Abstract 239: Intermittent EEG Testing and the Diagnosis and Treatment of Seizures After Cardiac Arrest
Background: The impact of seizures on outcome after cardiac arrest (CA) is not fully understood. EEG remains the gold standard for the diagnosis of seizures. In this study, we describe seizure events and the use of intermittent and scheduled EEG testing to monitor brain injury after CA.
Methods: We performed standard 30 min EEGs on 52 post-CA patients within a few hours after return of spontaneous circulation, and at 1, 3 and 7 days as part of a multicenter trial. Study population included in and out of hospital CA. Clinical seizure diagnosis, associated medical events, therapies and outcomes were collected prospectively. An investigator blinded to the clinical conditions evaluated the EEG for presence of electrographic seizures.
Results: During the first 7 days after CA, 29% (15/52) of subjects had 22 reported clinical seizures. Of these, 59% (13/22) had ongoing electrographic seizures at the time of EEG testing and 41% (9/22) did not show electrographic seizures. In those with electrographic seizures at EEG testing, seizures were clinically apparent in 46% (6/13) and subclinical in 54% (7/13). Anticonvulsants were provided to 100% (6/6) patients with and 71% (5/7) of patients without ongoing electrographic seizures. Overall 90-day mortality was 83% (39/47), and was 100% (13/13) in patients with ongoing electrographic seizures and 71% (5/7) in patients without ongoing electrographic seizures at time of EEG testing.
Conclusions: Seizures, mostly subclinical are common in the first week after CA. Intermittent EEG testing detected seizures in most patients with clinically reported seizures, however the limited EEG testing may have missed seizures, especially if EEG is done post-ictal. Subclinical seizures, medications and movement disorders may make the diagnosis of seizures difficult. Seizures are associated with poor outcome but earlier EEG diagnosis and aggressive treatment may improve outcomes. More studies are needed to define the best time and duration of EEG testing post CA.
- © 2010 by American Heart Association, Inc.