24 research outputs found
Reduced Gray to White Matter Tissue Intensity Contrast in Schizophrenia
BACKGROUND: While numerous structural magnetic resonance imaging (MRI) studies revealed changes of brain volume or density, cortical thickness and fibre integrity in schizophrenia, the effect of tissue alterations on the contrast properties of neural structures has so far remained mostly unexplored. METHODS: Whole brain high-resolution MRI at 3 Tesla was used to investigate tissue contrast and cortical thickness in patients with schizophrenia and healthy controls. RESULTS: Patients showed significantly decreased gray to white matter contrast in large portions throughout the cortical mantle with preponderance in inferior, middle, superior and medial temporal areas as well as in lateral and medial frontal regions. The extent of these intensity contrast changes exceeded the extent of cortical thinning. Further, contrast changes remained significant after controlling for cortical thickness measurements. CONCLUSIONS: Our findings clearly emphasize the presence of schizophrenia related brain tissue changes that alter the imaging properties of brain structures. Intensity contrast measurements might not only serve as a highly sensitive metric but also as a potential indicator of a distinct pathological process that might be independent from volume or thickness alterations
Disturbance of intentionality: a phenomenological study of body-affecting first-rank symptoms in schizophrenia.
OBJECTIVES: In 1950, Kurt Schneider proposed that a considerable number of schizophrenia patients develop first-rank symptoms (FRS). In such cases, patients report made experiences, replaced control of will, thought insertion, broadcast or withdrawal and delusional perception, respectively. Although a number of recent studies tend to explain FRS in terms of neurobiological and neuropsychological processes, the origin of these symptoms still remains unknown. In this paper, we explore the subjective experience of patients with the following two FRS: (1) "made" impulses and (2) "made" volitional acts. METHOD: The method applied for the study of two FRS consists first in the overview of psychiatric and philosophical literature and second in the further investigation of subjective experience in patients with FRS. Psychopathological and phenomenological aspects of FRS are discussed by means of patient cases. RESULTS: We discovered a profound transformation of intentionality and agency in schizophrenia patients with body-affecting FRS. This concept offers an insight into the interrelatedness between particular FRS. CONCLUSION: We propose that the subjective experience of schizophrenia patients with body-affecting FRS is rooted in the disturbance of intentionality and diminished sense of agency. This theoretical account of body-affecting FRS will open up new directions in both phenomenological and neurobiological psychiatric research
Evidence for Distinguishable Treatment Costs among Paranoid Schizophrenia and Schizoaffective Disorder.
Schizophrenia spectrum disorders result in enormous individual suffering and financial burden on patients and on society. In Germany, there are about 1,000,000 individuals suffering from schizophrenia (SZ) or schizoaffective disorder (SAD), a combination of psychotic and affective symptoms. Given the heterogeneous nature of these syndromes, one may assume that there is a difference in treatment costs among patients with paranoid SZ and SAD. However, the current the national system of cost accounting in psychiatry and psychosomatics in Germany assesses all schizophrenia spectrum disorders within one category.The study comprised a retrospective audit of data from 118 patients diagnosed with paranoid SZ (F20.0) and 71 patients with SAD (F25). We used the mean total costs as well as partial cost, i.e., mean costs for medication products, mean personal costs and mean infrastructure costs from each patient for the statistical analysis. We tested for differences in the four variables between SZ and SAD patients using ANCOVA and confirmed the results with bootstrapping.SAD patients had a longer duration of stay than patients with SZ (p = .02). Mean total costs were significantly higher for SAD patients (p = .023). Further, we found a significant difference in mean personnel costs (p = .02) between patients with SZ and SAD. However, we found no significant differences in mean pharmaceutical costs (p = .12) but a marginal difference of mean infrastructure costs (p = .05) between SZ and SAD. We found neither a common decrease of costs over time nor a differential decrease in SZ and SAD.We found evidence for a difference of case related costs of inpatient treatments for paranoid SZ and SAD. The differences in mean total costs seem to be primarily related to the mean personnel costs in patients with paranoid SZ and SAD rather than mean pharmaceutical costs, possibly due to higher personnel effort and infrastructure
Orbitofrontal cortex and impulsivity in borderline personality disorder: An MRI study of baseline brain perfusion
Behavioral and neuroimaging studies in patients with borderline personality disorder (BPD) have associated orbitofrontal cortex (OFC) dysfunction with distinct symptom clusters such as impulsivity. It is unclear, however, whether abnormal patterns of OFC activity are also present during resting-state conditions and whether OFC dysfunction is specifically associated with impulsivity in BPD. This study tested the hypothesis that BPD patients would exhibit changes of OFC baseline perfusion and explored the relationship between regional cerebral blood flow and distinct BPD symptom clusters, such as impulsivity, dissociation tension and depressive symptoms. Using continuous arterial spin labeling magnetic resonance imaging at 3 Tesla, we investigated 16 women with BPD according to DSM-IV criteria and 16 healthy female control participants during resting-state conditions. Between-group comparisons were conducted using an analysis of variance (p < 0.05 cluster corrected). Compared to controls, BPD patients exhibited decreased blood flow in the medial OFC, whereas increased blood flow was found in the left and right lateral OFC. Correlation analyses revealed a positive relationship between medial and lateral orbitofrontal blood flow and impulsivity scores, whereas measures of dissociation tension and depression did not exhibit a significant correlation with OFC perfusion. These data suggest that dysfunction of medial and lateral regions of the OFC could specifically mediate symptoms of impulsivity in BP
