Department of Electrophysiology, Shanghai Mental Health Center, Shanghai Jiao Tong University, Shanghai 200030, China.
Chin Med J (Engl). 2013;126(15):2886-9.
Few characteristic changes of linear electroencephalograph (EEG) have been reported in schizophrenia. The aim of the present study was to investigate the changes in temporal-spatial dimensional properties of EEG under different cognitive tasks in patients with schizophrenia.
EEG was recorded by using EEG-1518K system and mapping system (Nihon Kohden Tomioka Corporation, Japan) in 45 schizophrenic patients and 47 healthy adults (normal control, NC) under five states: eyes closed, eyes open, mental arithmetic test with eyes closed, memory test with eyes open, and number cancellation test. Correlation dimension (D2) and point-wise correlation dimension (PD2) were calculated for all EEG analyses.
(1) There were no significant differences of D2 and PD2 between NC and schizophrenic patients under states of eyes open and closed. (2) Compared with NC, schizophrenic patients showed decreased performance of D2 in mental arithmetic test with eyes closed and number cancellation test (mental arithmetic test with eyes closed: Nc 5.9 ± 0.6, Sch 3.0 ± 0.8; number cancellation test: Nc 6.0 ± 0.6, Sch 4.4 ± 0.7; P < 0.05 or P < 0.01). (3) Schizophrenic patients also showed decrease performance of PD2 in mental arithmetic test with eyes closed, memory test with eyes open, and number cancellation test (mental arithmetic test with eyes closed: Nc 6.9 ± 0.7, Sch 4.0 ± 0.8; memory test with eyes open: Nc 6.6 ± 0.8, Sch 5.0 ± 0.9; number cancellation test: Nc 7.1 ± 0.7, Sch 4.8 ± 0.9; P < 0.05 or P < 0.01).
Nonlinear dynamic analysis provided a new approach in clinical investigation of EEG signals. It was helpful to further understand the cerebral mechanism in schizophrenic cognitive process.
精神分裂症患者的线性脑电图（EEG）特征变化较少。本研究旨在探讨精神分裂症患者在不同认知任务下 EEG 的时-空维度特性变化。
使用 EEG-1518K 系统和映射系统（日本光电工业株式会社）对 45 例精神分裂症患者和 47 例健康成年人（正常对照组，NC）在 5 种状态下进行 EEG 记录：闭眼、睁眼、闭眼心算测试、睁眼记忆测试和数字删除测试。对所有 EEG 分析计算关联维数（D2）和逐点关联维数（PD2）。
（1）NC 和精神分裂症患者在睁眼和闭眼状态下的 D2 和 PD2 无显著差异。（2）与 NC 相比，精神分裂症患者在闭眼心算测试和数字删除测试中 D2 表现下降（闭眼心算测试：NC 5.9±0.6，Sch 3.0±0.8；数字删除测试：NC 6.0±0.6，Sch 4.4±0.7；P<0.05 或 P<0.01）。（3）精神分裂症患者在闭眼心算测试、睁眼记忆测试和数字删除测试中 PD2 表现也下降（闭眼心算测试：NC 6.9±0.7，Sch 4.0±0.8；睁眼记忆测试：NC 6.6±0.8，Sch 5.0±0.9；数字删除测试：NC 7.1±0.7，Sch 4.8±0.9；P<0.05 或 P<0.01）。
非线性动态分析为 EEG 信号的临床研究提供了一种新方法。有助于进一步了解精神分裂症认知过程中的大脑机制。
