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

Bleuler and Kraepelin are described as icons of the aggressively psychological and aggressively biologic approaches to schizophrenia. We suggest that methodologic advances in studying the function and structure of the brain now allow a reconciliation of these seemingly dissimilar approaches, particularly in the temporal lobe. We begin with a brief historic overview of these different approaches to schizophrenia and then describe structural (magnetic resonance imaging [MRI]), functional (event-related potential [ERP]), and neuropsychological studies in this disorder, including a summary of work conducted in our own laboratory. Recent MRI investigations agree on the presence of volume reductions in schizophrenia in the medial temporal lobe structures of the hippocampus-amygdala complex and of the para-hippocampal gyrus. Furthermore, two recent studies also indicate volume reductions in the superior temporal gyrus (STG). These volume reductions are most prominent in male patients and in the left hemisphere of right-handed patients with schizophrenia. Along with structural studies, there has been a burgeoning interest in MRI-clinical correlations, with volume reductions in the anterior STG being associated with hallucinations and those in the posterior STG being associated with thought disorder. Functional ERP studies also implicate the importance of the temporal lobe in schizophrenia; in addition, ERP abnormalities have been directly associated with a left greater than right MRI volume reduction of the posterior STG. Neuropsychological studies in nonpsychiatric patients are also consistent with a pattern of functional deficits shown to arise from temporal lobe abnormalities, whereas direct MRI-neuropsychological correlations in schizophrenic patients show that decreased performance on tests of verbal memory, abstraction, and categorization correlates with reduced MRI volume of left and right temporal lobe structures. Integration of these findings with those from basic neuroscience suggests a possible role of excitatory amino acid neurotransmission dysregulation and excitotoxicity in the pathology of schizophrenia. A data-based pathophysiologic characterization of schizophrenia is now becoming a reality, and the next few years should see a further unification of the Kraepelinian and Bleulerian approaches to this disorder.
 ...
PMID:Uniting Kraepelin and Bleuler: the psychology of schizophrenia and the biology of temporal lobe abnormalities. 938 26

Functional neuroimaging studies have been performed in many young patients with schizophrenia, but late-onset schizophrenia (LOS) remains largely unexamined by these techniques. We predicted that LOS would demonstrate regional cerebral blood flow (rCBF) abnormalities similar to those seen in early-onset schizophrenia (EOS), but with a basis in demonstrable coarse brain disease. The subjects were 15 LOS and 7 EOS patients and 27 healthy controls. Each was given a detailed clinical and neuropsychological assessment and underwent MRI and Tc99m-HMPAO single photon emission computed tomography (SPECT) scans. The LOS subjects had a significantly lower cerebral hemispheric perfusion than controls, with a lower perfusion in the frontal and temporal lobes bilaterally. The LOS group also had significantly lower left-to-right hemisphere blood flow ratios. EOS subjects had a lower frontal perfusion than the controls, which was significant in the left frontal region. The temporal perfusion in the EOS subjects was greater than in the LOS group, and not different from the control subjects. Left temporal perfusion was the most discriminating variable between LOS and control subjects on logistic regression. Correlations of perfusion with MRI were generally low with the exception that the asymmetry indices were significantly correlated, and basal ganglia perfusion correlated with basal ganglia hyperintensities on MRI. The total cerebral perfusion index correlated significantly with the mini-mental state examination (MMSE) score, and the temporal lobe perfusion correlated with MMSE scores and some verbal memory measures. In the schizophrenic groups, perfusion correlated nonsignificantly with symptom profiles. We conclude that our findings of temporal and frontal rCBF abnormalities, especially on the left side, in LOS are similar to those reported in schizophrenia in general. The results do not provide evidence for coarse brain disease underlying the rCBF abnormalities in LOS, or support the specificity of these abnormalities for particular subsyndromes of schizophrenia.
 ...
PMID:Regional cerebral blood flow in late-onset schizophrenia: a SPECT study using 99mTc-HMPAO. 941 41

