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P Nopoulos

Publications and source records attributed to P Nopoulos.

31 records · Page 2Linked to original sources
PubMed1998

Two-year outcome in first-episode schizophrenia: predictive value of symptoms for quality of life.

OBJECTIVE: Many studies have validated the grouping of schizophrenic symptoms into three independent dimensions: negative, psychotic, and disorganized. Negative symptoms are considered to be an important prognostic indicator, but this clinical observation requires further empirical study, especially with respect to psychosocial functioning. When present at the onset of the first episode, negative symptoms suggest that the patient will develop significant psychosocial impairment. The predictive values of the psychotic and disorganized symptom dimensions, on the other hand, have been less certain. METHOD: In this study of 50 first-episode schizophrenic patients, who were mostly neuroleptic-naive at intake, the authors examined the relationship between the severity of these three symptom dimensions (measured by using the Scale for the Assessment of Negative Symptoms and the Scale for the Assessment of Positive Symptoms) at index hospitalization and quality of life at 2-year follow-up. RESULTS: Negative symptom severity was positively and significantly correlated with later occupational impairment, financial dependence on others, impaired relationships with friends, impaired ability to enjoy recreational activities, and global assessment of functioning. The magnitudes of correlation between the levels of psychotic symptoms or disorganized symptoms and 2-year quality of life measures were comparatively lower. Analyses using multivariate regression statistics also revealed similar findings. CONCLUSIONS: Severity of negative symptoms at index hospitalization may be a portent of poor outcome. In general, severity of psychotic or disorganized symptoms at intake does not appear to predict subsequent quality of life.

Adult↗
PubMed1997

Hypofrontality in schizophrenia: distributed dysfunctional circuits in neuroleptic-naïve patients.

BACKGROUND: There have been reports that patients with schizophrenia have decreased metabolic activity in prefrontal cortex. However, findings have been confounded by medication effects, chronic illness, and difficulties of measurement. We aimed to address these problems by examination of cerebral blood flow with positron emission tomography (PET). METHODS: We studied 17 neuroleptic-naïve patients at the early stages of illness by means of image analysis and statistical methods that can detect abnormalities at the gyral level. FINDINGS: An initial omnibus test with a randomisation analysis indicated that patients differed from normal controls at the 0.06 level. In the follow-up analysis, three separate prefrontal regions had decreased perfusion (lateral, orbital, medial), as well as regions in inferior temporal and parietal cortex that are known to be anatomically connected. Regions with increased perfusion were also identified (eg, thalamus, cerebellum, retrosplenial cingulate), which suggests an imbalance in distributed cortical and subcortical circuits. INTERPRETATION: These distributed dysfunctional circuits may form the neural basis of schizophrenia through cognitive impairment of the brain, which prevents it from processing input efficiently and producing output effectively, thereby leading to symptoms such as hallucinations, delusions, and loss of volition.

Adult↗
PubMed1997

Cavum septi pellucidi in normals and patients with schizophrenia as detected by magnetic resonance imaging.

Cavum septi pellucidi (CSP) is a cavity between the two leaflets of the septum pellucidum. CSP is a developmental anomaly, yet the pathologic implications, if any, of an abnormally large CSP remain unclear. The reported incidence of CSP among normal populations varies greatly from 0.15% to 85%. Several studies have suggested that there is a higher incidence of CSP in patients with schizophrenia. We conducted a thin-slice magnetic resonance imaging study to evaluate the prevalence of CSP in a sample of 75 controls and 55 patients. There was a high incidence of small CSP among both groups: 58.8% in the controls and 58.2% in the patients, suggesting that a small cavum could be considered a normal variant; however, the patient group had significantly higher incidence of large CSP (20.7%) compared to the normal group (3%). The patients with large CSP were all male.

Adult↗
PubMed1997

Sex differences in brain morphology in schizophrenia.

