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Biomedical subjects

L E DeLisi

Publications and source records attributed to L E DeLisi.

At least 73 records · Page 4Linked to original sources
PubMed1993

Search for a genetic event in monozygotic twins discordant for schizophrenia.

When monozygotic twins are discordant for the diagnosis of schizophrenia, this discordance has been traditionally attributed to environmental factors acting upon a genome susceptible for the schizophrenia phenotype. The study presented here was designed to examine the occurrence of a genetic event, such as a postzygotic mitotic crossover, that could account for the discordance. Such a postzygotic event could affect cis-acting sequences and result in a phenotype of variable severity. We used molecular genetic methods to evaluate such an event with 94 microsatellite repeat polymorphic markers distributed on all autosomes and the X chromosome in five pairs of monozygotic twins discordant for schizophrenia. In this search, no genetic marker discordances were identified between the co-twins. The lack of a genetic difference may implicate nongenetic factors that are responsible in eliciting or suppressing the phenotype. However, the experiments performed in this study cannot eliminate the possibility that a tissue-specific mitotic crossover might have occurred in one of the discordant twins, which could not have been detected in our current study.

Adult↗
PubMed1993

Increased prevalence of cavum septum pellucidum in schizophrenia.

A previous report that the presence of a cavum septum pellucidum was significantly more common in schizophrenic patients than in control subjects (DeGreef et al., 1992) stimulated the present study of an independent but similar population of first admission schizophrenic patients. A high prevalence of this developmental anomaly (44.8%) was found in the patients (n = 85), although it could also be detected in 29.8% of similarly aged control subjects (n = 47). This finding was not associated with corpus callosum, ventricular, or temporal lobe size or asymmetries.

Adult↗
PubMed1992

The timing of brain morphological changes in schizophrenia and their relationship to clinical outcome.

The present study is an examination of ventricular and temporal lobe size in 50 DSM-III-R first-episode schizophreniform or schizoaffective patients who were ill for less than 6 months. Two-year clinical follow-up and magnetic resonance imaging (MRI) scan analyses are also reported from data collected on an initial group of 30 first-episode schizophrenic patients and controls. Left ventricular enlargement, which was present in our previously published report of first-episode cases of schizophrenia, is not present to the same extent in this larger group of schizophreniform patients closer to the onset of their illness, and no temporal lobe volume reduction was detected. However, lateral ventricular size at the time of the first-episode was generally correlated with outcome--the larger the ventricles, the poorer the outcome. No mean change in ventricular or temporal lobe size was found at rescanning 2 years later, but the degree of ventricular change was inversely correlated with the number of hospitalizations and the amount of time spent in hospital; it did not correlate with temporal lobe size. When rescanned, some patients showed change greater than 20% in ventricular size and 10% in temporal lobe size. Thus, these findings need further evaluation by serial scans over a longer time period before it can be determined that no progression of brain structural abnormalities is occurring as part of the pathology of schizophrenia, even in a subgroup of patients.

Adult↗
PubMed1992

The significance of age of onset for schizophrenia.

Age of onset is the single most important characteristic of schizophrenia that could yield clues to its origin. To identify the age of onset, however, the onset of the pathological process must be determined. This process may have more than one component occurring at distinctly different times in the life of an individual. Nevertheless, many studies, using either the first appearance of psychosis or the age of first hospitalization, have found gender, familial, and other "age of onset" differences among patients with schizophrenia. These differences may aid in examining genetic mechanisms for schizophrenia.

Age Factors↗
PubMed1992

Anomalous lateral sulcus asymmetry and cognitive function in first-episode schizophrenia.

This study examines the cognitive functioning of first-episode schizophreniform patients within several weeks of hospitalization and at 2 years into the illness. Differences between patients and controls are also reported for measurements of the length of the lateral sulcus, which borders the planum temporal, an area of the brain integral to language function. Neuropsychological test results are also correlated to magnetic resonance imaging structural variables at the time of first hospitalization. Findings on neuropsychological summary scales reveal a diffuse pattern of cognitive impairment in schizophreniform patients compared to controls, which appears to improve over time. An atypical pattern of anatomic lateral symmetry is found in female schizophreniform patients, with female appearing to have a reduction in the normally occurring left greater than right length of the lateral sulcus. Such atypical asymmetry of the lateral sulcus is also associated with better cognitive function, particularly in schizophreniform patients. These findings suggest that atypical lateralization in an area critical to language function may be related to cognitive function in schizophreniform illness.

Adult↗
PubMed1992

Neuropsychological functioning of first-episode schizophreniform patients.

OBJECTIVE AND METHOD: This study compared 32 consecutively admitted first-episode schizophreniform patients, 26 patients with chronic schizophrenia according to the DSM-III-R criteria, and 25 normal comparison subjects on a comprehensive battery of neuropsychological tests to determine the degree of cognitive impairment existing at the onset of schizophrenic illness. Patients were tested within 2 weeks of admission to the hospital, after their medication had been stabilized. RESULTS: With age and education controlled, the first-episode and chronic patients performed significantly worse than the normal subjects on neuropsychological summary measures of executive function, verbal memory, spatial memory, concentration/speed, and global cognitive function and on left and right hemisphere function scales. The first-episode patients were as cognitively impaired as the chronic patients on all summary scales and many of the individual tests. Both groups showed relatively greater left than right hemisphere dysfunction. CONCLUSIONS: These findings suggest that substantial cognitive deficits, comparable to those of chronic patients, are present early in the course of psychotic illness.

