1,721,133 research outputs found
BRAIN COMMUNICATION IN SCHIZOPHRENIA: INSIGHT FROM THE PREVENT STUDY
Full text linkIl ruolo del corpo calloso nella comunicazione interemisferica è documentato nell'uomo. Alterazioni della comunicazione interemisferica sono state evidenziate nei disturbi psichiatrici, soprattutto nella schizofrenia (Mohr et al., 2000). lo scopo dello studio è valutare la connettività interemisferica in un campione di soggetti con schizofrenia comparati a controlli sani mediante la risonanza magnetica funzionale. i risultati ottenuti dimostrano la presenza nei pazienti di diffuse iperattivazioni e ipoattivazioni localizzate, verosimilmente riconducibili a una condizione di overworking diffuso cerebrale durante l'esecuzione della task.Background: The role of the CC in sustaining inter-hemispheric connectivity is well documented in humans both for simple and more cognitively demanding tasks. Alterations in inter-hemispheric communication have been shown in schizophrenia subjects (Mohr et al., 2000) with few studies investigating interhemispheric information exchange using behavioural tasks. In contrast some studies found no differences between schizophrenia patients and normal controls, but also excessively slow responses involving the left hemisphere were present in schizophrenics (Shelton & Knight, 1984; Florio and colleagues, 2002; Bellani et al., 2010). Moreover, there is some evidence of abnormally long interhemispheric transfer time (IHTT) in schizophrenia showed by evoked related potential studies (Barnett et al., 2005; Barnett and Kirk 2005; Endrass et al., 2002).
Objectives: In the present study, we aimed to study interhemispheric connectivity in a sample of schizophrenia patients and healthy controls using functional Magnetic Resonance Imaging (fMRI) and a visuomotor task named Poffenberger’s task .
Methods: A sample of 21 healthy controls and 21 schizophrenia patients underwent a simple visual manual reaction-time (RT) task (Poffenberger’s paradigm) during a fMRI session. This paradigm was employed to measure interhemispheric transfer (IT) by subtracting mean reaction times (RT) for the uncrossed hemifield-hand conditions, that is, those conditions not requiring an IT, from the crossed hemifield-hand conditions, that is, those conditions requiring an IT to relay visual information from the hemisphere of entry to the hemisphere subserving the response. The obtained difference is widely believed to reflect callosal conduction time. fMRI data were acquired using a 3 Tesla Siemens scanner. We performed separate One Sample t-test CUD for patients and controls.
Results: The blood oxygenation level-dependent (BOLD) response was present in the genu of corpus callosum in males and females separately and in the whole group (p<0.01 uncorrected). In the patient group, there is a diffuse hyperactivation in the brain (p<0.01).
Hyper-activations and hypo-activations were found in the schizophrenic patients in comparison to the healthy controls depending on the area of the brain and on the task. The blood oxygenation level-dependent (BOLD) response was higher in the pre-central gyrus (frontal motor cortex), middle frontal gyrus, inferior frontal gyrus, post central gyrus (parietal sensory cortex), and in the putamen for the crossed-uncrossed difference condition. With p<0.01 (uncorrected) activations were wider and also included corpus callosum. Interestingly when females and males are analysed separately, significant hyperactivations persisted only in female SCZ patients excepted for putamen and precentral gyrus that were no more significant.
Conclusions: Our results confirmed previous published studies in humans that tested the implication of corpus callosum in visuo-motor task. In particular our results confirmed the structure-function relationship that involves brain interhemispheric processes in a sample healthy subjects and referred to a specific activation restricted in the genu of corpus callosum. The genu is thought to be associated with the prefrontal cortex to the premotor interhemispheric transfer.
We investigated the role of the CC in regulating functional communication between the hemispheres in schizophrenia patients compared to healthy controls and hyper-activations and hypo-activations were found. These results may reflect a brain diffuse overwork related to the demanding task that is not present in healthy subjects
Limited evidence that antipsychotic drug treatment is associated with reduced brain volume
No full textComment on Moncrieff J, Leo J. "A systematic review of the effects of antipsychotic drugs on brain volume" Psychol Med. 2010 Sep;40(9):1409-22
Corpus callosum, inter-hemispheric communication and language disturbances in schizophrenia
No full textIn the last decades, the study of the neural underpinnings of language has
mainly focused on intra-hemispheric networks. However, more recently,
there has been substantial research investigating the interplay between
linguistic processes and inter-hemispheric communication, which is mainly
mediated by the corpus callosum, in healthy subjects and in individuals
with schizophrenia. In particular, the disordered callosal communication
observed in schizophrenia may affect receptive and productive language
processing
Basal ganglia and restricted and repetitive behaviours in Autism Spectrum Disorders: current status and future perspectives.
