Clinical symptoms and regional cerebral blood flow in schizophrenia

Abstract

This study examined the relationship between clinical symptoms and regional cerebral blood flow (rCBF) in schizophrenic patients using single photon emission computed tomography (SPECT). The subjects were 26 medicated schizophrenic patients diagnosed according to DSM-III-R criteria. Clinical symptoms were assessed using the Scale for the Assessment of Negative Symptoms (SANS), selected items for the Positive and Negative Syndrome Scale (PANSS), and the scale for Schneider's first rank symptoms. Resting rCBF was measured using N-isopropyl-p-[I-123] iodoamphetamine (I-123 IMP) SPECT, and relative rCBF distribution was evaluated in nine regions of interest in each hemisphere. Factor analysis of symptom ratings indicated four separate syndromes: psychomotor poverty, alienation (hallucination and disturbance of the self), delusion, and disorganization. Stepwise multiple regression analysis showed the psychomotor poverty syndrome to be correlated with decreased rCBF in bilateral superior frontal areas and increased rCBF in the left thalamus and right basal ganglia. The disorganization syndrome was correlated with increased rCBF in bilateral anterior cingulates and decreased rCBF in bilateral middle frontal areas. The alienation syndrome was shown related to increased rCBF in the right inferior frontal area and parietal area. Dysfunction in distinctive neural networks involving various prefrontal areas would thus appear to underlie these syndromes in schizophrenia.

An event-related potential investigation of response inhibition in schizophrenia and psychopathy

“…For example, Ebmeier et al (1993), and Yuasa et al (1995) both confirmed that disorganization is associated with overactivity in anterior cingulate, though neither of these studies found an association with underactivity in the ventral frontal cortex.…”

“…There is a rather large body of evidence demonstrating that the anterior cingulate and lateral frontal cortex are abnormal in schizophrenia (Liddle et al 1992;Yuasa et al 1995) and growing evidence of such abnormalities in psychopathy (Kiehl et al 1999b). Given that response inhibition is most probably a function of a complex neural circuit located in a spatially distributed network, it may be possible that the topographic ERP differences observed between the patient groups may reflect abnormalities at one or more cerebral sites.…”

Neurobiological background of negative symptoms

“…Associations with specific prefrontal areas, i.e., the dorsolateral prefrontal cortex (DLPFC) and the ventral prefrontal region, as well as other brain areas, in particular temporal and parietal regions, were also reported [65][66][67]. However, some studies failed to confirm these relationships [63,68], while others reported associations of negative symptoms with increased metabolism in the left frontal region [69], left thalamus and right basal ganglia [70] and temporal regions [67,71].…”

Correlations Between rCBF and Symptoms in Two Independent Cohorts of Drug-Free Patients with Schizophrenia

“…Functional imaging studies seeking regional associations between brain metabolism and negative symptoms have been typically based on correlation (Wolkin et al, 1992;Sabri et al, 1997), factor analysis Kaplan et al, 1993;Yuasa et al, 1995;Kawasaki et al, 1996;Schroder et al, 1996) or categorical (ie deficit vs nondeficit schizophrenia) (Andreasen et al, 1992;Heckers et al, 1999;Lahti et al, 2001;Potkin et al, 2002;Tamminga et al, 1992) analyses. The majority of these studies have reported hypometabolism in frontal cortex during rest Wolkin et al, 1992;Kaplan et al, 1993;Yuasa et al, 1995;Sabri et al, 1997) and task-activated states (Andreasen et al, 1992;Schroder et al, 1996;Potkin et al, 2002) in association with negative symptoms. In addition, three of these studies also showed reduced functional recruitment of the inferior parietal cortex in deficit compared to nondeficit subjects either at rest (Tamminga et al, 1992) or during task performance Heckers et al, 1999).…”