Massimo Abbruzzese

Increased right caudate nucleus size in obsessive-compulsive disorder: detection with magnetic resonance imaging.

Magnetic resonance images were used to measure the volume of the head of the caudate nucleus in 20 patients with obsessive-compulsive disorder and 16 normal control subjects. The obsessive-compulsive patients showed a significant increase in the volume of the right side of the head of the caudate nucleus compared with that of control subjects. This finding was not correlated with demographic, psychopathological, or clinical characteristics.

The selective breakdown of frontal functions in patients with obsessive–compulsive disorder and in patients with schizophrenia: A double dissociation experimental finding

In an our recent preliminary study, we reported the neuropsychological finding of a double dissociation in the frontal lobe functioning between 25 OCD patients and 25 schizophrenics. The first group performed normally in the Wisconsin Card Sorting Test (WCST), which is considered sensitive to Dorso-Lateral Prefrontal Cortex (DLPFC) dysfunctions and abnormally to the Object Alternation Test (OAT), which has been proposed as a tool sensitive to Orbito-Frontal Cortex (OFC); on the other hand, schizophrenics performed abnormally to the WCST and normally to the OAT. The present study, conducted on a new sample of 60 schizophrenic in-patients, 60 OCD in-patients and 30 normal subjects, matched according to age, educational level, handedness and duration of illness, confirms our preliminary data and it suggests a more selective impairment of OFC system in OCD and of DLPFC in schizophrenia. Moreover, schizophrenic patients with paranoid subtype showed worse WCST performance compared to non-paranoid subtype. Our results could open some interesting perspectives about the neuroanatomical systems involved in these two major psychiatric illnesses and so, about their pharmacological treatment, on the basis of the prominent catecholaminergic characterization of the DLPFC and, respectively, the cholinergic innervation of the OFC.

Wisconsin Card Sorting Test performance in obsessive-compulsive disorder: no evidence for involvement of dorsolateral prefrontal cortex

Wisconsin Card Sorting Test (WCST) performances were studied in 33 patients with obsessive-compulsive disorder (OCD) and 33 age-, sex-, and education-matched normal comparison subjects; the OCD patients were divided into four subgroups on the basis of their symptomatology. Neither the two groups of subjects nor the four OCD subgroups differed on any of the WCST neuropsychological indices. No relationship was demonstrated between test performance and clinical-epidemiological characteristics of the OCD patients. All of the OCD patients were being treated with fluvoxamine maleate, which improves OCD symptoms and could also improve WCST performances. Nevertheless, no remarkable differences in the WCST indices were observed in patients treated with fluvoxamine when compared with patients who had not received a specific therapy for at least 3 weeks. Since the WCST is widely considered sensitive to dysfunction of the dorsolateral prefrontal cortex, our results do not support the involvement of that brain region in OCD.

Memory functions and temporal-limbic morphology in schizophrenia

Several psychopathological and morphological studies support the hypothesis of temporal-limbic involvement in the pathophysiology of schizophrenia. In the present study, magnetic resonance imaging was used to evaluate the areas of the temporal lobes and related structures in 18 schizophrenic patients and 18 normal control subjects who were homogeneous for sex and age. The Wechsler Memory Scale was used to assess the memory functions of all subjects. Although the MRI data did not reveal any significant differences between the two groups, the Wechsler Memory Scale indices of memory functions showed significant differences between the schizophrenic patients and the control subjects.

An assessment of the Wisconsin Card Sorting Test as an indicator of liability to schizophrenia

In order to test the hypothesis that a poor performance in the Wisconsin test (WCST) may be an indicator of liability to schizophrenia, we compared the WCST performances of patients with DSM III-R schizophrenia, normal controls, and patients with schizotypal personality disorder (SZT PD). While schizophrenic patients performed significantly worse than subjects in the other two groups, schizotypal and normal subjects showed no significant differences in the WCST execution. Moreover, patients with SZT PD with or without positive family history for the schizophrenic spectrum had similar WCST performances. Our observations are in keeping with other studies employing the WCST in paradigms of heightened liability to schizophrenia, and suggest that a poor performance in the test is more probably a feature of the disease process, than a trait marker of vulnerability to the illness demonstrable in high-risk subjects.

The Wisconsin Card Sorting Test discriminates schizophrenic patients and their siblings

The following report is an evaluation of the performances of 35 schizophrenic patients and 35 of their siblings on the Wisconsin Card Sorting Test (WCST), a neuropsychological test considered sensitive to frontal lobe functioning. Thirty five normal subjects matched for age and education were the comparison group. The purpose of this study was to examine the relationship of the neurofunctional basis for schizophrenia to its familiar occurrence. Non-schizophrenic siblings of schizophrenic patients did not perform significantly different from normal subjects on the WCST; however, schizophrenic patients performed significantly worse than both their siblings and normal subjects. These results indicate that WCST dysfunction seems to be a characteristic related to the presence of the disease and that non-genetic factors could contribute to the WCST pathological profile.

Smooth pursuit and saccadic eye movements and Wisconsin card sorting test performance in obsessive- compulsive disorder

Smooth pursuit eye movements (SPEMs), voluntary saccadic eye movements (VSEMs), and neuropsychological test (Touluse-Pieron Test and Wisconsin Card Sorting Test) performance were studied in 23 patients with obsessive-compulsive disorder and 27 age-matched normal control subjects. The patients performed more poorly than the control subjects on the SPEM and, to a lesser degree, VSEM measures. They also showed impairment on some aspects of the neuropsychological tests. No relationship was found between eye movement performance and neuropsychological impairment.

Performance on the Wisconsin Card Sorting Test in schizophrenia: Perseveration in clinical subtypes

Results are reported from a neuropsychological investigation of a large group of schizophrenic patients (n = 141) and normal control subjects (n = 59) who performed the Wisconsin Card Sorting Test (WCST). The schizophrenic patients were divided into two DSM-III-R diagnostic subgroups: paranoid and nonparanoid schizophrenia. The performance of the WCST by schizophrenic patients was poor compared with that by normal control subjects; furthermore, paranoid patients made a higher number of perseverative errors than did nonparanoid patients. The deficit in WCST performance, which has been widely reported to characterize patients with schizophrenia, appears to be related to the clinical profile and neuropathological differences that contribute to the heterogeneity of the disorder.

Influence of education on WCST performances in schizophrenic patients

Schizophrenic patients have been widely reported to fail in performing Wisconsin Card Sorting Test (WCST). These data have been mostly interpreted as cognitive difficulties and/or neurofunctional impairment inherent to schizophrenia. Nevertheless, checking sample characteristics, the importance of variables as education appears relevant. In our study we examined schizophrenic patients and controls with low and high educational levels respectively. ANOVA results show significant differences on WCST performances for the variable diagnosis (schizophrenics and controls) and for the variable educational level (low and high educational level). It therefore seems necessary call for caution in interpreting WCST results in schizophrenic patients when educational level is not considered.

Size of the corpus callosum and auditory comprehension in schizophrenics and normal controls

19 schizophrenic patients and 15 normal controls, matched for sex and age, were evaluated by magnetic resonance imaging for corpus callosal size and had neuropsychological functioning assessed using an auditory comprehension test. Although the MRI data did not reveal any significant differences between groups, the degree of laterality to the left versus right ear response was significantly correlated with the size of the posterior part of the corpus callosum in male schizophrenics.