[Biobanking in Psychiatry]. / Biobanking in der Psychiatrie.

Medical biobanking is concerned with establishing and maintaining large-scale repositories of biological specimens combined with comprehensive archives of clinical and biographical information on donors. This aims for controlled high and consistent quality of specimens for future biomedical research. One major objective is to assemble multiple blood components for various types of biochemical analysis and experimentation including different isolated cell types. With proper cryo-conservation, blood-derived cells can be conserved and revitalized after thawing and employed as in-vitro cell models carrying specific biological traits of donors. Optimizing pre-analytical methods can reduce pre-analytical variance thereby reducing imprecision of analytical data. This is particularly valuable for multivariate analyses of biological systems ("omics") and biomarker research. Introducing biobanking to psychiatry carries the challenge of making diagnostic allocation more compatible with biological entities than is achieved with current diagnostic categories of ICD-10 or DSM-V. Diagnostic or transdiagnostic subgroups can be stratified using biologically anchored clinical criteria. An important ethical issue of biobanking is the need for broad consent by the donors for specimen use in not yet defined future research projects. The organizational, logistic and financial costs of establishing and maintaining a biobank are considerable, but seem well warranted in view of the gainable advances in biomedical research quality, translations and clinical applications.

Oxytocin reactivity to an emotional challenge paradigm and its relation to social-cognitive functions in healthy volunteers.

The neuropeptide oxytocin (OT) is known to be an important modulator of social cognition. It has been shown that lower OT plasma concentrations are linked to impairments in social cognition. Studies have also shown that intranasal OT may enhance social-cognitive abilities in healthy subjects. We hypothesize that, besides baseline OT concentrations, the reactivity of the OT system may have an important role in social-cognitive functioning of individuals. In the present study, we explored if an emotional challenge paradigm is suitable to elicit OT release into plasma to make the reactivity of the OT system measurable. Therefore, 20 healthy male volunteers watched an emotional film clip, showing another person in pain during a severe dentist's treatment, while blood draws were conducted pre and post challenge. OT concentrations in plasma were measured by ELISA after solid phase extraction from plasma. OT plasma concentrations at baseline were significantly negatively correlated to an empathetic rating of our film clip and to measures of emotional empathy for positive and negative emotions, whereas the difference between post-challenge value and baseline was significantly positively correlated with the latter measures. Our data thus show that a short emotional video can be successfully employed as a challenge paradigm for eliciting an increase of peripheral OT in healthy male subjects. Calculating the relative OT change post- vs. pre-challenge may give a measure of OT reactivity. The combination of low peripheral OT at baseline with high OT reactivity may be a psychoendocrine trait that is linked to higher emotional functioning.

Genetic susceptibility for air pollution-induced airway inflammation in the SALIA study.

BACKGROUND: Long-term air pollution exposure has been associated with chronic inflammation providing a link to the development of chronic health effects. Furthermore, there is evidence that pathways activated by endoplasmatic reticulum (ER) stress induce airway inflammation and thereby play an important role in the pathogenesis of inflammatory diseases. OBJECTIVE: We investigated the role of genetic variation of the ER stress pathway on air pollution-induced inflammation. METHODS: We used the follow-up examination of the German SALIA study (N=402, age 68-79 years). Biomarkers of inflammation were determined in induced sputum. We calculated biomarker-specific weighted genetic risk scores (GRS) out of eight ER stress related single nucleotide polymorphisms and tested their interaction with PM2.5, PM2.5 absorbance, PM10 and NO2 exposure on inflammation by adjusted linear regression. RESULTS: Genetic variation of the ER stress pathway was associated with higher concentration of inflammation-related biomarkers (levels of leukotriene (LT)B4, tumor necrosis factor-α (TNF-α), the total number of cells and nitric oxide (NO) derivatives). Furthermore, we observed a significant interaction between air pollution exposure and the ER stress risk score on the concentration of inflammation-related biomarkers. The strongest gene-environment interaction was found for LTB4 (PM2.5: p-value=0.002, PM2.5 absorbance: p-value=0.002, PM10: p-value=0.001 and NO2: p-value=0.004). Women with a high GRS had a 38% (95%-CI: 16-64%) higher LTB4 level for an increase of 2.06µg/m³(IQR) in PM2.5 (no associations in women with a low GRS). CONCLUSION: These results indicate that genetic variation in the ER stress pathway might play a role in air pollution induced inflammation in the lung.

