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Biomedical subjects

M J Dewan

Publications and source records attributed to M J Dewan.

33 records · Page 2Linked to original sources
PubMed1986

A comprehensive study of chronic schizophrenic patients. I. Quantitative computed tomography: cerebral density, ventricle and sulcal measures.

Based on recent computed tomography (CT) studies that have suggested the presence of distinct structural abnormalities in the brains of chronic schizophrenics, the authors evaluated 23 chronic schizophrenics and 23 controls by CT, using linear and area lateral ventricular measures, sulcal and Sylvian fissure widths and cerebral density measures. Technical problems inherent in CT studies and their impact on the use of data generated by such studies are discussed. Although there were few differences between groups, there emerged a distinct subgroup of schizophrenic patients with mild lateral ventricle enlargement associated with increased cortical density. The possible etiopathology for this atypical combination is discussed, including the striking parallels with a recent neuropathological study's findings.

Adult↗
PubMed1986

A comprehensive study of chronic schizophrenic patients. II: Biological, neuropsychological, and clinical correlates of CT abnormality.

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.

Adult↗
PubMed1985

Are schizophrenics with abnormal dexamethasone suppression test results a distinct subgroup?

Nonsuppression on the dexamethasone suppression test (DST) in schizophrenics has been reported by three independent groups. To elucidate the significance of this finding a schizophrenic cohort was tested on a wide range of parameters: computed tomography (CT), electroencephalography (EEG), the Halstead-Reitan Neuropsychological Battery (HRB), platelet monoamine oxidase activity (MAO), serum dopamine-beta-hydroxylase levels (DBH), premorbid personality adjustment, response to medication and family history of mental illness. Our results indicate that DST nonsuppressing and DST suppressing schizophrenics are no different on any of these measures, lending support to the notion that DST nonsuppression in schizophrenics is a random and changing event.

Adult↗
PubMed1984

The ventricular system in chronic schizophrenic patients. A controlled computed tomography study.

Twenty-three chronic schizophrenic patients and 23 controls, all males between 20 and 40 years of age, were evaluated by CT scan. The lateral, third and fourth ventricles, the Sylvian fissures, and the largest sulcus from each of the frontal, parietal, and occipital lobes, were measured in order to determine whether the previously reported ventriculomegaly in schizophrenics was perhaps due to a disturbance of CSF flow or to atrophy, two common causes of ventricular enlargement. We found that in the schizophrenic group the third and fourth ventricles and both Sylvian fissures were significantly enlarged, but not the lateral ventricles or cerebral sulci. Our data suggest that these ventricular changes are not due to a disturbance of CSF flow or to cerebral atrophy. Other possible explanations are discussed.

Adult↗
PubMed1984

False-positive dexamethasone suppression test results related to antipsychotic drug withdrawal: case report.

A nonmelancholic schizophrenic patient showed a positive dexamethasone suppression test (DST) 3 days after antipsychotic drug withdrawal. The patient was then put on a stable dose of the antipsychotic and a repeat DST showed normal suppression. The drug was again stopped, and 3 days later a DST was positive. This indicates that antipsychotic withdrawal may lead to false-positive DST results. The theoretical implications and clinical relevance of this finding are discussed.

Adult↗
PubMed1983

Cerebellar morphology in chronic schizophrenic patients: a controlled computed tomography study.

Simple, objective, linear, and density measures were used to evaluate by computed tomography (CT) the cerebellum-fourth ventricular region of 23 chronic schizophrenic patients and 23 normal controls. Our data suggest that a subgroup of chronic schizophrenic patients have cerebellar atrophy associated with a strong but nonsignificant trend toward increased cerebellar density. The implications of these findings are discussed in view of previous CT and neuropathological studies.

Adult↗
PubMed1983

Central brain morphology in chronic schizophrenic patients: a controlled CT study.

A comprehensive quantitative computed tomography (CT) study of the diencephalic region of 23 chronic schizophrenic patients and 23 normal controls was done. The third ventricle width, the Sylvian fissure widths, and the densities of the head of the caudate nucleus, thalamic nucleus, and medial temporal lobe were measured. In the schizophrenic patients, there was a significant increase in third ventricle and Sylvian fissure widths and a significantly greater density of both periventricular nuclei. The several explanations for this atypical association of atrophy with greater density are discussed.

