Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036341 (schizophrenia)
 60,220 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Comparison of normal and medicated schizophrenic groups on the auditory P300 component of the event-related potential confirmed our earlier finding of a left temporal deficit in P300 amplitude in schizophrenia. A difference in P300 topography between groups was evident in both color mapping and in grand-averaged waveforms, which was statistically validated by the presence of a group-by-scalp region interaction (p less than 0.05). The left temporal area in schizophrenics was denoted as the region of greatest deficit and of maximal statistical separation (p less than 0.05) relative to normals by t statistic mapping (SPM), Hotelling's T-squared "protected" contrasts of individual scalp regions, and the relative ratio of left scalp amplitudes to right scalp amplitudes. The left temporal scalp region yielding maximal group separation in the previous study also statistically separated the schizophrenic group from the normal group. This feature correctly differentiated 9 of 11 schizophrenics and 7 of 9 controls. These findings are compatible with other histological, metabolic, and electrophysiological studies suggesting temporal lobe abnormality in schizophrenia.
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PMID:P300 in schizophrenia: confirmation and statistical validation of temporal region deficit in P300 topography. 336 56

Deficits in olfactory identification, despite normal odor perception, are found in some neuropsychiatric disorders, including schizophrenia. We examined if regional cerebral blood flow (rCBF) differed between schizophrenia patients and controls during odor identification, hypothesizing that these brain regions could be relevant to odor identification impairments. Eight schizophrenia and eight comparison subjects provided a baseline (picture identity matching) and activation (odor identification) SPECT scan, obtained using 99mTc-HMPAO in a low dose/high dose design. Six patients and seven controls had analyzable data. MEDX data saved in ANALYZE format for SPM 95 generated paired t-test statistical data for display in Talairach space, with rCBF changes given as Z-scores. There was no schizophrenia vs. control group difference in rCBF for the baseline picture-matching test. For odor identification, schizophrenia patients had a hypometabolic right-sided cortical region that included the frontal lobe Broca's area, superior temporal lobe, and supramarginal and angular gyri. Post hoc within-group contrasts of picture-matching vs. odor identification showed that the controls significantly increased rCBF in the right-sided inferior temporal fusiform gyrus, and bilateral hippocampi and visual association areas for the odor test. The schizophrenia group showed no rCBF differences for picture-matching compared to odor identification. Patients showed significant hypometabolism in right-sided cortical areas for odor identification. They also failed to show increased rCBF in the hippocampus and visual association area, as seen in controls for odor identification compared to picture-matching. These regions may be unique to schizophrenia or have broader implications for olfactory memory retrieval.
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PMID:SPECT imaging of odor identification in schizophrenia. 964 51

The aim of this study was to compare the gray matter segments from T1 structural MR images of the brain in first-episode schizophrenic subjects (n = 34) and normal control subjects (n = 36) using automated voxel-based morphometry (VBM). This study is novel in that few studies have examined subjects in their first episode of schizophrenia. The subjects were recruited for the Edinburgh High Risk project and regional brain volumes were previously measured using a semi-automated volumetric region of interest (ROI) method of analysis. The primary interest was to compare the results from the compatible parts of the ROI study and the primary VBM approach. Our secondary interest was to compare the results of a study-specific template that was constructed from the control group to those using the generic T1 template (152 Montreal Neurological Institute brains) supplied with SPM99 (statistical parametric mapping). The images were processed and statistically analyzed using the SPM99 program. VBM analysis identified significant decreases in gray matter in the schizophrenics relative to the normal control group at the corrected voxel level (P < 0.05) in the right anterior cingulate, right medial frontal lobe, left middle temporal gyrus, left postcentral gyrus, and the left limbic lobe. There were no increases in gray matter in the schizophrenics relative to the control group. The construction of a customized template appeared to improve the detection of structural abnormalities. The analyses were subsequently restricted to voxels within the amygdala-hippocampal complex using the SPM small-volume correction. This identified gray matter decreases in the schizophrenics, at the corrected voxel level (P < 0.05), in the left and right uncus and parahippocampal gyri and the right amygdala. These results are compatible with and extend the relevant findings of the previous volumetric ROI analysis, when allowing for the differences between the methods and interpretation of their results.
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PMID:Structural gray matter differences between first-episode schizophrenics and normal controls using voxel-based morphometry. 1237 62