Estrogen receptor beta polymorphisms and cognitive performance in women: associations and modifications by genetic and environmental influences.

Genetic and environmental risk factors contribute to the pathogenesis of Alzheimer's dementia. Besides known genetic risk factors like the apolipoprotein (APO) Eε4 allele, single nuclear polymorphisms (SNPs) of the estrogen receptors (ESRs) are candidate genetic risk factors, while air pollution represents an environmental risk factor for dementia. Effects of these risk factors and their interaction were investigated in the SALIA cohort of 834 non-demented elderly women. Cognitive function was assessed by the CERAD-plus test battery. Air pollution was estimated by land use regression (LUR) models. Genotyping was carried out for nine ESR1 and ESR2 SNPs and two ApoE SNPs. Carriers of minor ESR2 alleles showed significantly reduced cognitive performance in the CERAD total score with most pronounced deficits in semantic memory (rs1256062, rs10144225, and rs2274705) and executive function (rs1256062). The minor allele effects of ESR2 were stronger in carriers of APOEε4 for the cognitive domain 'executive function' (p value of interaction 0.023 for rs1256062). The investigated ESR1 SNPs were not associated with cognition. Furthermore, we found a significant gene-environment interaction between the ESR2 SNP rs1256062 and air pollution on cognition. Carriers of two major alleles of rs1256062 were more susceptible for an air pollution-induced decrease in performance of 'figure copying' than carriers of minor alleles (p value of interaction, e.g., 0.031 for PM2.5). In conclusion, ESR2 but not ESR1 minor alleles were associated with lower cognitive performance in elderly women with an indication of a gene-gene interaction with APOEε4. We also found indications for gene-environment interactions of ESR2 with traffic-related air pollution exposure on cognitive performance.

Association of air pollution with cognitive functions and its modification by APOE gene variants in elderly women.

BACKGROUND: Epidemiological studies have shown effects of long-term exposure to air pollution on cardiovascular and respiratory health. However, studies investigating the effects of air pollution on cognition and brain function are limited. We investigated if neurocognitive functions are associated with air pollution exposure and whether apolipoprotein E (ApoE) alleles modify the association of air pollution exposure with cognition. METHODS: We investigated 789 women from the SALIA cohort during the 22-year follow-up examination (2008-2009). Exposure to particulate matter (PM) size fractions and nitrogen oxides (NOx) were assigned to home addresses. Traffic indicators were used to assess residential proximity to high traffic load. Level of cognitive performance was assessed using the CERAD-Plus test. Air pollution effects on cognitive functioning were estimated cross-sectionally using adjusted linear regression models. RESULTS: Air pollution was negatively associated with cognitive function and cognitive performance in the subtests for semantic memory and visuo-construction. Significant associations could be observed for figure copying with an interquartile range increase of NO2 (ß=-0.28 (95%CI:-0.44;-0.12)), NOx (ß=-0.25 (95%CI:-0.40;-0.09)), PM10 (ß=-0.14 (95%CI:-0.26;-0.02)) and PM2.5 (ß=-0.19 (95%CI:-0.36;-0.02)). The association with traffic load was significant in carriers of one or two ApoE ɛ4 risk alleles. CONCLUSION: In this study of elderly women, markers of air pollution were associated with cognitive impairment in the visuospatial domain. The association of traffic exposure is significant in participants carrying the ApoE ε4 risk allele.

Proteomic, genomic and translational approaches identify CRMP1 for a role in schizophrenia and its underlying traits.