Longitudinal functional magnetic resonance imaging of cognition in preclinical Huntington's disease
Neuropsychological and functional neuroimaging studies have revealed early changes of cognition and brain function in individuals with the Huntington's disease (HD) gene mutation who are presymptomatic for the motor symptoms of the disease (preHD). However, little is known about whether changes of neural function progress over time. In this study, we used neuropsychological tests of attention, working memory and executive function, functional magnetic resonance imaging and voxel-based analyses of high-resolution structural data to explore the temporal dynamics of potential cognitive, functional and structural biomarkers in far from onset preHD (n = 13, mean time to the estimated motor symptom onset = 19.5 years) and healthy controls (n = 13) followed over a 2-year period. Behavioral measures were similar in preHD individuals and controls at baseline and remained normal 2 years later. At both time points, the left dorsolateral prefrontal cortex was less active in preHD than in controls during working memory performance. The left dorsolateral prefrontal cortex did not exhibit further loss of activity over time. Regions showing less gray matter volume in preHD at baseline did not show further volume loss over time. These data indicate that the activity in brain regions contributing to working memory processing differs consistently in HD expansion mutation carriers while cognitive performance remains normal. However, the present data do not support the notion of a progressive decline of left prefrontal cortex activity in far from onset preHD followed over a 2-year period. (C) 2011 Elsevier Inc. All rights reserved
Aberrant connectivity of resting-state networks in borderline personality disorder
Background: Several functional neuroimaging studies have reported regionally abnormal activation of the frontal cortex in individuals with borderline personality disorder (BPD) during cognitive and affective task performance. However, little is known about neural function in individuals with BPD during the resting state. Using functional magnetic resonance imaging (fMRI), this study investigated the functional connectivity of prefrontal and limbic networks in patients with BPD. Methods: Between January 2009 and March 2010, we investigated patients with BPD according to DSM-IV criteria and healthy controls by means of resting-state fMRI. The data were analyzed using a spatial group independent component analysis, and random effects t tests were used to compare spatial components between groups (p < 0.005, uncorrected). Results: There were 17 women with BPD and 17 female healthy controls enrolled in this study. Within a network comprising cortical midline regions ("default mode network"), patients with BPD showed an increase in functional connectivity in the left frontopolar cortex (FPC) and the left insula, whereas decreased connectivity was found in the left cuneus. Within a network comprising predominantly right lateral prefrontal and bilateral parietal regions, patients with BPD showed decreased connectivity of the left inferior parietal lobule and the right middle temporal cortex compared with healthy controls. Two networks comprising lateral prefrontal and cingulate regions did not exhibit significant between-group differences. We found correlations between functional connectivity of the FPC and measures of impulsivity as well as between connectivity of the insula/cuneus and dissociation tension. Limitations: Co-occurrent axis I disorders and medication use in this sample of patients with BPD have to be considered as potential limitations. Conclusion: These data suggest that abnormal functional connectivity of temporally coherent resting-state networks may underlie certain symptom clusters in patients with BPD
Longitudinal task-negative network analyses in preclinical Huntington's disease
Functional neuroimaging studies have reported task-related brain activation changes in preclinical individuals carrying the Huntington's disease (HD) gene mutation (preHD). Little is known about "task-negative" activity, i.e., patterns of task-related deactivation in preHD, and about the stability of any deactivation changes over the course of the disease. Here, we explored task-related deactivation and functional connectivity of "task-negative" networks (TNNs) in preHD followed over a time period of 2 years. Thirteen far-from-onset preHD (mean time to estimated motor onset = 19.5 years) and thirteen healthy controls were investigated. We used functional magnetic resonance imaging (fMRI), a verbal working memory task, and uni- and multivariate analysis techniques for fMRI data. Behavior was similar in preHD and controls at baseline and did not change 2 years later. At both time points, deactivation was similar in preHD and controls. Within two spatio-temporally distinct TNNs, preHD had lower functional connectivity in the posterior cingulate cortex and higher functional connectivity in the left anterior prefrontal cortex compared to controls (p < 0.05, cluster-corrected). These findings remained stable at follow-up. Anterior prefrontal connectivity correlated with disease burden scores both at baseline and at follow-up. Over time, preHD exhibited higher connectivity in a dorsal cingulate region. Functional connectivity differences within this region were inversely associated with changes of motor function. These data provide first evidence for TNN connectivity changes in preHD followed over a period of 2 years. The relationship between dorsal cingulate connectivity and motor function suggests that "task-negative" activity may capture time-sensitive neural and functional processes in preH
Mean values of personal, medication and infrastructure costs per case in Euro for patients with paranoid SZ (blue) and SAD (red).
<p>The ends of the whiskers indicate the standard deviation. Note that these partial costs do not exactly add up to the amount of total costs, since we did not compare costs for materials other than medication.</p
Demographic characteristics and costs (<i>n</i> = 189).
<p>Demographic characteristics and costs (<i>n</i> = 189).</p