James D. Christensen

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Previous reports have described accelerated loss of cerebral white matter in schizophrenia. Others have reported changes of ventricle volumes in schizophrenic patients, with greatest increases following remission of psychotic symptoms. In this study changes in cerebral white matter volumes and psychotic symptoms were measured in 16 recently decompensated(More)
BACKGROUND Second-generation antipsychotics (SGAs) differ from first-generation antipsychotics (FGAs) with respect to induction of less extrapyramidal morbidity, partially reducing negative symptoms, and causing modest improvement in neurocognitive functioning in patients with schizophrenia. SGAs demonstrate 5-HT2a antagonism. Differential effects of SGAs(More)
We have investigated proton magnetic resonance spectra of the basal ganglia in 41 medication-free outpatients with major depression, prior to starting an 8-week standardized trial of open-label fluoxetine, and 22 matched comparison subjects. Upon completing the trial, depressed subjects were classified as treatment responders (n = 18) or nonresponders (n =(More)
Functional connection among the information-processing (grey-matter) centres within the CNS are necessary for the coordinated processing of perception, affect, thought and behaviour. Myelinated neuronal bundles provide the links among such processing centres. Magnetic resonance diffusion tensor imaging (DTI) can assess the physical integrity of myelin.(More)
The biexponential relaxation behavior of the sodium nucleus affects the accuracy of quantitative measurement of in vivo tissue sodium concentration (TSC). Theoretical analysis and in vivo experimental results are used to demonstrate the extent of the large bias in the measured TSC that arises when the relaxation behavior in vivo differs significantly from(More)
Eleven drug-free patients with a DSM-IV diagnosis of schizophrenia who were in a period of psychotic exacerbation were treated with antipsychotics for 4 weeks. To evaluate treatment-associated changes in the basal ganglia and in psychotic symptomatology, the patients were studied with magnetic resonance imaging and with the Scale for the Assessment of(More)
Reliable interpretation of the MR signal intensity over the FOV of an image must consider the spatial heterogeneity of instrumental sensitivity. A major source of such variation is the nonuniformity of the B1 magnetic field of the radiofrequency coil. This heterogeneity can be minimized by coil design but is exaggerated by surface coils, which are used to(More)
Recent reports from serial brain scans suggest that the rate of ventricular expansion and/or brain atrophy may be accelerated in at least some schizophrenics. The authors assessed the effect of state changes upon such findings.Within-subject 3D MRIs were assessed for ventricular and brain volumes during periods of [partial] remission and of exacerbation of(More)
Thalamic volumes and psychotic symptoms were assessed during psychotic exacerbation and during antipsychotic drug treatment. Reduction of psychotic symptoms (SAPS) during four weeks of treatment was highly correlated with volumetric expansion as measured by magnetic resonance imaging in both left and right thalamus [r(s)=0.75 and r(s)=0.82, respectively(More)
The question of whether schizophrenic-like disorders are neurodevelopmental or degenerative in origin has been argued since the time of Kraepelin. The authors provide evidence for the existence of two etiologically distinct endophenotypes of the psychoses contained within the rubric of familial non-affective psychosis (schizophrenia), one atrophic and the(More)