Schizophrenia is a chronic illness of heterogenous biological origin. We hypothesized that, similar to chronic progressive brain conditions, persistent functional disturbances of neurons would result in disturbed proteostasis in the brains of schizophrenia patients, leading to increased abundance of specific misfolded, insoluble proteins. Identification of such proteins would facilitate the elucidation of molecular processes underlying these devastating conditions. We therefore generated antibodies against pooled insoluble proteome of post-mortem brains from schizophrenia patients in order to identify unique, disease-specific epitopes. We successfully identified such an epitope to be present on collapsin-response mediator protein 1 (CRMP1) in biochemically purified, insoluble brain fractions. A genetic association analysis for the CRMP1 gene in a large Finnish population cohort (n = 4651) corroborated the association of physical and social anhedonia with the CRMP1 locus in a DISC1 (Disrupted-in-schizophrenia 1)-dependent manner. Physical and social anhedonia are heritable traits, present as chronic, negative symptoms of schizophrenia and severe major depression, thus constituting serious vulnerability factors for mental disease. Strikingly, lymphoblastoid cell lines derived from schizophrenia patients mirrored aberrant CRMP1 immunoreactivity by showing an increase of CRMP1 expression, suggesting its potential role as a blood-based diagnostic marker. CRMP1 is a novel candidate protein for schizophrenia traits at the intersection of the reelin and DISC1 pathways that directly and functionally interacts with DISC1. We demonstrate the impact of an interdisciplinary approach where the identification of a disease-associated epitope in post-mortem brains, powered by a genetic association study, is rapidly translated into a potential blood-based diagnostic marker.

5-HT2A receptor antagonists for the treatment of neuroleptic-induced akathisia: a systematic review and meta-analysis.

Akathisia is a common and distressing extrapyramidal side-effect, which usually results from the use of antipsychotic medication. Previous reviews and meta-analyses have demonstrated a lack of evidence for the effectiveness of treatment strategies, which are traditionally used against neuroleptic-induced akathisia (NIA), i.e. beta-blockers, anticholinergic agents and benzodiazepines. In the last fifteen years, randomized trials have studied the effect of drugs with antiserotonergic properties on NIA. We conducted a systematic review of randomized control trials and used meta-analytic methods to quantify the overall effect size. PubMed and the Cochrane libraries were searched for eligible trials. Six randomized controlled trials were found, five of which included a placebo control group and qualified for our meta-analysis. The overall effect size in the analysis is RR = 7.10 with 95% CI 3.08-16.40 (p < 0.0001). Our findings suggest that 5-HT(2A) antagonists are effective in the treatment of NIA.

Investigating the spill-over hypothesis: analysis of the association between local inflammatory markers in sputum and systemic inflammatory mediators in plasma.

Exposure to air pollutants represents a risk factor not only for respiratory diseases and lung cancer, but also for cardiometabolic diseases. It has been hypothesised that local inflammation in the lung and systemic subclinical inflammation are linked by impaired lung function and the spill-over of proinflammatory factors from the lung into the circulation which could act as intermediaries between environmental exposures and disease risk. We wanted to investigate whether local and systemic inflammatory markers are associated, which would support the spill-over hypothesis. Sputum and plasma samples were obtained from 257 women of the German SALIA cohort. We performed immunoassays to measure multiple biomarkers of airway inflammation in sputum as well as cytokines, chemokines and soluble adhesion molecules in plasma. Correlations were calculated and adjusted for potentially confounding variables. Even though several significant associations were detected between inflammatory mediators in sputum and plasma, correlation coefficients were rather low ranging from r≥-0.20 to r≤0.20. Comparatively stronger associations were observed between nitrite, eosinophil cationic protein, leukotrienes C/D/E4 and interleukin-8 in sputum. Notably, correlations were positive with all proinflammatory biomarkers and interleukin-1 receptor antagonist in plasma, whereas negative correlations were observed with the anti-inflammatory adipokine adiponectin. In conclusion, local inflammation in the lung and systemic subclinical inflammation appear mainly independently regulated in elderly women from the general population. Although we found multiple significant correlations between inflammatory biomarkers in sputum and plasma, our results do not provide clear support for the spill-over hypothesis.

Air pollution and subclinical airway inflammation in the SALIA cohort study.

