Functional imaging and cognitive abnormalities.

Department of Cognitive Neurology, Hammersmith Hospital, London, UK.
The Lancet (Impact Factor: 39.21). 10/1995; 346(8975):615-20. DOI: 10.1016/S0140-6736(95)91441-2
Source: PubMed

ABSTRACT From its initial labelling as dementia praecox, the disorder we now call schizophrenia has always been associated with cognitive impairments. While there was a time when these deficits were believed to be secondary to treatment and institutionalisation, there is now overwhelming evidence that cognitive impairments are an essential feature of schizophrenia. Precise specification of the form of these impairments has important implications for the nature of the underlying brain malfunction.

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    ABSTRACT: Schizophrenia, a disease that has called the attention of many investigators through time and that affects people who are at the greater productive time of their life, continues presenting a world-wide prevalence of 1%. The marked deterioration and the functional disability that makes the families of the affected ones and society relegate them, or to turn them into one more "obligation", are the points that have been emphasized more. As far as the cognitive compromise, the findings are supported in neuroanatomic, functional and imaging basis, as well as in studies that utilizing neuropsychological tests, allow demonstrating the compromise of the attention, social cognitive and executive functions. The objective of the present revision is to update the neurological, neuropsychological and psychiatric concepts whereupon the neurocognitive alterations of schizophrenia are handled.
    01/2009; 17(1):87-94.
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    ABSTRACT: In order to analyze functional connectivity in untreated and treated patients with schizophrenia, resting-state fMRI data were obtained for whole-brain functional connectivity analysis from 22 first-episode neuroleptic-naïve schizophrenia (NNS), 61 first-episode neuroleptic-treated schizophrenia (NTS) patients, and 60 healthy controls (HC). Reductions were found in untreated and treated patients in the functional connectivity between the posterior cingulate gyrus and precuneus, and this was correlated with the reduction in volition from the Positive and Negative Symptoms Scale (PANSS), that is in the willful initiation, sustenance, and control of thoughts, behavior, movements, and speech, and with the general and negative symptoms. In addition in both patient groups interhemispheric functional connectivity was weaker between the orbitofrontal cortex, amygdala and temporal pole. These functional connectivity changes and the related symptoms were not treated by the neuroleptics. Differences between the patient groups were that there were more strong functional connectivity links in the NNS patients (including in hippocampal, frontal, and striatal circuits) than in the NTS patients. These findings with a whole brain analysis in untreated and treated patients with schizophrenia provide evidence on some of the brain regions implicated in the volitional, other general, and negative symptoms, of schizophrenia that are not treated by neuroleptics so have implications for the development of other treatments; and provide evidence on some brain systems in which neuroleptics do alter the functional connectivity.
    01/2014; 6. DOI:10.1016/j.nicl.2014.10.004
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    ABSTRACT: Symptoms of schizophrenia are related to deficits in self-monitoring function, which may be a consequence of irregularity in aspects of the default mode network (DMN). Schizophrenia can also be characterized by a functional abnormality of the brain activity that is reflected in the resting state. Oscillatory analysis provides an important understanding of resting brain activity. However, conventional methods using electroencephalography are restricted because of low spatial resolution, despite their excellent temporal resolution.The aim of this study was to investigate resting brain oscillation and the default mode network based on a source space in various frequency bands such as theta, alpha, beta, and gamma using magnetoencephalography. In addition, we investigated whether these resting and DMN activities could distinguish schizophrenia patients from normal controls. To do this, the power spectral density of each frequency band at rest was imaged and compared on a spatially normalized brain template in 20 patients and 20 controls.
    BMC Neuroscience 09/2014; 15(1):104. DOI:10.1186/1471-2202-15-104 · 2.85 Impact Factor