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Biomedical subjects

D G Daniel

Publications and source records attributed to D G Daniel.

At least 55 records · Page 3Linked to original sources
PubMed1989

Temporal lobe pathology in schizophrenia: a quantitative magnetic resonance imaging study.

Although numerous studies have confirmed the presence of larger cerebral ventricles in schizophrenia, the locus of tissue loss remains elusive. By analyzing magnetic resonance scans with computerized image analysis, the authors determined gray and white matter volumes in the temporal lobes and prefrontal regions of 17 patients with schizophrenia and 17 age- and sex-matched normal subjects. The volume of temporal lobe gray matter was 20% smaller in the patients than in the control subjects. The lateral ventricular volume was 67% larger in the patients and, when normalized for brain size, correlated inversely with the volume of temporal lobe gray matter.

Adult↗
PubMed1989

The effect of apomorphine on regional cerebral blood flow in schizophrenia.

A double-blind, placebo-controlled crossover study of the effects of apomorphine on regional cerebral blood flow (rCBF) during a prefrontal cortex activation task was undertaken to explore the role of dopamine on cortical function. The subjects were eight drug-free, chronically psychotic patients; six patients had schizophrenia. In each, apomorphine increased the relative prefrontal flow. The results suggest that enhanced prefrontal dopamine activity may reverse deficits in prefrontal cortex metabolism in schizophrenia.

Adult↗
PubMed1988

Computerized EEG in schizophrenia.

Despite advances in the processing and display of electroencephalographic (EEG) data, the utility of this inexpensive and noninvasive technique in the investigation of schizophrenia has not been well established. We studied the resting EEG in 19 medication-free patients with chronic schizophrenia and 21 normal controls. Patients with schizophrenia had increased delta activity which was not specific to the frontal regions. Schizophrenic patients also had increased fast activity, and this increase was left sided for the fast beta frequency. Alpha frequency was reduced (less than 10.2 Hz) in 7 of 16 schizophrenic patients. Moreover, those patients with an alpha frequency reduction had a significantly larger mean cerebral ventricular size. These results indicate that the EEG does detect neurophysiological changes in schizophrenia. Our understanding of these changes may be enhanced by other neuroimaging techniques such as computed tomography.

Adult↗
PubMed1988

Alpha frequency in schizophrenia: an association with enlarged cerebral ventricles.

Low alpha frequency (less than 10.2 Hz) occurred more frequently in medication-free schizophrenic patients than in normal control subjects, as determined by quantitative EEG analysis. Furthermore, those patients with low alpha frequency had significantly larger lateral ventricles, as measured by CT scan, than did other schizophrenic patients (mean +/- SD ventricle-brain ratios = 9.8 +/- 1.9 versus 5.0 +/- 2.4; p less than 0.01). This finding suggests the existence of a relationship between cerebral structural pathology and the alpha rhythm that may be based on involvement of alpha-generating structures which border the cerebral ventricles. Future EEG studies of schizophrenia may resolve these questions in the context of other brain findings.

Adult↗
PubMed1988

Dementia praecox revisited. Age disorientation, mental status, and ventricular enlargement.

Thirty-nine patients with DSM-III diagnoses of schizophrenia were examined for age disorientation, an inability to produce one's correct chronological age upon request. Six patients were age-disoriented and demented (as defined by Mini-Mental State evaluation), while two patients had delusions concerning their age, but were not demented. Age-disoriented, demented patients had very large cerebral ventricles and very low Mini-Mental State scores. This group differed on the cognitive and neuroanatomic variables from other demented, but not age-disoriented, patients, as well as from non-demented patients who were age-oriented. The age-disoriented patients appeared to be at an extreme end of the dementia spectrum in schizophrenia.

Adult↗
PubMed1987

Capgras delusion and seizures in association with therapeutic dosages of disulfiram.

We have described a patient in whom EEG abnormalities, a seizure disorder, and Capgras syndrome developed two weeks after she started taking disulfiram. That disulfiram has been shown to inhibit dopamine beta-hydroxylase in vitro suggests an etiologic role for dopaminergic pathways in at least some cases of Capgras syndrome. Our experience with this patient suggests that convulsions and psychosis may occur as a side effect of standard dosages of disulfiram in patients with no previous history of psychosis or brain disease. Furthermore, the symptoms may resolve spontaneously without the long-term use of antipsychotic or anticonvulsant medication.

Adult↗
PubMed1985

The effect of nonsedating doses of diazepam on regional cerebral blood flow.

Drugs like diazepam induce tranquilization in small doses and sedation in larger quantities. Regional cerebral blood flow (rCBF) was measured before and 5 min after the intravenous administration of nonsedating doses of diazepam or placebo (given on a double-blind basis) to 20 right-handed volunteers. Subjects who received diazepam showed marked right hemispheric rCBF decreases, especially in the frontal lobe, whereas controls did not show significant differences between the two sets of values. None of the subjects became sleepy during the experiment.

Adult↗
PubMed1985

Disguises of delirium.

In four patients, each of whom displayed overt signs and symptoms of a delirious state, the delirium was overlooked. We describe in detail the features of delirium because this syndrome is protean in its etiology and clinical presentations. It can be life-threatening, and it may not be recognized because the behavioral correlates are often attributed to a functional disorder.

Adult↗