BACKGROUND: The association between long-term exposure to air pollution and local inflammation in the lung has rarely been investigated in the general population of elderly subjects before. We investigated this association in a population-based cohort of elderly women from Germany. METHODS: In a follow-up examination of the SALIA cohort study in 2008/2009, 402 women aged 68 to 79 years from the Ruhr Area and Borken (Germany) were clinically examined. Inflammatory markers were determined in exhaled breath condensate (EBC) and in induced sputum (IS). We used traffic indicators and measured air pollutants at single monitoring stations in the study area to assess individual traffic exposure and long-term air pollution background exposure. Additionally long-term residential exposure to air pollution was estimated using land-use regression (LUR) models. We applied multiple logistic and linear regression analyses adjusted for age, indoor mould, smoking, passive smoking and socio-economic status and additionally conducted sensitivity analyses. RESULTS: Inflammatory markers showed a high variability between the individuals and were higher with higher exposure to air pollution. NO derivatives, leukotriene (LT) B4 and tumour necrosis factor-α (TNF-α) showed the strongest associations. An increase of 9.42 µg/m3 (interquartile range) in LUR modelled NO2 was associated with measureable LTB4 level (level with values above the detection limit) in EBC (odds ratio: 1.38, 95% CI: 1.02 -1.86) as well as with LTB4 in IS (%-change: 19%, 95% CI: 7% - 32%). The results remained consistent after exclusion of subpopulations with risk factors for inflammation (smoking, respiratory diseases, mould infestation) and after extension of models with additional adjustment for season of examination, mass of IS and urban/rural living as sensitivity analyses. CONCLUSIONS: In this analysis of the SALIA study we found that long-term exposure to air pollutants from traffic and industrial sources was associated with an increase of several inflammatory markers in EBC and in IS. We conclude that long-term exposure to air pollution might lead to changes in the inflammatory marker profile in the lower airways in an elderly female population.

Genetic interaction of PICALM and APOE is associated with brain atrophy and cognitive impairment in Alzheimer's disease.

BACKGROUND: Evidence has emerged indicating that the ε4 allele of APOE and PICALM interact in conferring risk of Alzheimer's disease (AD). The biologic basis of this interaction is unclear, but it is likely to have phenotypic relevance and contribute to the structural and clinical heterogeneity of AD. METHODS: The aim of this study was to investigate interaction effects of the APOE ε4 allele and the alleles at the single-nucleotide polymorphism rs3851179 located in the PICALM locus. We analyzed brain volumes and cognitive phenotypes of 165 patients with early AD dementia. RESULTS: There was a synergistic adverse effect of homozygosity for the PICALM risk allele G in rs3851179 and APOE ε4 on volume in prefrontal and performance on the Trail Making Test A, which is sensitive to processing speed and working memory function. CONCLUSIONS: The data suggest a neural mechanism for APOE-PICALM interactions in patients with manifest AD and indicate that the PICALM genotype modulates both brain atrophy and cognitive performance in APOE ε4 carriers.

Multielectrode array analysis of cerebrospinal fluid in Alzheimer's disease versus mild cognitive impairment: a potential diagnostic and treatment biomarker.

Pathological cerebrospinal fluid (CSF) alterations like changes in amyloid-ß1-42 and tau protein concentration are typical in Alzheimer's disease (AD). However, it remains unclear, if the composition of known or unknown pathological factors in native CSF has a functional significance in AD. In this pilot study, we used multielectrode array (MEA) neurochips to determine whether CSF of individuals with AD (AD-CSF) may have distinct neurofunctional properties that may distinguish it from that of individuals with mild cognitive impairment (MCI) - a differential diagnosis of high clinical importance. MEAs are neuronal cultures coupled to a multisite electrical recording system with the ability to reflect pharmacological or toxicological alterations on the functional level of whole neuronal networks. Collective rhythmical electrical activity was substantially enhanced after exposure to CSF of cognitively healthy subjects (controls) and of MCI individuals (MCI-CSF) alike. However, this activity increment was significantly reduced when MEAs were exposed to AD-CSF compared to MCI-CSF. Moreover, following AD-CSF exposure, networks showed significantly enhanced burst durations and less synchronous bursting, respectively. Thus, AD-CSF and MCI-CSF could be distinguished by characteristic changes of the network firing pattern on MEAs. When data of MCI individuals and AD patients were pooled, the network suppression correlated significantly with the degree of cognitive decline. The findings of this pilot study may set the stage for a unique and straightforward diagnostic bioassay of AD with particular value in the differential diagnosis to MCI and as a much needed biomarker for clinical trials.

Facial affect recognition performance and event-related potentials in violent and non-violent schizophrenia patients.