This paper compares the metabolic changes associated with risperidone treatment in schizophrenia to those induced by haloperidol, as a representative typical neuroleptic. A group of 11 schizophrenic patients of recent onset underwent two [18F] fluoro-desoxi-glucose (FDG)-positron emission tomography (PET) scans at rest: the first one at the moment of the diagnosis, after a minimal treatment with haloperidol followed by wash-out, and the second one after 6 months on risperidone. The study also included 34 patients on chronic haloperidol for comparison. PET images were analyzed using Statistical Parametric Mapping (SPM'99) methods. The only change after treatment with risperidone with respect to the baseline was a slight increase in activity in the primary visual area and the right insula. Patients on chronic haloperidol showed increased activity in the motor cortex and cerebellum, as compared to both minimally treated and risperidone-treated patients. The pattern of metabolic changes induced by risperidone appears to be different from that produced by typical antipsychotics.
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PMID:Cerebral metabolism and risperidone treatment in schizophrenia. 1250 32

The grey matter (GM) segments from T1 structural magnetic resonance (MR) images of the brain in subjects at high risk of schizophrenia (n=146) were compared with normal control subjects (n=36) and first episode schizophrenic subjects (n=34) using automated voxel-based morphometry (VBM). The subjects were recruited for the Edinburgh High Risk Study (EHRS) and regional brain volumes had previously been measured using a semi-automated volumetric region of interest (ROI) method of analysis. For the current report, the images were processed using a study specific template and statistically analysed using the SPM99 program. The small volume correction tool in SPM was also used to restrict the analyses to specific voxels. Reductions in the probability of grey matter (GM) density were seen bilaterally in the anterior cingulate, and as a trend in the left parahippocampal gyrus for the high-risk vs. control subjects. In contrast, first episode schizophrenia subjects had less GM than high-risk subjects in several frontal and temporal regions. These results are compatible with the findings of our previous volumetric ROI analysis.
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PMID:Voxel-based morphometry of grey matter densities in subjects at high risk of schizophrenia. 1451 96

Voxel-based morphometry (VBM) allows the output of structural data in a Statistical Parametric Map of the brain in the same way that the SPM can do with functional data. Using functional magnetic resonance (fMR), we studied brain activation in 14 patients with schizophrenia and 14 matched normal controls. We found significant hypoactivation in patients in several regions, especially in the right hemisphere, in the dorsolateral frontal and temporal regions and in the inferior parietal. Subcortically, we found strong hypoactivity in the thalamus. The optimized VBM method revealed gray matter (GM) abnormalities in the bilateral supramarginal gyrus and cingulate cortex, and in the right inferior temporal regions. Three regions involved in attentional processes showed both structural and functional deficits: the thalamus, the anterior cingulate and the inferior parietal. The results suggest that these regions may be involved in the attentional deficit in schizophrenia.
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PMID:Decreased cerebral activation during CPT performance: structural and functional deficits in schizophrenic patients. 1500 50

Schizophrenia has been characterized as a complex disease, in which various cerebral regions may be affected. The purpose of this study was to compare the cerebral regions that are involved in mild and severe negative symptoms, and to determine whether the degree of severity can be related to specific dysfunctional areas of the brain. The PANS Scale was used to form two groups of patients with prevalence of negative symptoms: Mildly Affected (MA), and Severely Affected (SA). Brain PETs were obtained in resting conditions, and SPM (Statistical Parametric Mapping) was used to perform statistical comparisons. The MA-group showed increased activity in: posterior cingulate gyrus, middle frontal gyrus, precentral gyrus, middle occipital gyrus, cuneus and post-central gyrus; decreased activity in inferior frontal gyrus, orbitofrontal and fusiform gyrus. The SA-group showed increased activity in: globus pallidus, insular cortex, cuneus, claustrum, post-central gyrus and pre-central gyrus; decreased activity in fusiform gyrus and superior temporal gyri. These results permit correlation of negative symptomatology with abnormalities in the cortico-striato-pallido-thalamic neural circuit. Severity of negative symptoms is clearly correlated to abnormal left external pallidal activation, evidencing the relevance of this nucleus for cognitive, planning and social capabilities. Specific therapeutic strategies might be derived from pallidal neurotransmitter systems studies. Key words: schizophrenia, negative symptoms, severity, PET, globus pallidus, claustrum.
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PMID:Severity of negative symptoms in schizophrenia correlated to hyperactivity of the left globus pallidus and the right claustrum. A PET study. 1504 31