In this MRI investigation T2 relaxation times were studied in schizophrenic patients compared to normal control subjects. Approximate T2 relaxation times were calculated using signal intensity at two echo times in several brain regions of 25 male schizophrenic patients and 25 age-matched, normal male control subjects. The schizophrenic patients showed significantly longer T2 relaxation times as compared to normal control subjects in the left anterior column of the fornix. This is a small structure, prone to partial volume effects and this may account for these findings. There was a trend towards longer T2 times in the left frontal cortex and shorter T2 times in [corrected] right temporal cortex in schizophrenic patients as compared to control subjects. There were right/left differences in relaxation times within each group. In both patients and control subjects, frontal lobe white matter T2 was longer on the right than on the left side. This finding is probably due to brain asymmetry and unrelated to the presence or absence of psychiatric illness. In schizophrenic patients only the left temporal cortex showed longer T2 times than the right side. This observation could indicate left sided temporal lobe pathology in schizophrenia.
 ...
PMID:MRI T2 relaxation times of brain regions in schizophrenic patients and control subjects. 943 74

Multifactorial inheritance applied to brain development implies a large continuum of normal variation with deviation from the norm at the extremes of maturational rate. The greater population of neurons, greater arborization of neural networks and excessive synaptic density in early maturation imply that adaptability (plasticity) is a main advantage, as opposed to a deficit in adaptability associated with the reduced number of neurons, reduced connectivity and reduced synaptic density in late slow maturation. It is hypothesised that Planum Temporale (PT) asymmetry and hand-preference predict the rate of CNS maturation as does the cognitive profile on the Wechsler Adult Intelligence Scale (WAIS): PT leftward asymmetry, right-handedness and a left-hemisphere cognitive advantage signifies early fast maturation: PT rightward asymmetry, left-handedness and a right-hemisphere cognitive advantage signify late maturation, while PT symmetry and ambilaterality represent rates of maturation in between. The slower development of males implies a male predominance in disorders affecting late maturers: Developmental Dyslexia (DD) with a predominance of rightward PT asymmetry/symmetry, left-handedness and multiple functional deficits, as well as excessive regressive events confirmed on PT/MRI. Schizophrenia, hypothesised to be a disorder in late maturers, is distinguished by rightward asymmetry/symmetry. Left-handedness and DD are common as is prior delayed development supporting excessive regressive events as do the findings on PT/MRI. To reduce the risk of DD and schizophrenia requires a reduction in late maturation through the enhancement of maturational rate by optimal nutrition before and during pregnancy and later.
 ...
PMID:Cerebral lateralisation and rate of maturation. 950 10

A disturbance in the frontal-striatal-thalamic circuitry has been proposed for schizophrenia, but this concept has been based primarily on indirect evidence from psychopharmacology and analogies with animal research. Diffusion tensor imaging, a new MRI technique that permits direct assessment of the large axon masses stretching from the prefrontal cortex to the striatum, was used to study white matter axon bundles. Diffusion tensor images, high-resolution structural MRI and positron emission tomography scans with 18-fluorodexoyglucose were obtained on five patients with schizophrenia and six age- and sex-matched normal controls. Significantly lower diffusion anisotropy in the white matter of the prefrontal cortex in schizophrenic patients than in normal controls was observed in statistical probability maps. Co-registered PET scans revealed significantly lower correlation coefficients between metabolic rates in the prefrontal cortex and striatum in patients than in controls. These twin findings provide convergent evidence for diminished fronto-striatal connectivity in schizophrenia.
 ...
PMID:MRI white matter diffusion anisotropy and PET metabolic rate in schizophrenia. 951 84

In 40 schizophrenic patients, various criteria of clinical improvement after neuroleptic treatment were compared in order to establish correlations between improvement after treatment and some clinical and MRI parameters. Three ways of evaluation of clinical improvement (CGI scale, PANSS index, percentage of improvement) correlated strongly with one another. Only the distribution of numbers of patients with different clinical improvement evaluated by the use of PANSS index was not statistically significant. Clinical improvement, evaluated with all three methods, significantly correlated with basal PANSS score as well as with the severity of positive symptoms and affective blunting, but not with the severity of schizophrenia negative symptoms. Only clinical improvement with the use of CGI demonstrated significantly better improvement in patients who had good previous response to neuroleptics. This particular method of clinical improvement evaluation, in contrast to other two methods, failed to reveal better response to neuroleptics among patients with no cortical atrophy found in MRI. Among patients with different improvement after treatment, evaluated with the use of all three methods, selected MRI parameters did not show significant differences with the exception of CGI improvement which correlated positively with the intensity of signal in T2-weighted image of gray matter in left medial frontal gyrus.
 ...
PMID:[Improvement criteria after neuroleptic treatment and clinical and neuroradiological factors in schizophrenic psychoses. Preliminary studies]. 952 52

