Abstracts

Rationale: The study was designed to determine whether certain LTM EEG patterns in neuro-icu patiens with altered mental status (AMS) correlate with clinical outcome, using modified Rankin scale, and if, these EEG patterns differ in varying degeees of altered mental status from coma/stupor (CS+) to lethargy (CS-). Methods: A retrospective chart review of University of Minnesota Medical Center mostly Neuro-ICU admission between 2005-2013 of 88 adults patients identified with a minimum of 48 hours of continuous LTM EEG and AMS changes was performed. Outcome was measured at discharge using modified Rankin scale (RS). Correlation of different EEG patterns with RS was done using chi square analysis in both cohorts.. The predominating EEG variables assessed, i.e in more than 60% of the LTM EEG, were: slowing--focal or generalized theta, delta of all forms; periodic paroxysmal patterns (PLEDS, -Bi-PlLEDS,GPEDs;; triphasic pattern and burst suppression. Variables where collpased into 2 categories: slow or paroxysmal for purpose of analysis as in Table 2 Incidence in the 2 cohorts of nonconvulsive status (NCSE) patterns, of differtent forms, where also assessed. Results: Fifty five patients were identified as being in a clinical state of stupor or coma (CS+) while thirty three patients, on the other hand, were identified, in the same time frame, as having AMS w/o CS+ and only mild AMS or CS-. Demographics of the groups and LTM EEG findings correlation with RS are given on table 1. Table 2 also shows the correlation of the collapsed EEG patterns, i.e slow vs paroxysmal, in the 2 groups with the RS outcome. Unsuspected NCSE was found in 24 %, higher in the CS+ group (p.003) and treated.Conclusions: No correlation of specific EEG patterns, slow and paroxysmal, and RS outcome was established in this pilot study in either group of patients with different degrees of AMS changes, i.e CS+ or CS-. Etiology of AMS and other variables did not correlate with RS outcome either but clinical classification of AMS into the 2 groups did correlate with poorer outcome in the CS+ group only (p value<0.001) LTM of EEG in Neuro-ICU patients detected NCSE in 24 % of subjects with AMS changes more commonly in the CS+ group (p.003). Further studies with larger number of subjects is needed.