碩士 / 臺北醫學大學 / 醫學資訊研究所 / 94 / Background
Typical EEG findings of Alzheimer's disease are increase of slow waves and decrease of fast waves. These changes are not specific for this disease, so it is commonly regarded EEG as of limited value for disease diagnosis. Long-term clinical observation suggests that the degree of these EEG changes seemed to be associated with the severity of the disease, and EEG study may serve as a potential tool to help clinical follow-up of these patients. However, most past studies of EEG and Alzheimer's disease focused on the issue of differentiation
of Alzheimer's disease and other dementia syndromes. Description of the correlation of EEG parameters and the clinical course of Alzheimer's disease are rare and there's no unique recommended EEG parameter, so its clinical application is limited. We conducted this study to find sensitive and useful EEG parameters and provide a applicable model for the clinical assessment of Alzheimer's disease.
Method
This retrospective study included three medical institutes and fifty-nine patients of Alzheimer's disease. Based on spectral analysis, we calculated and presented spectral profile、power ratio、interhemispheric alpha coherence and intrahemispheric alpha coherence of individual EEG. We grouped the patients as very mild、mild、moderate、and severe groups according to the information of CDR
or GDS and analyzed the correlation of these EEG parameters and different groups.
Results
Spectral profile provides valuable information of EEG about the dominant frequency and the power of different frequencies. We found characteristic profile of each group, however, it's a semi-quantitive method and is not suitable for further comparison. Mean power ratio of each group is 0.72 in very mild group、1.17 in mild group、1.86 in moderate group and 3.00 in severe group, respectively. Higher value suggest more severe disease. Interhemispheric alpha coherence showed diffuse decrease as the advance of disease. Among the electrode
pairs, P3-P4 showed better correlation with the disease severity. Mean alpha coherence in each group is 0.474 in very mild group、0.415 in mild group、 0.347 in moderate group and 0.271 in severe group, respectively. Lower value of P3-P4 alpha coherence suggest more severe disease. As for interhemispheric alpha coherence, we cannot find apparent correlation with disease severity. According
to ROC curve, cutoff value among groups were suggested. Correct classification was 62.7% and 52.5% by power ratio and P3-P4 alpha coherence respectively.
Conclusion
EEG is a objective diagnostic tool, suitable of providing information of severity of Alzheimer's disease. Among various parameters, we recommended power ratio and P3-P4 alpha coherence as the tools to assess Alzheimer's disease. Although not sensitive enough to compare with clinical assessment scales, such as CDR or GDS, it can be a objective tool to supplement current assessment method. Our study provide a practical model that can be widely applied among institutes to follow up these patients. Further studies are necessary to assess the value of interval change of individual patient 、drug response and correlation with other diagnostic tools.
| Identifer | oai:union.ndltd.org:TW/094TMC00674011 |
| Date | January 2006 |
| Creators | Chih-Chung Chen, 陳致中 |
| Contributors | Chien-Yeh Hsu, Hung-Wen Chiu, 徐建業, 邱泓文 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 77 |
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