Adult↗
PubMed1991

Brain morphology in first-episode schizophrenic-like psychotic patients: a quantitative magnetic resonance imaging study.

Brain morphology was examined using magnetic resonance imaging in 30 first-episode patients with a schizophreniclike psychosis, 15 chronic schizophrenics, and 20 neurological controls. Statistical analyses of computer-generated measurements of regions of interest were controlled for gender, age, social class, and total brain volume. Lateral ventricular size was increased in both first-episode and chronic schizophrenic patients, with greater significance on the left than on the right side. Only the chronic patients, however, had reduced temporal lobe size, which also was greater on the left side. No major correlations of regional brain morphological measurements with cognitive functioning were found, although some measurements of verbal memory were correlated with parahippocampal size. This is a report of a preliminary study that suggests that some morphological brain changes may be present at the time of first treatment for a psychotic illness, whereas others may occur later in the course of illness. Future prospective studies may determine the clinical significance of these changes and whether they progress with the development of illness chronicity.

Adolescent↗
PubMed1991

Familial thyroid disease and delayed language development in first admission patients with schizophrenia.

One hundred consecutive first admission patients with a DSM-III-R diagnosis of schizophrenia, schizoaffective disorder, or schizophreniform disorder were compared with 100 randomly selected community controls. Childhood histories of physical, medical, and perinatal trauma, as well as physical and cognitive development, were examined by structured interviews with all available mothers of patients and controls. The prevalence of specific psychiatric disorders and several medical illnesses among first degree and more distant relatives was determined by family history questionnaires. The patient group did not have an excess of childhood head injuries, serious infections, or perinatal/birth complications compared with controls. With social class level taken into account, it was found that the acquisition of reading skills occurred significantly later in patients than controls. Family histories of schizophrenia and thyroid disorders were significantly more frequent among patients than controls. These data fail to indicate any childhood physical or medical environmental trauma that could lead to an increased risk for schizophrenia, although patients were substance abusers to a greater extent than controls. This study also confirms the already known contribution of familial factors and suggests an association of the inheritance of thyroid disorders with schizophrenia. Delayed development of reading skills suggests that precursers of illness may appear early in life before psychosis is evident.

Adult↗
PubMed1990

Reduction in temporal lobe size in siblings with schizophrenia: a magnetic resonance imaging study.

Twenty-eight individuals with familial schizophrenia, from 16 unrelated families (12 sibling pairs and 4 individuals whose siblings refused scanning), and 21 normal control subjects were examined by cerebral magnetic resonance imaging (MRI). Measurements of the cerebrum, temporal lobes, and cerebral lateral ventricles were obtained using consecutive coronal sections containing these structures. Temporal lobe volume was significantly decreased by approximately 10% in these early onset schizophrenic siblings compared with normal controls. These findings add to recent post-mortem and neuroradiological evidence for morphological alteration in the temporal lobes in schizophrenia.

Adult↗
PubMed1989

Increased temporal lobe glucose use in chronic schizophrenic patients.

Temporal lobe glucose metabolic rate was assessed in 21 off-medication patients with schizophrenia and 19 normal controls by positron emission tomography with 18F-deoxyglucose. Patients with schizophrenia had significantly greater metabolic activity in the left than the right anterior temporal lobe, and the extent of this lateralization was in proportion to the severity of psychopathology.

Adult↗
PubMed1989

Corpus callosum dimensions measured by magnetic resonance imaging in bipolar affective disorder and schizophrenia.

Magnetic resonance imaging (MRI) brain scans were performed on 24 schizophrenic patients, 22 bipolar affective patients, and 25 normal control subjects without medical or psychiatric illness using a Picker Vista 0.5 tesla scanner. Specific callosal regions and the cerebral area on the midsagittal slice were measured utilizing the technique described by Nasrallah et al. (1986). No significant differences were found among diagnostic groups in anterior, mid, or posterior callosal width, callosal area, cerebral area, callosal to cerebral area ratio, or the genu (first quartile) to splenium (fourth quartile) ratio. However, male subjects had a significantly greater callosal and cerebral area than female subjects. Gender differences were shown in the genu to splenium ratio in the control groups, but not the affective or schizophrenic groups. The implications of these gender differences are discussed in relation to other studies.

Adult↗
PubMed1989

Evidence for a sex chromosome locus for schizophrenia.

The sex chromosomes are strong candidates for a genetic locus for schizophrenia and the affective psychoses. Gender differences in the clinical expression of illness and familial risks, concordance for gender and illness in relatives, and an association of X chromosome anomalies with psychosis suggest an X chromosome locus. The presence of male-to-male transmission in some families, in the face of a lack of strong evidence for heterogeneity, specifically focuses the search within the pseudoautosomal region of the X and Y chromosomes where sequence homology and recombination takes place.

Female↗