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Biomedical subjects

J R DeQuardo

Publications and source records attributed to J R DeQuardo.

At least 19 recordsLinked to original sources
PubMed2001

Hippocampus and amygdala in schizophrenia: assessment of the relationship of neuroanatomy to psychopathology.

The hippocampus and amygdala are believed to be involved in the pathology of schizophrenia. In this study, we attempted to replicate the reported bilateral volume reduction of the hippocampus and amygdala and to study the relationship of the volumes of these structures to the symptoms of schizophrenia. The hippocampus-amygdala complex (HAC) was manually traced on 3-mm coronal T(1)-weighted MRIs, resampled into 1-mm coronal slices, from 20 male patients with schizophrenia and 20 age-matched male controls. The complex was divided into three parts: anterior one-third representing the amygdala and middle and posterior thirds representing the anterior and posterior halves of the hippocampus. Positive and negative symptoms and severity of hallucinations and thought disorder (conceptual disorganization) were quantified using the Brief Psychiatric Rating Scale (BPRS). None of the above structures, controlled for brain volume, differed significantly in patients compared with normal controls. When the relationship between volumes and symptoms was examined, the left HAC was found to inversely correlate with thought disorder and negative symptoms. Specifically, significant inverse correlations were found between (i) left amygdala and thought disorder, (ii) left hippocampus and negative symptoms, and (iii) left anterior and posterior hippocampus volumes and positive and negative symptoms, respectively. Our findings further support the role of the HAC in the pathophysiology of schizophrenia and suggest unique associations between individual structures and specific symptoms of the illness.

Adult↗
PubMed2000

Phasic and enduring negative symptoms in schizophrenia: biological markers and relationship to outcome.

Negative symptoms have been associated with poor response to neuroleptics, enlarged ventricles, cognitive impairment, and poor outcome in schizophrenia. These associations appear, however, to be dependent on the phase of study, suggesting that acute-phase (phasic) negative symptoms may be pathophysiologically distinct from enduring negative symptoms that persist through the residual phase. To compare correlates of enduring and phasic negative symptoms, we studied 60 drug-free schizophrenic patients (DSM-III-R and SADS/RDC) at baseline, 4 weeks after neuroleptic treatment, and assessed the 1 year outcome. We rated positive and negative symptoms at baseline and 4 weeks after treatment. At baseline, premorbid function, neuropsychological function, ventricle-brain ratio (VBR) and symptom response to an anticholinergic agent were assessed, and a two-night sleep EEG and 1mg dexamethasone suppression test (DST) were conducted. Phasic negative symptoms were defined as the change in negative symptoms (baseline to 4 weeks) and enduring negative symptoms as severity of negative symptoms at 4 weeks. Patients had varying proportions of phasic and enduring symptoms; the two did not define distinct subgroups. Phasic negative symptoms were significantly correlated with global treatment response, positive symptom treatment response, response to anticholinergic agent, baseline post-dexamethasone cortisol, and shortened REM latency. Enduring negative symptoms were significantly correlated with residual positive symptoms and global psychopathology, VBR, poor performance on neuropsychological testing, decreased slow-wave sleep, poor premorbid function, and poor 1 year outcome. These data suggest that phasic negative symptoms and enduring negative symptoms may be caused by different pathophysiological mechanisms.

Adult↗
PubMed2000

Superior temporal gyrus in schizophrenia: a volumetric magnetic resonance imaging study.

The left superior temporal gyrus (STG) has been reported to be smaller in patients with schizophrenia. The volume of the STG has been found to correlate negatively with severity of hallucinations and thought disorder. In this study, we measured the STG volume of 20 normal controls and 20 patients with schizophrenia using 3 mm contiguous coronal T1 magnetic resonance images. We found that patients had a significantly smaller left anterior STG, and that the volume of this region negatively correlated with the severity of hallucinations. The left posterior STG was not significantly smaller in patients than in controls, but its volume negatively correlated with severity of thought disorder. We also found that the left anterior STG was smaller than the right STG in patients but not in controls. The STG has at least three histologically distinct areas, each with different connections to the rest of the brain. These data are consistent with the proposition that dysfunction of the primary auditory cortex in the anterior and middle STG and auditory association cortex in the posterior STG may play a role in the production of auditory perceptual abnormalities and poor organization of thought respectively.

Adult↗
PubMed1999

Landmark-based morphometric analysis of first-episode schizophrenia.