We investigated whether male inpatients with schizophrenia and a history of hands-on violent offences (forensic schizophrenic, FOS) are more impaired in emotion recognition than matched schizophrenia patients without any history of violence (general psychiatric schizophrenic, GPS). This should become apparent in performance in psychometry and in scalp event-related brain potentials (ERPs) evoked by pictures of facial affect. FOS and GPS (each n = 19) were matched concerning age, intelligence, comorbid addiction, medication and illness duration. FOS revealed significantly poorer affect recognition (AR) performance, especially of neutral and fear stimuli. Analysis of ERPs revealed a significant interaction of hemisphere, electrode position and group of the N250 component. Post hoc analysis of group effect showed significantly larger amplitudes in FOS at FC3. These results support the hypothesis that in FOS emotional faces are more salient and evoke higher arousal. Larger impairment in AR performance combined with higher salience and arousal may contribute to the occurrence of violent acts in schizophrenia patients.

Nicotinic acetylcholine receptor expression on B-lymphoblasts of healthy versus schizophrenic subjects stratified for smoking: [3H]-nicotine binding is decreased in schizophrenia and correlates with negative symptoms.

Heavy smoking and schizophrenia are diversely associated with nicotinic acetylcholine receptor expression, as was shown for brain and lymphocytes. Most studies so far have not systematically differentiated between schizophrenia smokers and non-smokers and were confined either to in vivo or post-mortem study approaches. In order to avoid variable in vivo influences or post-mortem bias, we used stably transformed B-lymphoblast cultures derived from healthy and schizophrenia subjects stratified for smoking versus non-smoking in order to differentiate these clinical conditions with regard to nicotinic acetylcholine receptor expression and regulation. Receptor quantities were measured using [(3)H]-nicotine and [(3)H]-epibatidine binding. At baseline, [(3)H]-nicotine binding was not statistically different between healthy smokers and never-smokers (1.59 ± 0.73 vs. 1.26 ± 0.91 fmol/10(6) cells), while it was reduced in schizophrenia smokers compared to healthy smokers (1.05 ± 0.69 fmol vs. 1.44 ± 0.84/10(6) cells, P = 0.01). In schizophrenia, baseline [(3)H]-nicotine correlated inversely with higher PANSS negative subscale scores. After long-term nicotine incubation (1 µM), [3H]-nicotine binding increased in the group of schizophrenia smokers only (from 1.05 ± 0.69 to 1.54 ± 0.77 fmol/106 cells, P = 0.013), while [(3)H]-epibatidine binding decreased in this group (4.52 ± 1.52 to 3.82 ± 1.38 fmol/10(6) cells, P = 0.038). Our data are in further support of a decrease of nicotinic acetylcholine receptor expression in schizophrenia linked to negative psychotic symptoms, which may be counter-regulated by nicotine exposure.

The relation of regional cerebral perfusion and atrophy in mild cognitive impairment (MCI) and early Alzheimer's dementia.

The spatial and temporal relations between regional cerebral blood flow (rCBF) and brain volume (rVOL) changes in incipient and early Alzheimer's dementia (AD) are not fully understood. The participants comprised 30 subjects with mild cognitive impairment (MCI) and 15 with mild AD who were examined using structural and perfusion-weighted magnetic resonance imaging (MRI) at 1.5 Tesla. Hippocampus and amygdala volumes were measured by manual volumetry. A region-of-interest co-localisation method was used to calculate rCBF values. DNA samples were genotyped for apolipoprotein E (APO E). In comparisons of AD with MCI, rCBF was reduced in the posterior cingulum only, while profound rVOL reductions occurred in both right and left amygdala and in the right hippocampus, and as a trend, in the left hippocampus. Brain volumes of the hippocampus and the amygdala were uncorrelated with the respective rCBF variables in both MCI and AD. Hippocampal but not amygdalar volumes were associated with presence of one or two APOE epsilon4 alleles in MCI and mild AD, while there was no association of APOE epsilon4 allele with rCBF. These data support earlier indications that rCBF and rVOL changes are at least partly dissociated in the early pathogenesis of AD and heterogeneously associated with the APOE risk allele. The data also support the concept of functional compensatory brain activation and the diaschisis hypothesis as relevant in incipient and early AD.

