Paolo Stratta

Risperidone, negative symptoms and cognitive deficit in schizophrenia: an open study

The aim of this study was to evaluate the effects of a new antipsychotic compound on negative symptoms and cognitive deficit in schizophrenia. Psychiatric symptoms and cognition were assessed in 25 patients with schizophrenia, at baseline and after they had taken risperidone for 4 weeks. The Positive and Negative Symptoms Scale (PANSS), the Wisconsin Card Sorting Test (WCST) and two WAIS sub‐tests were used to assess the patients. After the study period, both negative and positive symptoms and also measures of cognitive performance improved significantly. The WCST results correlated with negative symptom scores before and after treatment. This suggests that negative symptoms and cognitive deficit have a common underlying substrate which is the target of the risperidone treatment. Our data show that risperidone may have a substantial effect on complex cognitive functions in schizophrenia, and they suggest that certain cognitive deficits are relatively dependent on the negative symptoms of this disorder.

Magnetic resonance imaging findings of amygdala- anterior hippocampus shrinkage in male patients with schizophrenia

Recent magnetic resonance imaging (MRI) studies found abnormalities of medial temporal lobe and basal ganglia structures. We used an inversion recovery (IR) protocol with the assistance of the Talairach atlas to identify neuroanatomical regions of interest in 19 male schizophrenic patients and 14 matched control subjects. The patient group showed smaller amygdala-hippocampus volume as compared with normal control subjects. This finding was more pronounced for the left side, although no diagnosis X side interaction was present. Third ventricle volume was also enlarged in schizophrenic patients. Trends toward an overall reduction of basal ganglia (striatum and lenticular nucleus) and limbic structures and toward an increase in ventricle-brain ratio were also seen. The study confirms previous evidence of mesial temporal lobe shrinkage, more evident on the left side in a group of relapsing noninstitutionalized male schizophrenic patients.

Planum temporale in schizophrenia: a magnetic resonance study

Magnetic resonance imaging (MRI) scans were used to examine the size and asymmetry of the planum temporale (PT) in 20 schizophrenic patients and 12 strictly matched healthy volunteers. PT lengths from coronal sections were measured and then summed to obtain an estimate of their areas. Schizophrenics showed the lack of the physiological PT area asymmetry evidenced in the control sample and a statistically significant diagnosis by side interaction was observed (F = 4.96; p less than 0.05). The study of PT asymmetry could permit us to better analyse the role of laterality in the pathophysiology of schizophrenia.

Planum temporale asymmetry and thought disorder in schizophrenia

Magnetic resonance imaging (MRI) was used to investigate the size and the asymmetry of the planum temporale (PT) in 22 schizophrenic patients and 23 strictly matched healthy volunteers. The degree of thought disorder was related to the reduction of the physiological PT asymmetry. When thought disordered patients were contrasted with non-thought disordered patients and healthy controls for a measure of PT laterality, those with thought disorder showed a statistically significant loss of PT laterality. This finding suggests that thought disordered schizophrenics may be characterized by an abnormal development of cerebral lateralization in a region crucial for language processing.

Cognitive function in euthymic bipolar patients, stabilized schizophrenic patients, and healthy controls

Abstract Studies on cognitive function in bipolar disorder have led to contrasting results and few data are available on affected subjects during the euthymic phase. In the present study we investigated the cognitive function of a cohort of bipolar ( n =40) and schizophrenic ( n =66) patients compared to healthy controls ( n =64). Patients were evaluated in the outpatient setting over at least 3 months using a computerized version of Wisconsin Card Sorting Test. Schizophrenic patients showed the worst performance while that of the bipolar patients was somewhere between schizophrenic and controls. A discriminant analysis was able to classify correctly 60.59% of the subjects (schizophrenics 48.5%, bipolars 40%; healthy controls 85.9%). The scores of the Wisconsin Card Sorting Test were entered into a principal component analysis, which yielded a 2-factor solution. Even in that analysis bipolar patients showed intermediate features in comparison with the other groups. These data indicate that bipolar patients have subtle neurocognitive deficits even after the resolution of an affective disorder. As well as observing quantitative differences between groups, the results show different dimensions of cognitive performance within groups suggesting that the deficit of euthymic bipolars could be a dishomogeneous entity, probably more heterogeneous than that in schizophrenia. Studies administering a more complete neuropsychological battery could further clarify the nature and meaning of the cognitive deficits in schizophrenia and bipolar disorder.

Processing of context information in schizophrenia: relation to clinical symptoms and WCST performance

Failure in contextual information processing has been hypothesized as being the single function responsible for several impairments in cognitive tasks and symptoms, through an involvement of the prefrontal cortex, in patients with schizophrenia. A variant of the Continuous Performance Test (CPT) designed specifically to elicit deficits in the processing of contextual information has been administered to 20 schizophrenic patients and 20 healthy controls. The relation to Wisconsin Card Sorting Test (WCST), relatively specific to prefrontal damage and executive dysfunctioning, and clinical status by using scales for the assessment of positive, negative symptoms and outcome has been investigated. The data show that multi-episode schizophrenic patients manifest inability to use contextual information to inhibit habitual response to an ambiguous stimulus and to maintain information across delay, without a general attention deficit. We also found a relationship between contextual reasoning and WCST unique errors, hallucinations, formal thought disorders, and outcome evaluation. Our results further support the hypothesis that the deficit of contextual reasoning could account for cognitive impairments and symptoms of patients with schizophrenia.

Insight and neuropsychological function in patients with schizophrenia and bipolar disorder with psychotic features.

Objectives: This study investigates the pattern of association between patient unawareness of illness and neuropsychological tests of frontal lobe function in subjects with schizophrenia and bipolar disorder (BD) with psychotic features. Method: We administered the Wisconsin Card Sort Test (WCST) and a shortened version of the Scale to Assess Unawareness of Mental Disorder (SUMD) to a sample of 64 patients with psychosis (42 with schizophrenia and 22 with BD). Results: None of the correlations between WCST scores and insight scores were statistically significant, either in the total group or in each group analyzed separately. Further, no differences were seen in insight scores between sexes and between the diagnostic groups. Conclusions: The 3 insight dimensions (that is, awareness of mental disorder, awareness of social consequences of mental disorder, and awareness of the benefits of medication) do not appear to be associated with frontal impairment, as measured by the WCST.

Computer-aided neurocognitive remediation as an enhancing strategy for schizophrenia rehabilitation

Cognitive dysfunction is a chronically disabling feature of schizophrenia, associated with limits in obtaining rehabilitation improvements. The purpose of this study is to assess the effectiveness of intensive computer-aided cognitive remediation treatment (CRT) added to a standard rehabilitation treatment (SRT), in enhancing neuropsychological performances and daily functioning in patients with schizophrenia. A 12-week, randomized, controlled, single-blind trial of neurocognitive remediation was carried out on 86 patients with clinically stabilized DSM-IV schizophrenia. Patients were assessed on cognitive and daily functioning before and after either CRT or placebo training that had been added to their SRT. After 3 months the repeated measure ANOVA showed a significant time x treatment interaction for executive function and attention performances and in daily functioning assessment in favour of patients in the SRT+CRT treatment. Results confirmed that cognitive remediation added to the SRT of schizophrenia enhanced its neuropsychological effects and increased the effects of a long-term rehabilitation programme in terms of functional outcomes.

Tower of Hanoi and WCST performance in schizophrenia: problem-solving capacity and clinical correlates

We administered a computerized version of WCST, a well established test, sensitive to executive function deficits in schizophrenia that involves many features of cognitive processing, and of Tower of Hanoi, a test that may offer cognitive challenges more specifically related to planning and sequencing, to 28 schizophrenic patients and 28 matched controls to examine a worthwhile question regarding the relative ability of these two tasks to differentiate schizophrenia and normal groups as well as exploring the relationship of these two instruments to clinical variables. The schizophrenic patients performed significantly worse than normal subjects both on Tower of Hanoi test and on WCST. The discriminant analysis identified in a multivariate way a pattern of indexes that differentiate the two groups. This pattern, characterized by specific indexes of WCST and TOH, could suggest the existence of a common underlying factor that determines the cognitive impairment in problem-solving of schizophrenics. These findings and the relationship with positive and negative symptoms have been discussed in the light of the model of the impairment in the internal representation of context information.

No deficit in Wisconsin Card Sorting Test performance of schizophrenic patients' first-degree relatives.

The Wisconsin Card Sorting Test (WCST) was administered to 92 schizophrenic patients, 25 first-degree relatives and 60 normal subjects in order to investigate whether this task could be considered a trait marker of vulnerability to schizophrenia. The schizophrenic patients performed significantly worse than either their relatives or normal subjects, but unaffected relatives did not differ from controls. Our results suggest that WCST performance is more likely a feature inherent to the disease process rather than an index of the genetic susceptibility to the illness.