No full textThis editorial offers a concise overview of the recent structural magnetic resonance imaging studies that evaluate the basal ganglia (BG) volumes in autism spectrum disorders (ASD). The putative relationship between the repetitive or stereotyped behaviours of ASD and BG volumes is also explored, with a focus on possible translational approaches
Can brain imaging address psychosocial functioning and outcome in schizophrenia?
No full textIn the last two decades, brain imaging has made a pivotal contribution in the comprehension of the biological features of schizophrenia. In particular, magnetic resonance imaging (MRI) represents nowadays the gold standard technique for in vivo exploring the pathophysiology of the disease, because of its high contrast sensitivity and spatial resolution, without radiation exposure. Based on the imaging studies, there is evidence that schizophrenia is characterised by fronto-temporal and callosal abnormalities, which may partly sustain the deficits of cognition and functioning. Since 2003, the Inter-University Center for Behavioural Neurosciences (ICBN) has been specifically exploring the neural underpinnings of schizophrenia, confirming, along with other international laboratories, the presence of disrupted microstructure of the corpus callosum and of the cortical white matter in the disease. The ICBN has therefore been trying to contribute to the understanding of the pathophysiology of schizophrenia and has currently been attempting to couple imaging findings to psychosocial psychiatry, continuing and expanding Professor Tansella's epidemiological studies
Diffusion imaging studies of white matter integrity in bipolar disorder
No full textDiffusion tensor imaging (DTI) is a neuroimaging technique with a potential to elucidate white matter integrity. Recently, it has been used in the field of psychiatry to further understand the pathophysiology of major diseases, including bipolar disorder (BD). This review sought to focus on existing DTI findings on white matter organization in BD
Physical activity interventions to improve cognition in first-episode psychosis: What we know so far
Full text linkBackground: Cognitive impairment is a core feature of psychosis, which adversely affects global functioning and quality of life and has been consistently reported from the early stages of illness. Patients with first-episode psychosis (FEP) exhibit deficits in processing speed, short-term memory, attention, working memory, and executive functioning, which respond poorly to psychotropic drugs. Among non-pharmacological approaches, physical activity has shown promise in improving cognitive functioning in schizophrenia spectrum disorders. However, current evidence lacks specific data on individuals with FEP. In this review, we aim to explore the potential role of physical activity-based interventions in ameliorating the cognitive functions of people with FEP. Methods: The literature search was conducted on PubMed, PsycINFO, and Web of Science in March 2024, identifying 127 de-duplicated records. One additional article was identified by screening the reference lists of the included studies. A total of six studies fulfilled the inclusion criteria and were reviewed. They all analyzed the effect of structured physical activity interventions on the cognitive functioning of patients with FEP. Results: Preliminary findings suggest that physical activity interventions enhance memory, attention, and executive functions of patients with FEP but not social cognition and motor function. Conclusions: Study differences in sample characteristics, design, and intervention protocols prevent firm conclusions about the cognitive-boosting effects of the interventions in FEP. Further studies using more rigorous methodologies are needed to understand the durability of these effects and the underlying mechanisms
Myelination in bipolar patients and the effects of mood stabilizers on brain anatomy
No full textIn this review, we debate the evidence for abnormal white matter microstructure and myelination in bipolar disorder, as mainly detected by diffusion tensor imaging (DTI) studies. The effects of mood stabilizers on white matter are discussed, based on available findings from human and animal studies. Last, perspectives in this field of research are also drawn
Discordant twins as a tool to unravel the aetiology of bipolar disorder.
No full textThis editorial focuses on discordant twins as a valuable epidemiological design for psychiatric aetiological research. First, we summarise the advantages and strengths of this design over the classical matched case-control study. Then, we draw attention to the use of this method in bipolar disorder, revising previous discordant-twin studies. A future greater use of discordant twins is desirable to gain further relevant insights in the aetiology of bipolar disorder
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