Abstracts

Rationale: The utilization of continuous EEG (cEEG) monitoring in critical care settings for the diagnosis and management of non-convulsive seizures and/or status epilepticus (NCS/NCSE) has rapidly increased in recent years. Although the mean duration of cEEG monitoring is around 40 hours based on the largest cohort study of more than 4500 patients, some monitoring session last more than 28 days1. The goal of our study was to characterize the patients undergoing such Super prolonged cEEG (SUPEEG) monitoring and compare them to a matched cohort to find factors predicting SPEEG Methods: After IRB approval, we searched our prospectively maintained cEEG database to find patients = 18 years of age who underwent monitoring session lasting at least 30 days between 01/01/2012 to 03/31/2017. Demographical, clinical, cEEG and outcome variables were analyzed for this population. To help analyze predictors of SUPEEG monitoring, a comparison cohort of three control patients, matched by age (±2 years) and mental status to each SUPEEG patient, using a sequential retrospective chart review from the study duration, was identified. Descriptional statistical analysis tools along with chi-square and t-test were used as required. p value of < 0.05 was considered significant. Results: A total of 25 patients, including 11 (44%) females, with mean age of 48.9 ±19.1 years underwent SUPEEG monitoring. The median duration of SUPEEG was 39 (range: 30 – 111) days. Seven (28%) had history of epilepsy while 3 (12%) presented after cardiac arrest. The etiology was acute structural lesion in 8 (32%) patients, 5 (20%) suffered from encephalitis and one each (4%) had a brain tumor and synthetic marijuana intoxication. Twenty-one (84%) patients presented with convulsive seizures. cEEG showed 18 (72%) to be in electrographic status epilepticus with rest having acute repetitive seizures. A median of 5 (range 2-7) anti-epileptic drugs (AEDs) were used with 22 (88%) patients requiring IV anesthetic agents. Seventeen (68%) patients had super-refractory status epilepticus (SRSE) with a median of 3 (range 1-7) 24 hour epochs of burst suppression on cEEG followed by breakthrough seizures. Two (8%) patient underwent emergent respective epilepsy surgery for management of status epilepticus. Median Glasgow outcome score was 3 (range 1-4) with eight patients expiring during the hospitalization. Comparison with matched cohort (Table 1) showed that patients undergoing SUPEEG were more than 10 times (p < 0.001) likely to present with convulsive seizure and significantly more (p < 0.01) likely to suffer from encephalitis. Conclusions: Patients undergoing SUPEEG are younger than historically reported cEEG monitored patients population1. A quarter of them had epilepsy and one in five were diagnosed with encephalitis. A majority of them suffered SRSE and had several occasions of breakthrough seizures despite achievement of burst suppression for prolonged periods. Presence of convulsive seizure at presentation and diagnosis of encephalitis predict a patient requiring SUPEEG. Larger, multi-center effort is required for early identification of patients who would be SUPEEG candidates. Funding: None