title: Relative power and coherence of EEG series are related to amnestic mild cognitive impairment in diabetes.
abstract: OBJECTIVE
  Diabetes is a risk factor for dementia and mild cognitive impairment. The aim of this study was to investigate whether some features of resting-state EEG (rsEEG) could be applied as a biomarker to distinguish the subjects with amnestic mild cognitive impairment (aMCI) from normal cognitive function in type 2 diabetes.
  
  
  METHODS
  In this study, 28 patients with type 2 diabetes (16 aMCI patients and 12 controls) were investigated. Recording of the rsEEG series and neuropsychological assessments were performed. The rsEEG signal was first decomposed into delta, theta, alpha, beta, gamma frequency bands. The relative power of each given band/sum of power and the coherence of waves from different brain areas were calculated. The extracted features from rsEEG and neuropsychological assessments were analyzed as well.
  
  
  RESULTS
  The main findings of this study were that: (1) compared with the control group, the ratios of power in theta band [P(theta)] vs. power in alpha band [P(alpha)] [P(theta)/P(alpha)] in the frontal region and left temporal region were significantly higher for aMCI, and (2) for aMCI, the alpha coherences in posterior, fronto-right temporal, fronto-posterior, right temporo-posterior were decreased; the theta coherences in left central-right central (LC-RC) and left posterior-right posterior (LP-RP) regions were also decreased; but the delta coherences in left temporal-right temporal (LT-RT) region were increased.
  
  
  CONCLUSIONS
  The proposed indexes from rsEEG recordings could be employed to track cognitive function of diabetic patients and also to help in the diagnosis of those who develop aMCI.
authors.affiliation: Institute of Electrical Engineering, Yanshan University Qinhuangdao, China.
authors.forename: Zhijie
authors.initials: Z
authors.lastname: Bian
authors.affiliation: Department of Neurology, The Second Artillery General Hospital of PLA Beijing, China.
authors.forename: Qiuli
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of Neurology, The Second Artillery General Hospital of PLA Beijing, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.affiliation: Institute of Electrical Engineering, Yanshan University Qinhuangdao, China.
authors.forename: Chengbiao
authors.initials: C
authors.lastname: Lu
authors.affiliation: Department of Neurology, The Second Artillery General Hospital of PLA Beijing, China.
authors.forename: Shimin
authors.initials: S
authors.lastname: Yin
authors.affiliation: State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University Beijing, China ; Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University Beijing, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Li
keywords: amnestic mild cognitive impairment; coherence; diabetes; relative power; resting-state EEG