99m-Tc-ECD SPECT Study of Differences on Relative Cerebral Blood Flow between Drug-Naive and Drug-Free Schizophrenic Patients

Kim, Se Joo; Ahn, Suk Kyoon; Jon, Duk In; Lee, Jong Doo; Min, Sung Kil

Abstract

OBJECTIVES
In schizophrenics, regional cerebral blood flow(rCBF) are affected by various confounding variables, i.e., age, sex, duration of illness, and clinical status. The pharmacological condition of patients is also a particular important variable to be taken into consideration. However, few data are available regarding the differences between the relative rCBF findings in drug-free and drug-naive schizophrenic patients. Currently, numerous studies have included drug-free and drug-naive schizophrenic patients in the same 'unmedicated' group under the assumption that the rCBF is identical between drug-free and drug-naive cases. Therefore, the aim of this study was to compare the rCBF between a group of drug-free schizophrenic patients and a group of drug-naive schizophrenic patients about the effects of age, sex, duration of illness, and clinical status(positive and negative symptoms) under control.
METHODS
Eighteen drug-naive schizophrenics and fifteen drug-free schizophrenics were in-cluded in the study. Regional cerebral blood flow was studied with the single-photon emission computed tomography(SPECT) under resting state. Symptoms were assessed with Positive and Negative Syndrome Scale(PANSS). Regions of interest were both inferior temporal lobe, inferior frontal lobe, superior temporal lobe, thalamus, basal ganglia, parieto-occipital lobe, superior frontal lobe, and parietal lobe.
RESULTS
No significant differences of relative rCBF were found between drug-free and drug-naive schizophrenic patients in left inferior temporal lobe, right inferior frontal lobe, both superior temporal lobe, both thalamus, both basal ganglia, right parieto-occipital lobe, and both superior frontal lobe. But, drug-free schizophrenic patients had a significant increase of perfusion in the right inferior temporal lobe and left inferior frontal lobe and a significant decrease of perfusion in both parietal lobes and left parieto-occipital lobe.
CONCLUSIONS
Relative rCBF in drug-free schizophrenic patients is different from that in drug-naive schizophrenic patients. So, in the relative rCBF studies of schizophrenic patients, it must be considered whether the patients were previously medicated or not.