Regional Prefrontal Abnormalities During Working Memory in Schizophrenia: A Topography-based Functional Activation Study

Original Article

Psychiatry Investigation 2004;1(1):37-43.

Jae-Jin Kim, MD, PhD*1,2;Yu Jin Lee, MD1;Dong Soo Lee, M.D, PhD3;Myung Chul Lee, MD, PhD3; and Jun Soo Kwon, MD, PhD4;

¹;Department of Psychiatry, Yonsei University College of Medicine, Seoul, ²;Institute of Behavioral Science in Medicine, Yonsei University College of Medicine, Seoul, ³;Department of Nuclear Medicine, Seoul National University, Seoul, ⁴;Department of Psyc

Abstract

<p class="MsoPlainText" style="word-spacing: 1; line-height: 150%; margin-top: 0; margin-bottom: 0" align="left"><font face="HY중고딕" size="2">Although most functional and structural neuroimaging studies have reported that cognitive deficits in patients with schizophrenia are associated with prefrontal abnormalities, their findings vary considerably. The aim of this study is to find evidence of functional abnormalities in the prefrontal cortex of schizophrenia patients on the basis of exact topographical parcellation. Magnetic resonance (MR) images were obtained in 12 patients with schizophrenia and 12 age-and sex-matched normal volunteers, and parceled into 8 frontal subregions using topographic landmarks. [¹⁵
O]H₂
O PET scans were obtained during the visual working memory task and the control task, and the activities of the parceled frontal subregions were counted on the registered PET images. In the comparison of the subregional functional activities, the normal healthy group showed a tendency to activate the right rostral anterior cingulate during the working memory task. Comparatively, the patient group showed reduced activation of the right orbitofrontal cortex and the right caudal anterior cingulate. The results suggest that the functional changes observed in schizophrenia may result from the abnormal activation of the neural system for the purpose of performing working memory tasks. In particular, reduced ventromedial prefrontal activities seem to play an important role in such cognitive impairment in schizophrenia.

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Key words Schizophrenia;Frontal subregions;MRI;PET;Working memory.