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Query: UMLS:C0036341 (schizophrenia)
 60,220 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Seeking to unite psychological and biological approaches, this paper links cognitive and cellular hypotheses and data about thought and language abnormalities in schizophrenia. The common thread, it is proposed, is a dysregulated suppression of associations (at the behavioral and functional neural systems level), paralleled by abnormalities of inhibition at the cellular and molecular level, and by an abnormal anatomical substrate (reduced MRI gray matter volume) in areas subserving language. At the level of behavioral experiments and connectionist modeling, data suggest an abnormal semantic network connectivity (strength of associations) in schizophrenia, but not an abnormality of network size (number of associates). This connectivity abnormality is likely to be a preferential processing of the dominant (strongest) association, with the neglect of preceding contextual information. At the level of functional neural systems, the N400 event-related potential amplitude is used to index the extent of "search" for a semantic match to a word. In a short stimulus-onset-asynchrony condition, both schizophrenic and schizotypal personality disorder subjects showed, compared with controls, a reduced N400 amplitude to the target words that were related to cues, e.g. cat-dog, a result compatible with behavioral data. Other N400 data strongly and directly suggest that schizophrenics do not efficiently utilize context.
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PMID:Cognitive dysfunction in schizophrenia: unifying basic research and clinical aspects. 1065 12

Recent evidence from controlled CT and MRI longitudinal studies suggests that some cerebral ventricular enlargement and hemispheric volumetric reductions (e.g. cerebral atrophy) may have a progressive component in patients with schizophrenia. These studies vary in cohort composition, stage of illness examined, duration of follow-up interval, imaging techniques used, and specific brain regions with findings. They also conflict with earlier evidence suggesting that schizophrenia is a neurodevelopmental disorder with brain pathological deviance occurring prior to the illness onset. The newer brain imaging reports may be detecting subtle brain plasticity that results from a continuing cortical disruptive process, may be epi-phenomena caused by scanning and image analysis artifacts or may possibly reflect systemic physiological fluctuations. Future longitudinal studies of subjects at all stages of illness using a variety of new technologies are needed to clarify these findings.
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PMID:Defining the course of brain structural change and plasticity in schizophrenia. 1068 56

Fifty first-episode patients with schizophrenia were followed for 5 years subsequent to their first hospitalization. The course of illness was charted prospectively and premorbid childhood histories were obtained retrospectively at the initial evaluation, and MRI scans were obtained initially and at each follow-up. Fifteen different life-time patterns of illness course emerged, although none were specifically associated with structural brain change. A deterioration in premorbid scores was positively correlated with larger ventricular volume at the first hospitalization, and the larger the ventricles, the less the subsequent change in ventricular size thereafter. An analysis to see whether initial hemispheric and ventricular size could predict different course types only revealed that patients with an acute onset and complete recovery had significantly smaller ventricles than all others. No differences emerged for initial hemispheric size. Thirty-four percent of patients individually showed some association of brain ventricular size and 28% hemisphere volume reductions with fluctuation in psychotic symptoms. Paradoxically, most showed larger ventricles and smaller hemispheres to be associated with clinical improvement, rather than the predicted reverse. These latter data question the notion that the structural brain changes seen over time in some patients are related to poor outcome, although small ventricular size in those patients with acute onset may be predictive of recovery. Thus, brain structural change is occurring early in the course of illness and may be a consequence of the process leading to resolution.
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PMID:Association of brain structural change with the heterogeneous course of schizophrenia from early childhood through five years subsequent to a first hospitalization. 1071 Jan 65