Multicentre variability of MRI-based medial temporal lobe volumetry in Alzheimer's disease.

Magnetic resonance imaging (MRI)-based volumetry of medial temporal lobe regions is among the best established biomarker candidates of Alzheimer's disease (AD) to date. This study assessed the effect of multicentre variability of MRI-based hippocampus and amygdala volumetry on the discrimination between patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI) and on the association of morphological changes with ApoE4 genotype and cognition. We studied 113 patients with clinically probable AD and 150 patients with amnestic MCI using high-resolution MRI scans obtained at 12 clinical sites. We determined effect sizes of group discrimination and random effects linear models, considering multicentre variability. Hippocampus and amygdala volumes were significantly reduced in AD compared with MCI patients using data pooled across centres. Multicentre variability did not significantly affect the power to detect a volume difference between AD and MCI patients. Among cognitive measures, delayed recall of verbal and non-verbal material was significantly correlated with hippocampus and amygdala volumes. Amygdala and hippocampus volumes were not associated with ApoE4 genotype in AD or MCI. Our data indicate that multicentre acquisition of MRI data using manual volumetry is reliable and feasible for cross-sectional diagnostic studies, and they replicate essential findings from smaller scale monocentre studies.

Ranking the Harm of Psychoactive Drugs Including Prescription Analgesics to Users and Others-A Perspective of German Addiction Medicine Experts.

Background: Over the past 15 years, comparative assessments of psychoactive substance harms to both users and others have been compiled by addiction experts. None of these rankings however have included synthetic cannabinoids or non-opioid prescription analgesics (NOAs, e.g., gabapentinoids) despite evidence of increasing recreational use. We present here an updated assessment by German addiction medicine experts, considering changing Western consumption trends-including those of NOAs. Methods: In an initial survey, 101 German addiction medicine physicians evaluated both physical and psychosocial harms (in 5 dimensions) of 33 psychoactive substances including opioids and NOAs, to both users and others. In a second survey, 36 addiction medicine physicians estimated the relative weight of each health and social harm dimension to determine the overall harm rank of an individual substance. We compared our ranking with the most recent European assessment from 2014. Results: Illicit drugs such as methamphetamine, heroin, cocaine and also alcohol were judged particularly harmful, and new psychoactive drugs (cathinones, synthetic cannabinoids) were ranked among the most harmful substances. Cannabis was ranked in the midrange, on par with benzodiazepines and ketamine-somewhat more favorable compared to the last European survey. Prescribed drugs including opioids (in contrast to the USA, Canada, and Australia) were judged less harmful. NOAs were at the bottom end of the ranking. Conclusion: In Germany, alcohol and illicit drugs (including new psychoactive substances) continue to rank among the most harmful addictive substances in contrast to prescribed agents including opioid analgesics and NOAs. Current laws are incongruent with these harm rankings. This study is the first of its kind to include comparative harm rankings of several novel abused substances, both licit/prescribed and illicit.

Blood biomarkers of osteoporosis in mild cognitive impairment and Alzheimer's disease.

Previous studies revealed some comorbidity of Alzheimer's disease and osteoporosis not only for advanced disease, but also for the incipient conditions cognitive decline and decline of bone mineral density. To detect comorbidity with osteoporosis at a subclinical level, we studied concentrations of biochemical osteoporosis markers in blood plasma of subjects with mild cognitive impairment and mild Alzheimer's disease compared to subjects with primary osteoporosis and age-matched cognitively normal controls in an explorative approach. Regarding disease-spanning molecular pathology we also studied osteoprotegerin, a decoy receptor of RANKL and TRAIL. Equally increased C-terminal collagen fragments, marking bone catabolism, were seen in osteoporosis and Alzheimer's disease (+68%) versus controls. Osteocalcin, marking bone remodelling and anabolism, was concomitantly increased in osteoporosis (+63%), as a trend, and significantly in Alzheimer's disease (+76%). Osteoprotegerin was unchanged between patient groups and controls. 25 (OH) vitamin D plasma levels were low normal and of equal amount in all groups except for the osteoporosis group. These results point to increased bone catabolism and concomitant remodelling/anabolism unrelated to vitamin D state in mild Alzheimer's disease, but not in mild cognitive impairment. This corroborates previous findings of comorbidity of Alzheimer's disease with osteoporosis in the early disease course at the level of biochemical blood markers. Regarding osteoprotegerin, previously reported plasma level increases in Alzheimer's disease were not observed in this study, which does not rule out subtle changes to be detected in larger samples or the possibility that other components of osteoprotegerin pathways are affected in Alzheimer's disease.

