Nonlinear Dynamic Analysis in EEG of Alzheimer's Dementia: A Preliminary Report Using Correlation Dimension.
- Author:
Jeong Ho CHAE
;
Dai Jin KIM
;
Jaeseung JEONG
;
Soo Yong KIM
;
Hyo Jin GO
;
In Ho PAIK
- Publication Type:Original Article
- Keywords:
Dementia of Alzheimer type;
Chaos;
Nonlinear;
Dynamic;
EEG;
Correlation dimension
- MeSH:
Alzheimer Disease;
Brain;
Dementia*;
Electroencephalography*;
Head;
Humans;
Nonlinear Dynamics*
- From:Journal of the Korean Society of Biological Psychiatry
1997;4(1):67-73
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
The changes of electroencephalogram(EEG) in patients with dementia are most commonly studied by analyzing power or magnitude in certain traditionally defined frequency bands. However because of the absence of on identified metric which quantifies the complex amount of information, there are many limitations in using such a linear method. According to chaos theory, irregular signals of EEG cal also result from low dimensional deterministic chaos. Chaotic nonlinear dynamics in the EEG can be studied by calculating the correlation dimension. The authors have analyzed EEG epochs from three patients with dementia of Alzheimer type and three matched control subject. The result showed that patients with dementia of Alzheimer type had significantly lower correlation dimension than non-demented controls on 12 channels. Topographic analysis showed that the correlation dimensions were significantly lower in patients with Alzheimer's disease on frontal, temporal, central, and occipital head regions. These results show that brains of patients with dementia with dementia of Alzheimer type have a decreased complexity of electrophysiological behavior. We conclude that the nonlinear analysis such as calculating correlation dimension can be a promising tool for detecting changes in the complexity of brain dynamics.