Adult↗
PubMedDate not supplied

A positive view of psychiatrists and psychiatry.

A review of the literature on the personalities, mental health, and professional status of psychiatrists was the basis of a questionnaire designed to assess perceptions of these characteristics by psychiatrists themselves and by their medical colleagues. The 374 physician respondents were divided into two groups, psychiatrists and nonpsychiatrists, and beliefs and perceptions were compared between the two groups and with findings from the research literature. Results revealed some differences in opinion between psychiatrists and nonpsychiatrists, most notably concerning the mental health of psychiatrists. This was also the area in which the literature was least conclusive. Findings indicated, however, that physicians across specialties have a positive overall opinion of psychiatrists and their professional worth, and that psychiatrists see themselves as healthy, effective, and useful practitioners.

Adaptation, Psychological↗
PubMedDate not supplied

Toward a definite diagnosis of Alzheimer's disease.

There is a significant, and growing, number of patients who suffer from dementia of the Alzheimer's type (DAT). However, due to clinical variability and symptom overlap, and despite millions of dollars spent in diagnostic work-ups, the diagnosis of DAT remains one of exclusion or by neuropathologic study (usually postmortem). This report evaluates two promising methods, the newly refined clinical criteria sets (e.g., NINCDS-ADRDA) and single-photon emission computed tomography (SPECT), on their capacity for definite, accurate, and early diagnosis of DAT patients. We found that clinical diagnosis of DAT can achieve a weighted average for sensitivity of 72%, specificity of 86%, and diagnostic confidence of 72%; however, when NINCDS-ADRDA criteria are used, these results improve to 88%, 91%, and 92%, respectively. SPECT scans could differentiate DAT patients from normals with 86% sensitivity, 96% specificity, and 98% diagnostic confidence. Comparable figures for DAT versus multi-infarct dementia (MID) are 82%, 81%, and 86%, respectively. We conclude that, although a definite clinical diagnosis of DAT is still elusive and more research is needed, the use of either NINCDS-ADRDA criteria or SPECT scans may enhance diagnostic accuracy.

Aged↗
PubMedDate not supplied

Factors associated with antidepressant choice.

Previous studies have suggested that nonpsychiatrists tend to prescribe antidepressants (ADs) with the most side effects (SEs), whereas psychiatrists are more likely to prescribe more ADs with fewer SEs. The authors used a questionnaire to examine the antidepressant prescribing pattern, conditions for which ADs were prescribed, and SEs of concern to physicians. Of those surveyed, the psychiatrists reported prescribing significantly more nortriptyline and desipramine, whereas the nonpsychiatrists prescribed more amitriptyline. The nonpsychiatrists were more likely to prescribe ADs for pain, and they were significantly less concerned with orthostatic hypotension. Possible lower dosing and level of concern about orthostatic hypotension may be related. Further study is proposed to assess other factors that might influence AD choice.

Antidepressive Agents↗
PubMedDate not supplied

The use of antidepressants in the elderly: 1986 and 1989.

Depression is a frequent disorder in the elderly that is often treated with antidepressants. It is generally accepted that, since all antidepressants are equally effective and the elderly are differentially more susceptible to side effects, those antidepressants with the least side effects should be preferentially used. The actual use of antidepressants in 1986 and 1989 was reviewed. We found that (1) contrary to expectation, antidepressants were prescribed in 1986 in quantities that were directly proportional to their side effects, ie, the greater the side effects, the more they were used, and (2) there was a distinct shift to a more thoughtful pattern in 1989. After reviewing the side effect profiles of antidepressants, it is recommended that amitriptyline and doxepin be avoided and that the initial choice be restricted to desipramine, nortriptyline, fluoxetine, and possibly bupropion. This simple change would reduce the relatively high rate of falls and fractures from antidepressant-induced hypotension and of delirium in the elderly. It would also promote increased compliance and greater efficacy, since larger doses will be tolerated.

Aged↗