OBJECTIVE: The current literature on sex differences in schizophrenia with regard to structural brain abnormalities is inconsistent. Several studies have suggested that male and female patients may differ in severity of brain abnormalities. Efforts to explore this issue have been hindered by small study groups, unbalanced groups (i.e., those with many more men than women), or both. The relatively smaller number of female schizophrenic patients in most studies may have made it more difficult to detect differences between patients and comparison subjects. This study was designed to evaluate brain morphology in a carefully selected group of patients with schizophrenia and healthy comparison subjects who were balanced by sex. METHOD: Eighty patients (40 male and 40 female) and 80 healthy volunteers matched by sex and age were studied. Magnetic resonance imaging scans were analyzed with the use of an automated method that yields volumes of major brain regions. RESULTS: There was a significant sex-by-diagnosis interaction for ventricular volume, with male patients having significantly larger ventricles than male comparison subjects but female patients showing no significant enlargement in comparison with healthy female subjects. Although the overall distribution of structural brain differences was very similar in the male and female patients, the male patients had a greater number of significant abnormalities than the female patients. CONCLUSIONS: These findings indicate that male and female patients with schizophrenia have the same pattern of structural brain abnormalities, but male patients appear to manifest greater severity, especially with regard to ventricular enlargement.

Adult↗
PubMed1996

Pattern of brain morphology in patients with schizophrenia and large cavum septi pellucidi.

Cavum septi pellucidi (CSP) is a midline developmental anomaly shown to have increased incidence in patients with schizophrenia. The etiology of CSP may involve dysgenesis of the temporal lobes. This study evaluated the pattern of brain changes in three groups: 1) normal control subjects, 2) schizophrenic subjects without large CSP, and 3) schizophrenic subjects with large CSP. Patients without large CSP had decreased total brain, frontal, and temporal lobe volumes; patients with the anomaly had more pronounced right > left asymmetry and volume decrement limited to the left temporal lobe. These findings indicate that patients with schizophrenia and large CSP may show a different pattern of disturbed brain morphology than patients without this abnormality.

Adolescent↗
PubMed1995

A longitudinal study of symptom dimensions in schizophrenia. Prediction and patterns of change.

BACKGROUND: Factor analytic studies have suggested that the symptoms of schizophrenia may be divided into three uncorrelated dimensions. This study examines the longitudinal course of the symptoms of schizophrenia using this three-dimensional perspective. METHODS: The sample was composed primarily of neuroleptic-naive patients suffering from schizophrenia. Subjects were studied in a prospective longitudinal design, with comprehensive structured assessments at index, discharge, and 6-month intervals after discharge over a 2-year period. RESULTS: Negative symptoms were already relatively prominent at the time of index evaluation; they tended to remain stable throughout the follow-up period. The two dimensions of positive symptoms, psychoticism and disorganization, although prominent at index evaluation, declined over the course of the follow-up period and tended to be less stable. A longitudinal factor analysis was conducted to determine whether the changes in symptoms followed any consistent pattern. We observed that all three groups of symptoms tended to change in unison and independently from one another. CONCLUSIONS: These results suggest that these three dimensions of psychopathology show different patterns of exacerbation and remission during the course of schizophrenia. This independent pattern of evolution suggests that these three dimensions should be studied further with respect to response to treatment, cognitive mechanisms, psychosocial correlates, and neural substrates.

Adult↗
PubMed1995

Abnormalities in midline attentional circuitry in schizophrenia: evidence from magnetic resonance and positron emission tomography.

The syndrome of schizophrenia presents with a complex array of symptoms that are difficult to explain at the neural level. Data collected using magnetic resonance (MR) and positron emission tomography (PET) suggest that this complex array could occur as a consequence of misconnections and mismatches in midline circuitry that is reticular-thalamic-cingulate-cortical. MR studies have shown a variety of abnormalities, including callosal agenesis, cavum septi pellucidi, decreased thalamic size, decreased frontal size, and changes in signal intensity in white matter tracts between the thalamus and the frontal cortex. PET studies using a dichotic listening paradigm suggest that patients suffering from schizophrenia have brain blood flow abnormalities consistent with a difficulty in focusing or shifting attention, which may reflect the functional substrate of the anatomic abnormalities.

Attention↗
PubMed1995

Correlational studies of the Scale for the Assessment of Negative Symptoms and the Scale for the Assessment of Positive Symptoms: an overview and update.

The interrelationships between the various symptoms of schizophrenia may be explored by examining their intercorrelations. Five different factor analytic studies, which examine these interrelationships, are summarized. Three major factors emerge consistently: psychotic, disorganized, and negative. These three factors appear to represent three dimensions of the psychopathology of schizophrenia.

