Quantitative EEG Correlates of Outcome in Older Psychiatric Patients: Part I: Cross-Sectional and Longitudinal Assessment of Patients With Dementia

Using quantitative electroencephalographic coherence (a measure of synchronized electrical activity between brain regions) the authors examined heterogeneity in clinical presentation and outcome inpatients with dementia. Patients (N = 114) with mild-to-moderate dementia of the Alzheimer's type (DAT) or multi-infarct dementia (MID) were examined for coherence from the left hemisphere. More than 70% diagnostic accuracy in distinguishing between DAT and MID subjects was achieved using coherence measures alone. Also, decreased coherence measured across the Rolandic fissure in the left hemisphere was significantly associated with poorer functional status of subjects at 2-year follow-up, despite similar levels of cognitive impairment at baseline. These findings suggest that coherence is a useful measure for assessment and for prediction of the course of illness inpatients with dementia.