[Perfomance in WCST in patients with schizophrenia: influence of clinical variables in manual laterality]

The authors review the neuropsychological evaluation of schizophrenia diagnosed patients. The fundamental characteristics of the most useful and effective tests are summarized.

A study of cases and controls was performed. The sample had a total of 53 subjects (23 controls and 30 schizophrenics according to the ICD-10). The participants were evaluated by PANSS, WCST and the Annett test of manual preference.

Schizophrenic patients had a significantly worse performance in number of total errors and T score, conceptual answers and the total completed categories of the WCST in comparison with the group control. There are statistically significant differences in the schizophrenic group between right handed and left-handed subjects in the variables: number of errors (total score), number of errors (T score), total % of perseverative answers and perseverative errors, conceptual answers (total% and %T). On the contrary, no statistically significant<

>values were found in the case of the controls. Those having more positive symptoms are those who commit a greater number of errors (correlation of 0.394 for a p=0.042).

It has been confirmed that performances on the WCST in schizophrenics are worse than in healthy subjects. These differences are not due to the difference in the educational level. Schizophrenic patients with left-handed manual preference patterns have a greater tendency to perservation (perseverative answers and perseverative errors) than right-handed patients. To study the relationship between symptom seriousness and WCST performance, larger samples must be studied and we must focus on individual symptoms of the PANSS. The limitations of this study are mainly the reduced sample and the non-randomization of the control group.