Biological Psychiatry Main Editor: J. Mendlewicz (Brussels) Original Paper Neuropsychobiology 1999;39:117–124 Regional Cerebral Blood Flow in Schizophrenia Using Stable Xenon-Enhanced Computed Tomography Kazuhiko Mori a,b Katsuya Teramoto c Masatsugu Nagao a Jun Horiguchi b Shigeto Yamawaki b a Nagao Mental Hospital, Nagao, and b Department of Psychiatry and Neurosciences, Hiroshima University School of Medicine, and c Department of Psychiatry and Neurology, Hiroshima City Hospital, Hiroshima, Japan Shigeto Yamawaki, MD, PhD Department of Psychiatry and Neurosciences, Hiroshima University School of Medicine 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551 (Japan) Tel. +81 82 257 5207, Fax +81 82 257 5209 E-Mail yamawaki@mcai.med.hiroshima-u.ac.jp ABC Fax + 41 61 306 12 34 E-Mail karger@karger.ch www.karger.com © 1999 S. Karger AG, Basel 0302–282X/99/0393–0117$17.50/0 Accessible online at: http://BioMedNet.com/karger Key Words Regional cerebral blood flow W Stable xenon-enhanced CT W Schizophrenia W Antipsychotics W Thalamus Abstract To investigate the regional cerebral blood flow (rCBF) and the factors affecting the rCBF in schizophrenia, we measured the rCBF using stable xenon-enhanced com- puted tomography in 118 schizophrenic patients and 21 healthy subjects. A multiple regression analysis was applied to assess the potential affecting factors, i.e. age, gender, duration of illness, dose of antipsychotics and usage of antiparkinsonism and antianxiety drugs. The rCBF of the schizophrenic patients was significantly low- er than that of the healthy subjects in all regions except for the occipital region. The rCBF was decreased with increasing age in both groups to the same extent. The dosage of antipsychotic drugs taken had a significant regression relationship with the rCBF in the bilateral thal- amus. Introduction Schizophrenia is associated with structural changes (e.g. a mild degree of ventricular enlargement) in the brain, although whether these changes precede the onset of illness or progress with episodes is not established. Some authors [1–3] proposed that the neurodevelopment disturbance was the principal cause of schizophrenia. This theory was well grounded by many postmortem stud- ies [4–9]. Based on morphological neuroimaging studies, some authors [10–12] have supported this theory. Al- though many functional neuroimaging studies of schizo- phrenia have been conducted, there are no reports regard- ing this theory, to our knowledge. To clarify the cause of schizophrenia, it is important to investigate the progres- sive changes in the course of the illness. Since Ingvar and Franzen [13] reported their observations regarding the regional cerebral blood flow (rCBF) of schizophrenics, several groups have reported decreased frontal blood flow, or ‘hypofrontality’, in schizophrenics [14–18]. How- ever, there are a few contradicting reports [19–23], and there is no general agreement about rCBF in schizophren- ic patients.