title: Global dimensional complexity of multichannel EEG in mild Alzheimer's disease and age-matched cohorts.
abstract: Multichannel EEG as sequence of momentary brain field maps constitutes a trajectory through K-dimensional state space (K = number of channels); the complexity of this trajectory is assessed by the nonlinear measure of global correlation dimension (Global Dimensional Complexity, GDC) with the number of electrodes as embedding dimension. We analyzed eyes-closed EEG of three age-matched subject groups: mild Alzheimer's disease (AD; n = 21), mild cognitive impairment (29) and subjective memory complaint (29). Kruskal-Wallis statistics showed an overall effect between groups. AD patients differed significantly (GDC = 4.56) from mild cognitive impairments (GDC = 4.98) and from subjective memory complaints (GDC = 4.93). GDC also had significant positive correlations with mental condition and performance (MMSE and WAIS-R scores). Thus, the dynamics of brain state development over time in mild AD differs from that in mild cognitive impairment and in subjective memory complaint cases.
authors.affiliation: KEY Institute for Brain-Mind Research, University Hospital of Psychiatry, Zürich, Switzerland.
authors.forename: T
authors.initials: T
authors.lastname: Yagyu
authors.forename: J
authors.initials: J
authors.lastname: Wackermann
authors.forename: M
authors.initials: M
authors.lastname: Shigeta
authors.forename: V
authors.initials: V
authors.lastname: Jelic
authors.forename: T
authors.initials: T
authors.lastname: Kinoshita
authors.forename: K
authors.initials: K
authors.lastname: Kochi
authors.forename: P
authors.initials: P
authors.lastname: Julin
authors.forename: O
authors.initials: O
authors.lastname: Almkvist
authors.forename: L O
authors.initials: LO
authors.lastname: Wahlund
authors.forename: I
authors.initials: I
authors.lastname: Kondakor
authors.forename: D
authors.initials: D
authors.lastname: Lehmann
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000150:complications / Q000175:diagnosis*; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology; D015331:Cohort Studies; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis / Q000209:etiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D011446:Prospective Studies; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric