RESUMO
OBJECTIVE: Patients with borderline personality disorder (BPD) report to be especially prone to social emotions like shame and guilt. At the same time, these emotions seem to play an important role in BPD pathology. The present study aimed to deepen the knowledge about the processes behind shame and guilt in patients with BPD. METHODS: Twenty patients with BPD and twenty healthy controls (HCs) took part in an experiment that induced shame and guilt by imagining scenarios during scanning using functional brain imaging. Participants also filled out self-report questionnaires and took part in diagnostic interviews. RESULTS: BPD patients reported more proneness to guilt but not to shame than the HCs. There was no difference in the self-reported intensity rating of experimentally induced emotions between the groups. Between-group contrast of neural signals in the shame condition revealed a stronger activation of cingulate and fusiform gyrus for the BPD patients compared to the controls, and a more pronounced activation in the lingual gyrus and cuneus for the HCs. In the guilt condition, activation in the caudate nucleus, the fusiform gyrus, and the posterior cingulate cortex was stronger in BPD patients, while HC showed stronger activations in cuneus, lingual gyrus, and fronto-temporal regions. CONCLUSIONS: Differences in the neuro-functional processes between BPD patients and HC were found, even though the two groups did not differ in their self-report of subjective proneness to guilt and emotional intensity of shame and guilt during the experiment. While the HCs may be engaged more by the emotional scenarios themselves, the BPD patients may be more occupied with cognitive regulatory and self-referential processing.
RESUMO
BACKGROUND: Attachment theory offers an important framework for understanding interpersonal interaction experiences. In the present study, we examined the neural correlates of attachment patterns and oxytocin in schizophrenic patients (SZP) compared to healthy controls (HC) using fMRI. We assumed that male SZP shows a higher proportion of insecure attachment and an altered level of oxytocin compared to HC. On a neural level, we hypothesized that SZP shows increased neural activation in memory and self-related brain regions during the activation of the attachment system compared to HC. METHODS: We used an event-related design for the fMRI study based on stimuli that were derived from the Adult Attachment Projective Picture System to examine attachment representations and their neural and hormonal correlates in 20 male schizophrenic patients compared to 20 male healthy controls. RESULTS: A higher proportion of insecure attachment in schizophrenic patients compared to HC could be confirmed. In line with our hypothesis, Oxytocin (OXT) levels in SZP were significantly lower than in HC. We found increasing brain activations in SZP when confronted with personal relevant sentences before attachment relevant pictures in the precuneus, TPJ, insula, and frontal areas compared to HC. Moreover, we found positive correlations between OXT and bilateral dlPFC, precuneus, and left ACC in SZP only. CONCLUSION: Despite the small sample sizes, the patients' response might be considered as a mode of dysregulation when confronted with this kind of personalized attachment-related material. In the patient group, we found positive correlations between OXT and three brain areas (bilateral dlPFC, precuneus, left ACC) and may conclude that OXT might modulate within this neural network in SZP.
RESUMO
The aim of this study was to explore the potential of default mode network (DMN) functional connectivity for predicting the success of smoking cessation in patients with tobacco dependence in the context of a real-time function al MRI (RT-fMRI) neurofeedback (NF) supported therapy.Fifty-four tobacco-dependent patients underwent three RT-fMRI-NF sessions including resting-state functional connectivity (RSFC) runs over a period of 4 weeks during professionally assisted smoking cessation. Patients were randomized into two groups that performed either active NF of an addiction-related brain region or sham NF. After preprocessing, the RSFC baseline data were statistically evaluated using seed-based ROI (SBA) approaches taking into account the smoking status of patients after 3 months (abstinence/relapse).The results of the real study group showed a widespread functional connectivity in the relapse subgroup (n = 10) exceeding the DMN template and mainly low correlations and anticorrelations in the within-seed analysis. In contrast, the connectivity pattern of the abstinence subgroup (n = 8) primarily contained the core DMN in the seed-to-whole-brain analysis and a left lateralized correlation pattern in the within-seed analysis. Calculated Multi-Subject Dictionary Learning (MSDL) matrices showed anticorrelations between DMN regions and salience regions in the abstinence group. Concerning the sham group, results of the relapse subgroup (n = 4) and the abstinence subgroup (n = 6) showed similar trends only in the within-seed analysis.In the setting of a RT-fMRI-NF-assisted therapy, a widespread intrinsic DMN connectivity and a low negative coupling between the DMN and the salience network (SN) in patients with tobacco dependency during early withdrawal may be useful as an early indicator of later therapy nonresponse.
Assuntos
Neurorretroalimentação , Abandono do Hábito de Fumar , Encéfalo , Mapeamento Encefálico/métodos , Eletroencefalografia , Humanos , Imageamento por Ressonância Magnética/métodos , Neurorretroalimentação/métodos , Recidiva , NicotianaRESUMO
OBJECTIVES: We investigate in what percentage of cases and to what extent radiological reports change when radiologists directly communicate with patients after imaging examinations. METHODS: One hundred twenty-two consecutive outpatients undergoing MRI examinations at a single center were prospectively included. Radiological reports of the patients were drafted by two radiologists in consensus using only the clinical information that was made available by the referring physicians. Thereafter, one radiologist talked directly with the patient and recorded the duration of the conversation. Afterwards, the additional information from the patient was used to reevaluate the imaging studies in consensus. The radiologists determined whether the radiological report changed based on additional information and, if yes, to what extent. The degree of change was graded on a 4-point Likert scale (1, non-relevant findings, to 4, highly relevant findings). RESULTS: Following direct communication (duration 170.9 ± 53.9 s), the radiological reports of 52 patients (42.6%) were changed. Of the 52 patients, the degree of change was classified as grade 1 for 8 patients (15.4 %), grade 2 for 27 patients (51.9%), grade 3 for 13 patients (25%), and grade 4 for 4 patients (7.7%). The reasons leading to changes were missing clinical information in 50 cases (96.2%) and the lack of additional external imaging in 2 cases (3.8%). CONCLUSIONS: Radiologists should be aware that a lack of accurate information from the clinician can lead to incorrect radiological reports or diagnosis. Radiologists should communicate directly with patients, especially when the provided information is unclear, as it may significantly alter the radiological report. KEY POINTS: ⢠Direct communication between radiologists and patients for an average of 170's resulted in a change in the radiological reports of 52 patients (42.6%). ⢠Of the 42.6% of cases where the reports were changed, the alterations were highly relevant (grades 3 and 4) in 32.7%, indicating major changes with significant impact towards patient management.
Assuntos
Radiologistas , Radiologia , Comunicação , Humanos , Imageamento por Ressonância Magnética , RadiografiaRESUMO
In schizophrenia, neurocognitive subtypes can be distinguished based on cognitive performance and they are associated with neuroanatomical alterations. We investigated the existence of cognitive subtypes in shortly medicated recent onset psychosis patients, their underlying gray matter volume patterns and clinical characteristics. We used a K-means algorithm to cluster 108 psychosis patients from the multi-site EU PRONIA (Prognostic tools for early psychosis management) study based on cognitive performance and validated the solution independently (N = 53). Cognitive subgroups and healthy controls (HC; n = 195) were classified based on gray matter volume (GMV) using Support Vector Machine classification. A cognitively spared (N = 67) and impaired (N = 41) subgroup were revealed and partially independently validated (Nspared = 40, Nimpaired = 13). Impaired patients showed significantly increased negative symptomatology (pfdr = 0.003), reduced cognitive performance (pfdr < 0.001) and general functioning (pfdr < 0.035) in comparison to spared patients. Neurocognitive deficits of the impaired subgroup persist in both discovery and validation sample across several domains, including verbal memory and processing speed. A GMV pattern (balanced accuracy = 60.1%, p = 0.01) separating impaired patients from HC revealed increases and decreases across several fronto-temporal-parietal brain areas, including basal ganglia and cerebellum. Cognitive and functional disturbances alongside brain morphological changes in the impaired subgroup are consistent with a neurodevelopmental origin of psychosis. Our findings emphasize the relevance of tailored intervention early in the course of psychosis for patients suffering from the likely stronger neurodevelopmental character of the disease.
Assuntos
Transtornos Psicóticos , Esquizofrenia , Encéfalo/diagnóstico por imagem , Cognição , Substância Cinzenta/diagnóstico por imagem , Humanos , Transtornos Psicóticos/diagnóstico por imagem , Esquizofrenia/diagnóstico por imagemRESUMO
BACKGROUND: Various reasons may lead to cognitive symptoms in elderly, including the development of cognitive decline and dementia. Often, mixed pathologies such as neurodegeneration and cerebrovascular disease co-exist in these patients. Diagnostic work-up commonly includes imaging modalities such as FDG PET, MRI, and CT, each delivering specific information. OBJECTIVE: To study the informative value of neuroimaging-based data supposed to reflect neurodegeneration (FDG PET), cerebral small vessel disease (MRI), and cerebral large vessel atherosclerosis (CT) with regard to cognitive performance in patients presenting to our memory clinic. METHODS: Non-parametric partial correlations and an ordinal logistic regression model were run to determine relationships between scores for cortical hypometabolism, white matter hyperintensities, calcified plaque burden, and results from Mini-Mental State Examination (MMSE). The final study group consisted of 162 patients (female: 94; MMSE: 6-30). RESULTS: Only FDG PET data was linked to and predicted cognitive performance (r(157)â=â-0.388, pâ<â0.001). Overall, parameters linked to cerebral small and large vessel disease showed no significant association with cognition. Further findings demonstrated a relationship between white matter hyperintensities and FDG PET data (r(157)â=â0.230, pâ=â0.004). CONCLUSION: Only FDG PET imaging mirrors cognitive performance, presumably due to the examination's ability to reflect neurodegeneration and vascular dysfunction, thus capturing a broader spectrum of pathologies. This makes the examination a useful imaging-based diagnostic tool in the work-up of patients presenting to a memory clinic. Parameters of vascular dysfunction alone as depicted by conventional MRI and CT are less adequate in such a situation, most likely because they reflect one pathology complex only.
Assuntos
Disfunção Cognitiva/diagnóstico por imagem , Tomografia por Emissão de Pósitrons/métodos , Idoso , Idoso de 80 Anos ou mais , Doenças de Pequenos Vasos Cerebrais/metabolismo , Cognição , Feminino , Fluordesoxiglucose F18 , Alemanha , Humanos , Imageamento por Ressonância Magnética , Masculino , Memória , Pessoa de Meia-Idade , Compostos Radiofarmacêuticos , Estudos RetrospectivosRESUMO
BACKGROUND: The aim of the study is to investigate how well patients remember the radiologist's name after a radiological examination, and whether giving the patient a business card improves the patient's perception of the radiologist's professionalism and esteem. METHODS: In this prospective and randomized two-centre study, a total of 141 patients with BI-RADS 1 and 2 scores were included. After screening examination comprising mammography and ultrasound by a radiologist, 71 patients received a business card (group 1), while 70 received no business card (group 2). Following the examination, patients were questioned about their experiences. RESULTS: The patients in group 1 could remember the name of the radiologist in 85% of cases. The patients in group 2, in contrast, could only remember the name in 7% of cases (p < 0.001). 90% of the patients in group 1 believed it was very important that they are able to contact the radiologist at a later time, whereas only 76% of patients in group 2 felt that this was a very important service (p < 0.025). A total of 87% of the patients in group 1 indicated that they would contact the radiologist if they had any questions whereas 73% of the patients in group 2 would like to contact the radiologist but were not able to do so, because they could not remember the name (p < 0.001). All questions were analysed with a Cochran-Mantel-Haenszel (CMH) test that took study centre as stratification into account. In some cases, two categories were collapsed to avoid zero cell counts. CONCLUSIONS: Using business cards significantly increased the recall of the radiologist's name and could be an important tool in improving the relationships between patients and radiologists and enhancing service professionalism. TRIAL REGISTRATION: We have a general approval from our ethics committee. The patients have given their consent to this study.
Assuntos
Neoplasias da Mama/diagnóstico por imagem , Mamografia , Profissionalismo , Radiologistas , Ultrassonografia Mamária , Adulto , Idoso , Idoso de 80 Anos ou mais , Detecção Precoce de Câncer , Feminino , Humanos , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
BACKGROUND: In clinical routine, SUVmax and SUVpeak are most often used to determine the glucose metabolism in tumours by 18F-FDG PET/CT. Both metrics can be further normalised to SUVs in reference regions resulting in a SUV ratio (SUVratio). The aim of the study was to directly compare several widely used SUVs/SUVratios with regard to differentiation between common tumours in paediatric patients; a special focus was put on characteristics of reference region SUVs. METHODS: The final study population consisted of 61 children and adolescents with diagnoses of non-Hodgkin lymphoma (NHL, n = 25), Hodgkin lymphoma (HL, n = 14), and sarcoma (n = 22). SUV metrics included SUVmax and SUVpeak as well as both parameters normalised to liver and mediastinal blood pool, respectively, yielding the SUVratios SUVmax/liver, SUVmax/mediastinum, SUVpeak/liver, and SUVpeak/mediastinum. RESULTS: The metrics SUVmax, SUVpeak, SUVmax/liver, and SUVpeak/liver all proved to be sensitive for tumour differentiation (p ≤ 0.008); in contrast, SUVmax/mediastinum and SUVpeak/mediastinum revealed to be non-sensitive approaches. Correlation analyses showed inverse associations between reference region SUVs and SUVratios (p < 0.05). Multiple regression analyses demonstrated significant effects of factors as bodyweight and uptake time on reference region SUVs (p < 0.01), and thus indirectly on the corresponding SUVratios. CONCLUSIONS: In the paediatric population, the ability to differentiate between common tumours remarkably varies between SUV metrics. When using SUVratios, the choice of reference region is crucial. Factors potentially influencing reference region SUVs (and thus SUVratios) should be taken into account in order to avoid erroneous conclusions. When not possible, SUVmax and SUVpeak represent less complex, more robust alternatives.
RESUMO
Late-life depression, even when of subsyndromal severity, has shown strong associations with mild cognitive impairment (MCI) and Alzheimer's disease (AD). Preclinical studies have suggested that serotonin selective reuptake inhibitors (SSRIs) can attenuate amyloidogenesis. Therefore, we aimed to investigate the effect of SSRI medication on amyloidosis and grey matter volume in subsyndromal depressed subjects with MCI and AD during an interval of two years. 256 cognitively affected subjects (225 MCI/ 31 AD) undergoing [18F]-AV45-PET and MRI at baseline and 2-year follow-up were selected from the ADNI database. Subjects with a positive depression item (DEP(+); n = 73) in the Neuropsychiatric Inventory Questionnaire were subdivided to those receiving SSRI medication (SSRI(+); n = 24) and those without SSRI treatment (SSRI(-); n = 49). Longitudinal cognition (Δ-ADAS), amyloid deposition rate (standardized uptake value, using white matter as reference region (SUVRWM), and changes in grey matter volume were compared using common covariates. Analyses were performed separately in all subjects and in the subgroup of amyloid-positive subjects. Cognitive performance in DEP(+)/SSRI(+) subjects (Δ-ADAS: -5.0%) showed less deterioration with 2-year follow-up when compared to DEP(+)/SSRI(-) subjects (Δ-ADAS: +18.6%, p < 0.05), independent of amyloid SUVRWM at baseline. With SSRI treatment, the progression of grey matter atrophy was reduced (-0.9% versus -2.7%, p < 0.05), notably in fronto-temporal cortex. A slight trend towards lower amyloid deposition rate was observed in DEP(+)/SSRI(+) subjects versus DEP(+)/SSRI(-). Despite the lack of effect to amyloid PET, SSRI medication distinctly rescued the declining cognitive performance in cognitively affected patients with depressive symptoms, and likewise attenuated grey matter atrophy.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Amiloidose/tratamento farmacológico , Disfunção Cognitiva/tratamento farmacológico , Depressão/tratamento farmacológico , Substância Cinzenta/efeitos dos fármacos , Inibidores Seletivos de Recaptação de Serotonina/uso terapêutico , Idoso , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/patologia , Doença de Alzheimer/psicologia , Amiloide/efeitos dos fármacos , Amiloide/metabolismo , Amiloidose/metabolismo , Amiloidose/patologia , Amiloidose/psicologia , Compostos de Anilina , Atrofia , Cognição/efeitos dos fármacos , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/patologia , Disfunção Cognitiva/psicologia , Depressão/complicações , Depressão/diagnóstico por imagem , Depressão/patologia , Etilenoglicóis , Feminino , Seguimentos , Substância Cinzenta/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Masculino , Tamanho do Órgão , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Seio Sagital Superior , Resultado do TratamentoRESUMO
Body weight loss in late-life is known to occur at a very early stage of Alzheimer's disease (AD). Apolipoprotein E4 (ApoE4) represents a major genetic risk factor for AD and is linked to an increased cortical amyloid-ß (Aß) accumulation. Since the relationship between body weight, ApoE4, and AD pathology is poorly investigated, we aimed to evaluate whether ApoE4 allelic status modifies the association of body mass index (BMI) with markers of AD pathology. A total of 368 Aß-positive cognitively healthy or mild cognitive impaired subjects had undergone [18F]-AV45-PET, [18F]-FDG-PET, and T1w-MRI examinations. Composite cortical [18F]-AV45 uptake and [18F]-FDG uptake in posterior cingulate cortex were calculated as surrogates of cortical Aß load and glucose metabolism, respectively. Multiple linear regressions were performed to assess the relationships between these PET biomarkers with BMI, present cognitive performance, and cognitive changes over time. Multivariate analysis of covariance was conducted to test for statistical differences between ApoE4/BMI categories on the PET markers and cognitive scores. In carriers of the ApoE4 allele only, BMI was inversely associated with cortical amlyoid load (ß=â-0.193, pâ<â0.005) and recent cognitive decline (ß=â-0.209, pâ<â0.05), and positively associated with cortical glucose metabolism in an AD-vulnerable region (ß=â0.145, pâ<â0.05). ApoE4/BMI category analyses demonstrated lower Aß load, higher posterior cingulate glucose metabolism, improved cognitive performance, and lower progression of cognitive decline in obese ApoE4 carriers. The effect of ApoE4 in promoting the accumulation of cortical amyoid, which may itself be a driver for weight loss, may be moderated by altering leptin signaling in the hypothalamus.
Assuntos
Amiloide/metabolismo , Apolipoproteína E4/genética , Índice de Massa Corporal , Encéfalo/diagnóstico por imagem , Disfunção Cognitiva/diagnóstico por imagem , Doenças Neurodegenerativas/diagnóstico por imagem , Proteínas Adaptadoras de Transdução de Sinal , Idoso , Compostos de Anilina , Encéfalo/metabolismo , Cognição , Disfunção Cognitiva/genética , Disfunção Cognitiva/metabolismo , Etilenoglicóis , Feminino , Fluordesoxiglucose F18 , Seguimentos , Glucose/metabolismo , Heterozigoto , Humanos , Masculino , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/metabolismo , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Proteínas Repressoras , Redução de Peso , Proteínas de Peixe-ZebraRESUMO
The ε4 allelic variant of the Apolipoprotein E gene (APOE ε4) is the best-established genetic risk factor for late-onset Alzheimer's disease (AD). White matter (WM) microstructural damages measured with Diffusion Tensor Imaging (DTI) represent an early sign of fiber tract disconnection in AD. We examined the impact of APOE ε4 on WM microstructure in elderly individuals from the multicenter European DTI Study on Dementia. Voxelwise statistical analysis of fractional anisotropy (FA), mean diffusivity, radial and axial diffusivity (MD, radD and axD respectively) was carried out using Tract-Based Spatial Statistics. Seventy-four healthy elderly individuals - 31 APOE ε4 carriers (APOE ε4+) and 43 APOE ε4 non-carriers (APOE ε4-) -were considered for data analysis. All the results were corrected for scanner acquisition protocols, age, gender and for multiple comparisons. APOE ε4+ and APOE ε4- subjects were comparable regarding sociodemographic features and global cognition. A significant reduction of FA and increased radD was found in the APOE ε4+ compared to the APOE ε4- in the cingulum, in the corpus callosum, in the inferior fronto-occipital and in the inferior longitudinal fasciculi, internal and external capsule. APOE ε4+, compared to APOE ε4- showed higher MD in the genu, right internal capsule, superior longitudinal fasciculus and corona radiate. Comparisons stratified by center supported the results obtained on the whole sample. These findings support previous evidence in monocentric studies indicating a modulatory role of APOE É4 allele on WM microstructure in elderly individuals at risk for AD suggesting early vulnerability and/or reduced resilience of WM tracts involved in AD.
Assuntos
Apolipoproteína E4/genética , Encéfalo/diagnóstico por imagem , Imagem de Tensor de Difusão , Heterozigoto , Imageamento por Ressonância Magnética , Substância Branca/diagnóstico por imagem , Idoso , Envelhecimento/genética , Envelhecimento/patologia , Encéfalo/patologia , Europa (Continente) , Feminino , Humanos , Internacionalidade , Modelos Lineares , Masculino , Vias Neurais/diagnóstico por imagem , Testes Neuropsicológicos , Estudos Retrospectivos , Substância Branca/patologiaRESUMO
Relative quantitative analysis of amyloid plaque burden in Alzheimer's disease (AD) patients can be reported as standardized uptake value ratio (SUVR) from positron emission tomography (PET). Here, the SUVR is the ratio of the mean amyloid radioligand retention in a composite (COMP) neocortical volume of interest (VOI) to that in a reference VOI, such as the cerebellum, brainstem (BST)/pons, or white matter (WM). Some longitudinal PET investigations show that the rate of amyloid accumulation to follow-up has an inverted U relationship with baseline amyloid SUVR relative to cerebellar or brainstem/pons reference VOIs. The corresponding association with SUVR relative to WM is unknown. To test the possible benefits of WM normalization, we analyzed [18F]-AV45 PET data from 404 subjects in the AD Neuroimaging Initiative (ADNI) database at baseline and 2-year follow-up (144 cognitively normal controls, 225 patients with mild cognitive impairment, and 35 AD patients). Reference regions included subcortical WM as well as conventional cerebellar gray matter (CBL), and BST. We tested associations between each subject's inter-session change (∆) of SUVR and their baseline SUVR by applying linear, logarithmic, and quadratic regression analyses. Unscaled standardized uptake values (SUVs) were correlated between VOIs at baseline and follow-up, and within VOIs in the longitudinal run. The association between ∆SUVR and baseline SUVR relative to WM reference was best described by an inverted U-shaped function. Correlation analyses demonstrated a high regional and temporal correlation between COMP and WM VOI SUVs. For WM normalization, we confirm that the rate of amyloid accumulation over time follows an inverted U-shaped function of baseline amyloid burden. Reference region selection, however, has substantial effects on SUVR results. This reflects the extent of covariance between SUVs in the COMP VOI and those in the various reference VOIs. We speculate that PET labeling of amyloid deposition within target regions is partially confounded by effects of longitudinal changes of cerebral blood flow (CBF) on tracer delivery. Indeed, CBF may be the leading factor influencing longitudinal SUV changes. We suggest that SUVR relative to WM may be more robust to changes in CBF, and thus fitter for sensitive detection of amyloid accumulation in intervention studies.
Assuntos
Amiloide/metabolismo , Neuroimagem/normas , Idoso , Idoso de 80 Anos ou mais , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Feminino , Humanos , Imageamento por Ressonância Magnética/normas , Masculino , Tomografia por Emissão de Pósitrons/normas , Padrões de Referência , Fatores de TempoRESUMO
The European DTI Study on Dementia (EDSD) is a multicenter framework created to study the diagnostic accuracy and inter-site variability of DTI-derived markers in patients with manifest and prodromal Alzheimer's disease (AD). The dynamically growing database presently includes 493 DTI, 512 T1-weighted MRI, and 300 FLAIR scans from patients with AD dementia, patients with Mild Cognitive Impairment (MCI) and matched Healthy Controls, acquired on 13 different scanner platforms. The imaging data is publicly available, along with the subjects' demographic and clinical characterization. Detailed neuropsychological information, cerebrospinal fluid information on biomarkers and clinical follow-up diagnoses are included for a subset of subjects. This paper describes the rationale and structure of the EDSD, summarizes the available data, and explains how to gain access to the database. The EDSD is a useful database for researchers seeking to investigate the contribution of DTI to dementia diagnostics.
Assuntos
Doença de Alzheimer/diagnóstico por imagem , Disfunção Cognitiva/diagnóstico por imagem , Bases de Dados Factuais , Imagem de Tensor de Difusão , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Disseminação de Informação , Masculino , Pessoa de Meia-IdadeRESUMO
Progressive supranuclear palsy (PSP) is a neurodegenerative movement disorder characterized by deposition of fibrillar aggregates of 4R tau-protein in neurons and glial cells of the brain. These deposits are a key neuropathological finding, allowing a diagnosis of "definite PSP," which is usually established post mortem. To date criteria for clinical diagnosis of PSP in vivo do not include biomarkers of tau pathology. For intervention trials, it is increasingly important to (i) establish biomarkers for an early diagnosis and (ii) to develop biomarkers that correlate with disease progression of PSP. [18F]-THK5351 is a novel PET-ligand that may afford in vivo visualization and quantification of tau-related alterations. We investigated binding characteristics of [18F]-THK5351 in patients with clinically diagnosed PSP and correlate tracer uptake with clinical findings. Eleven patients (68.4 ± 7.4 year; N = 6 female) with probable PSP according to current clinical criteria and nine healthy controls (71.7 ± 7.2 year; N = 4 female) underwent [18F]-THK5351 PET scanning. Voxel-wise statistical parametric comparison and volume-of-interest based quantification of standardized-uptake-values (SUV) were conducted using the cerebellar cortex as reference region. We correlated disease severity as measured with the help of the PSP Rating Scale (PSPRS) as well as several other clinical parameters with the individual PET findings. By voxel-wise mapping of [18F]-THK5351 uptake in the patient group we delineated typical distribution patterns that fit to known tau topology for PSP post mortem. Quantitative analysis indicated the strongest discrimination between PSP patients and healthy controls based on tracer uptake in the midbrain (+35%; p = 3.01E-7; Cohen's d: 4.0), followed by the globus pallidus, frontal cortex, and medulla oblongata. Midbrain [18F]-THK5351 uptake correlated well with clinical severity as measured by PSPRS (R = 0.66; p = 0.026). OCT and MRI delineated PSP patients from healthy controls by use of established discrimination thresholds but only OCT did as well correlate with clinical severity (R = 0.79; p = 0.024). Regional [18F]-THK5351 binding patterns correlated well with the established post mortem distribution of lesions in PSP and with clinical severity. The contribution of possible MAO-B binding to the [18F]-THK5351 signal needs to be further evaluated, but nevertheless [18F]-THK5351 PET may still serve as valuable biomarker for diagnosis of PSP.
RESUMO
Negative symptoms are highly relevant in the long-term course of schizophrenia and are an important target domain for the development of novel interventions. Recently, transcranial direct current stimulation (tDCS) of the prefrontal cortex has been investigated as a treatment option in schizophrenia. In this proof-of-concept study, 20 schizophrenia patients with predominantly negative symptoms were randomized to either 10 sessions of add-on active (2 mA, 20min) or sham tDCS (anode: left DLPFC/F3; cathode: right supraorbital/F4). Primary outcome measure was the change in the Scale for the Assessment of Negative Symptoms (SANS) sum score; secondary outcomes included reduction in Positive and Negative Syndrome Scale (PANSS) scores and improvement of depressive symptoms, cognitive processing speed, and executive functioning. Sixteen patients underwent 4 functional connectivity magnetic resonance imaging (fcMRI) scans (pre and post 1st and pre and post 10th tDCS) to investigate changes in resting state network connectivity after tDCS. Per-protocol analysis showed a significantly greater decrease in SANS score after active (-36.1%) than after sham tDCS (-0.7%). PANSS sum scores decreased significantly more with active (-23.4%) than with sham stimulation (-2.2%). Explorative analysis of fcMRI data indicated changes in subgenual cortex and dorsolateral prefrontal cortex (DLPFC) connectivity within frontal-thalamic-temporo-parietal networks. The results of this first proof-of-concept study indicate that prefrontal tDCS may be a promising intervention for treatment of schizophrenia with predominant negative symptoms. Large-scale randomized controlled studies are needed to further establish prefrontal tDCS as novel treatment for negative symptoms in schizophrenia.
Assuntos
Conectoma/métodos , Rede Nervosa/fisiopatologia , Avaliação de Resultados em Cuidados de Saúde , Córtex Pré-Frontal/fisiopatologia , Esquizofrenia/fisiopatologia , Estimulação Transcraniana por Corrente Contínua/métodos , Adulto , Método Duplo-Cego , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
Acetylcholinesterase inhibitors (AChEIs) are efficacious for the treatment of mild to moderate forms of Alzheimer's dementia (AD). Default-mode network (DMN) connectivity is considered to be early impaired in AD. Long-term effects of AChEIs on the DMN in AD have not yet been investigated. Twenty-eight AD patients and 11 age-matched healthy volunteers (HC) participated in the prospective study. AD patients were randomly assigned to either a pharmacotherapy arm (Galantamine, AD G) or to a placebo arm (AD P+G) for the period of 6 months followed by open-label Galantamine therapy from month 7-12. All subjects underwent neuropsychological testing, resting-state functional and structural MRI at baseline and after 12 months, AD patients additionally in between after 6 months. Thirteen AD patients completed the treatment trial and underwent all functional MRI follow-up sequences of good quality. Functional connectivity significantly increased within the AD G group in the posterior cingulate cortex and in the Precuneus between baseline and 12 months follow-up (pcorr<0.05). Between-group analyses demonstrated that functional connectivity in the AD G group significantly increased in the posterior cingulate cortex as well as in the Precuneus compared to the HC group and in the anteromedial aspect of the temporal lobes compared to the AD P+G group, respectively, at 12 months follow-up (pcorr<0.05). Cognitive performance remained stable within groups over time indicating that resting-state fMRI may be sensitive for the detection of pharmacologically induced effects on brain function of AD patients.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Encéfalo/efeitos dos fármacos , Galantamina/farmacologia , Galantamina/uso terapêutico , Modelos Neurológicos , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Inibidores da Colinesterase/farmacologia , Inibidores da Colinesterase/uso terapêutico , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Oxigênio/sangue , Análise de Componente Principal , Escalas de Graduação Psiquiátrica , Descanso , Fatores de TempoRESUMO
Does a religion shape belief-related decisions and influence neural processing? We investigated an eminent bishop of the Catholic Church in Germany by using functional magnetic resonance imaging (fMRI) to assess neural processing while he was responding to short sentences of the Christian Bible, the Islamic Quran, and the Daodejing ascribed to Laozi in Experiment 1. In Experiment 2, continuous praying was further compared to the resting state activity. In contrast to explicit statements of agreeing or not agreeing to different statements from the Bible and the Quran, we found in Experiment 1 no difference in neural activation when the bishop was reading these statements from the two religions. However, compared to reading statements from the Bible, reading statements from the Daodejing resulted in significantly higher activation in the left inferior and middle frontal cortices and the left middle temporal gyrus, although he equally agreed to both statements explicitly. In Experiment 2, no difference during continuous praying and the resting state activity was observed. Our results confirm the difference between explicit and implicit processing, and they suggest that a highly religious person may pray always-or never. On a more general level this observation suggests that ritualized activities might be subliminally represented in resting state activities.
Assuntos
Mapeamento Encefálico , Encéfalo/fisiologia , Catolicismo/psicologia , Religião e Psicologia , Idoso , Encéfalo/anatomia & histologia , Alemanha , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Modelos Neurológicos , LeituraRESUMO
Synchronizing neural processes, mental activities, and social interactions is considered to be fundamental for the creation of temporal order on the personal and interpersonal level. Several different types of synchronization are distinguished, and for each of them examples are given: self-organized synchronizations on the neural level giving rise to pre-semantically defined time windows of some tens of milliseconds and of approximately 3 s; time windows that are created by synchronizing different neural representations, as for instance in aesthetic appreciations or moral judgments; and synchronization of biological rhythms with geophysical cycles, like the circadian clock with the 24-hr rhythm of day and night. For the latter type of synchronization, an experiment is described that shows the importance of social interactions for sharing or avoiding common time. In a group study with four subjects being completely isolated together for 3 weeks from the external world, social interactions resulted both in intra- and interindividual circadian synchronization and desynchronization. A unique phenomenon in circadian regulation is described, the "beat phenomenon," which has been made visible by the interaction of two circadian rhythms with different frequencies in one body. The separation of the two physiological rhythms was the consequence of social interactions, that is, by the desire of a subject to share and to escape common time during different phases of the long-term experiment. The theoretical arguments on synchronization are summarized with the general statement: "Nothing in cognitive science makes sense except in the light of time windows." The hypothesis is forwarded that time windows that express discrete timing mechanisms in behavioral control and on the level of conscious experiences are the necessary bases to create cognitive order, and it is suggested that time windows are implemented by neural oscillations in different frequency domains.
Assuntos
Ritmo Circadiano/fisiologia , Relações Interpessoais , Percepção do Tempo , Humanos , Estudos Longitudinais , Masculino , Modelos Biológicos , Fatores de TempoRESUMO
LITERATURE: One prominent symptom in addiction disorders is the strong desire to consume a particular substance or to display a certain behaviour (craving). Especially the strong association between craving and the probability of relapse emphasises the importance of craving in the therapeutic process. Neuroimaging studies have shown that craving is associated with increased responses, predominantly in fronto-striatal areas. AIM AND METHODS: The aim of the present study is the modification of craving-related neuronal responses in patients with alcohol addiction using fMRI real-time neurofeedback. For that purpose, patients with alcohol use disorder and healthy controls participated once in neurofeedback training; during the sessions neuronal activity within an individualized cortical region of interest (ROI) (anterior cingulate cortex, insula, dorsolateral prefrontal cortex) was evaluated. In addition, variations regarding the connectivity between brain regions were assessed in the resting state. RESULTS AND DISCUSSION: The results showed a significant reduction of neuronal activity in patients at the end of the training compared to the beginning, especially in the anterior cingulate cortex, the insula, the inferior temporal gyrus and the medial frontal gyrus. Furthermore, the results show that patients were able to regulate their neuronal activities in the ROI, whereas healthy subjects achieved no significant reduction. However, there was a wide variability regarding the effects of the training within the group of patients. After the neurofeedback-sessions, individual craving was slightly reduced compared to baseline. The results demonstrate that it seems feasible for patients with alcohol dependency to reduce their neuronal activity using rtfMRI neurofeedback. In addition, there is some evidence that craving can be influenced with the help of this technique. FUTURE PROSPECTS: In future, real-time fMRI might be a complementary neurophysiological-based strategy for the psychotherapy of patients with psychiatric or psychosomatic diseases. For that purpose, the stability of this effect and the generalizability needs to be assessed.
Assuntos
Alcoolismo/terapia , Córtex Cerebral/fisiopatologia , Fissura/fisiologia , Neuroimagem Funcional , Giro do Cíngulo/fisiopatologia , Imageamento por Ressonância Magnética , Neurorretroalimentação/métodos , Córtex Pré-Frontal/fisiopatologia , Adulto , Alcoolismo/fisiopatologia , Alcoolismo/psicologia , Sistemas Computacionais , Conectoma , Sinais (Psicologia) , Feminino , Humanos , Masculino , Adulto JovemRESUMO
This study capitalizes on individual episodic memories to investigate the question, how dif-ferent environments affect us on a neural level. Instead of using predefined environmental stimuli, this study relied on individual representations of beauty and pleasure. Drawing upon episodic memories we conducted two experiments. Healthy subjects imagined pleasant and non-pleasant environments, as well as beautiful and non-beautiful environments while neural activity was measured by using functional Magnetic Resonance Imaging. Although subjects found the different conditions equally simple to visualize, our results revealed more distribut-ed brain activations for non-pleasant and non-beautiful environments than for pleasant and beautiful environments. The additional regions activated in non-pleasant (left lateral prefrontal cortex) and non-beautiful environments (supplementary motor area, anterior cortical midline structures) are involved in self-regulation and top-down cognitive control. Taken together, the results show that perceptual experiences and emotional evaluations of environments within a positive and a negative frame of reference are based on distinct patterns of neural activity. We interpret the data in terms of a different cognitive and processing load placed by exposure to different environments. The results hint at the efficiency of subject-generated representations as stimulus material.