RT Journal Article
SR Electronic
T1 Absence of early epileptiform abnormalities predicts lack of seizures on continuous EEG
JF Neurology
JO Neurology
FD Lippincott Williams & Wilkins
SP 1796
OP 1801
DO 10.1212/WNL.0b013e3182703fbc
VO 79
IS 17
A1 Mouhsin M. Shafi
A1 M. Brandon Westover
A1 Andrew J. Cole
A1 Ronan D. Kilbride
A1 Daniel B. Hoch
A1 Sydney S. Cash
YR 2012
UL http://n.neurology.org/content/79/17/1796.abstract
AB Objective: To determine whether the absence of early epileptiform abnormalities predicts absence of later seizures on continuous EEG monitoring of hospitalized patients. Methods: We retrospectively reviewed 242 consecutive patients without a prior generalized convulsive seizure or active epilepsy who underwent continuous EEG monitoring lasting at least 18 hours for detection of nonconvulsive seizures or evaluation of unexplained altered mental status. The findings on the initial 30-minute screening EEG, subsequent continuous EEG recordings, and baseline clinical data were analyzed. We identified early EEG findings associated with absence of seizures on subsequent continuous EEG. Results: Seizures were detected in 70 (29%) patients. A total of 52 patients had their first seizure in the initial 30 minutes of continuous EEG monitoring. Of the remaining 190 patients, 63 had epileptiform discharges on their initial EEG, 24 had triphasic waves, while 103 had no epileptiform abnormalities. Seizures were later detected in 22% (n = 14) of studies with epileptiform discharges on their initial EEG, vs 3% (n = 3) of the studies without epileptiform abnormalities on initial EEG (p < 0.001). In the 3 patients without epileptiform abnormalities on initial EEG but with subsequent seizures, the first epileptiform discharge or electrographic seizure occurred within the first 4 hours of recording. Conclusions: In patients without epileptiform abnormalities during the first 4 hours of recording, no seizures were subsequently detected. Therefore, EEG features early in the recording may indicate a low risk for seizures, and help determine whether extended monitoring is necessary. cEEG=continuous EEG; HIE=hypoxic-ischemic encephalopathy; NCS=nonconvulsive seizure; PED=periodic epileptiform discharge; SAH=subarachnoid hemorrhage; TBI=traumatic brain injury