Functional MRI study on the cortical activation during saccadic and antisaccadic eye movements in schizophrenia

Functional MRI study on the cortical activation during saccadic and antisaccadic eye movements in schizophrenia

Neurobnage 13, Number 6, 2001, Part 2 of 2 Parts ID E a[@ PSYCHIATRY Functional MRI study on the cortical activation during saccadicand antisacc...

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Neurobnage

13, Number

6, 2001,

Part 2 of 2 Parts ID

E a[@

PSYCHIATRY

Functional MRI study on the cortical activation during saccadicand antisaccadiceye movements in schizophrenia Hidekazu Serizawa*, Hiromi Ohkubo*, Tetsuya Matsuda*t, Tatsunobu Ohkubo*, Masato Matsuura*, Kentaro Inoue$, Masato TairaS, Hideo SakataS, Takuya Kojima* *Department of Neuropsychiatry, Nihon University School of Medicine, Tokyo, Japan j-Section of Liaison Psychiatry & Palliative Medicine, Graduate school of Tokyo Medical & Dental University, Tokyo, Japan $lst. Department of Physiology, Nihon University School of Medicine, Tokyo, Japan Introduction Our previous studies in healthy volunteers showed that during the saccade task, significant activations were found in the frontal eye field (FEF), the supplementary motor area @MA), the superior parietal lobule (PEF), and the inferior occipital gyrus (Vl). During the antisaccade task, significant activations were shown in the identical regions as those during the saccade task with additional significant activation in the dorsolateral prefrontal cortex (DLPFC). Our results suggested that the DLPFC had an important role for inhibition of the inappropriate reflexive saccades and for generation of the correct saccades to the contralateral side. In this study, we examined the cortical activation during saccadic and antisaccadic eye movements in schizophrenia. This study had received an approval of the Ethics Committee of Nihon University School of Medicine. Subjects

and Methods

We chose the patients who could perform as well as healthy volunteers in EOG examination on the saccadic and antisaccadic eye movements in advance of fMRl examination. We acquired the fMRI images of nine schizophrenic patients (35.8X 10.6 years old) and age-matched nine healthy volunteers. Gradient echo planar imaging (EPI) was used for the fMRI (TR 393lms, TE 50ms, FA 90 deg., FOV 192_192mm, Matrix 64-64, Slice thickness 3mm). Tasks were saccadic and antisaccadic eye movements. Both of them were on-off tasks that had rest and task turn about every 40 seconds. We did it 5 times each. We analyzed the data with SPM99. Results

and Discussion

We found the significant cortical activations in FEF, SMA, PEF and Vl during both tasks in the schizophrenic patients. Though the activated regions were similar to those of healthy volunteers, two types of abnormalities were revealed in the patients. One was a decrease in activations in individual cortical region without activation of DLPFC during both tasks, the other was an increase in activations in many regions with activation of DLPFC during both tasks. Thus, we propose that there are abnormalities in neural network related to saccadic and antisaccadic eye movements in schizophrenia.

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