This paper summarises the available information on MRI-determined hippocampal morphometry in first-episode patients as an illustration of the value and interpretation of findings in the neurobiology of early phase schizophrenia. We report a thin slice (1.5 mm) study of 32 first episode and 39 high risk patients which demonstrated significantly smaller hippocampi (right -9%, left -11%) in first episode patients that were of a similar magnitude to those found in chronic patients (right -10%, left -11%) but non-significant volume reductions in high risk individuals, including the 15 subjects who subsequently developed psychoses. Consideration is given to the implications of these findings, including the possible role of early and later neurodevelopmental influences. We present animal data showing that chronic placental insufficiency, as elicited by uterine artery ligation can give rise to substantial reduction (31%) in hippocampal volumes and reflect on other potentially relevant pathophysiological mechanisms, including those that may occur during the early phases of psychotic illnesses, including their prodromes. Greater attention needs to be paid to the study of early phase psychosis in order to obtain a clearer understanding of the nature and time course of neurobiological changes associated with it. Although there is a growing literature on first episode psychosis, there is a striking dearth of information on the neurobiology of the prodrome.
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PMID:Neurobiological findings in early phase schizophrenia. 1071 44

The corpus callosum is one of several brain regions thought to be abnormal in schizophrenia. We sought to investigate whether the size of the corpus callosum would be abnormally small in schizophrenic subjects from families with familial schizophrenia and their healthy relatives. We wished to determine whether an abnormal corpus callosum size is found in healthy relatives who are genetically at a greater risk than normal of developing or transmitting the disorder. Twenty-seven familial schizophrenics, 53 of their healthy first-degree relatives, and 35 normal volunteers underwent MRI brain scans. We defined 11 of the relatives as presumed 'obligate carriers', i.e. an individual who appears to be transmitting the schizophrenic gene(s). The mid-sagittal slice of the corpus callosum and the whole brain volume were measured blind to diagnostic and family group. We found no difference between schizophrenics, their relatives, and normal controls in the mid-sagittal area of the corpus callosum. There remained no difference when the relatives were divided into two groups comprising presumed 'obligate carriers' and 'non-obligate carriers'. Adjusting for age and whole brain area made no difference to the results. Families with several schizophrenic members are not associated with abnormality in the size of the corpus callosum.
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PMID:A magnetic resonance imaging study of corpus callosum size in familial schizophrenic subjects, their relatives, and normal controls. 1072 17

The administration of the omega-3 fatty acid eicosapentaenoic acid (EPA) to a drug-naive patient with schizophrenia, untreated with conventional antipsychotic medication, led to a dramatic and sustained clinical improvement in both positive and negative symptoms. This was accompanied by a correction in erythrocyte membranes of abnormalities in both n-3 and n-6 highly unsaturated fatty acids and with reduced neuronal membrane phospholipid turnover, as evidenced by serial 31-phosphorus cerebral magnetic resonance spectroscopy. Using recently developed techniques of image segmentation, subvoxel registration and quantitation, analysis of serial high-resolution 3D cerebral MRI scans showed that, in the year before EPA treatment, cerebral atrophy was taking place and that this atrophy was reversed by six months of EPA treatment. These results demonstrate that EPA can reverse both the phospholipid abnormalities previously described in schizophrenia and cerebral atrophy. They provide strong further evidence in support of the membrane phospholipid model of schizophrenia.
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PMID:Eicosapentaenoic acid treatment in schizophrenia associated with symptom remission, normalisation of blood fatty acids, reduced neuronal membrane phospholipid turnover and structural brain changes. 1075 Feb 63

A variety of brain structural abnormalities, which can be identified only by qualitative methods, have been shown to correlate with clinical presentation and course of schizophrenia. In the present study, MRI scans of 122 patients with DSM-IV schizophrenia and 81 non-psychiatric controls were evaluated. Among males, the frequency of CNS developmental abnormalities (CDAs) was higher in patients than in controls. Lateral ventricular enlargement (LVE) was more frequent in patients than in controls; when subjects were grouped in three age classes, LVE was more frequent in patients than in controls in the youngest and the oldest age group. Patients with LVE or third VE were older than those without these abnormalities. Schizophrenic patients with LVE or cortical atrophy (CA) had a longer duration of illness than those without these abnormalities. Both patients with LVE and those with third VE had a poorer outcome than those without these abnormalities. CDA findings add to the evidence of a higher frequency of neurodevelopmental abnormalities in male schizophrenic patients. Results concerning LVE suggest that both developmental and degenerative processes underlie this abnormality. The association of LVE and third VE with a poor outcome indicates that qualitative MRI evaluation might be of clinical relevance.
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PMID:Qualitative MRI findings in patients with schizophrenia: a controlled study. 1076 37

