EPV 18. Localized changes of oscillatory activity in delirium: Evidence for biomarkers of cognitive dysfunction from a large retrospective case-control quantitative EEG study

Abstract

Objective Delirium is a common disorder that is associated with increased morbidity. The clinically heterogeneous phenotype and lack of objective disease markers are major causes of misdiagnosis leading to variable and potentially detrimental treatment decisions. A better understanding of pathophysiological mechanisms underlying this disorder are necessary to facilitate diagnosis and guide therapy. Methods We searched the EEG database of a German university hospital between years 2004 and 2014 for recordings of patients diagnosed with delirium (DSM-V criteria) and age-matched controls (n = 129 and 414, respectively). Standardized total and frequency band specific power spectra of continuous EEG data were compared between conditions (i.e. control vs. delirium) by analysis of variance and topographically by source statistics. Results As well-established, spectral variability was decreased in the delta and theta band in the delirium group. Faster frequencies exhibited increased variability. The occipital peak frequency was slowed from 10 Hz in the control group to 1 Hz in the delirium group. CONDITION x FREQUENCY exhibited a significant interaction (F = 845, p Fig. 1 ). Conclusions This is the first study to provide evidence for topographically specific changes in oscillatory activity in delirium. These results contribute to our understanding of pathomechanisms underlying behavioral disturbances and provide the intriguing perspective to serve as diagnostic and therapeutic biomarkers. Yet, current evidence requires confirmation by prospective studies including standardized diagnostic criteria and behavioral tests.