BACKGROUND: The goal of this investigation was to utilize landmark-based shape analysis and image averaging to determine the sites and extent of specific structural changes in first-episode schizophrenia. METHODS: Neuroanatomic structures identified on midsagittal magnetic resonance imaging (MRI) scans were compared between 20 patients with schizophrenia and 22 normal control subjects. The difference between averaged landmark configurations in the two groups was visualized as a shape deformation by a thin-plate spline and through averaged MRI images for both groups. RESULTS: A shape difference was found to be statistically significant; by inspection, it is contrast between differences in two closely abutting regions, involving primarily the posterior corpus callosum and upper brain stem--the "focus" is the relation between them. CONCLUSIONS: The findings are consistent with prior studies suggesting involvement in schizophrenia of the corpus callosum and the limbic structures contributing to the corpus callosum; the possibility of local pathology primarily involving the brain stem cannot be excluded. The methods of landmark-based shape analysis and image averaging utilized in this study can complement the "region-of-interest" method of investigating morphometric abnormalities by characterizing the spatial relationships among structural brain abnormalities in schizophrenia.

Adolescent↗
PubMed1999

Electroconvulsive treatment of a bipolar adolescent postcraniotomy for brain stem astrocytoma.

This is the first reported use of electroconvulsive treatment (ECT) in an adolescent with bipolar mania who had been treated with craniectomy for an intracranial neoplasm. The reported case is of a 16-year-old girl with a history of brain stem glioma (pontomesencephalic astrocytoma) diagnosed at 13 years of age. She presented in a psychiatric emergency room with suicidal ideation, depressed mood, irritability, olfactory hallucinations, early insomnia, grandiosity, and guilt. Her symptoms failed to respond to a trial of an antidepressant, mood stabilizer alone, and mood stabilizer in conjunction with a neuroleptic. The decision to use ECT was based on suicidal ideation, extreme disinhibition, and danger to self and others. Significant improvement in mood and remission in psychosis were noted after the eighth treatment. Comparison of 2-week pre-ECT and 3-month post-ECT cognitive testing revealed no change in IQ. This report highlights rapid response and the ability to tolerate ECT in an adolescent diagnosed with bipolar disorder, who had also been treated with radiation and craniotomy.

Adolescent↗
PubMed1998

Effects of antipsychotic treatment on polysomnographic measures in schizophrenia: a replication and extension.

OBJECTIVE: The authors sought to replicate and extend previous observations of improvement in some EEG sleep measures during the course of antipsychotic treatment in schizophrenia patients. METHOD: Fourteen medication-free patients with schizophrenia underwent 2 nights of sleep EEG monitoring before and after 3-4 weeks of treatment with clinically determined doses of haloperidol or thiothixene. RESULTS: Measures of sleep continuity improved consistently. REM latency increased, although five of 14 patients continued to exhibit short REM latencies (less than 60 minutes). Stage 3 sleep increased during neuroleptic treatment, while stage 4 sleep did not change. CONCLUSIONS: These data demonstrate partial improvement of some but not all EEG sleep measures in schizophrenic patients through the course of neuroleptic treatment. They suggest that shortened REM latency and disturbed sleep continuity might represent reversible state abnormalities, while reduced slow-wave sleep may represent a more persistent trait abnormality in schizophrenia.

Adolescent↗
PubMed1998

Pharmacologic treatment of first-episode schizophrenia: early intervention is key to outcome.

The early recognition and management of a first episode of schizophrenic illness is a difficult task, with identification complicated by a broad differential diagnosis, lack of definitive data on the prognostic implications of premorbid/prodromal symptoms, and, until recently, treatment limited to pharmacologic agents with severe adverse effects. The first psychotic episode in patients with schizophrenia is the most responsive to treatment in terms of both rate and degree. However, first-episode patients are also more likely to develop motor side effects, even at lower medication doses, than multiepisode patients. Considerable evidence supports the assertion that early treatment can improve outcome and possibly prevent the development of full-blown illness in high-risk individuals. There is evidence that atypical antipsychotic medications are effective in the treatment of first-episode schizophrenia and are well tolerated. The improved tolerability associated with the newer antipsychotic medications, including a lower risk for motor side effects and possible lower risk for development of tardive dyskinesia, has swung the risk-benefit balance in favor of early and aggressive treatment. By intervening early and providing long-term maintenance treatment, the course of schizophrenic illness may be altered in the coming years with overall decreased deterioration and chronicity and overall improved functioning resulting in lower societal costs.

Antipsychotic Agents↗
PubMed1996

Biological predictors of 1-year outcome in schizophrenia in males and females.