We report a young adult female case of Wilson's disease presenting with mental disorder and frontal lobe signs. The patient was admitted to our neurological unit on October 4, 1999 because of schizophrenia-like symptom, dysphagia, dysarthria and gait disturbance. She showed slowly progressive rigidity and dystonia. Her parents were the second cousins. Neurological examination revealed bilateral pyramidal and extrapyramidal signs, frontal lobe signs (include the imitation behavior). Tendon reflexes were slightly exaggerated in all extremities. Bilateral Babinski, Chaddock and Hoffmann signs were positive. Her verbal IQ on the Wechsler Adult Intelligence Scale-revised was 49. Biochemical examination revealed low plasma copper and ceruloplasmin concentration. Cerebrospinal fluid was normal. Cranial MRI demonstrated diffuse brain atrophy and enlargement of the lateral ventricles. T2-weighted images of the MRI demonstrated hyperintense signal in both thalamus and basal ganglia. SPECT showed hypoperfusion in the left frontal lobe, both thalamus and basal ganglia. EEG revealed diffuse theta wave. The diagnosis of Wilson's disease was made and the treatment of D-penicillamine 900 mg per day was started. This hypoperfusion of SPECT and EEG findings improved after 2 months under D-penicillamine therapy. Neurological findings showed slight improvement. A few Wilson's disease patients presenting with mental disorder have been reported. Wilson's disease should always be considered in differential diagnosis of mental disorders. We emphasize the importance of early diagnosis and treatment of Wilson's disease.
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PMID:[A young adult female case of Wilson's disease presenting with mental disorder and frontal lobe signs]. 1108 96

The advent of new and improved imaging devices has allowed an impressive increase in the accuracy and precision of MRI acquisitions. However, the volumetric nature of the image formation process implies an inherent uncertainty, known as the partial volume effect, which can be further affected by artifacts such as magnetic inhomogeneities and noise. These degradations seriously challenge the application to MRI of any segmentation method, especially on data sets where the size of the object or effect to be studied is small relative to the voxel size, as is the case in multiple sclerosis and schizophrenia. We develop an approach to this problem by estimating a set of bounds on the spatial location of each organ to be segmented. First, we describe a method for 3D segmentation from voxel data which combines statistical classification and geometry-driven segmentation; then we discuss how the partial volume effect is estimated and object measurements are obtained. A comprehensive validation study and a set of results on clinical applications are also described.
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PMID:Segmentation and measurement of brain structures in MRI including confidence bounds. 1114 8

Some cognitive disturbances accompanying schizophrenia may be due to abnormalities in the thalamus and components of the limbic system. The fornix is an important white-matter relay pathway connecting these structures and is likely to be affected in schizophrenia as well.Magnetic resonance images of the fornix were analyzed in 15 schizophrenic patients and 15 matched comparison group subjects. Fornix volume was compared between the two groups and was also correlated with the volumes of other neuroanatomical structures, as well as with illness presentation, clinical status, and cognitive/psychological measures. There was no significant difference in fornix volume between the two groups. Of note, fornix volume correlated significantly with the volumes of the hippocampus, parahippocampus, and the superior temporal gyrus in the schizophrenic subjects, but not in the controls. Moreover, the correlation between fornix and parahippocampal gyrus volumes differed significantly between the two groups. No association was found between fornix volume and illness presentation or between fornix and cognitive/clinical measures.Results suggest that there are no marked changes in fornix volume in schizophrenia by MRI. The fornix, however, may be part of a network of structures affected in schizophrenia, as indicated by correlated volumetric changes.
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PMID:A quantitative MR measure of the fornix in schizophrenia. 1116 48


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