Abstract Details

Title The Relationship Between EEG Characteristics During Critical Illness and Long-Term Cognitive Impairment

Topic Aging, Dementia, and Behavioral Neurology

Presentation(s) P6 - Poster Session 6 (12:00 PM-1:00 PM)

Poster/Presentation
Number 10-001

Background As many as 30%-80% of ICU survivors suffer disabling long-term cognitive impairment (LTCI), including memory and executive dysfunction, after critical illness. ICU delirium is a risk factor for LTCI, and the underlying pathophysiology is poorly understood. EEG noninvasively evaluates neurophysiologic activity and shows characteristic findings in delirium. Yet there is a paucity of data examining the relationship between EEG characteristics during critical illness and LTCI.

Objective To compare electroencephalography (EEG) characteristics during critical illness with patients’ 1-year neuropsychological outcomes.

Design/Methods We performed a post-hoc analysis of patients in the BRAIN-ICU study (Pandharipande, NEJM 2013) who had undergone EEG for clinical purposes during their index admission (N=10). We included all participants with inpatient EEG recordings who completed cognitive assessments (Repeatable Battery for the Assessment of Neuropsychological Status - RBANS) at 12-month follow-up. We evaluated conventional EEG characteristics by visual inspection and computed 11 quantitative EEG features (spectral band power and variability in four spectral bands, interhemispheric coherence and approximate entropy) using MATLAB®. Associations between EEG features and patterns of LTCI were explored using Spearman’s rank correlations.

Results

Of the 10 patients (50% female, median age 45 years), 7 screened positive for delirium or coma within 24 hours of EEG. All but one EEG showed generalized background slowing. Relative alpha power correlated with visuospatial/constructional ability (VC; rho=0.78, p=0.008). Peak interhemispheric coherence correlated negatively with delayed memory (DM; rho=-0.81, p=0.018). This relationship appeared stronger among EEGs recorded in ICU (rho=-1.0, p=0.017). Among ICU EEGs, theta-range spectral variability also correlated negatively with DM (rho=-0.89, p=0.033).

All patients demonstrated cognitive impairment in at least one domain at follow-up. The most common deficits occurred in DM (median index 62) and VC (median index 69).

Conclusions These data support subsequent investigation of the hypothesis that there is a relationship between EEG characteristics during critical illness and long-term cognitive impairment.

Authors/Disclosures
Shawniqua Williams Roberson, MD PRESENTER	Dr. Williams Roberson has received personal compensation in the range of $0-$499 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Neurology Today. The institution of Dr. Williams Roberson has received research support from the National Institute on Aging. The institution of Dr. Williams Roberson has received research support from Brain & Behavior Research Foundation. Dr. Williams Roberson has received personal compensation in the range of $0-$499 for serving as a Reviewer with the National Institutes of Health. Dr. Williams Roberson has received personal compensation in the range of $0-$499 for serving as a Visiting Speaker with University of Pennsylvania. Dr. Williams Roberson has received personal compensation in the range of $0-$499 for serving as a Faculty Speaker with the International Symposium for Intensive Care and Emergency Medicine.
Shawniqua Williams Roberson, MD	Dr. Williams Roberson has received personal compensation in the range of $0-$499 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Neurology Today. The institution of Dr. Williams Roberson has received research support from the National Institute on Aging. The institution of Dr. Williams Roberson has received research support from Brain & Behavior Research Foundation. Dr. Williams Roberson has received personal compensation in the range of $0-$499 for serving as a Reviewer with the National Institutes of Health. Dr. Williams Roberson has received personal compensation in the range of $0-$499 for serving as a Visiting Speaker with University of Pennsylvania. Dr. Williams Roberson has received personal compensation in the range of $0-$499 for serving as a Faculty Speaker with the International Symposium for Intensive Care and Emergency Medicine.
Randip S. Taneja, MD (Vanderbilt University Medical Center)	No disclosure on file
	No disclosure on file
	No disclosure on file
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