The Clinical Application Of Quantitative Electroencephalogram In Alzheimer’s Disease:A Meta-analysis

Objective: To evaluate the clinical application of quantitative electroencephalogram in Alzheimer’s disease by meta-analysis of related literature.Methods: Key words were searched in Pubmed,Embase,Cochrane library,Wanfang and China Knowledge Network databases.The articles were screened according to the inclusion and exclusion criteria.Data were extracted.RevMan 5.3(The Cochrane Collaboration,London,UK)was used for the analysis of extracted data.Results: A total of 685 subjects were included in 13 studies,including352 patients with Alzheimer’s disease and 333 healthy adults.The global absolute beta power of the AD group was lower than that of the normal control group,the difference was-1.15(95% CI=-1.98~-0.33,P=0.006).The global relative beta power of the AD group was lower than that of the normal control group,and the difference was-4.25(95% CI=-6.17~-2.33,P<0.0001).The global absolute alpha power of patients with AD was lower than that of the normal control group,with a difference of-0.99(95%CI=-1.51~-0.47,P=0.0002).The global relative alpha power of the AD group was smaller than the normal group,and the difference was-0.50(95 % CI=-0.83~-0.18,P=0.002).The global absolute theta power of the AD group was greater than that of the normal control group,with a difference of 0.64(95% CI=0.28~0.99,P=0.0005).The global relative theta power of the AD group was greater than the normal group,with a difference of 0.93(95% CI= 0.58~1.28,P < 0.00001).The global absolute delta power of the AD group was greater than that of the normal control group,the difference was 5.16(95% CI=2.56~7.77,P=0.0001).There was no significant difference in the global relative delta power between the AD group and the normal group.The difference was 0.35.(95% CI=0.04~0.65,P=0.03).The ratio of delta+theta to alpha+beta power of the AD group was smaller than the normal group,with a difference of 1.04(95%CI=0.76~1.32,P<0.00001).The global mean frequency of the AD group was lower than that of the normal group,and the difference was-0.72(95%CI =-1.14~-0.29,P < 0.0009).Conclusion: The global absolute alpha power and beta power of the AD group are lower than the normal group.The global absolute theta power and delta power of the AD group are greater than the normal group.In other words,the trend of EEG changes in AD patients is a decrease in alpha and beta power,while an increase in theta and delta power.However,absolute power is not a stable indicator because of its large individual variation.The global relative alpha and beta power of the AD group was lower than the normal group.The global relative theta power of the ADgroup is greater than the normal group.The global relative alpha power,relative beta power,and relative theta power can distinguish between AD patients and normal people.The global relative theta power may be expected to be an indicator of early screening for AD patients.In addition,the ratio of delta+theta to alpha+beta power is an index that can reflect the changes of fast and slow waves in AD patients,which is significantly larger than that in normal patients.Moreover,we observed that the average power of the whole brain was smaller in the AD group than in the normal group,and it also reflected the slowing of brain waves in AD patients.