And Perfusion--Training-Induced changes after Stroke’) nested within a randomized controlled trial (intervention: 4-week training vs. relaxation). Relative VS, Q, cerebral blood volume (rCBV) and –flow (rCBF) were calculated for: ischemic lesion, perilesional tissue, and region corresponding to ischemic lesion on the contralateral side (mirrored lesion). Linear mixed-models detected significantly increased rVS and decreased rQ within the ischemic lesion compared to the mirrored lesion (coefficient[standard error]: 0.2[0.08] p = 0.03 and −1.0[0.3] p = 0.02, respectively); lesion rCBF and rCBV were also significantly reduced. Mixed-models did not identify time-to-MRI, nor training as modifying factors in terms of rVS or rQ up to two months post-stroke. Larger lesion VS was associated with larger lesion volumes (β 34, 95%CI 6.2–62; p = 0.02) and higher baseline NIHSS (β 3.0, 95%CI 0.49–5.3;p = 0.02), but was not predictive of six-month outcome. In summary, VSI can assess the cerebral microvasculature and tissue perfusion in the subacute phases of ischemic stroke, and may carry relevant prognostic value in terms of lesion volume and stroke severity.
Free light chains (FLC) are a promising biomarker to detect intrathecal inflammation in patients with inflammatory central nervous system (CNS) diseases, including multiple sclerosis (MS). The diagnostic use of this biomarker, in particular the kappa isoform of FLC (“KFLC”), has been investigated for more than 40 years. Based on an extensive literature review, we found that an agreement on the correct method for evaluating KFLC concentrations has not yet been reached. KFLC indices with varying cut-off values and blood-CSF-barrier (QAlbumin) related non-linear formulas for KFLC interpretation have been investigated in several studies. All approaches revealed high diagnostic sensitivity and specificity compared with the oligoclonal bands, which are considered the gold standard for the detection of intrathecally synthesized immunoglobulins. Measurement of KFLC is fully automated, rater-independent, and has been shown to be stable against most pre-analytic influencing factors. In conclusion, the determination of KFLC represents a promising diagnostic approach to show intrathecal inflammation in neuroinflammatory diseases. Multicenter studies are needed to show the diagnostic sensitivity and specificity of KFLC in MS by using the latest McDonald criteria and appropriate, as well as standardized, cut-off values for KFLC concentrations, preferably considering non-linear formulas such as Reiber’s diagram.
One of the great challenges the world faces in terms of health care is the increasing number of
people living with neuro-disabilities that affect their ability to participate in societal activities.
Various neurological conditions such as stroke, multiple sclerosis, or Parkinson’s disease, to name
just a few, change cognitive, sensory, or motor capacities, alter the emotional well-being of those
affected, and lead to disability in their everyday lives.
Over the last few decades, aging populations and reduced mortality in many regions of the world
have increased the number of people living with neuro-disabilities considerably, an effect that is
still ongoing (1): for 2017, the worldwide prevalence of stroke (thousands) has been estimated to
be as high as 104178.7 (95% confidence interval, 95% CI 98454.0–110125.0), and years lived with
disabilities (YLD) (counts in thousands) caused by stroke were reported to amount to 18695.4
(95% CI 13,574–23686.9). The stroke-related increase in YLD (percentage change in counts)
was 40% (95% CI 38.4–41.4) from 1990 to 2007 and another 43.6% (39.6–47.8) during only 10
years from 2007 to 2017. The numbers are similarly impressive for other neurological disorders
(i.e., dementias, Parkinson’s disease, epilepsy, multiple sclerosis, motor neuron disease, headache
disorders, and others). Taken together, their worldwide prevalence (in thousands) in 2017 was
3121435.3 (95% CI 2951124.5–3316268.0), while YLD (thousands) in 2017 were 3121435.3 (95%
CI 2951124.5–3316268.0), with an increase in YLD by 35.1% (95% CI 31.9–38.1) from 1990 to 2007
and by a further 17.8% (95% CI 15.8–20.2) from 2007 to 2017.
These numbers not only demonstrate the huge global burden of disease and prevailing
neuro-disabilities, but they indicate a considerable increase in the number of people living with
neuro-disabilities with an accelerating dynamic over time (for stroke).