It remains controversial as to what determines the neurodegenerative course in schizophrenia. This study administered a modified version of the Stroop task and investigated the relationship between functional magnetic resonance imaging (fMRI) signal changes in dysfunctioned task-related regions and clinical course variables. Functional MRI data during task performance were acquired from 10 right-handed schizophrenic patients (mean+/-SD age=29.2+/-10.3 years, range of illness duration=0.8-14 years, number of episodes=1-5) and 10 healthy controls (mean+/-SD age=30.3+/-6.4). Imaging data were investigated on a voxel-by-voxel basis for single group analysis and for between-group analysis according to the random effect model using Statistical Parametric Mapping (SPM 99b). Correlation analysis with age as a covariate identified those brain regions whose fMRI signal changes were significantly related to clinical course variables in schizophrenia. The number of psychotic episodes was negatively correlated with the fMRI signal change in the right inferior frontal and the right frontal precentral gyri among the activated regions during the Stroop task in schizophrenia, whereas the length of illness was not so correlated. The number of psychotic episodes was also negatively correlated with the fMRI signal change in the left paracingulate in which functional activity was diminished in the patients relative to the controls. Our results indicate that recurrent psychotic episodes are related to the neurodegenerative course in some dysfunctional brain regions in schizophrenia.
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PMID:Functional imaging evidence of the relationship between recurrent psychotic episodes and neurodegenerative course in schizophrenia. 1605 43

In this paper, we introduce an automated method of calculating Gyrification Index (GI), a measure of cortical folding. Automated GI (A-GI) is an in vivo GI implementation applied to MRI T1 weighted scans and is designed as an extension to the SPM analysis package. The A-GI tool is unbiased in its application, and is unlimited in the size of test cohort to which it can be applied. In comparison to manual methods, A-GI substantially reduces the time costs and improves repeatability. The current A-GI implementation is limited to analysis of prefrontal lobes, but an extension to provide whole brain A-GI is under consideration. In determination of the GI inner contour, A-GI traces high spatial frequencies typically missed in manual tracing, and thus, A-GI reports a high GI value. We examine the operation of this tool in two scan cohorts. We establish that the tool has good repeatability through its application to a cohort where 5 well individuals were scanned 5 times over a period of 6 months. This indicates that A-GI has low susceptibility to scanner noise and is not affected by the variability in brain representation given by repeat scans. We demonstrate replication of hand tracing results by comparisons with a manual GI study that has shown differences between high risk subjects who go on to develop schizophrenia and those who are at high risk but remain well. Direct scan by scan comparisons are carried out between manual and A-GI methods. In respect of scan orientation and coronal sampling, the methods differ, and these considerations contribute to a between methods right prefrontal ICC of 0.67 and left prefrontal ICC of 0.63. The replication results demonstrate that A-GI has discriminatory power equivalent to manual methods. A-GI is therefore a reliable measure of cortical folding that could be usefully applied to a number of MRI data sets of the brain in health and disease.
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PMID:Automated computation of the Gyrification Index in prefrontal lobes: methods and comparison with manual implementation. 1660 Jun 39

Subjects with schizophrenia have cognitive alterations. The functional consequences of these deficits need to be fully determined, in order to implement more effective rehabilitation programs for patients with schizophrenia. This research explores the relationships between cognitive functioning and social problem-solving skills in a group of 20 chronic schizophrenic patients compared with those found in a group of 20 healthy subjects. The following cognitive domains were evaluated: verbal memory (Rey Auditory-Verbal Test; RAVLT), visuo-spatial organization and visuo-spatial memory (Rey-Osterrieth complex figure test; RF), executive functioning (semantic verbal fluency test; VF, design fluency task; DF and Wisconsin Card Sorting Test; WCST), attention (d 2 cancellation test) and general intellectual ability (Standard Progressive Matrices of Raven; SPM). Social problem-solving skills were assessed with a video-based test; the Assessment of Interpersonal Problem-Solving Skills (AIPSS). As a group, patients performed significantly worse than control subjects on every cognitive variable and on AIPSS receiving, processing and sending constructs. Among schizophrenic patients, correlations between AIPSS constructs and neuropsychological tests were observed for VF, DF, d2 and SPM whilst these associations were not replicated in healthy subjects. However, in the whole sample, after adjusting for age, gender and education, SPM displayed significant associations with all three AIPSS constructs. Moreover, after taking SPM into account, neither diagnostic groups (patients versus control) nor cognitive variables, except d2, provided an additional contribution to AIPSS performance. Cognitive impaired performances, mainly frontal, have a deleterious effect on social problem-solving skills in the schizophrenic group. It is suggested that alterations in social problem-solving skills may reflect social anxiety and/or " theory of mind " impairment. These factors may explain the lack of association among healthy subjects. The results support the inclusion of cognitive remediation programs designed to enhance social skills for patients where a cognitive deficit is clearly ascertained.
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PMID:Cognitive functions related to interpersonal problem-solving skills in schizophrenic patients compared with healthy subjects. 1663 29


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