Regional cerebral blood flow SPECT study, at rest and during Wisconsin Card Sorting Test (WCST) performance, in schizophrenia naive patients or treated with atypical neuroleptics

Abstract

Introduction. To corroborate the hypothesis of hypofrontality in schizophrenia and to study the relationship between positive/negative symptoms (measured by the positive and negative syndrome scale [PANSS]) and regional cortical blood flow (rCBF), both at rest and during the Wisconsin Card Sorting Test (WCST) performance (activation).

Methods. We compared a control group (n = 18) to a group of patients with schizophrenia (n = 21) in terms of rCBF, measured by single photon emission computed tomography (SPECT).

Results. We found significantly higher left-frontal-CBF (during the WCST performance and at rest) and right-frontal-CBF (only at rest) in control subjects. Only the control group showed a right-frontal-CBF increase during activation. Only the patients group showed a significant rightoccipital-CBF increase during the activation. We observed a positive significant correlation between the PANSS-P score and the left-frontal index at rest. Some negative symptoms such as difficulty in abstract thinking (N5) and lack of spontaneity and flow of conversation (N6) are associated to low frontal blood flow at rest. Affective blunting (N1) is associated to low left-frontal blood flow during activation.

Conclusions. Our data support the hypothesis of hypofrontality, at rest and during activation, which means the incapacity of schizophrenic patients to increase the frontal CBF while performing the WCST (activation). Schizophrenia positive symptoms are associated to high left-frontal blood flow.