This paper describes a prospective study designed to ascertain the predictive value of biological factors associated with schizophrenia in males and females. In a sample of 59 medication-free schizophrenic inpatients (41 males; 18 females), we assessed the correlation of four factors--rapid eye movement (REM) sleep latency, delta (slow-wave) sleep, dexamethasone suppression test (DST) cortisol levels, and ventricle-brain ratio (VBR)--with several dimensions of outcome at 1-year post-discharge. In the total sample, shorter REM latency was associated with poor outcome on all dimensions measured: rehospitalization, employment, social activity, symptomatology, and global functioning. However, none of the other biological factors were associated with any measure of outcome. The predictive value of REM latency appeared to be gender-specific; in general, the relationships between reduced REM latency and poor outcome were consistently noted in females, but were not significant in males. These results suggest that a common, possibly gender-related, pathophysiological mechanism might underlie both abnormal REM latency and poor outcome. The findings underscore the importance of considering gender differences in studies of schizophrenia.

Electroencephalography↗
PubMed1996

VBR in schizophrenia: relationship to family history of psychosis and season of birth.

Ventricular enlargement has been consistently demonstrated in schizophrenia using both CT and MRI. Despite this, the structural changes that underlie increased ventricle-brain ratio (VBR) and its relationship to environmental factors (intrauterine viral exposure, obstetric complications, etc.) and family history of schizophrenia remain poorly defined. Increased VBR has been shown in some studies to correlate with an absence of family history of schizophrenia and with Winter-Spring birth. In an attempt to obtain a clearer picture of the contribution of environmental and genetic factors to VBR, we studied 54 patients with DSM III-R schizophrenia. VBR was determined from head CT scans via computerized planimetry. Family history of psychosis and non-psychotic mood disorder was determined with the family informant method. Season of birth was encoded in several ways, including season, trimester and dichotomously. Patients without a family history of psychosis had significantly larger VBR than patients with such a history; family history of mood disorder was not related to VBR. Season of birth was not predictive of VBR. Family history of psychosis and season of birth were not related to each other. These results are in line with prior work demonstrating an association between increased VBR and sporadic (non-familial) schizophrenia. We did not find a relationship between VBR and season of birth, which suggests that risk of perinatal viral exposure and other seasonal environmental factors may not account for the ventricular enlargement in non-familial schizophrenia observed in our sample.

Adult↗
PubMed1996

Spatial relationships of neuroanatomic landmarks in schizophrenia.

Two new morphometric techniques, landmark-based shape analysis and landmark-based image averaging, were applied to magnetic resonance images (MRIs) to investigate the sites and extent of structural neuropathology in schizophrenia. These analyses allow the identification of averaged anatomy through joint registration on multiple landmarks simultaneously. MRI scans obtained in the midsagittal plane were compared between 14 patients with schizophrenia and 14 normal subjects. The relation between averaged landmark configuration in the two groups was visualized as a deformation. There were no large-scale shape abnormalities noted, although the patients had significantly smaller brains. The data suggest that the neuroanatomic abnormality associated with schizophrenia, in the midsagittal plane, is circumscribed (focal), involving primarily the region of the posterior corpus callosum, upper brainstem, and quadrigeminal cistern. Also, the thickness of the corpus callosum is reduced all along its length. The findings are consistent with prior studies suggesting involvement in schizophrenia of the cerebellum, the corpus callosum and, possibly, the limbic structures contributing to the corpus callosum. The methods of image averaging and shape analysis used in this study complement the 'region of interest' method of investigating morphometric abnormalities by characterizing the precise locations and spatial relationships among relevant structural brain abnormalities in schizophrenia.

Adult↗
PubMed1996

Biological predictors of suicidality in schizophrenia.

The objective of this study was to determine whether polysomnographic rapid eye movement (REM) sleep abnormalities and cortisol response to the dexamethasone suppression test (DST) differentiate between schizophrenic patients with and without a history of suicidal behaviour. We assessed a sample of 96 schizophrenic in-patients at the end of a 2-week medication-free period with the DST, polysomnography, and an extensive clinical assessment battery. Patients exhibiting suicidal behaviour were significantly more likely to have increased total REM time and increased total REM activity. We found no significant relationship between suicidal behaviour and DST non-suppression. This study confirms a previous finding suggesting an association between REM sleep abnormalities and suicidal behaviour in schizophrenia. It is postulated that this observed association may be related to serotonergic dysfunction in schizophrenia.

Adult↗
PubMed1996

ECT in genetically confirmed Huntington's disease.

The authors report successful ECT treatment of a severely depressed man with genetically confirmed Huntington's disease. He responded well to treatment and showed no abnormal movements or worsening in his cognitive status.

Aged↗