Factor Analysis, Statistical↗
PubMed1995

Brain morphology in first-episode schizophrenia.

OBJECTIVE: Neuroimaging studies have provided robust evidence that schizophrenia is associated with structural brain abnormalities. However, the underlying pathophysiology of these changes is still unknown. By evaluating brain morphology early in the course of illness, confounding effects of treatment and duration of illness are minimized. The goal of this study was to evaluate brain structure in patients early in the course of schizophrenia who had received no or minimal neuroleptics. METHOD: Magnetic resonance imaging was used to evaluate 12 male and 12 female patients experiencing their first episode of schizophrenia (mean duration of psychotic episode = 14 weeks) and 12 male and 12 female normal volunteers equivalent in age, height, and parents' socioeconomic status. A totally automated method was used to analyze scans, yielding volumes of brain tissue and CSF, divided into lobes. RESULTS: The patient group had significantly more total CSF than the comparison subjects. This was accounted for by higher levels of intersulcal CSF as well as ventricular CSF. There were no differences in total volume of brain tissue between the two groups, but patients had a significant regionally specific decrement in frontal lobe tissue compared with the normal subjects. CONCLUSIONS: These findings indicate that structural brain abnormalities are present very early in schizophrenia and may not be due to factors such as treatment or chronicity of illness. Rather, since the abnormalities are present near the onset of the illness, a neurodevelopmental mechanism may be suggested.

Adult↗
PubMed1994

Stability of cognitive functioning early in the course of schizophrenia.

This study evaluated the longitudinal course of neuropsychological deficits in a group of patients with new or recent onset schizophrenia. Thirty-five inpatients with DSM-III-R diagnoses of schizophrenia were administered a comprehensive battery of neuropsychological tests during their index hospitalization, and either 1 or 2 years after intake. Cognitive function remained stable in most domains, including motor speed, verbal and nonverbal memory, and verbal learning. Significant improvement in neuropsychological performance was observed on a task of complex attention (Trails B) and a set response shifting task (Stroop). These improvements were correlated with changes in clinical symptoms, but not with changes in medication dose. These findings suggest that most of the neuropsychological functioning in schizophrenia is stable over the first few years of the illness. Moreover, those neuropsychological deficits that remain unchanging appear to be independent of significant change in clinical symptoms, suggesting they may be a trait of the illness. However, a small subset of functions such as complex attention and response inhibition appear to fluctuate with time, and in particular, with clinical symptomatology, and may be considered 'state' dependent.

Adult↗
PubMed1994

Positive and negative symptoms of schizophrenia: past, present, and future.

The "group of schizophrenias," normally referred to with a single nominative, is phenomenologically heterogeneous. Its symptoms represent multiple psychological domains, including perception, inferential thinking, language, attention, social interaction, emotion expression, and volition. Studies of psychopathology have simplified this complex array in several ways; one has been a subdivision into positive and negative symptoms. Reports by our group and others suggest that the symptoms of schizophrenia fall into three natural dimensions: positive symptoms subdivided into psychotic and disorganized dimensions, while a third negative dimension also emerges. Since these dimensions have impressive consistency across studies, future work must examine their relationship to clinically relevant concepts such as prognosis or etiology and examine four different aspects: longitudinal course, neural mechanisms, relationship to treatment, and interrelationships in other pathological conditions.

Brain↗
PubMedDate not supplied

Color enhancement of multispectral MR images: improving the visualization of subcortical structures.

PURPOSE: The current investigation was undertaken to evaluate a new method for creating MR multispectral color images, which we call "Superimages." They were developed to improve the delineation of small brain structures composed of mixed tissue types, such as the basal ganglia. METHOD: To qualitatively validate the method, visual comparisons were made of six unimodal and multispectral images, including the Superimage. Quantitative validation was undertaken by comparing the reliability values for parcellation of the globus pallidus (GP) using either a gray scale (T1-weighted) image or the Superimage. RESULTS: Qualitative assessment of the Superimage revealed enhanced visualization of the GP, caudate, and putamen. Quantitative assessment resulted in good reliability for Superimage traces. CONCLUSION: The Superimage significantly improves both the visualization and the parcellation of structures visualized by MRI.

Adult↗