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

Local cerebral glucose metabolism was determined with 18-F-fluorodeoxyglucose using positron emission tomography in a sample of 12 unmedicated schizophrenics and 12 matched normal controls. The data were analyzed for absolute metabolic rates and region/whole-brain ratios using the cortical-subcortical, antero-posterior, and laterality dimensions. Lobar areas within cortical regions were also compared. Across groups, subcortical metabolism was higher than cortical metabolism. Patients had lower metabolism, cortically and subcortically, and a steeper subcortical to cortical gradient. Patients with higher scores on the Brief Psychiatric Rating Scale had higher absolute metabolism and higher left relative to right hemispheric metabolism than did patients with lesser severity. The results did not show "hypofrontality" in schizophrenia. These findings provide some support for cerebral dysfunction in schizophrenia and indicate the need for further examination of the cortical-subcortical dimension.
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PMID:Regional brain function in schizophrenia. I. A positron emission tomography study. 349 82

Reaction time, set index, critical flicker frequency, two-flash threshold, a sustained performance task and psychophysiological parameters from people with chronic schizophrenic disorder (n = 14) and a control group (n = 12) were analysed to assess the association between arousal, attentional dysfunction and social dysfunction in schizophrenia. Shorter reaction time, rated ability to mime and, in the schizophrenic group, scores on Venable's ward activity scale correlated with each other. In the schizophrenic group, prolonged reaction time latency correlated positively with skin conductance level in the right hand and negatively with skin conductance variability in the left hand, the latter being in the opposite direction to that for the control group. The results may provide support for the hypothesis that lateralised cerebral dysfunction is associated with performance deficits in people with chronic schizophrenic symptoms.
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PMID:Chronic schizophrenic disorder. II. Reaction time, social performance and arousal. 366 8

There are numerous reports of lateral cerebral ventricle enlargement on computed tomography (CT) in schizophrenics, but the significance and its relationship to traditional notions of organicity remain unclear. Therefore we studied a subgroup of chronic schizophrenics who had lateral ventriculomegaly (and also cortical hyperdensity) on a battery of relevant biological, neuro-psychological, and clinical parameters such as electroencephalogram (EEG), platelet monoamine oxidase (MAO) and serum dopamine-beta-hydroxylase (DBH) activity, the Halstead Reitan Neuropsychological Battery (HRB), premorbid personality adjustment, drug response, positive and negative symptoms, employment history, and family history. Our findings support the notion that there is an "organic" subgroup of schizophrenia that has 1) CT structural abnormalities such as lateral ventricle enlargement and cortical hyperdensity; and cerebral dysfunction or deficits as evidenced by 2) an increased incidence of abnormal EEGs and also 3) greater impairment on neuropsychological tests. The biochemical measures, platelet MAO and serum DBH activity, nor any of the clinical measures could differentiate between the subgroups. The implications of these findings for the subtyping of schizophrenia are discussed.
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PMID:A comprehensive study of chronic schizophrenic patients. II: Biological, neuropsychological, and clinical correlates of CT abnormality. 370 93

Numerous homeostatic mechanisms regulate impulse traffic in the neural pathways of the brain. If, for whatever reason, these mechanisms are unable to maintain neural activity within normal levels, the resulting disruption of the balance of impulse traffic produces brain dysfunction such as mental or neurological disorders. Drug treatment of these disorders involves the use of agents that return impulse traffic to homeostatic levels. Such agents have been found only for certain disorders such as Parkinson's Disease, certain affective disorders and some aspects of schizophrenia. The development of therapeutic interventions for currently untreatable conditions such as Huntington's Chorea or Alzheimer's Disease and the design of drugs for the more efficient treatment of psychiatric disorders, would be greatly facilitated by more detailed knowledge of the specific homeostatic mechanisms controlling brain function.
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PMID:Neurochemical psychiatry as a source of hypotheses concerning the role of homeostatic mechanisms in brain function. 615 Sep 4

A comprehensive overview of the clinical aspects of lithium therapy is presented. Emphasis is placed on recent developments regarding the clinical uses of Li2CO3 in non-psychiatric conditions. The established efficacy of the drug in the treatment and prophylaxis of mania and bipolar affective disorders is noted, and the evidence supporting the use of lithium salts as a prophylactic agent in unipolar depression, aggressive behavior, schizophrenic disorders and organic brain dysfunction is discussed. The use of lithium carbonate in various disorders of movement and in certain extrapyramidal diseases is summarized, as are the results of its trials in alcoholism and drug abuse. In addition, uses of Li2CO3 in asthma, thyroid diseases, granulocytopenia, headache, bowel disease, anesthesiology, cardiology, and sleep disorders are summarized. The data suggests the potential effectiveness of Li2CO3 in a variety of clinical conditions other than those for which it is classically indicated, provided more detailed double-blind studies are performed.
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PMID:Clinical uses of lithium salts. 641 55