MR imaging of the head was performed in forty schizophrenics (DSM-IV). Mental status was evaluated before and during 8-weeks of neuroleptic treatment. Cortical atrophy in frontal and temporal regions was found in 40% of subjects. They were older, had longer history of schizophrenia, were less active professionally and were more frequently hospitalized. Patients with and without cortical atrophy in MRI did not differ in the severity of schizophrenic psychopathology at baseline. During neuroleptic treatment negative schizophrenia symptoms were significantly better diminished in patients without cortical atrophy than in subjects with cortical atrophy in MRI; this regarded specially the severity of emotional blunting. Clinical improvement after 8-weeks of neuroleptic administration was less favorable in patients with cortical atrophy.
 ...
PMID:[Cortical atrophy in MRI, mental status and neuroleptic treatment effect in schizophrenia]. 954 81

We present the case report of a young woman who suffered from schizophrenia-like psychosis leading to polydipsia and consequent water intoxication. Because of progressive somnolence and epileptic seizures therapy on the intensive care unit became necessary. Findings of MRI and cerebrospinal fluid were consistent with the diagnosis of chronic inflammatory disease of the central nervous system. As other possible causes could be excluded, multiple sclerosis seemed to be most probable. Simultaneous incidence of schizophrenia and multiple sclerosis and the differential diagnosis of central pontine myelinolysis following hyponatremia are discussed.
 ...
PMID:[Schizophreniform psychosis with polydipsia and electrolyte imbalance in multiple sclerosis]. 975 22

Accumulating evidence suggests alterations in brain structure, especially in the prefrontal and temporal cortex, in schizophrenia. Previous studies examining the progression of brain structural alterations in schizophrenia have led to conflicting results. Morphometric studies of the superior temporal gyrus (STG) volumes were conducted in a series of neuroleptic-naive first-episode schizophrenic patients, non-schizophrenic first-episode psychotic patients, and matched healthy controls. Three-dimensional MRI scans were carried out in these subjects before and after one year of treatment. Volume reductions were seen at baseline in the left superior temporal gyrus (adjusted for intracranial volume) in both of the patient groups. Pretreatment illness duration was inversely related to the volume of the left superior temporal gyrus; this relation was confined to males. One-year follow-up MRI investigations in a smaller subset of patients suggested that the STG volume reductions may be reversible. No significant changes were noted in the STG volumes in matched healthy controls who were also scanned at baseline as well as at one-year follow-up. These findings have implications for understanding the nature of the neuropathological processes in early schizophrenia, as well as the potential impact of early treatment.
 ...
PMID:Superior temporal gyrus and the course of early schizophrenia: progressive, static, or reversible? 979 69

Neuroleptics have revolutionized the treatment of schizophrenia and other psychoses since the early 1950s. Several adverse neurobiological effects are, however, associated with the long-term use of these agents. This article will review human and animal studies of these adverse effects, and also present some new data. Tardive dyskinesia (TD) is the most widely studied potentially persistent movement disorder resulting from long-term neuroleptic treatment, and several risk factors for TD development have been identified. Although drug-induced parkinsonism (DIP) usually disappears after the offending agent is withdrawn, a small portion of patients may have persistent parkinsonism. It is however, unclear if this is an aging-related effect. Persistent cognitive impairment associated with long-term use of typical neuroleptics has not been well documented. Atypical antipsychotics may produce improvement in cognitive performance in patients with chronic schizophrenia. MRI changes that are secondary to neuroleptics are possible, but have not yet been studied adequately. There is one unconfirmed report of neurofibrillary tangles associated with long-term neuroleptic use. A number of investigators have reported vacuous chewing movements, and neuropathologic changes following prolonged administration of neuroleptics in animals. We discuss the implications of the various reported adverse effects of long-term use of neuroleptics.
 ...
PMID:Adverse neurobiological effects of long-term use of neuroleptics: human and animal studies. 979 74


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>