Early and differential diagnosis of dementia and mild cognitive impairment: design and cohort baseline characteristics of the German Dementia Competence Network.

BACKGROUND: The German Dementia Competence Network (DCN) has established procedures for standardized multicenter acquisition of clinical, biological and imaging data, for centralized data management, and for the evaluation of new treatments. METHODS: A longitudinal cohort study was set up for patients with mild cognitive impairment (MCI), patients with mild dementia and control subjects. The aims were to establish the diagnostic, differential diagnostic and prognostic power of a range of clinical, laboratory and imaging methods. Furthermore, 2 clinical trials were conducted with patients suffering from MCI and mild to moderate Alzheimer's Disease (AD). These trials aimed at evaluating the efficacy and safety of the combination of galantamine and memantine versus galantamine alone. RESULTS: Here, we report on the scope and projects of the DCN, the methods that were employed, the composition and flow within the diverse groups of patients and control persons and on the clinical and neuropsychological baseline characteristics of the group of 2,113 subjects who participated in the observational and clinical trials. CONCLUSION: These data have an impact on the procedures for the early and differential clinical diagnosis of dementias, the current standard treatment of AD as well as on future clinical trials in AD.

Quantitative EEG in progressing vs stable mild cognitive impairment (MCI): results of a 1-year follow-up study.

OBJECTIVE: The study objective is to evaluate the use of qEEG data for the cross-sectional differentiation of mild cognitive impairment (MCI) from mild Alzheimer's disease (AD) and in the longitudinal prediction of cognitive decline in MCI. METHODS: Eighty-eight subjects with MCI and 42 subjects with mild probable AD were enrolled. Baseline EEGs were recorded using a 32-channel system with electrode positioning according to the international 10-20 system. Digitalized EEG data were further studied by quantitative spectral analysis. Study subjects were followed up for 1 year and reassessed psychometrically. An increase of the total ADAS-cog score of >or= 4 points was regarded as a significant cognitive decline. Using this cut-off, MCI subjects were sub-grouped into stable MCI (s-MCI) and progressing MCI (p-MCI). RESULTS: AD subjects and p-MCI subjects were differentiated from s-MCI subjects by a reduction of alpha power over posterior leads. Reduction of alpha power and mean frequency were significantly correlated with poorer cognitive performance in psychometric tests. Baseline values of alpha power over posterior leads had the highest positive predictive power for MCI and AD (69-80%) and predicted cognitive decline in MCI within a 1-year follow up. CONCLUSIONS: qEEG revealed decreased alpha activity in progressing MCI and mild AD prior to an increase of slow wave activity, which typically occurs in advancing AD. This finding may reflect an affection of thalamo-cortical relay activity and cortical connectivity in the early disease course of AD. Reduced alpha activity in MCI subjects at baseline may have prognostic value regarding future cognitive decline.

Brugada syndrome as a potential cardiac risk factor during electroconvulsive therapy (ECT).

A case of asystole (> 5 s) during electroconvulsive therapy (ECT) is reported in a patient who was subsequently diagnosed to have Brugada syndrome (BS). This hereditary sodium-channelopathy is characterized by typical, though intermittent, ECG abnormalities and carries a high risk of ventricular arrythmia and sudden cardiac death. The general occurence of BS is rare; however, it is more prevalent in men and in southeast Asian populations. As in the reported case, BS carriers may lack a telltale medical history and can present with normal ECG recordings. In these cases, BS can only be unmasked by repeated ECG recordings over time or by specialist cardiological examinations. To our knowledge, BS, which was first characterized in 1992, has not yet been in the focus of cardiac complications during ECT. However, as the presented case illustrates, this syndrome should be considered as a rare but potentially severe cardiac risk factor in the context of ECT.