The present study was an attempt to investigate hypotheses about the interrelationship of brain dysfunction and symptoms of schizophrenia using the Brief Psychiatric Rating Scale (BPRS) and a measure of cerebral ventricular size. The ventricular brain ratio (VBR) was correlated with admission and discharge scores on the BPRS in 46 schizophrenic patients. A significant relationship was found between VBR and discharge BPRS scores. In general, the results were partially supportive of relationships found between neuropsychological data and the BPRS in a previous study, but shed little light on the relationships between brain damage and negative and positive symptoms. Limitations of using the BPRS, as well as possible sampling variations, are discussed.
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PMID:The BPRS in assessing symptom correlates of cerebral ventricular enlargement in acute and chronic schizophrenia. 660 28

Both schizophrenia and substance abuse have been associated with cerebral impairment, although the neuro psychological performance of schizophrenic patients with substance abuse histories has not been examined. In this study, the Luria-Nebraska Neuropsychological Battery was administered to schizophrenic patients with or without histories of substance abuse. The study found that the schizophrenics without substance abuse histories showed evidence of cerebral dysfunction, while those schizophrenics with histories of substance abuse could not be differentiated from normal.
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PMID:Neuropsychological performance in schizophrenics with histories of substance abuse. 716 91

Assessed the efficacy of the Whitaker Index of Schizophrenic Thinking, Form A, in differentiating schizophrenics with and without brain damage. Two groups of 26 state hospital residents each were selected on the basis of evidence of schizophrenia and (or lack of evidence) of brain damage. Results indicated that at least one subtest, total time, and Index significantly discriminated between groups. Additionally, a cut-off index reliably discriminated schizophrenics with brain damage. Discussed were implications for diagnosis and treatment of the populations examined as well as the relationship between brain dysfunction and cognitive processes of schizophrenia.
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PMID:Differentiation of schizophrenics with and without brain damage using the Whitaker Index of Schizophrenic Thinking. 726 70

We used the Wechsler Adult Intelligence Scale (WAIS) to study a sample of patients with affective disorder (N = 52), schizophrenia (N = 17) and organic brain disease (N = 8). Schizophrenic patients had lower verbal, performance and full-scale IQs than patients with affective disorder, but were no different from those with organic brain disease. An individual WAIS subscale analysis showed that, compared with affectives, schizophrenics had relatively poorer performance on language than non-language tasks. These differences were independent of age, sex, handedness, educational level or drug administration and are consistent with a variety of studies demonstrating significant cerebral dysfunction in carefully diagnosed schizophrenic patients.
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PMID:Cognitive dysfunction in schizophrenia, affective disorder and organic brain disease. 731 99

An association has been established between the multifactorially inherited rate of physical maturation and the final step in brain development, when some 40% of synapses are eliminated. This may imply that similarly to endocrine disease entities, we have cerebral disease entities at the extremes of the maturational rate continuum. The restriction of prepubertal pruning to excitatory synapses leaving the number of inhibitory ones fairly constant, implies changes in cerebral excitability as a function of rate of maturation (age at puberty). In early maturation there will be an excess in excitatory drive due to prematurely abridged pruning, which compounds a synchronization tendency inherent in excessive synaptic density. Lowering excitatory level with antiepileptics is hypothesized to be a logical treatment in this type of brain dysfunction. In late maturation, a deficit in excitatory drive due to failure to shut down the pruning process associated with a tendency to the breakdown of circuitry and desynchronization, adds to a similar adversity inherent in reduced synaptic density. Raising the excitatory level with convulsants is hypothesized to be the treatment for this type of CNS dysfunction. The maturational theory of Kraepelin's psychoses holds that they are naturally occurring contrasting chemical signaling disorders in the brain at the extremes of the maturational rate continuum: manic depressive psychosis is a disorder of the early maturer and comprises raised cerebral excitability and a raised density of synapses. This is successfully treated with anti-epileptics like sodium valproate and carbamazepin. Schizophrenia is a disorder in late maturation with reduced cerebral excitability and reduced synaptic density. This is accordingly treated with convulsants such as typical and atypical neuroleptics. However, the conventional effective treatments in both disorders act on inhibition only by either lowering or raising inhibitory level. While the neuroleptics drugs are superior anti-psychotics they nevertheless do not affect the deviation in cerebral excitability which would explain why they do not cure. Disturbed circadian rhythms which precede psychotic episodes in manic depressives accord with a primary dysfunction in the CNS, the suprachiasmatic nucleus of the hypothalamus via its direct input the glutamatergic retinohypothalamic tract. The residual deficits in schizophrenia accord with persistently disconnected circuitry and communication which is a consequence of reduced excitatory level and is manifested in insufficient motivation, a reduced drive associated hypofunction, and neuromuscular dysfunction.
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PMID:The maturational theory of brain development and cerebral excitability in the multifactorially inherited manic-depressive psychosis and schizophrenia. 777 16


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